CN116417073A - A method and system for analyzing the electrochemical oxidation performance of alloy catalyst hydrogen - Google Patents

Abstract

The invention provides an analysis method and system for electrochemical oxidation performance of alloy catalyst hydrogen. The method comprises the following steps: constructing an alloy unit cell model, namely a first model, and further constructing an alloy catalyst surface model, namely a second model; optionally constructing an alloy catalyst surface model containing an alkaline aqueous solution layer, namely a third model, based on the second model; optionally respectively constructing structural models of reactants, intermediates and products on the surface of the alloy catalyst in the third model to obtain a fourth model; performing structural optimization on the fourth model to obtain an alkaline aqueous solution/alloy catalyst surface model with an optimal structure, wherein the alkaline aqueous solution/alloy catalyst surface model contains reactants, intermediates and products, namely a fifth model; the oxidation potential analysis of the alloy catalyst is performed based on the second model, and/or the H adsorption free energy analysis of the alloy catalyst is performed based on the second model or the third model, and/or the Tafel polarization curve determination of the alloy catalyst is performed based on the fifth model.

Description

A method and system for analyzing the electrochemical oxidation performance of alloy catalyst hydrogen

technical field

The invention belongs to the measurement and characterization of catalytic activity of electrode materials, and in particular relates to an analysis method and system for the hydrogen electrochemical oxidation performance of an alloy catalyst.

Background technique

In recent decades, with the development of society, the problems of environmental pollution and energy shortage have become increasingly serious, and the demand for the development of new clean energy is particularly urgent. Alkaline fuel cell (AFC) can directly convert the chemical energy stored in H ₂ and O ₂ into electrical energy, and the only by-product is water. It is an efficient and clean green power source with simple structure, rapid start-up, Advantages of low operating temperature. Especially in recent years, the development of alkaline anion exchange membrane technology not only maintains the characteristics of alkaline electrolyte, but also avoids the problem of electrolyte carbonation, making AFC more competitive. In AFC, the cathode oxygen reduction reaction (ORR) has low overpotential and high reaction kinetics, and a variety of relatively inexpensive cathode electrocatalysts such as Ag, metal oxides, and carbon materials have been developed. However, the _H2 oxidation reaction (HOR) rate at the AFC anode is relatively slow, and Pt-based noble metal catalysts are still used at present. There are very few reports on efficient and stable non-noble metal HOR electrocatalysts. Therefore, the development of high-efficiency and low-cost non-noble metal HOR electrocatalysts suitable for alkaline media is of great significance for the commercial development of AFC technology.

Fe, Co, Ni and other transition metals are abundant and cheap, and they are ideal alternative materials for Pt noble metal catalysts. However, in general, such catalysts are less stable and prone to corrosion. Compared with other non-noble metals, Ni-based catalysts have relatively high activity and corrosion resistance under alkaline conditions, showing that it is a class of highly potential non-noble metal HOR electrocatalysts. However, the HOR activity of such catalysts is still significantly lower than that of Pt catalysts; and the catalysts still oxidize when the overpotential is higher than 0.1V. In this regard, alloying nickel to tune its oxidation resistance and HOR activity is an effective approach. For example, the AFC with 17.5mg/cm ² NiW alloy as the anode catalyst can reach a maximum output power of 40mW/cm ² at 60°C (see International Journal of Hydrogen Energy 2013,38:16264–16268). With 4 mg/cm ² carbon-supported NiMo catalyst as the anode, the maximum output power of the prepared AFC reached 120 mW/cm ² at 80 °C (see Journal of Materials Chemistry A 2017, 5:24433–24443). With 4 mg/cm ² carbon-supported NiCu catalyst as the anode, the maximum output power of the prepared AFC reached 350 mW/cm ² at 80 °C (see Sustainable Energy Fuels, 2018, 2:2268–2275). However, compared with the maximum power of 1000mW/cm ² of the proton exchange membrane fuel cell, the power is still low. CN103869045A discloses a method for testing the activity of an anode material of a methanol fuel cell. Through specific quantum chemical calculation simulation, the activity of the anode material of the battery is tested to improve the accuracy of judging the activity and efficiency of the battery. However, this method cannot analyze the structural stability of the catalyst, and only analyzes the activity from the reaction energy barrier (activation energy). The characterization means are single, incomplete, and relatively abstract, and cannot be directly compared and verified with the results of electrochemical experiments.

At present, the method for evaluating the HOR activity of electrode catalysts under alkaline conditions is mainly an experimental method, that is, the catalyst is first prepared by an experimental method, and then the HOR experiment is performed under alkaline conditions. However, alkaline electrolytes are easily carbonated in the air, and _H2 is a flammable and explosive substance. Therefore, the experimental operating environment is harsh, the experimental equipment is complicated, and the experimental cost is high. In addition, due to the lack of theoretical guidance, the selection and preparation of new catalysts is blind to a certain extent, and time and material resources are seriously wasted.

First-principles calculation is a method based on the density functional theory of quantum mechanics, through computer simulation calculations, to study the structure and properties of materials from the electronic level. In recent years, with the development of computational chemistry and the improvement of computer hardware, the first-principles method has been increasingly used to study the catalytic properties of materials, design and find new catalytic materials, and has become a research with equal emphasis on experimental methods. means. The first-principles method only needs to carry out computer simulation calculations without real experiments. It has high efficiency, low cost, short calculation cycle and high accuracy. It can not only greatly save time and material costs, but also guide the design, preparation and application. However, there are no research cases in the world that have used the first-principle calculation simulation method to measure and characterize the electrochemical oxidation performance of _alloy catalysts in detail.

Contents of the invention

The object of the present invention is to provide a method and system that can be used to analyze the _H2 electrochemical oxidation performance of alloy catalysts including nickel-based non-noble metal alloy catalysts.

In order to achieve the above object, the present invention provides a method for analyzing the electrochemical oxidation performance of alloy catalyst hydrogen, wherein the method comprises:

The first model construction step: constructing the alloy unit cell model, that is, the first model;

The second model building step: building a surface model of the alloy catalyst based on the first model, that is, the second model;

Optionally, a third model construction step: constructing a surface model of the alloy catalyst containing an alkaline aqueous solution layer based on the second model, i.e. the third model;

Optionally, the fourth model construction step: in the third model, the structure models of the reactants, intermediates and products are respectively constructed on the surface of the alloy catalyst containing the alkaline aqueous solution layer to obtain an alkaline aqueous solution/ The initial model of the alloy catalyst is the fourth model;

Optionally, the fifth model construction step: performing structural optimization on the fourth model to obtain the surface model of the alkaline aqueous solution/alloy catalyst containing reactants, intermediates and products with the optimal structure, that is, the fifth model;

_H Electrochemical oxidation performance evaluation step: based on the second model, carry out the oxidation potential analysis of the alloy catalyst; and/or; based on the second model or the third model, carry out the H adsorption free energy analysis of the alloy catalyst; and/or; The fifth model is to determine the Tafel polarization curve of the alloy catalyst.

In the above analysis method, preferably, based on the second model, performing the oxidation potential analysis of the alloy catalyst includes:

obtain the energy of the second model;

Obtain the energy after the alloy catalyst removes the oxidized metal atoms;

Obtain the energy of the oxidized metal atoms in the alloy catalyst when they are in a simple state;

Obtain the standard oxidation potential of the oxidized metal in the alloy catalyst when it is in a simple state;

Based on the energy of the second model, the energy of the alloy catalyst after removing the oxidized metal atom, the energy of the oxidized metal atom in the alloy catalyst when it is in a simple state, and the standard for obtaining the oxidized metal in an alloy catalyst when it is in a simple state Oxidation potential, to determine the oxidation potential of the alloy catalyst (that is, the external potential required when the alloy is oxidized into a metal oxide or metal hydroxide);

More preferably, based on the second model, performing the oxidation potential analysis of the alloy catalyst further includes:

Based on the oxidation potential of the alloy catalyst, the oxidation resistance performance of the alloy catalyst was evaluated;

More preferably, determining the oxidation potential of the alloy catalyst is preferably carried out by the following formula:

U _ox ＝U _ox (met1,bulk)-(E(A _x B _y )-E(A _x B _yz )-z·E(B))÷n

In the formula, U _ox is the oxidation potential of the alloy catalyst, V; U _ox (met1,bulk) is the standard oxidation potential of the oxidized metal B in the alloy catalyst in a simple state, V; E(A _x B _y ) is The energy of the second model, eV; E(A _{x Byz} ) is the energy of the alloy catalyst after removing the oxidized z metal B atoms, eV; E(B) is the oxidized metal B atoms in the alloy catalyst in the single substance The energy in the state, eV; n is the number of electrons e transferred when the alloy catalyst is oxidized, number.

In the above analysis method, preferably, based on the second model or the third model, the H adsorption free energy analysis of the alloy catalyst includes:

determining the H adsorption free energy of the alloy catalyst based on the second model or the third model;

Based on the H adsorption free energy of the alloy catalyst, the HOR catalytic activity of the alloy catalyst was evaluated; the closer the H adsorption free energy of the alloy catalyst was to 0.414eV, the stronger the HOR catalytic activity of the alloy catalyst.

In the above analysis method, preferably, the Tafel polarization curve determination of the alloy catalyst based on the fifth model includes:

Based on the fifth model, the optimal reaction path of _H2 electrochemical oxidation reaction on the surface of the alloy catalyst is determined;

On the basis of the fifth model, different electrode charges are applied to the alloy catalyst unit cell in the fifth model and background charges of the same amount are introduced to maintain the electrical neutrality of the unit cell, thereby obtaining the sixth model corresponding to different charges; among them, When the applied charge is 0, the corresponding sixth model is the fifth model;

Based on the optimal reaction path of the _H2 electrochemical oxidation reaction on the surface of the alloy catalyst and the sixth model corresponding to different applied charges, the reaction energy barriers of the HOR forward and reverse reactions of the alloy catalyst under different applied charge conditions were determined;

Based on the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst under different applied charge conditions, determine the reaction energy barriers of the alloy catalyst for the HOR forward reaction and reverse reaction at different electrode potentials;

Determine the equilibrium potential of the alloy catalyst based on the reaction energy barriers of the HOR forward and reverse reactions of the alloy catalyst at different electrode potentials;

Based on the equilibrium potential of the alloy catalyst, determine a given potential range, and then determine the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst within the given potential range;

Based on the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst within a given potential range, the kinetic current density of the alloy catalyst within a given potential range is determined, and then the polarization curve of the alloy catalyst is obtained (that is, the kinetic current density of the alloy catalyst Curves that vary with potential);

More preferably, on the basis of the fifth model, respectively apply different electrode charges to the alloy catalyst unit cell in the fifth model and introduce background charges of the same amount to maintain the electrical neutrality of the unit cell, thereby obtaining different charges corresponding to The sixth model includes:

On the basis of the fifth model, different electrode charges are applied to the alloy catalyst unit cell in the fifth model and background charges of the same amount are introduced to maintain the electrical neutrality of the unit cell to obtain the fifth model with different electrode charges applied;

Structural optimization is performed on the fifth model with different electrode charges applied to obtain the sixth model corresponding to different charges;

Further preferably, the structural optimization of the fifth model to which different electrode charges are applied, to obtain the sixth model corresponding to different charges includes:

For the fifth model with different electrode charges applied, the first-principle molecular dynamics simulation (AIMD) was carried out to screen out several relatively stable models of reactants, intermediates and products, and then the screened reactants, intermediates The structure of the alkaline aqueous layer in the model with relatively stable body and product is optimized based on first-principle calculations, and the model with the most stable energy is selected, namely the sixth model;

Preferably, the reaction energy barrier based on the HOR forward reaction and the reverse reaction of the alloy catalyst in a given potential range is determined to determine the kinetic current density of the alloy catalyst in a given potential range through the following formula:

Among them, j _kox is the oxidation kinetic current density, mA/cm ² ; j _kred is the reduction kinetic current density, mA/cm ² ; A(U) is the exponent antecedent (usually 12.0-14.0), dimensionless; R is the gas constant (usually 8.3145), J/mol K; T is the temperature, K; E _a ^ox (U) is the reaction energy barrier of the HOR forward reaction of the alloy catalyst at U potential, eV; E _a ^red (U ) is the reaction energy barrier of the HOR reverse reaction of the alloy catalyst at U potential, eV; j _k (U) is the kinetic current density of the alloy catalyst at U potential, mA/cm ² .

In the above analysis method, preferably, when the analysis method includes determining the Tafel polarization curve of the alloy catalyst based on the fifth model, the step of evaluating the electrochemical oxidation performance of _H further includes performing an alloy catalyst based on the polarization curve of the alloy catalyst. The exchange current density analysis of the catalyst;

Wherein, the exchange current density analysis of the alloy catalyst based on the polarization curve of the alloy catalyst includes:

Based on the polarization curve of the alloy catalyst, determine the exchange current density of the alloy catalyst;

More preferably, based on the polarization curve of the alloy catalyst, performing the exchange current density analysis of the alloy catalyst further includes:

Based on the exchange current density of the alloy catalyst, evaluate the HOR catalytic activity of the alloy catalyst;

More preferably, based on the polarization curve of the alloy catalyst, determining the exchange current density of the alloy catalyst is achieved in the following manner: using the Butter-Volmer equation to fit the polarization curve, and the coefficient obtained from the fitting is the exchange current density of the alloy catalyst; Specifically, the Butter-Volmer equation is:

其中，η＝U-U⁰

Among them, η=UU ⁰

In the formula, j _k is the kinetic current density of the alloy catalyst, mA/cm ² ; j ₀ is the exchange current density of the alloy catalyst, mA/cm ² ; α is the transfer coefficient, dimensionless; F is the Faraday constant, C/mol ; η is the overpotential, V; U is the potential corresponding to j _k , V; U ⁰ is the equilibrium potential, V.

In the above analysis method, preferably, the _H2 electrochemical oxidation performance evaluation step further includes based on the first model, the analysis of the formation energy of the alloy catalyst is carried out;

Described based on the first model, carrying out the formation energy analysis of alloy catalyst comprises:

Based on the first model, determining the formation energy of the alloy catalyst;

Based on the formation energy of the alloy catalyst, the stability of the alloy catalyst is determined.

In the above analysis method, preferably, the _H2 electrochemical oxidation performance evaluation step further includes based on the fifth model, carrying out the reaction energy barrier analysis of the alloy catalyst;

Wherein, said based on the fifth model, carrying out the reaction energy barrier analysis of alloy catalyst includes:

Based on the fifth model, the optimal reaction path of _H2 electrochemical oxidation reaction on the surface of the alloy catalyst is determined;

Based on the optimal reaction path of the _H2 electrochemical oxidation reaction on the surface of the alloy catalyst and the fifth model, the reaction energy barrier of the alloy catalyst in the HOR positive reaction is determined;

Based on the reaction energy barrier of the alloy catalyst, the catalytic activity of the alloy catalyst is determined.

In the above analysis method, preferably, the third model building step includes:

On the basis of the second model, an alkaline aqueous solution model is added to obtain an initial model of the surface of the alloy catalyst containing an alkaline aqueous solution layer;

First-principles molecular dynamics simulation (AIMD) was performed on the initial model of the alloy catalyst surface containing an alkaline aqueous solution layer, and several relatively stable models were screened out;

Structural optimization based on first-principles calculations was carried out on the alkaline aqueous solution layer in the selected relatively stable model, and the most energy-stable model was selected as the third model of the alloy catalyst surface model containing the alkaline aqueous solution layer.

In the above analysis method, preferably, the fourth model building step includes:

Perform first-principles molecular dynamics simulation (AIMD) on the fourth model, and screen out several relatively stable models of reactants, intermediates and products;

Structural optimization based on first-principle calculations is carried out on the alkaline aqueous solution layer in the relatively stable model of reactants, intermediates and products screened out, and the model with the most stable energy is selected as the optimal structure containing reactants, intermediates The alkaline aqueous solution/alloy catalyst surface model of body and product is the fifth model.

和/>

In the above analysis method, preferably, the energy, displacement and gradient convergence criteria of structural optimization based on first-principles calculations are 5.442×10 ^-4 eV, respectively,

and />

In the above analysis method, preferably, the alloy is a nickel-based non-noble metal alloy; more preferably, the non-noble metal includes one or more than two of Cr, Mn, Fe, Co, Ni, Cu and Zn, etc. The combination.

The present invention also provides an analysis system for the electrochemical oxidation performance of alloy catalyst hydrogen, wherein the system includes:

The first model building block: used to construct the alloy unit cell model, that is, the first model;

The second model building module: used to build the surface model of the alloy catalyst based on the first model, that is, the second model;

Optionally, the third model construction module: used to construct the surface model of the alloy catalyst containing the alkaline aqueous solution layer based on the second model, that is, the third model;

Optionally, the fourth model building block: used to construct the structure models of reactants, intermediates and products on the surface of the alloy catalyst containing the alkaline aqueous solution layer in the third model, and obtain the basic structure model containing reactants, intermediates and products. The initial model of the aqueous solution/alloy catalyst is the fourth model;

Optionally, the fifth model building block: used to optimize the structure of the fourth model to obtain an alkaline aqueous solution/alloy catalyst surface model containing reactants, intermediates and products, that is, the fifth model;

_H2 electrochemical oxidation performance evaluation module: including oxidation potential analysis submodule, H adsorption free energy analysis submodule, and/or, polarization curve determination submodule; wherein,

The oxidation potential analysis sub-module is used to analyze the oxidation potential of the alloy catalyst based on the second model;

The H adsorption free energy analysis submodule is used to analyze the H adsorption free energy of the alloy catalyst based on the second model or the third model;

The polarization curve determination sub-module is used to determine the Tafel polarization curve of the alloy catalyst based on the fifth model.

In the above analysis system, preferably, the oxidation potential analysis submodule includes:

The first energy determination unit: used to obtain the energy of the second model;

The second energy determination unit: used to obtain the energy of the alloy catalyst after removing the oxidized metal atoms;

The third energy determination unit: used to obtain the energy of the oxidized metal atoms in the alloy catalyst when they are in a simple state;

Standard oxidation potential determination unit: used to obtain the standard oxidation potential of the oxidized metal in the alloy catalyst when it is in a simple state;

Oxidation potential determination unit: used for energy based on the second model, the energy of the alloy catalyst after removing the oxidized metal atoms, the energy of the oxidized metal atoms in the alloy catalyst when they are in a simple state, and the acquisition of the oxidized metal in the alloy catalyst The standard oxidation potential in the elemental state determines the oxidation potential of the alloy catalyst (that is, the external potential required when the alloy is oxidized to a metal oxide or metal hydroxide);

More preferably, the oxidation potential analysis submodule further includes:

Anti-oxidation performance evaluation unit: used to evaluate the oxidation resistance performance of alloy catalysts based on the oxidation potential of alloy catalysts;

More preferably, determining the oxidation potential of the alloy catalyst is preferably carried out by the following formula:

U _ox ＝U _ox (met1,bulk)-(E(A _x B _y )-E(A _x B _yz )-z·E(B))÷n

In the formula, U _ox is the oxidation potential of the alloy catalyst, V; U _ox (met1,bulk) is the standard oxidation potential of the oxidized metal B in the alloy catalyst in a simple state, V; E(A _x B _y ) is The energy of the second model, eV; E(A _{x Byz} ) is the energy of the alloy catalyst after removing the oxidized z metal B atoms, eV; E(B) is the oxidized metal B atoms in the alloy catalyst in the single substance The energy in the state, eV; n is the number of electrons e transferred when the alloy catalyst is oxidized, number.

In the above analysis system, preferably, the H adsorption free energy analysis submodule includes:

H adsorption free energy determination unit: for determining the H adsorption free energy of the alloy catalyst based on the second model or the third model;

The first catalytic activity determining unit: used for evaluating the HOR catalytic activity of the alloy catalyst based on the H adsorption free energy of the alloy catalyst; wherein, the closer the H adsorption free energy of the alloy catalyst is to 0.414eV, the stronger the HOR catalytic activity of the alloy catalyst.

In the above analysis system, preferably, the polarization curve determination submodule includes:

Optimal reaction path determination unit: used to determine the optimal reaction path of the _H2 electrochemical oxidation reaction on the surface of the alloy catalyst based on the fifth model;

The sixth model determination unit: on the basis of the fifth model, it is used to apply different electrode charges to the alloy catalyst unit cell in the fifth model and introduce the background charge of the same amount to maintain the electrical neutrality of the unit cell, thereby obtaining different charges The corresponding sixth model; wherein, when the applied charge is 0, the corresponding sixth model is the fifth model;

Reaction energy barrier determination unit for forward and reverse reactions under different charges: for the optimal reaction path of _H2 electrochemical oxidation reaction based on the surface of the alloy catalyst and the sixth model corresponding to different applied charges, to determine the HOR of the alloy catalyst under different applied charges Reaction barriers for forward and reverse reactions;

Reaction barrier determination unit for forward and reverse reactions at different potentials: used to determine the HOR forward and reverse reactions of alloy catalysts at different electrode potentials based on the reaction energy barriers of the forward and reverse HOR reactions of the alloy catalyst under different applied charge conditions Energy barrier;

Equilibrium potential determination unit: used to determine the equilibrium potential of the alloy catalyst based on the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst at different electrode potentials;

Polarization curve determination unit: used to determine the given potential range based on the equilibrium potential of the alloy catalyst, and then determine the reaction energy barriers of the HOR forward and reverse reactions of the alloy catalyst within the given potential range; based on the alloy catalyst within the given potential range The reaction energy barrier of HOR forward reaction and reverse reaction, determine the kinetic current density of the alloy catalyst within a given potential range, and then obtain the polarization curve of the alloy catalyst (that is, the curve of the kinetic current density of the alloy catalyst changing with the potential);

More preferably, the sixth model determination unit includes:

Charge applying subunit: on the basis of the fifth model, it is used to apply different electrode charges to the alloy catalyst unit cell in the fifth model and introduce the same amount of background charge to maintain the electrical neutrality of the unit cell to obtain different electrodes fifth model of charge;

The sixth model determination subunit: used to optimize the structure of the fifth model with different electrode charges applied to obtain the sixth model corresponding to different charges;

Further preferably, the sixth model determination subunit includes:

The first optimization group: for the fifth model with different electrode charges applied, perform first-principles molecular dynamics simulation (AIMD) respectively, and screen out several relatively stable models of reactants, intermediates and products;

The second optimization group: used to perform structural optimization based on first-principle calculations on the alkaline aqueous solution layer in the relatively stable model of the screened reactants, intermediates and products, and screen out the model with the most stable energy, namely the sixth model ;

Preferably, the reaction energy barrier based on the HOR forward reaction and the reverse reaction of the alloy catalyst in a given potential range is determined to determine the kinetic current density of the alloy catalyst in a given potential range through the following formula:

Among them, j _kox is the oxidation kinetic current density, mA/cm ² ; j _kred is the reduction kinetic current density, mA/cm ² ; A(U) is the exponent antecedent (usually 12.0-14.0), dimensionless; R is the gas constant (usually 8.3145), J/mol K; T is the temperature, K; E _a ^ox (U) is the reaction energy barrier of the HOR forward reaction of the alloy catalyst at U potential, eV; E _a ^red (U ) is the reaction energy barrier of the HOR reverse reaction of the alloy catalyst at U potential, eV; j _k (U) is the kinetic current density of the alloy catalyst at U potential, mA/cm ² .

In the above analysis system, preferably, when the _H2 electrochemical oxidation performance evaluation module includes a polarization curve determination submodule, the _H2 electrochemical oxidation performance evaluation module further includes:

Exchange current density analysis sub-module: used to analyze the exchange current density of the alloy catalyst based on the polarization curve of the alloy catalyst;

Among them, the exchange current density analysis sub-module includes:

Exchange current density determination unit: used to determine the exchange current density of the alloy catalyst based on the polarization curve of the alloy catalyst;

More preferably, the exchange current density analysis submodule further includes:

The second catalytic activity evaluation unit: used for evaluating the HOR catalytic activity of the alloy catalyst based on the exchange current density of the alloy catalyst;

More preferably, based on the polarization curve of the alloy catalyst, determining the exchange current density of the alloy catalyst is achieved in the following manner: using the Butter-Volmer equation to fit the polarization curve, and the coefficient obtained from the fitting is the exchange current density of the alloy catalyst; Specifically, the Butter-Volmer equation is:

其中，η＝U-U⁰

Among them, η=UU ⁰

In the formula, j _k is the kinetic current density of the alloy catalyst, mA/cm ² ; j ₀ is the exchange current density of the alloy catalyst, mA/cm ² ; α is the transfer coefficient, dimensionless; F is the Faraday constant, C/mol ; η is the overpotential, V; U is the potential corresponding to j _k , V; U ⁰ is the equilibrium potential, V.

In the above analysis system, preferably, the _H2 electrochemical oxidation performance evaluation module further includes:

Formation energy analysis sub-module: used to analyze the formation energy of alloy catalysts based on the first model;

Among them, the formation energy analysis sub-module includes:

Formation energy determination unit: used to determine the formation energy of the alloy catalyst based on the first model;

Stability evaluation unit: used to determine the stability of the alloy catalyst based on the formation energy of the alloy catalyst.

In the above analysis system, preferably, the _H2 electrochemical oxidation performance evaluation module further includes:

Reaction energy barrier analysis sub-module: used to analyze the reaction energy barrier of alloy catalysts based on the fifth model;

Reaction barrier analysis submodules include:

Optimal reaction path determination unit: used to determine the optimal reaction path of the _H2 electrochemical oxidation reaction on the surface of the alloy catalyst based on the fifth model;

Reaction energy barrier determination unit: used to determine the reaction energy barrier of the alloy catalyst in the HOR forward reaction based on the optimal reaction path of the electrochemical oxidation reaction of _H2 on the surface of the alloy catalyst and the fifth model;

The third catalytic activity analysis unit: used to determine the catalytic activity of the alloy catalyst based on the reaction energy barrier of the alloy catalyst.

In the above analysis system, preferably, the third model building module includes:

Initial model construction sub-module: used to add an alkaline aqueous solution model on the basis of the second model to obtain an initial model of the surface of the alloy catalyst containing an alkaline aqueous solution layer;

The first model optimization sub-module: used to perform first-principles molecular dynamics simulation (AIMD) on the initial model of the alloy catalyst surface containing an alkaline aqueous solution layer, and screen out several relatively stable models;

The second model optimization sub-module: it is used to perform structural optimization based on first-principle calculations on the alkaline aqueous solution layer in the screened relatively stable model, and select the model with the most stable energy as an alloy containing an alkaline aqueous solution layer The catalyst surface model is the third model.

In the above analysis system, preferably, the fourth model building module includes:

The third model optimization sub-module: used to perform first-principles molecular dynamics simulation (AIMD) on the fourth model, and screen out several relatively stable models of reactants, intermediates and products;

The fourth model optimization sub-module: it is used to perform structural optimization based on first-principle calculations on the alkaline aqueous solution layer in the relatively stable model of the screened reactants, intermediates and products, and select the model with the most stable energy as The surface model of alkaline aqueous solution/alloy catalyst containing reactants, intermediates and products with optimal structure is the fifth model.

和/>

In the above analysis system, preferably, the energy, displacement and gradient convergence criteria of structure optimization based on first-principles calculations are 5.442×10 ^-4 eV, respectively,

and />

In the above analysis method, preferably, the alloy is a nickel-based non-noble metal alloy; more preferably, the non-noble metal includes one or more than two of Cr, Mn, Fe, Co, Ni, Cu and Zn, etc. The combination.

The technical scheme provided by the present invention can realize the analysis of the _H2 electrochemical oxidation performance of alloy catalysts including nickel-based non-precious metal alloy catalysts without indoor experiments, and overcome the need of the prior art to carry out the _H2 electrochemical oxidation performance of alloy catalysts through experimental techniques. The defects and deficiencies in the analysis of chemical oxidation performance include overcoming the problems of the existing experimental technology for _H2 electrochemical oxidation experimental equipment and corresponding operations under alkaline conditions and the blindness of the experimental synthesis of new alkaline _H2 electrochemical oxidation catalysts, which greatly Save time and material costs.

Description of drawings

Fig. 1 is a schematic flow chart of the evaluation method for the electrochemical oxidation performance of alloy catalyst _H2 provided by Example 1 of the present invention.

FIG. 2A is the surface model of the Ni ₃ Cr alloy catalyst established in Example 1 of the present invention.

FIG. 2B is a surface model of the Ni ₂ Cr ₂ alloy catalyst established in Example 1 of the present invention.

FIG. 2C is the surface model of the NiCr ₃ alloy catalyst established in Example 1 of the present invention.

FIG. 3A is a surface model of a Ni ₃ Cr alloy catalyst containing an alkaline aqueous solution layer established in Example 1 of the present invention.

FIG. 3B is a surface model of the Ni ₂ Cr ₂ alloy catalyst containing an alkaline aqueous solution layer established in Example 1 of the present invention.

FIG. 3C is a surface model of a NiCr ₃ alloy catalyst containing an alkaline aqueous solution layer established in Example 1 of the present invention.

Fig. 4A is the Tafel polarization curve of the Ni ₃ Cr alloy catalyst in Example 1 of the present invention.

Fig. 4B is the Tafel polarization curve of the Ni ₃ Cr alloy catalyst in Example 1 of the present invention.

FIG. 4C is the Tafel polarization curve of the Ni ₃ Cr alloy catalyst in Example 1 of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Apparently, the described embodiments are some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The principle and spirit of the present invention will be described in detail below with reference to several representative embodiments of the present invention.

A specific embodiment of the present invention provides a kind of alloy catalyst _H The evaluation method of electrochemical oxidation performance, wherein, this method comprises:

Step S1: Construct the alloy unit cell model, that is, the first model;

Step S2: Constructing the surface model of the alloy catalyst based on the first model, that is, the second model;

Optional step S3: Constructing the surface model of the alloy catalyst containing the alkaline aqueous solution layer, that is, the third model based on the second model;

Optional step S4: Construct the structure models of the reactants, intermediates and products on the surface of the alloy catalyst containing the alkaline aqueous solution layer in the third model, and obtain the structure model of the alkaline aqueous solution/alloy catalyst containing the reactants, intermediates and products The initial model is the fourth model;

Optional step S5: performing structural optimization on the fourth model to obtain the surface model of the alkaline aqueous solution/alloy catalyst containing reactants, intermediates and products with the optimal structure, that is, the fifth model;

Step S6: based on the second model, performing an oxidation potential analysis of the alloy catalyst; and/or

Based on the second model or the third model, carry out the H adsorption free energy analysis of the alloy catalyst; and/or

Based on the fifth model, the Tafel polarization curve of the alloy catalyst was determined.

In some specific embodiments, the analysis method of the alloy catalyst _H2 electrochemical oxidation performance adopts mode one to carry out, specifically includes:

Step S1: Construct the alloy unit cell model, that is, the first model;

Step S2: Constructing the surface model of the alloy catalyst based on the first model, that is, the second model;

Optional step S3: constructing the surface model of the alloy catalyst containing the alkaline aqueous solution layer, that is, the third model (belonging to the bulk alloy catalyst model) based on the second model;

Step S6: Based on the second model or the third model, analyze the H adsorption free energy of the alloy catalyst;

Among them, method 1 can specifically adopt method A or method B:

Method A includes:

Step S1: Construct the alloy unit cell model, that is, the first model;

Step S2: Constructing the surface model of the alloy catalyst based on the first model, that is, the second model;

Step S6: Based on the second model, analyze the oxidation potential of the alloy catalyst;

Method B includes:

Step S1: Construct the alloy unit cell model, that is, the first model;

Step S2: Constructing the surface model of the alloy catalyst based on the first model, that is, the second model;

Step S3: Constructing the surface model of the alloy catalyst containing the alkaline aqueous solution layer, namely the third model, based on the second model;

Step S6: Based on the third model, analyze the oxidation potential of the alloy catalyst.

In some specific implementations, the analysis method of the alloy catalyst _H2 electrochemical oxidation performance is carried out in mode two, specifically including:

Step S1: Construct the alloy unit cell model, that is, the first model;

Step S2: Constructing the surface model of the alloy catalyst based on the first model, that is, the second model;

Step S3: Constructing the surface model of the alloy catalyst containing the alkaline aqueous solution layer, namely the third model, based on the second model;

Step S6: Based on the second model, perform H adsorption free energy analysis of the alloy catalyst.

In some specific implementations, the analysis method of the alloy catalyst _H2 electrochemical oxidation performance is carried out in mode three, specifically including:

Step S1: Construct the alloy unit cell model, that is, the first model;

Step S2: Constructing the surface model of the alloy catalyst based on the first model, that is, the second model;

Step S3: Constructing the surface model of the alloy catalyst containing the alkaline aqueous solution layer, namely the third model, based on the second model;

Step S4: Construct the structure models of the reactants, intermediates and products on the surface of the alloy catalyst containing the alkaline aqueous solution layer in the third model, and obtain the initial model of the alkaline aqueous solution/alloy catalyst containing the reactants, intermediates and products, namely the fourth model;

Step S5: Perform structural optimization on the fourth model to obtain the surface model of the alkaline aqueous solution/alloy catalyst containing reactants, intermediates and products with the optimal structure, that is, the fifth model;

Step S6: Based on the fifth model, determine the Tafel polarization curve of the alloy catalyst.

In some specific embodiments, the method for analyzing the electrochemical oxidation performance of the alloy catalyst _H2 is carried out using the fourth method, which specifically includes: at least two of the first method, the second method and the third method.

In some embodiments, the alloy is a nickel-based non-noble metal alloy;

Further, the non-noble metal includes one or a combination of two or more of Cr, Mn, Fe, Co, Ni, Cu and Zn.

In some embodiments, the oxidation potential analysis of the alloy catalyst includes:

Step S611: Obtain the energy of the second model;

Step S612: Obtain the energy of the alloy catalyst after removing the oxidized metal atoms;

Step S613: Obtain the energy of the oxidized metal atoms in the alloy catalyst when they are in a simple state;

Step S614: Obtain the standard oxidation potential of the oxidized metal in the alloy catalyst when it is in a simple state;

Step S615: Based on the energy of the second model, the energy of the alloy catalyst after removing the oxidized metal atoms, the energy of the oxidized metal atoms in the alloy catalyst when they are in a simple state, and obtain the oxidized metal in the alloy catalyst in a simple state The standard oxidation potential at the time determines the oxidation potential of the alloy catalyst (that is, the external potential required when the alloy is oxidized into a metal oxide or metal hydroxide);

Further, determining the oxidation potential of the alloy catalyst is preferably carried out by the following formula:

U _ox ＝U _ox (met1,bulk)-(E(A _x B _y )-E(A _x B _yz )-z·E(B))÷n

In the formula, U _ox is the oxidation potential of the alloy catalyst, V; U _ox (met1,bulk) is the standard oxidation potential of the oxidized metal B in the alloy catalyst in a simple state, V; E(A _x B _y ) is The energy of the second model, eV; E(A _{x Byz} ) is the energy of the alloy catalyst after removing the oxidized z metal B atoms, eV; E(B) is the oxidized metal B atoms in the alloy catalyst in the single substance The energy in the state, eV; n is the number of electrons e transferred when the alloy catalyst is oxidized, number;

Among them, the energy of the second model, the energy of the alloy catalyst after removing the oxidized metal atoms, and the energy of the oxidized metal atoms in the alloy catalyst when they are in a simple state can be obtained by conventional methods in the field, such as through first-principle calculations get;

Among them, the standard oxidation potential of the oxidized metal in the alloy catalyst when it is in a single substance state can be obtained by querying the Handbook of Physical Chemistry;

为NiM合金催化剂中发生氧化的金属在其为单质状态时的标准氧化势(即当NiM合金催化剂中的M(或Ni)发生了氧化，则/>

为M(或Ni)处于单质晶体时对应的标准氧化势，

数据可查物理化学手册)；该方式基于金属单质的标准氧化势结合第一性原理计算得到合金状态下的氧化势；Taking the NiM alloy catalyst as an example, assuming that there are z metal B atoms oxidized in the A _x B _y alloy catalyst (corresponding to the NiM alloy catalyst) (because the oxidation of the metal cannot be oxidized all at once, and it is partially oxidized at the beginning), use Above-mentioned U _ox =U _ox (met1, bulk)-(E(A _x B _y )-E(A _x B _yz )-z·E(B))÷n calculates the oxidation potential of NiM alloy catalyst, wherein, E( A _x B _y ) is the energy of the calculated surface model of the NiM alloy catalyst; z is the number of oxidized metal atoms; E(A _x B _yz ) is the energy of the NiM alloy catalyst after removing z oxidized metal atoms ( Calculated by first-principle calculation); _EB is the energy of the oxidized atom when it is in its metal state (calculated by first-principle calculation); n is the number of electrons e transferred when the NiM alloy catalyst is oxidized;

is the standard oxidation potential of the oxidized metal in the NiM alloy catalyst when it is in a simple state (that is, when M (or Ni) in the NiM alloy catalyst has been oxidized, then />

is the standard oxidation potential corresponding to M (or Ni) in a single crystal,

The data can be found in the Handbook of Physical Chemistry); this method is based on the standard oxidation potential of the metal element combined with first-principle calculations to obtain the oxidation potential in the alloy state;

Further, the oxidation potential analysis of the alloy catalyst further includes:

Step S615: Based on the oxidation potential of the alloy catalyst, evaluate the oxidation resistance of the alloy catalyst;

Among them, the oxidation potential of the alloy catalyst can represent the oxidation resistance of the alloy catalyst under alkaline conditions; if the alloy catalyst is positive, it means that the alloy can undergo oxidation reaction, and the larger the oxidation potential, the easier the alloy is to be oxidized. The worse the oxidation resistance; if the alloy catalyst is negative, it means that the alloy is not easy to undergo oxidation reaction, and the smaller the oxidation potential, it means that the alloy is less likely to be oxidized, and the oxidation resistance of the alloy catalyst is stronger.

In some specific embodiments, alloy catalyst H adsorption free energy analysis includes:

Step S621: determining the H adsorption free energy of the alloy catalyst based on the second model or the third model;

Wherein, the H adsorption free energy of the alloy catalyst based on the second model or the third model can be determined in a conventional way, for example, first calculate the energy after H is adsorbed on the surface of the alloy catalyst in the second model or the third model minus the unadsorbed H When the energy of the second model or the third model and the energy of 1/2H ₂ molecules are added, then the zero-point energy correction, entropy change correction and pH value correction can be added to obtain the H adsorption free energy;

Step S622: Based on the H adsorption free energy of the alloy catalyst, evaluate the HOR catalytic activity of the alloy catalyst; wherein, the closer the H adsorption free energy of the alloy catalyst is to 0.414eV, the stronger the HOR catalytic activity of the alloy catalyst;

The electrochemical oxidation of _H2 on the alloy catalyst is closely related to the adsorption strength of H on the catalyst surface. The adsorption of H on the NiM alloy surface is too weak, which is not conducive to the decomposition of _H2 into H on the catalyst surface; if H is adsorbed on the alloy surface If it is too strong, it is not conducive to the further oxidation of the adsorbed H into water. Therefore, the H adsorption free energy can be used to characterize the _H2 electrochemical oxidation performance of the alloy catalyst;

At present, when using the free energy of H adsorption to judge the catalytic activity, it is generally believed that the closer the free energy of H adsorption is to zero, the better the catalytic activity of the catalyst. However, this judgment method is suitable for the judgment of catalytic activity under acidic conditions; Under active conditions, the best H adsorption free energy is 0.414eV, that is, the theoretical value of H adsorption free energy on the surface of the alloy catalyst with the highest activity is 0.414eV; thus, in the technical solution of the present invention, the closer the H adsorption free energy is to 0.414 eV, the stronger the HOR activity of the alloy catalyst.

In some specific embodiments, the determination of the polarization curve of the alloy catalyst comprises:

Step S631: Determine the optimal reaction path of _H2 electrochemical oxidation reaction on the surface of the alloy catalyst based on the fifth model (see step S661 below);

Step S632: On the basis of the fifth model, apply different electrode charges to the alloy catalyst unit cell in the fifth model and introduce background charges of the same amount to maintain the electrical neutrality of the unit cell, thereby obtaining the sixth model corresponding to different charges ; Among them, when the applied charge is 0, the corresponding sixth model is the fifth model;

Step S633: Based on the optimal reaction path of the electrochemical oxidation reaction of _H2 on the surface of the alloy catalyst and the sixth model corresponding to different applied charges, determine the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst under different applied charge conditions;

Step S634: Based on the reaction energy barriers of the alloy catalyst's HOR forward reaction and reverse reaction under different applied charge conditions, determine the reaction energy barriers of the alloy catalyst's HOR forward reaction and reverse reaction under different electrode potentials;

Step S635: Determine the equilibrium potential of the alloy catalyst based on the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst at different electrode potentials;

Step S636: Based on the equilibrium potential of the alloy catalyst, determine a given potential range, and then determine the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst within the given potential range;

Step S637: Based on the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst within a given potential range, determine the kinetic current density of the alloy catalyst within a given potential range, and then obtain the polarization curve of the alloy catalyst (that is, the kinetic energy of the alloy catalyst The curve of the current density versus the potential change);

Further, step S632 includes:

Step S6321: On the basis of the fifth model, respectively apply different electrode charges to the alloy catalyst unit cell in the fifth model and introduce background charges of the same amount to maintain the electrical neutrality of the unit cell to obtain the fifth model with different electrode charges applied. Model;

Step S6322: Structural optimization is performed on the fifth model with different electrode charges applied to obtain the sixth model corresponding to different charges; wherein, when the applied charge is 0, the corresponding sixth model is the fifth model;

Further: Step S6322 includes:

For the fifth model with different electrode charges applied, the first-principle molecular dynamics simulation (AIMD) was carried out to screen out several relatively stable models of reactants, intermediates and products, and then the screened reactants, intermediates The structure of the alkaline aqueous layer in the model with relatively stable body and product is optimized based on first-principle calculations, and the model with the most stable energy is selected, namely the sixth model;

Further: based on the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst in a given potential range, the kinetic current density of the alloy catalyst in a given potential range is determined by the following formula:

Among them, j _kox is the oxidation kinetic current density, mA/cm ² ; j _kred is the reduction kinetic current density, mA/cm ² ; A(U) is the exponent antecedent (usually 12.0-14.0), dimensionless; R is the gas constant (usually 8.3145), J/mol K; T is the temperature, K; E _a ^ox (U) is the reaction energy barrier of the HOR forward reaction of the alloy catalyst at U potential, eV; E _a ^red (U ) is the reaction energy barrier of the HOR reverse reaction of the alloy catalyst under the U potential, eV; j _k (U) is the kinetic current density of the alloy catalyst under the U potential, mA/cm ² ;

Taking the NiM alloy catalyst as an example, the catalyst/solution interface is simulated by the dual reference electrode model, that is, the electrode is simulated by the fifth model, and the electrode charge q is simulated by the charge carried by the alloy catalyst unit cell; Do the background charge to maintain the electrical neutrality of the unit cell; when calculating, apply a certain amount of charge q (ie, electrode charge) to the alloy catalyst model, and then calculate the HOR positive reaction (ie, oxidation) and reverse reaction on the alloy catalyst under this charge (i.e. reduction) reaction energy barrier. Change the amount of applied charge, and calculate the reaction energy barrier values of HOR forward reaction (ie, oxidation) and reverse reaction (ie, reduction) on the alloy catalyst under the condition of different applied charge amount q, so as to obtain the HOR forward reaction energy barrier and reverse reaction energy barrier respectively with Two curves of electrode charge q change;

The electrode charge q is related to the work function W and the electrode potential U; after a certain amount of electrode charge is applied, the work function W of the alloy catalyst model under the charge q can be calculated; then according to the formula U=W÷eU _NHE (W is the work function; UNHE is the standard hydrogen electrode potential), and the electrode potential U on the alloy catalyst model is calculated under a given electrode charge q, so that the two curves of the HOR forward reaction energy barrier and reverse reaction energy barrier changing with the electrode charge q are converted into Curves of HOR forward reaction energy barrier and reverse reaction energy barrier changing with electrode potential U;

When the HOR forward reaction energy barrier and reverse reaction energy barrier cross the curves that vary with the electrode potential U, the corresponding electrode potential is the reversible electrode potential, that is, the equilibrium potential.

确定给定电极电势值下的HOR动力学电流密度；其中，j_kox为氧化动力学电流密度；j_kred为还原动力学电流密度；A(U)为指前因子；R为气体常数；T为温度；E_a ^ox(U)为U电势下合金催化剂的HOR正反应的反应能垒；E_a ^red(U)为U电势下合金催化剂的HOR逆反应的反应能垒；j_k(U)为U电势下合金催化剂的动力学电流密度。Control the potential in the vicinity of the equilibrium potential, determine the HOR forward reaction energy barrier and reverse reaction energy barrier under a given electrode potential value, and further use

Determine the HOR kinetic current density at a given electrode potential value; where j _kox is the oxidation kinetic current density; j _kred is the reduction kinetic current density; A(U) is the pre-exponential factor; R is the gas constant; T is temperature; E _a ^ox (U) is the reaction energy barrier of the HOR forward reaction of the alloy catalyst at the U potential; E _a ^red (U) is the reaction energy barrier of the HOR reverse reaction of the alloy catalyst at the U potential; j _k (U) is the U Kinetic current density of alloy catalysts at electric potential.

In some specific embodiments, when the analysis method includes determining the Tafel polarization curve of the alloy catalyst based on the fifth model, the step of evaluating the electrochemical oxidation performance of _H further includes performing the determination of the alloy catalyst based on the polarization curve of the alloy catalyst. Exchange current density analysis;

Wherein, the exchange current density analysis of the alloy catalyst based on the polarization curve of the alloy catalyst includes:

Step S641: Based on the polarization curve of the alloy catalyst, determine the exchange current density of the alloy catalyst;

Further, based on the polarization curve of the alloy catalyst, the exchange current density of the alloy catalyst is determined by the following method: the polarization curve is fitted using the Butter-Volmer equation, and the coefficient obtained by the fitting is the exchange current density of the alloy catalyst; specifically In terms of, the Butter-Volmer equation is:

其中，η＝U-U⁰

Among them, η=UU ⁰

In the formula, j _k is the kinetic current density of the alloy catalyst, mA/cm ² ; j ₀ is the exchange current density of the alloy catalyst, mA/cm ² ; α is the transfer coefficient, dimensionless; F is the Faraday constant, C/mol ; η is the overpotential, V; U is the potential corresponding to j _k , V; U ⁰ is the equilibrium potential, V.

Further, the analysis of the exchange current density of the alloy catalyst based on the polarization curve of the alloy catalyst further includes:

Step S642: Based on the exchange current density of the alloy catalyst, evaluate the HOR catalytic activity of the alloy catalyst;

Among them, the larger the exchange current density of _H electrochemical oxidation, the stronger the catalytic activity of the alloy catalyst, and the smaller the exchange current density, the weaker the catalytic activity of the alloy catalyst.

In some specific implementations, step S6 further includes the analysis of the formation energy of the alloy catalyst, specifically including:

Step S651: Based on the first model, determine the formation energy of the alloy catalyst;

Wherein, the formation energy of the alloy catalyst can be determined in a conventional manner, for example, the formation energy of the alloy catalyst can be obtained by subtracting the energy of the corresponding elemental metal from the energy of the alloy catalyst (determined by the first model);

Taking the NiM alloy catalyst as an example, the formation energy of the NiM alloy catalyst can be obtained by subtracting the energy of the corresponding elemental Ni and M from the energy of the alloy NiM (determined by the first model);

Further, the formation energy analysis of the alloy catalyst further includes:

Step S652: Based on the formation energy of the alloy catalyst, determine the stability of the alloy catalyst;

Among them, the formation energy of the alloy catalyst can represent the feasibility of the corresponding metal to form an alloy. If the calculated formation energy is negative, the alloy catalyst can be formed, and the smaller the formation energy, the more stable the structure of the alloy catalyst; if the calculated formation energy is positive The value cannot form an alloy catalyst;

Taking NiM alloy catalyst as an example, the formation of NiM alloy catalyst can represent the feasibility of Ni and M to form an alloy; if the formation energy of NiM alloy catalyst is negative, Ni and M can form alloy, and the formation of NiM alloy catalyst The smaller the energy, the more stable the structure of the NiM alloy catalyst is; if the formation energy of the NiM alloy catalyst is positive, the two metals, Ni and M, will form independent phases and cannot form an alloy catalyst.

In some specific implementations, step S6 further includes analysis of the reaction energy barrier of the alloy catalyst, specifically including:

Step S661: Determine the optimal reaction path of _H2 electrochemical oxidation reaction on the surface of the alloy catalyst based on the fifth model;

Step S662: Based on the optimal reaction path of the _H2 electrochemical oxidation reaction on the surface of the alloy catalyst and the fifth model, determine the reaction energy barrier of the alloy catalyst in the HOR positive reaction;

Among them, the determination of the reaction energy barrier of the alloy catalyst in the HOR forward reaction can be determined in a conventional way. For example, firstly, the geometric structure of the initial state and the final state of each elementary reaction on the fifth model is optimized to obtain the initial state and the final state. Stable structure; then starting from the stable structure of the initial state and final state of the reaction, search for the corresponding transition state through the linear synchronous transition/quadratic synchronous transition (LST/QST) method, and verify the correctness of the transition state by frequency calculation; finally calculate The reaction energy between the initial state and the final state and the reaction energy barrier between the initial state and the transition state; determine the optimal reaction path on the surface of the alloy catalyst according to the size of the reaction energy barrier, and determine the rate of the reaction process on the surface of the alloy catalyst The control step, the reaction energy barrier corresponding to the rate control step in the reaction process on the surface of the alloy catalyst is the reaction energy barrier of the alloy catalyst in the positive reaction of HOR;

Taking the NiM alloy catalyst as an example, under alkaline conditions, the calculation of the _H2 electrochemical oxidation reaction path on the fifth model involves the initial state, final state, and transition state of the three elementary reactions of Tafel, Heyrovsky, and Volmer; first The geometric structure optimization of the initial state and the final state of each elementary reaction on the fifth model is carried out to obtain the stable structure of the initial state and the final state; Synchronous transition (LST/QST) method searches for the corresponding transition state, and verifies the correctness of the transition state through frequency calculation; finally calculates the reaction energy between the initial state and the final state and the reaction energy barrier between the initial state and the transition state; Determine the optimal reaction path on the surface of the NiM alloy catalyst according to the size of the reaction energy barrier, and determine the rate control step in the reaction process on the surface of the NiM alloy catalyst. The reaction energy barrier corresponding to the rate control step in the reaction process on the surface of the NiM alloy catalyst is is the reaction energy barrier of the positive reaction of NiM alloy catalyst in HOR;

Further, the reaction energy barrier analysis of the alloy catalyst further includes:

Step S663: Determine the catalytic activity of the alloy catalyst based on the reaction energy barrier of the alloy catalyst in the HOR positive reaction;

Among them, the reaction energy barrier of the alloy catalyst in the forward reaction of HOR can characterize the catalytic activity of the alloy catalyst, the lower the reaction energy barrier of the alloy catalyst in the forward reaction of HOR, the stronger the catalytic activity of the alloy catalyst.

In some specific implementations, step S1 constructs the first model based on existing alloy structure data;

Taking the NiM alloy catalyst as an example, a Ni unit cell model is established according to the existing nickel crystal structure data; Cell model; wherein, according to the existing nickel crystal structure data, the establishment of the Ni unit cell model can be carried out using the Visualizer module in the Materials Studio software package; wherein, on the basis of the Ni unit cell model, some Ni atoms are replaced in proportion to Non-noble metal atoms M, to establish a NiM alloy unit cell model, can replace some Ni atoms with non-noble metal atoms Cr, Mn, Fe, Co, Ni, Cu or Zn in proportion.

In some specific embodiments, step S2 constructs the second model by cutting out the corresponding alloy surface on the basis of the alloy unit cell model;

Taking the NiM alloy catalyst as an example to illustrate, the corresponding NiM surface is cut out on the basis of the NiM alloy unit cell model to obtain the NiM alloy catalyst surface model.

In some specific implementation manners, step S3 includes:

Step S31: adding an alkaline aqueous solution model on the basis of the second model to obtain an initial surface model of the alloy catalyst containing an alkaline aqueous solution layer;

Step S32: performing first-principles molecular dynamics simulation (AIMD) on the initial model of the surface of the alloy catalyst containing the alkaline aqueous solution layer, and screening out several relatively stable models;

Step S33: Perform structural optimization based on first-principles calculations on the alkaline aqueous solution layer in the selected relatively stable model, and select the model with the most stable energy as the surface model of the alloy catalyst containing the alkaline aqueous solution layer, that is, the third Model;

In this embodiment, the structure optimization of the initial model is carried out by means of first-principles molecular dynamics simulation and then first-principles calculation, which has higher accuracy;

Further, step S31 includes:

On the alloy surface of the second model, a vacuum layer is set; an alkaline aqueous solution model is added to the vacuum layer to obtain an initial model of the alloy catalyst surface containing an alkaline aqueous solution layer;

其中，碱性水溶液模型可以由水分子和K⁺、OH^-离子组成。Taking the NiM alloy catalyst as an example, a vacuum layer is set on the NiM surface of the NiM alloy catalyst surface model; an alkaline aqueous solution model is added to a position close to the NiM surface in the vacuum layer to obtain a NiM alloy catalyst surface containing an alkaline aqueous solution layer The initial model is the third model; among them, the set vacuum layer height can be

Among them, the alkaline aqueous solution model can be composed of water molecules and K ⁺ , OH ^- ions.

In some specific implementation manners, step S4 includes:

Step S41: Perform first-principles molecular dynamics simulation (AIMD) on the fourth model, and screen out a number of relatively stable models of reactants, intermediates and products;

Step S42: Perform structural optimization based on first-principles calculations on the alkaline aqueous solution layer in the relatively stable model of reactants, intermediates and products screened out, and select the model with the most stable energy as the optimal structure containing reaction Alkaline aqueous solution/alloy catalyst surface model of substances, intermediates and products, namely the fifth model;

In this embodiment, the structure optimization of the initial model is carried out by means of first-principle molecular dynamics simulation and then first-principle calculation, which has higher accuracy.

和/>

In some specific embodiments, the energy, displacement and gradient convergence criteria of the structure optimization based on the first-principles calculation are 5.442×10 ^-4 eV, respectively,

and />

In some specific embodiments, in the structural optimization process based on first-principles calculations, the spin-unrestricted calculation method is used to calculate the PBE functional approximated by the generalized gradient, and the long-range dispersion force is calculated by Grimme's PBE-D2 method, The ionic nuclei of metal atoms are described by density functional theory semi-nuclear pseudopotentials, and the valence electron functions are described by double numerical plus polarization (DNP) basis sets.

The embodiment of the present invention also provides an analysis system for the electrochemical oxidation performance of the alloy catalyst H2. Preferably, the system is used to realize the above-mentioned method embodiment.

The system includes:

The first model building block: used to construct the alloy unit cell model, that is, the first model;

The second model building module: used to build the surface model of the alloy catalyst based on the first model, that is, the second model;

Optionally, the third model construction module: used to construct the surface model of the alloy catalyst containing the alkaline aqueous solution layer based on the second model, that is, the third model;

Optionally, the fourth model building block: used to construct the structure models of reactants, intermediates and products on the surface of the alloy catalyst containing the alkaline aqueous solution layer in the third model, and obtain the basic structure model containing reactants, intermediates and products. The initial model of the aqueous solution/alloy catalyst is the fourth model;

Optionally, the fifth model building block: used to optimize the structure of the fourth model to obtain an alkaline aqueous solution/alloy catalyst surface model containing reactants, intermediates and products, that is, the fifth model;

_H2 electrochemical oxidation performance evaluation module: including oxidation potential analysis submodule, H adsorption free energy analysis submodule, and/or, polarization curve determination submodule; wherein,

The oxidation potential analysis sub-module is used to analyze the oxidation potential of the alloy catalyst based on the second model;

The H adsorption free energy analysis submodule is used to analyze the H adsorption free energy of the alloy catalyst based on the second model or the third model;

The polarization curve determination sub-module is used to determine the Tafel polarization curve of the alloy catalyst based on the fifth model.

In some specific embodiments, the oxidation potential analysis submodule includes:

The first energy determination unit: used to obtain the energy of the second model;

The second energy determination unit: used to obtain the energy of the alloy catalyst after removing the oxidized metal atoms;

The third energy determination unit: used to obtain the energy of the oxidized metal atoms in the alloy catalyst when they are in a simple state;

Standard oxidation potential determination unit: used to obtain the standard oxidation potential of the oxidized metal in the alloy catalyst when it is in a simple state;

Oxidation potential determination unit: used for energy based on the second model, the energy of the alloy catalyst after removing the oxidized metal atoms, the energy of the oxidized metal atoms in the alloy catalyst when they are in a simple state, and the acquisition of the oxidized metal in the alloy catalyst The standard oxidation potential in the elemental state determines the oxidation potential of the alloy catalyst (that is, the external potential required when the alloy is oxidized to a metal oxide or metal hydroxide);

Further, the oxidation potential analysis submodule further includes:

Anti-oxidation performance evaluation unit: used to evaluate the oxidation resistance performance of alloy catalysts based on the oxidation potential of alloy catalysts;

Further, determining the oxidation potential of the alloy catalyst is preferably carried out by the following formula:

U _ox ＝U _ox (met1,bulk)-(E(A _x B _y )-E(A _x B _yz )-z·E(B))÷n

In the formula, U _ox is the oxidation potential of the alloy catalyst, V; U _ox (met1,bulk) is the standard oxidation potential of the oxidized metal B in the alloy catalyst in a simple state, V; E(A _x B _y ) is The energy of the second model, eV; E(A _{x Byz} ) is the energy of the alloy catalyst after removing the oxidized z metal B atoms, eV; E(B) is the oxidized metal B atoms in the alloy catalyst in the single substance The energy in the state, eV; n is the number of electrons e transferred when the alloy catalyst is oxidized, number.

In some specific embodiments, the H adsorption free energy analysis submodule includes:

H adsorption free energy determination unit: for determining the H adsorption free energy of the alloy catalyst based on the second model or the third model;

The first catalytic activity determining unit: used for evaluating the HOR catalytic activity of the alloy catalyst based on the H adsorption free energy of the alloy catalyst; wherein, the closer the H adsorption free energy of the alloy catalyst is to 0.414eV, the stronger the HOR catalytic activity of the alloy catalyst.

In some specific embodiments, the polarization curve determination submodule includes:

Optimal reaction path determination unit: used to determine the optimal reaction path of the _H2 electrochemical oxidation reaction on the surface of the alloy catalyst based on the fifth model;

The sixth model determination unit: on the basis of the fifth model, it is used to apply different electrode charges to the alloy catalyst unit cell in the fifth model and introduce the background charge of the same amount to maintain the electrical neutrality of the unit cell, thereby obtaining different charges The corresponding sixth model; wherein, when the applied charge is 0, the corresponding sixth model is the fifth model;

Reaction energy barrier determination unit for forward and reverse reactions under different charges: for the optimal reaction path of _H2 electrochemical oxidation reaction based on the surface of the alloy catalyst and the sixth model corresponding to different applied charges, to determine the HOR of the alloy catalyst under different applied charges Reaction barriers for forward and reverse reactions;

Reaction barrier determination unit for forward and reverse reactions at different potentials: used to determine the HOR forward and reverse reactions of alloy catalysts at different electrode potentials based on the reaction energy barriers of the forward and reverse HOR reactions of the alloy catalyst under different applied charge conditions Energy barrier;

Equilibrium potential determination unit: used to determine the equilibrium potential of the alloy catalyst based on the reaction energy barriers of the HOR forward reaction and reverse reaction of the alloy catalyst at different electrode potentials;

Polarization curve determination unit: used to determine the given potential range based on the equilibrium potential of the alloy catalyst, and then determine the reaction energy barriers of the HOR forward and reverse reactions of the alloy catalyst within the given potential range; based on the alloy catalyst within the given potential range The reaction energy barrier of HOR forward reaction and reverse reaction, determine the kinetic current density of the alloy catalyst within a given potential range, and then obtain the polarization curve of the alloy catalyst (that is, the curve of the kinetic current density of the alloy catalyst changing with the potential);

Further, the sixth model determination unit includes:

Charge applying subunit: on the basis of the fifth model, it is used to apply different electrode charges to the alloy catalyst unit cell in the fifth model and introduce the same amount of background charge to maintain the electrical neutrality of the unit cell to obtain different electrodes fifth model of charge;

The sixth model determination subunit: used to optimize the structure of the fifth model with different electrode charges applied to obtain the sixth model corresponding to different charges;

Further, the sixth model determination subunit includes:

The first optimization group: for the fifth model with different electrode charges applied, perform first-principles molecular dynamics simulation (AIMD) respectively, and screen out several relatively stable models of reactants, intermediates and products;

The second optimization group: used to perform structural optimization based on first-principle calculations on the alkaline aqueous solution layer in the relatively stable model of the screened reactants, intermediates and products, and screen out the model with the most stable energy, namely the sixth model ;

Further, based on the reaction energy barrier of the HOR forward reaction and reverse reaction of the alloy catalyst within a given potential range, determining the kinetic current density of the alloy catalyst within a given potential range is performed by the following formula:

Among them, j _kox is the oxidation kinetic current density, mA/cm ² ; j _kred is the reduction kinetic current density, mA/cm ² ; A(U) is the exponent antecedent (usually 12.0-14.0), dimensionless; R is the gas constant (usually 8.3145), J/mol K; T is the temperature, K; E _a ^ox (U) is the reaction energy barrier of the HOR forward reaction of the alloy catalyst at U potential, eV; E _a ^red (U ) is the reaction energy barrier of the HOR reverse reaction of the alloy catalyst at U potential, eV; j _k (U) is the kinetic current density of the alloy catalyst at U potential, mA/cm ² .

In some specific embodiments, when the _H2 electrochemical oxidation performance evaluation module includes a polarization curve determination submodule, the _H2 electrochemical oxidation performance evaluation module further includes:

Exchange current density analysis sub-module: used to analyze the exchange current density of the alloy catalyst based on the polarization curve of the alloy catalyst;

Among them, the exchange current density analysis sub-module includes:

Exchange current density determination unit: used to determine the exchange current density of the alloy catalyst based on the polarization curve of the alloy catalyst;

Further, the exchange current density analysis submodule further includes:

The second catalytic activity evaluation unit: used for evaluating the HOR catalytic activity of the alloy catalyst based on the exchange current density of the alloy catalyst;

Further, based on the polarization curve of the alloy catalyst, the exchange current density of the alloy catalyst is determined by the following method: the polarization curve is fitted using the Butter-Volmer equation, and the coefficient obtained by the fitting is the exchange current density of the alloy catalyst; specifically In terms of, the Butter-Volmer equation is:

其中，η＝U-U⁰

Among them, η=UU ⁰

In the formula, j _k is the kinetic current density of the alloy catalyst, mA/cm ² ; j ₀ is the exchange current density of the alloy catalyst, mA/cm ² ; α is the transfer coefficient, dimensionless; F is the Faraday constant, C/mol ; η is the overpotential, V; U is the potential corresponding to j _k , V; U ⁰ is the equilibrium potential, V.

In some specific embodiments, the _H2 electrochemical oxidation performance evaluation module further includes:

Formation energy analysis sub-module: used to analyze the formation energy of alloy catalysts based on the first model;

Further, the formation energy analysis sub-module includes:

Formation energy determination unit: used to determine the formation energy of the alloy catalyst based on the first model;

Stability evaluation unit: used to determine the stability of the alloy catalyst based on the formation energy of the alloy catalyst.

In some specific embodiments, the _H2 electrochemical oxidation performance evaluation module further includes:

Reaction energy barrier analysis sub-module: used to analyze the reaction energy barrier of alloy catalysts based on the fifth model;

Further, the reaction energy barrier analysis submodule includes:

Optimal reaction path determination unit: used to determine the optimal reaction path of the _H2 electrochemical oxidation reaction on the surface of the alloy catalyst based on the fifth model;

Reaction energy barrier determination unit: used to determine the reaction energy barrier of the alloy catalyst in the HOR forward reaction based on the optimal reaction path of the electrochemical oxidation reaction of _H2 on the surface of the alloy catalyst and the fifth model;

The third catalytic activity analysis unit: used to determine the catalytic activity of the alloy catalyst based on the reaction energy barrier of the alloy catalyst.

In some specific embodiments, the third model building block includes:

Initial model construction sub-module: used to add an alkaline aqueous solution model on the basis of the second model to obtain an initial model of the surface of the alloy catalyst containing an alkaline aqueous solution layer;

The first model optimization sub-module: used to perform first-principles molecular dynamics simulation (AIMD) on the initial model of the alloy catalyst surface containing an alkaline aqueous solution layer, and screen out several relatively stable models;

The second model optimization sub-module: it is used to perform structural optimization based on first-principle calculations on the alkaline aqueous solution layer in the screened relatively stable model, and select the model with the most stable energy as an alloy containing an alkaline aqueous solution layer The catalyst surface model is the third model.

In some specific embodiments, the fourth model building block includes:

The third model optimization sub-module: used to perform first-principles molecular dynamics simulation (AIMD) on the fourth model, and screen out several relatively stable models of reactants, intermediates and products;

The fourth model optimization sub-module: it is used to perform structural optimization based on first-principle calculations on the alkaline aqueous solution layer in the relatively stable model of the screened reactants, intermediates and products, and select the model with the most stable energy as The surface model of alkaline aqueous solution/alloy catalyst containing reactants, intermediates and products with optimal structure is the fifth model.

和/>

In some specific embodiments, the energy, displacement and gradient convergence criteria of structure optimization based on first-principles calculations are 5.442×10 ^-4 eV, respectively,

and />

In some embodiments, the alloy is a nickel-based non-noble metal alloy;

Further, the non-noble metal includes one or a combination of two or more of Cr, Mn, Fe, Co, Ni, Cu and Zn.

Example 1

The present embodiment provides a kind of NiCr alloy catalyst H The evaluation method of electrochemical oxidation performance,

As shown in Figure 1, the method includes:

Step 1. Model construction, including:

的镍晶体结构，利用MaterialsStudio软件包中的Visualizer模块建立4×4的Ni晶胞模型。Step 1.1, Ni unit cell model establishment: according to the lattice parameter is

The Ni crystal structure of Ni, using the Visualizer module in the MaterialsStudio software package to establish a 4 × 4 Ni unit cell model.

Step 1.2, NiCr alloy unit cell model establishment: on the basis of the 4×4 Ni unit cell model, according to the Ni/Cr atomic ratio of 3:1, 2:2, 1:3, evenly replace part of Ni atoms with Cr Atoms, to establish Ni ₃ Cr, Ni ₂ Cr ₂ , NiCr ₃ alloy unit cell model, that is, the first model of Ni ₃ Cr, Ni ₂ Cr ₂ , NiCr ₃ alloy catalyst; Ni ₃ Cr, Ni ₂ Cr ₂ , NiCr ₃ alloy The parameters of the unit cell model are shown in Table 1;

Table 1 Lattice parameters of NiCr alloy

真空层，相应的结构如图2A-图2C所示。Step 1.2, NiCr alloy catalyst surface model construction: on the basis of Ni ₃ Cr, Ni ₂ Cr ₂ , NiCr ₃ alloy unit cell models, Ni ₃ Cr(111), Ni ₂ Cr ₂ (111), NiCr ₃ ( 111) Surface, obtain the surface model of Ni ₃ Cr, Ni ₂ Cr and NiCr ₃ alloy catalyst, that is, the second model of Ni ₃ Cr, Ni ₂ Cr ₂ and NiCr ₃ alloy catalyst, wherein the thickness of the alloy is 4 layers, and the height is set for

The vacuum layer, the corresponding structure is shown in Figure 2A-Figure 2C.

Step 1.3, construction of the surface model of the NiCr alloy catalyst containing the alkaline aqueous solution layer: in the vicinity of the surface of the alloy catalyst in the vacuum layer, 13 water molecules and 2 K ⁺ /OH ^- ions were added to establish the alkaline solution layer model, and the model containing The surface model of the Ni ₃ Cr, Ni ₂ Cr, NiCr ₃ alloy catalyst in the alkaline aqueous solution layer, that is, the third model of the Ni ₃ Cr, Ni ₂ Cr ₂ , NiCr ₃ alloy catalyst, the results are shown in Figure 3A-Figure 3C.

Step 1.4, _the fourth model construction: Ni ₃ Cr (111 ₎ , Ni ₂ Cr ₂ (111), NiCr _{3 ( 111} ) on the surface to further construct the structure models of reactants, intermediates and products, and obtain the initial model of alkaline aqueous solution/Ni ₃ Cr alloy catalyst containing reactants, intermediates and products and the base model containing reactants, intermediates and products The initial model of alkaline aqueous solution/Ni ₂ Cr ₂ alloy catalyst and the initial model of alkaline aqueous solution/NiCr ₃ alloy catalyst containing reactants, intermediates and products, that is, the first model of Ni ₃ Cr, Ni ₂ Cr ₂ , NiCr ₃ alloy catalyst Four models.

Step 1.5, construction of the fifth model: optimize the structure of the fourth model to obtain the surface model of the alkaline aqueous solution/alloy catalyst containing reactants, intermediates and products with the optimal structure, that is, the fifth model;

Specifically, first-principles molecular dynamics simulation (AIMD) was carried out on the fourth model of Ni ₃ Cr alloy catalyst, and several relatively stable models of reactants, intermediates and products were screened out; using first-principles density functional Theory optimizes and calculates the structure of the reactants, intermediates and products in the process of the three elementary reactions on the Ni ₃ Cr(111) surface of the screened model, and screens out the model with the most stable energy as the optimal structure containing The alkaline aqueous solution/Ni ₃ Cr alloy catalyst surface model of reactants, intermediates and products is the fifth model of Ni ₃ Cr alloy catalyst;

First-principles molecular dynamics simulation (AIMD) was carried out on the fourth model of Ni ₂ Cr ₂ alloy catalyst, and several relatively stable models of reactants, intermediates and products were screened out; the first-principle density functional theory was used to screen The structure optimization and calculation of the reactants, intermediates and products in the three elementary reaction processes on the Ni ₂ Cr ₂ (111) surface of the model were carried out, and the model with the most stable energy was screened out as the optimal structure containing reactants , intermediate and product alkaline aqueous solution/Ni ₂ Cr ₂ alloy catalyst surface model is the fifth model of Ni ₂ Cr ₂ alloy catalyst;

First-principles molecular dynamics simulation (AIMD) was carried out on the fourth model of NiCr ₃ alloy catalyst, and several relatively stable models of reactants, intermediates and products were screened out; The structure optimization and calculation of the reactants, intermediates and products in the process of the three elementary reactions on the NiCr ₃ (111) surface of the model were carried out, and the model with the most stable energy was screened out. As the optimal structure containing the reactants, intermediates and The alkaline aqueous solution/NiCr ₃ alloy catalyst surface model of product is the fifth model of NiCr ₃ alloy catalyst;

和/>

Among them, the structure optimization adopts the spin-unrestricted calculation, and the calculation adopts the PBE functional approximated by the generalized gradient. The long-range dispersion force is calculated by Grimme's PBE-D2 method. The ion nucleus of the metal atom is described by the semi-nuclear pseudopotential of the density functional theory, and the valence electron function is described by the double numerical plus polarization (DNP) basis set; the energy and displacement in the structure optimization and gradient convergence criteria are 5.442× ^10-4 eV, respectively,

and />

Step 2, acquisition of _H2 electrochemical oxidation performance evaluation parameters, including:

Step 2.1. Determine the formation energy of the alloy catalyst: determine the energy of the Ni ₃ Cr alloy based on the Ni ₃ Cr alloy unit cell model, and then subtract the energy of elemental Ni and Cr to obtain the formation energy of the Ni ₃ Cr alloying agent; based on the Ni ₂ The Cr ₂ alloy unit cell model determines the energy of the Ni ₂ Cr ₂ alloy, and then subtracts the energy of the elemental Ni and Cr to obtain the formation energy of the Ni ₃ Cr alloying agent; based on the NiCr ₃ alloy unit cell model, the energy of the NiCr ₃ alloy is determined, Further subtracting the energy of elemental Ni and Cr, the formation energy of Ni ₃ Cr alloying agent was obtained; the formation energy of Ni ₃ Cr, Ni ₂ Cr ₂ and NiCr ₃ alloy catalysts were determined to be -2.76eV, -2.53eV, - 2.34eV.

Step 2.2, determine the oxidation potential of the alloy catalyst:

When Ni in Ni ₃ Cr(111), Ni ₂ Cr ₂ (111) and NiCr ₃ (111) is oxidized to Ni(OH) ₂ , the surface of Ni ₃ Cr, Ni ₂ Cr ₂ (and NiCr ₃ alloy catalyst The energy of the model; obtain the energy of Ni ₃ Cr, Ni ₂ Cr ₂ , and NiCr ₃ alloy catalysts after removing the oxidized Ni metal atoms; obtain the energy of Ni metal atoms in the simple state; obtain the Ni metal in the simple state The standard oxidation potential; and then by the following formula, determine the oxidation potential when Ni in Ni ₃ Cr (111), Ni ₂ Cr ₂ (111) and NiCr ₃ (111) is oxidized to Ni(OH) ₂ :

U _ox ＝U _ox (met1,bulk)-(E(A _x B _y )-E(A _x B _yz )-z·E(B))÷n

In the formula, U _ox is the oxidation potential of the alloy catalyst, V; U _ox (met1,bulk) is the standard oxidation potential of the oxidized metal B in the alloy catalyst in a simple state, V; E(A _x B _y ) is The energy of the second model, eV; E(A _{x Byz} ) is the energy of the alloy catalyst after removing the oxidized z metal B atoms, eV; E(B) is the oxidized metal B atoms in the alloy catalyst in the single substance The energy in the state, eV; n is the number of electrons e transferred when the alloy catalyst is oxidized, number;

Surface models of Ni ₃ Cr, Ni ₂ Cr ₂ and NiCr ₃ alloy catalysts obtained when Cr in Ni 3 Cr(111), Ni _{2 Cr 2 (} 111) and NiCr ₃ (111) is oxidized to Cr(OH) ₃ the energy of Ni ₃ Cr, Ni ₂ Cr ₂ , and NiCr ₃ alloy catalysts to remove the oxidized Cr metal atoms; to obtain the energy of Cr metal atoms in the simple state; to obtain the energy of Cr metal in the simple state Standard oxidation potential; then by the above formula, determine the oxidation potential _when Cr is oxidized to Cr(OH) in Ni ₃ Cr (111), Ni ₂ Cr ₂ (111) and NiCr ₃ (111);

The oxidation potentials of the obtained Ni ₃ Cr(111), Ni ₂ Cr ₂ (111) and NiCr ₃ (111) when Ni is oxidized to Ni(OH) ₂ are 0.68V, 0.50V and 0.47V respectively; Ni ₃ The oxidation potentials of Cr to Cr(OH) ₃ in Cr(111), Ni ₂ Cr ₂ (111) and NiCr ₃ (111) are 1.27V, 1.14V and 1.03V, respectively.

Step 2.3, determining the reaction energy barrier catalyzed by the alloy:

Under alkaline conditions, the electrochemical oxidation of _H2 mainly includes three elementary reactions of Tafel, Heyrovsky and Volmer. Tafel reaction refers to the direct decomposition of _H2 molecules into two adsorbed H on the catalyst surface; Heyrovsky reaction refers to the process in which _H2 molecules react with basic anion ^OH- to generate adsorbed H and _H2O and release an electron; Volmer reaction Refers to the process in which the adsorbed H reacts with the basic anion ^OH- to generate H ₂ O and release an electron; therefore, the electrochemical oxidation of H ₂ can be carried out through the Tafel-Volmer process, and may also be carried out through the Heyrovsky-Volmer process;

Under alkaline conditions, the calculation of the H ₂ electrochemical oxidation reaction path on the fifth model of Ni ₃ Cr, Ni ₂ Cr ₂ , NiCr ₃ alloy catalysts involves the initial state and final state of the three elementary reactions of Tafel, Heyrovsky, and Volmer and transition state; firstly, optimize the geometric structure of the initial state and final state of each elementary reaction on the fifth model to obtain the stable structure of the initial state and final state; then start from the stable structure of the initial state and final state of the reaction, through the Synchronous Transition/Quadratic Synchronous Transition (LST/QST) method searches for the corresponding transition state, and verifies the correctness of the transition state through frequency calculation; finally calculates the reaction energy between the initial state and the final state, and the reaction energy between the initial state and the transition state. The reaction energy barrier; determine the optimal reaction path on the NiM alloy catalyst surface according to the reaction energy barrier size, and determine the rate control step in the reaction process on the NiM alloy catalyst surface, the rate control step in the reaction process on the NiM alloy catalyst surface corresponds to The reaction energy barrier is the reaction energy barrier of the NiM alloy catalyst in the positive reaction of HOR;

Wherein, when pH=13 Ni ₃ Cr (111), Ni ₂ Cr ₂ (111), NiCr ₃ (111) the reaction energy barrier of Tafel, Heyrovsky, Volmer reaction on the surface is as shown in table 2; Can see by table 2 The energy barrier of the Tafel reaction is obviously lower than that of Heyrovsky, therefore, the optimal reaction path for the electrochemical oxidation of _H2 on the surface of NiCr catalyst is Tafel-Volmer; compared with the Tafel reaction, the energy barrier of the Volmer reaction is obviously higher, so the Volmer step is the whole The rate-determining step _in the electrochemical oxidation of _H2 ; thus, the reaction energy barriers for the rate _- determining step on _Ni3Cr (111), _Ni2Cr2 (111) and _NiCr3 (111) (i.e., _Ni3Cr , _Ni2Cr2 , NiCr ₃ alloy catalyst in HOR positive reaction reaction energy barrier) were 0.67eV, 2.20eV and 1.08eV.

Table 2 Energy barriers of Tafel, Heyrovsky and Volmer reactions on NiCr alloy catalysts at pH=13

catalyst Tafel(eV) Heyrovsky(eV) Volmer(eV) Ni ₃ Cr 0.15 0.53 0.67 Ni ₂ Cr ₂ 0.17 0.50 2.20 _NiCr3 0.24 0.34 1.08

Step 2.4, determine the H adsorption free energy of alloy catalysis:

H may be adsorbed on the top of the metal atom on the catalyst surface, that is, the top position; it may also be adsorbed on the position between two metal atoms on the catalyst surface, that is, the bridge position; or adsorbed on the position between three metal atoms on the catalyst surface, That is, the vacancy; the most stable H adsorption site on the NiCr alloy surface is the vacancy. When H is initially placed on the top and bridge sites of the NiCr alloy surface, H will automatically transfer to the vacancy during the geometric structure optimization process.

Calculate the energy of H adsorbed on the surface of the alloy catalyst of the second model of Ni ₃ Cr alloy catalyst minus the energy of the second model of Ni ₃ Cr alloy catalyst when H is not adsorbed and the energy of 1/2 H ₂ molecule, and then add zero Energy correction, entropy change correction and pH value correction can obtain H adsorption free energy;

Calculate the energy after H is adsorbed on the surface of the alloy catalyst of the second model of the Ni ₂ Cr ₂ alloy catalyst minus the energy of the second model of the Ni ₂ Cr ₂ alloy catalyst when H is not adsorbed and the energy of 1/2 H ₂ molecules, and then add The upper zero point energy correction, entropy change correction and pH value correction can obtain H adsorption free energy;

Calculate the energy of H adsorbed on the surface of the alloy catalyst of the second model of the NiCr ₃ alloy catalyst minus the energy of the second model of the NiCr ₃ alloy catalyst when H is not adsorbed and the energy of 1/2 H ₂ molecule, and then add the zero point energy correction , entropy change correction and pH value correction can obtain H adsorption free energy;

When pH=13 under alkaline conditions, on the Ni ₃ Cr (111 ₎ surface of Ni ₃ Cr alloy catalyst, on the Ni ₂ Cr ₂ (111) surface of Ni ₂ Cr ₂ alloy catalyst, on the NiCr ₃ ( 111) The free energies of H adsorption on the surface are 0.494eV, 0.699eV and 0.238eV, respectively.

Step 2.5. Determine the polarization curve and exchange current density of alloy catalysis

The pole is simulated by the fifth model, using the charge carried by the alloy catalyst unit cell to simulate the electrode charge q; by introducing the counter charge of the same amount as the background charge to maintain the electrical neutrality of the unit cell; when calculating, apply a certain amount to the alloy catalyst model The charge q (i.e. the electrode charge), and then calculate the reaction energy barriers of HOR forward reaction (i.e. oxidation) and reverse reaction (i.e. reduction) on the alloy catalyst under this charge; change the amount of applied charge and calculate the condition of different applied charge amount q The reaction energy barrier values of HOR forward reaction (i.e. oxidation) and reverse reaction (i.e. reduction) on the alloy catalyst below, so as to obtain two curves of HOR forward reaction energy barrier and reverse reaction energy barrier changing with electrode charge q respectively;

The electrode charge q is related to the work function W and the electrode potential U; after a certain amount of electrode charge is applied, the work function W of the alloy catalyst model under the charge q can be calculated; then according to the formula U=W÷eU _NHE (W is the work function; UNHE is the standard hydrogen electrode potential), and the electrode potential U on the alloy catalyst model is calculated under a given electrode charge q, so that the two curves of the HOR forward reaction energy barrier and reverse reaction energy barrier changing with the electrode charge q are converted into The curves of HOR forward reaction energy barrier and reverse reaction energy barrier changing with electrode potential U respectively;

When the HOR forward reaction energy barrier and reverse reaction energy barrier respectively cross the curves that vary with the electrode potential U, the corresponding electrode potential is the reversible electrode potential, that is, the equilibrium potential;

确定给定电极电势值下的HOR动力学电流密度，从而得到合金催化剂的Tafel极化曲线；其中，j_kox为氧化动力学电流密度；j_kred为还原动力学电流密度；A(U)为指前因子；R为气体常数；T为温度；E_a ^ox(U)为U电势下合金催化剂的HOR正反应的反应能垒；E_a ^red(U)为U电势下合金催化剂的HOR逆反应的反应能垒；j_k(U)为U电势下合金催化剂的动力学电流密度；Control the potential in the vicinity of the equilibrium potential, determine the HOR forward reaction energy barrier and reverse reaction energy barrier under a given electrode potential value, and further use

Determine the HOR kinetic current density at a given electrode potential value to obtain the Tafel polarization curve of the alloy catalyst; where j _kox is the oxidation kinetic current density; j _kred is the reduction kinetic current density; A(U) is the index Prefactor; R is the gas constant; T is the temperature; E _a ^ox (U) is the reaction energy barrier of the HOR forward reaction of the alloy catalyst at U potential; E _a ^red (U) is the reaction of the HOR reverse reaction of the alloy catalyst at U potential energy barrier; j _k (U) is the kinetic current density of the alloy catalyst at U potential;

The polarization curve of the alloy catalyst is fitted using the Bulter-Volmer equation, and the coefficient obtained by fitting is the exchange current density of the alloy catalyst; the Buter-Volmer equation is:

其中，η＝U-U⁰

Among them, η=UU ⁰

In the formula, j _k is the kinetic current density of the alloy catalyst, mA/cm ² ; j ₀ is the exchange current density of the alloy catalyst, mA/cm ² ; α is the transfer coefficient, dimensionless; F is the Faraday constant, C/mol ; η is the overpotential, V; U is the potential corresponding to j _k , V; U ⁰ is the equilibrium potential, V.

The Tafel polarization curves of Ni ₃ Cr, Ni ₂ Cr ₂ , and NiCr ₃ alloy catalysts were determined according to the above method, and the results are shown in Figure 4A-Figure 4C; Ni ₃ Cr, Ni ₂ Cr ₂ , NiCr ₃ were determined according to the above method For the exchange current density of the alloy catalyst, see Table 3 for the results. It can be seen from Table 3 that the exchange current density of the electrochemical oxidation of H ₂ over the Ni ₃ Cr, Ni ₂ Cr ₂ , and NiCr ₃ alloy catalysts is 0.82mA/cm ² , 7.78×10 ^-15 mA/cm ² and 2.31×10 ^-7 mA/cm ² .

Table 3 Calculation of H adsorption free energy and exchange current density on NiCr alloy catalyst at pH=13.

Step 3, _H2 electrochemical oxidation performance evaluation, including:

Step 3.1, based on the formation energy of the alloy catalyst, determine the stability of the alloy catalyst:

The formation energy of an alloy catalyst can represent the feasibility of the corresponding metal to form an alloy. If the calculated formation energy is a negative value, an alloy catalyst can be formed, and the smaller the formation energy, the more stable the structure of the alloy catalyst; if the calculated formation energy is a positive value, it cannot Alloying catalysts;

Specifically, the formation energies of Ni ₃ Cr, Ni ₂ Cr ₂ , and NiCr ₃ alloy catalysts are -2.76eV, -2.53eV, -2.34eV, respectively; the calculated formation energies are all negative, indicating that Ni and Cr can form stable Ni ₃ Cr, Ni ₂ Cr ₂ , NiCr ₃ alloys.

Step 3.2, based on the oxidation potential of the alloy catalyst, evaluate the oxidation resistance of the alloy catalyst:

The oxidation potential of the alloy catalyst can represent the oxidation resistance of the alloy catalyst under alkaline conditions; if the alloy catalyst is positive, it means that the alloy can undergo oxidation reaction, and the larger the oxidation potential, the easier the alloy is to be oxidized, and the alloy is more resistant to oxidation. The worse the ability is; if the alloy catalyst is negative, it means that the alloy is not easy to oxidize, and the smaller the oxidation potential, it means that the alloy is less likely to be oxidized, and the oxidation resistance of the alloy is stronger;

Specifically, the oxidation potentials of Ni oxidized to Ni(OH) ₂ in Ni ₃ Cr, Ni ₂ Cr ₂ and NiCr ₃ alloy catalysts are 0.68 V, 0.50 V and 0.47 V, respectively, which are higher than the oxidation potential of pure Ni 0.72 V low; the oxidation potentials of Cr oxidized to Cr(OH) ₃ in Ni ₃ Cr, Ni ₂ Cr ₂ and NiCr ₃ are 1.27V, 1.14V and 1.03V, respectively, which are also lower than the oxidation potential of pure Cr 1.48V; It can be seen that the oxidation potential of Ni and Cr after alloying is lower than that of the corresponding simple substance, indicating that the oxidation resistance of NiCr alloying is significantly improved.

Step 3.3, based on the H adsorption free energy of the alloy catalyst, evaluate the HOR catalytic activity of the alloy catalyst;

The closer the H adsorption free energy of the alloy catalyst is to 0.414eV, the stronger the HOR catalytic activity of the alloy catalyst is;

Specifically, the H adsorption free energies of Ni ₃ Cr, Ni ₂ Cr ₂ and NiCr ₃ alloy catalysts are 0.494eV, 0.699eV and 0.238eV, respectively, and the absolute values of their differences from the optimal H adsorption free energy of 0.414eV are 0.08eV, 0.285eV _, and 0.176eV, indicating that the upper H adsorption free energy _of the Ni ₃ Cr alloy catalyst is closest to the optimal H adsorption free energy of 0.414eV, and has the highest H ₂ electrochemical oxidation activity. The chemical oxidation activity is next, and the H ₂ electrochemical oxidation activity of the Ni ₂ Cr ₂ alloy catalyst is the worst.

Step 3.4, based on the reaction energy barrier of the alloy catalyst in the HOR forward reaction, determine the catalytic activity of the alloy catalyst;

The reaction energy barrier of the alloy catalyst in the HOR positive reaction can characterize the catalytic activity of the alloy catalyst, the lower the reaction energy barrier of the alloy catalyst in the HOR forward reaction, the stronger the catalytic activity of the alloy catalyst;

Specifically, the reaction energy barriers of Ni ₃ Cr, Ni ₂ Cr ₂ and NiCr ₃ alloy catalysts in the positive reaction of HOR are 0.67eV, 2.20eV and 1.08eV, indicating that the Ni ₃ Cr alloy catalyst has the highest electrochemical oxidation activity of H ₂ , and NiCr ₃ alloy catalysts followed by Ni ₂ Cr ₂ alloy catalysts had the worst electrochemical oxidation activity of H ₂ .

Step 3.5, based on the exchange current density of the alloy catalyst, evaluate the HOR catalytic activity of the alloy catalyst;

The larger the exchange current density of the electrochemical oxidation of _H2 , the stronger the catalytic activity of the alloy catalyst, and the smaller the exchange current density, the weaker the catalytic activity of the alloy catalyst;

Specifically, the H ₂ electrochemical oxidation exchange current densities of Ni ₃ Cr, Ni ₂ Cr ₂ and NiCr ₃ alloy catalysts were 0.82 mA/cm ² , 7.78×10 ^-15 mA/cm ² and 2.31×10 ^-7 mA, respectively /cm ² , indicating that the order of H ₂ electrochemical oxidation activity is Ni ₃ Cr>NiCr ₃ >Ni ₂ Cr ₂ .

In the present invention, specific examples have been applied to explain the principles and implementation methods of the present invention, and the descriptions of the above examples are only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to this The idea of the invention will have changes in the specific implementation and scope of application. To sum up, the contents of this specification should not be construed as limiting the present invention.

Claims (24)

1. A method for analyzing electrochemical oxidation performance of alloy catalyst hydrogen, wherein the method comprises the following steps:

a first model construction step: constructing an alloy unit cell model, namely a first model;

and a second model construction step: constructing an alloy catalyst surface model, namely a second model, based on the first model;

optionally a third model building step: constructing an alloy catalyst surface model containing an alkaline aqueous solution layer, namely a third model, based on the second model;

Optionally a fourth model building step: respectively constructing structural models of reactants, intermediates and products on the surface of the alloy catalyst containing the alkaline aqueous solution layer in the third model to obtain an initial model, namely a fourth model, of the alkaline aqueous solution/alloy catalyst containing the reactants, the intermediates and the products;

optionally a fifth model building step: performing structural optimization on the fourth model to obtain an alkaline aqueous solution/alloy catalyst surface model with an optimal structure, wherein the alkaline aqueous solution/alloy catalyst surface model contains reactants, intermediates and products, namely a fifth model;

H ₂ and (3) evaluating electrochemical oxidation performance: performing oxidation potential analysis of the alloy catalyst based on the second model; and/or; based on the second model or the third model, carrying out H adsorption free energy analysis of the alloy catalyst; and/or; based on the fifth model, tafel polarization curve determination of the alloy catalyst was performed.

2. The method of claim 1, wherein performing an oxidation potential analysis of the alloy catalyst based on the second model comprises:

acquiring energy of the second model;

obtaining energy of the alloy catalyst after removing oxidized metal atoms;

obtaining energy of oxidized metal atoms in the alloy catalyst when the metal atoms are in a simple substance state;

Obtaining a standard oxidation potential of oxidized metal in the alloy catalyst when the oxidized metal is in a simple substance state;

determining the oxidation potential of the alloy catalyst based on the energy of the second model, the energy of the alloy catalyst after removing the oxidized metal atoms, the energy of the oxidized metal atoms in the alloy catalyst when the oxidized metal atoms are in the simple substance state, and the standard oxidation potential of the oxidized metal in the alloy catalyst when the oxidized metal atoms are in the simple substance state;

preferably, based on the second model, performing the oxidation potential analysis of the alloy catalyst further comprises:

based on the oxidation potential of the alloy catalyst, the oxidation resistance of the alloy catalyst is evaluated.

3. The method according to claim 2, wherein determining the oxidation potential of the alloy catalyst is preferably performed by the following formula:

U _ox ＝U _ox (met1,bulk)-(E(A _x B _y )-E(A _x B _y-z )-z·E(B))÷n

in U _ox Is the oxidation potential of the alloy catalyst, V; u (U) _ox (met 1, bulk) is the standard oxidation potential, V, of the oxidized metal B in the alloy catalyst when in the elemental state; e (A) _x B _y ) Energy of the second model, eV; e (A) _x B _y-z ) Energy after z metal B atoms subjected to oxidation are removed for the alloy catalyst, and eV; e (B) is the energy of oxidized metal B atoms in the alloy catalyst in the simple substance state, eV; n is the number of electrons e transferred when the alloy catalyst is oxidized.

4. The method of claim 1, wherein performing H-adsorption free energy analysis of the alloy catalyst based on the second model or the third model comprises:

determining the H adsorption free energy of the alloy catalyst based on the second model or the third model;

based on the H adsorption free energy of the alloy catalyst, carrying out HOR catalytic activity evaluation of the alloy catalyst; wherein, the closer the H adsorption free energy of the alloy catalyst is to 0.414eV, the stronger the HOR catalytic activity of the alloy catalyst.

5. The method of claim 1, wherein the determining the Tafel polarization curve of the alloy catalyst based on the fifth model comprises:

determining H of the alloy catalyst surface based on the fifth model ₂ An optimal reaction path for electrochemical oxidation reaction;

on the basis of a fifth model, respectively applying different electrode charges to alloy catalyst cells in the fifth model and introducing background charges with the same electric quantity to keep the neutrality of the cells, thereby obtaining a sixth model corresponding to the different charges; wherein, when the applied charge is 0, the corresponding sixth model is the fifth model;

h based on alloy catalyst surface ₂ Determining the reaction energy barriers of HOR positive reaction and reverse reaction of the alloy catalyst under different charge application conditions according to an optimal reaction path of the electrochemical oxidation reaction and a sixth model corresponding to different charge application conditions;

Determining the reaction energy barriers of the HOR positive reaction and the HOR negative reaction of the alloy catalyst under different electrode potentials based on the reaction energy barriers of the HOR positive reaction and the HOR negative reaction of the alloy catalyst under different applied charge conditions;

determining the equilibrium potential of the alloy catalyst based on the reaction energy barriers of the forward and reverse reactions of the HOR of the alloy catalyst at different electrode potentials;

determining a given potential range based on the equilibrium potential of the alloy catalyst, and further determining the reaction energy barriers of the HOR positive reaction and the HOR negative reaction of the alloy catalyst in the given potential range; and determining the kinetic current density of the alloy catalyst in the given potential range based on the reaction energy barriers of the HOR positive reaction and the HOR negative reaction of the alloy catalyst in the given potential range, so as to obtain the polarization curve of the alloy catalyst.

6. The method of claim 5, wherein applying different electrode charges to the alloy catalyst cells in the fifth model and introducing the same amount of background charge to maintain the neutrality of the cells on the basis of the fifth model, respectively, thereby obtaining a sixth model corresponding to the different charges comprises:

respectively applying different electrode charges to alloy catalyst cells in a fifth model on the basis of the fifth model, and introducing the electric neutrality of background charge holding cells with the same electric quantity to obtain a fifth model applied with different electrode charges;

Respectively carrying out structural optimization on the fifth model applied with different electrode charges to obtain a sixth model corresponding to the different charges;

preferably, the performing structural optimization on the fifth models to which the different electrode charges are applied respectively, and obtaining the sixth model corresponding to the different charges includes:

aiming at a fifth model applied with different electrode charges, respectively carrying out first principle molecular dynamics simulation, and screening out a plurality of relatively stable models of reactants, intermediates and products;

and then, carrying out structural optimization based on first principle calculation on the alkaline aqueous solution layer in the models with relatively stable reactants, intermediates and products which are screened out, and screening out a model with the most stable energy, namely a sixth model.

7. The method of claim 5, wherein the determining the kinetic current density of the alloy catalyst over the given potential range based on the reaction energy barriers of the HOR positive and negative reactions of the alloy catalyst over the given potential range is performed by the following equation:

wherein j is _kox For oxidation kinetic current density, mA/cm ² ；j _kred mA/cm for reduction kinetic current density ² The method comprises the steps of carrying out a first treatment on the surface of the A (U) is a pro-factor, dimensionless; r is a gas constant, J/mol.K; t is the temperature, K; e (E) _a ^ox (U) is the reaction energy barrier of the HOR positive reaction of the alloy catalyst under the potential of U, eV; e (E) _a ^red (U) is the reaction energy barrier of the HOR reverse reaction of the alloy catalyst under the potential of U, eV; j (j) _k (U) is the kinetic current density of the alloy catalyst under the potential of U, mA/cm ² 。

8. The method according to claim 1 or 5, wherein, when the analysis method includes Tafel polarization curve determination of the alloy catalyst based on the fifth model, H ₂ The electrochemical oxidation performance evaluation step further comprises carrying out exchange current density analysis of the alloy catalyst based on a polarization curve of the alloy catalyst;

wherein the exchange current density analysis of the alloy catalyst based on the polarization curve of the alloy catalyst comprises: determining the exchange current density of the alloy catalyst based on the polarization curve of the alloy catalyst;

preferably, performing the exchange current density analysis of the alloy catalyst based on the polarization curve of the alloy catalyst further comprises: based on the exchange current density of the alloy catalyst, performing HOR catalytic activity evaluation of the alloy catalyst;

preferably, the determination of the exchange current density of the alloy catalyst is achieved based on the polarization curve of the alloy catalyst by: fitting a polarization curve by using a Bulter-Volmer equation, wherein the coefficient obtained by fitting is the exchange current density of the alloy catalyst.

9. The method of claim 1, wherein H ₂ The electrochemical oxidation performance evaluation step further includes performing formation energy analysis of the alloy catalyst based on the first model;

wherein the performing the analysis of the formation energy of the alloy catalyst based on the first model comprises:

determining the formation energy of the alloy catalyst based on the first model;

the stability of the alloy catalyst is determined based on the formation energy of the alloy catalyst.

10. The method of claim 1, wherein H ₂ The electrochemical oxidation performance evaluation step further includes performing a reaction energy barrier analysis of the alloy catalyst based on the fifth model;

wherein, based on the fifth model, the performing the reaction energy barrier analysis of the alloy catalyst includes:

determining H of the alloy catalyst surface based on the fifth model ₂ An optimal reaction path for electrochemical oxidation reaction;

h based on alloy catalyst surface ₂ Determining an optimal reaction path of the electrochemical oxidation reaction and a fifth model, and determining a reaction energy barrier of the alloy catalyst in the positive reaction of the HOR;

the catalytic activity of the alloy catalyst is determined based on the reaction energy barrier of the alloy catalyst.

11. The method of claim 1, wherein the third model building step comprises:

Adding an alkaline aqueous solution model on the basis of the second model to obtain an initial model of the alloy catalyst surface containing an alkaline aqueous solution layer;

carrying out first principle molecular dynamics simulation on an initial model of the surface of the alloy catalyst containing the alkaline aqueous solution layer, and screening a plurality of relatively stable models;

and (3) performing structural optimization based on first principle calculation on the alkaline aqueous solution layer in the screened relatively stable models, and screening the model with the most stable energy as a third model which is an alloy catalyst surface model containing the alkaline aqueous solution layer.

12. The method of claim 1, wherein the fourth model building step comprises:

carrying out first principle molecular dynamics simulation on the fourth model, and screening out a plurality of relatively stable models of reactants, intermediates and products;

and (3) performing structural optimization on an alkaline aqueous solution layer in the models with relatively stable reactants, intermediates and products which are screened out based on a first principle, screening out the model with the most stable energy, and taking the model as a fifth model which is an alkaline aqueous solution/alloy catalyst surface model with the optimal structure and containing the reactants, intermediates and products.

13. The method of claim 1, wherein the alloy is a nickel-based non-noble metal alloy;

Preferably, the non-noble metal includes one or a combination of two or more of Cr, mn, fe, co, ni, cu and Zn and the like.

14. An analysis system for electrochemical oxidation performance of alloy catalyst hydrogen, wherein the system comprises:

a first model building module: the method is used for constructing an alloy unit cell model, namely a first model;

and a second model building module: the method comprises the steps of constructing an alloy catalyst surface model, namely a second model, based on a first model;

optionally a third model building module: constructing an alloy catalyst surface model containing an alkaline aqueous solution layer, namely a third model, based on the second model;

optionally a fourth model building module: the surface of the alloy catalyst containing the alkaline aqueous solution layer in the third model is respectively constructed with structural models of reactants, intermediates and products to obtain an initial model, namely a fourth model, of the alkaline aqueous solution/alloy catalyst containing the reactants, the intermediates and the products;

optionally a fifth model building module: the method comprises the steps of performing structural optimization on a fourth model to obtain an alkaline aqueous solution/alloy catalyst surface model containing reactants, intermediates and products with an optimal structure, namely a fifth model;

H ₂ electrochemical oxidation performance evaluation module: comprises an oxidation potential analysis submodule and an H adsorption free energy analysis A sub-module, and/or a polarization curve determining sub-module; wherein,,

the oxidation potential analysis submodule is used for carrying out oxidation potential analysis of the alloy catalyst based on the second model;

the H adsorption free energy analysis submodule is used for carrying out H adsorption free energy analysis of the alloy catalyst based on the second model or the third model;

the polarization curve determination submodule is used for determining the Tafel polarization curve of the alloy catalyst based on the fifth model.

15. The system of claim 14, wherein the oxidation potential analysis submodule includes:

a first energy determination unit: for acquiring energy of the second model;

a second energy determination unit: the method is used for obtaining the energy of the alloy catalyst after removing oxidized metal atoms;

a third energy determination unit: the method comprises the steps of obtaining energy of metal atoms oxidized in an alloy catalyst when the metal atoms are in an elemental state;

standard oxidation potential determination unit: the method comprises the steps of obtaining a standard oxidation potential of oxidized metal in an alloy catalyst when the metal is in an elemental state;

oxidation potential determining unit: the oxidation potential of the alloy catalyst (namely, the potential required to be applied when the alloy is oxidized into metal oxide or metal hydroxide) is determined based on the energy of the second model, the energy of the alloy catalyst after removing the oxidized metal atoms, the energy of the oxidized metal atoms in the alloy catalyst when the alloy catalyst is in an elemental state and the standard oxidation potential of the oxidized metal in the alloy catalyst when the alloy catalyst is in the elemental state;

Preferably, the oxidation potential analysis submodule further includes:

oxidation resistance evaluation unit: the method is used for evaluating the oxidation resistance of the alloy catalyst based on the oxidation potential of the alloy catalyst.

16. The system of claim 15, wherein determining the oxidation potential of the alloy catalyst is preferably performed by the following formula:

U _ox ＝U _ox (met1,bulk)-(E(A _x B _y )-E(A _x B _y-z )-z·E(B))÷n

in U _ox Is the oxidation potential of the alloy catalyst, V; u (U) _ox (met 1, bulk) is the standard oxidation potential, V, of the oxidized metal B in the alloy catalyst when in the elemental state; e (A) _x B _y ) Energy of the second model, eV; e (A) _x B _y-z ) Energy after z metal B atoms subjected to oxidation are removed for the alloy catalyst, and eV; e (B) is the energy of oxidized metal B atoms in the alloy catalyst in the simple substance state, eV; n is the number of electrons e transferred when the alloy catalyst is oxidized.

17. The system of claim 14, wherein the H-adsorption free energy analysis submodule comprises:

h adsorption free energy determination unit: determining the H adsorption free energy of the alloy catalyst based on the second model or the third model;

a first catalytic activity determination unit: the method is used for evaluating the HOR catalytic activity of the alloy catalyst based on the H adsorption free energy of the alloy catalyst; wherein, the closer the H adsorption free energy of the alloy catalyst is to 0.414eV, the stronger the HOR catalytic activity of the alloy catalyst.

18. The system of claim 14, wherein the polarization curve determination submodule includes:

an optimal reaction path determination unit: h for determining alloy catalyst surface based on fifth model ₂ An optimal reaction path for electrochemical oxidation reaction;

a sixth model determination unit: the method comprises the steps of on the basis of a fifth model, respectively applying different electrode charges to alloy catalyst cells in the fifth model and introducing background charges with the same electric quantity to keep the neutrality of the cells, so as to obtain a sixth model corresponding to the different charges; wherein, when the applied charge is 0, the corresponding sixth model is the fifth model;

a reaction energy barrier determining unit for forward and reverse reactions under different charges: h for alloy-based catalyst surfaces ₂ Determining the reaction energy barriers of HOR positive reaction and reverse reaction of the alloy catalyst under different charge application conditions according to an optimal reaction path of the electrochemical oxidation reaction and a sixth model corresponding to different charge application conditions;

a reaction energy barrier determining unit for forward and reverse reactions at different potentials: the method comprises the steps of determining the reaction energy barriers of the HOR positive reaction and the HOR negative reaction of the alloy catalyst under different electrode potentials based on the reaction energy barriers of the HOR positive reaction and the HOR negative reaction of the alloy catalyst under different applied charge conditions;

Balance potential determining unit: determining an equilibrium potential of the alloy catalyst based on the reaction energy barriers of the HOR positive and negative reactions of the alloy catalyst at different electrode potentials;

polarization curve determination unit: the method comprises the steps of determining a given potential range based on the equilibrium potential of the alloy catalyst, and further determining the reaction energy barriers of the HOR positive reaction and the HOR negative reaction of the alloy catalyst in the given potential range; and determining the kinetic current density of the alloy catalyst in the given potential range based on the reaction energy barriers of the HOR positive reaction and the HOR negative reaction of the alloy catalyst in the given potential range, so as to obtain the polarization curve of the alloy catalyst.

19. The system of claim 14 or 18, wherein when H ₂ When the electrochemical oxidation performance evaluation module comprises a polarization curve determination sub-module, H ₂ The electrochemical oxidation performance evaluation module further includes:

exchange current density analysis submodule: the method is used for carrying out exchange current density analysis of the alloy catalyst based on a polarization curve of the alloy catalyst;

wherein the exchange current density analysis submodule includes:

exchange current density determining unit: for determining an exchange current density of the alloy catalyst based on the polarization curve of the alloy catalyst;

Preferably, the exchange current density analysis sub-module further comprises:

second catalytic activity evaluation unit: the method is used for evaluating the HOR catalytic activity of the alloy catalyst based on the exchange current density of the alloy catalyst.

20. The system of claim 14, wherein H ₂ The electrochemical oxidation performance evaluation module further includes:

forming an analyzable sub-module: for performing a formation energy analysis of the alloy catalyst based on the first model;

wherein forming the analyzable submodule includes:

a formation energy determination unit: for determining the formation energy of the alloy catalyst based on the first model;

stability evaluation unit: for determining the stability of the alloy catalyst based on the formation energy of the alloy catalyst.

21. The system of claim 14, wherein H ₂ The electrochemical oxidation performance evaluation module further includes:

reaction energy barrier analysis submodule: for performing a reaction energy barrier analysis of the alloy catalyst based on the fifth model;

wherein, the reaction energy barrier analysis submodule includes:

an optimal reaction path determination unit: h for determining alloy catalyst surface based on fifth model ₂ An optimal reaction path for electrochemical oxidation reaction;

a reaction energy barrier determining unit: h for alloy-based catalyst surfaces ₂ Determining an optimal reaction path of the electrochemical oxidation reaction and a fifth model, and determining a reaction energy barrier of the alloy catalyst in the positive reaction of the HOR;

third catalytic activity analysis unit: for determining the catalytic activity of an alloy catalyst based on the reaction energy barrier of the alloy catalyst.

22. The system of claim 14, wherein the third model building module comprises:

an initial model construction sub-module: the method comprises the steps of adding an alkaline aqueous solution model on the basis of a second model to obtain an initial model of the alloy catalyst surface containing an alkaline aqueous solution layer;

a first model optimization sub-module: the method is used for carrying out first principle molecular dynamics simulation on an initial model of the surface of the alloy catalyst containing the alkaline aqueous solution layer, and screening a plurality of relatively stable models;

a second model optimization sub-module: the method is used for carrying out structural optimization on the alkaline aqueous solution layer in the screened relatively stable models based on first sex principle calculation, and screening out the model with the most stable energy as a third model which is an alloy catalyst surface model containing the alkaline aqueous solution layer.

23. The system of claim 14, wherein the fourth model building module comprises:

third model optimization sub-module: the method is used for carrying out first principle molecular dynamics simulation on the fourth model and screening out a plurality of relatively stable models of reactants, intermediates and products;

Fourth model optimization submodule: the method is used for carrying out structural optimization on an alkaline aqueous solution layer in the models with relatively stable reactants, intermediates and products which are screened out based on a first principle, screening out the model with the most stable energy, and taking the model as a fifth model which is an alkaline aqueous solution/alloy catalyst surface model with the optimal structure and containing the reactants, intermediates and products.

24. The system of claim 14, wherein the alloy is a nickel-based non-noble metal alloy;

preferably, the non-noble metal includes one or a combination of two or more of Cr, mn, fe, co, ni, cu and Zn and the like.

Images