CN113136600B - Electrocatalyst and preparation method and application thereof - Google Patents

Abstract

The invention discloses an electrocatalyst and a preparation method and application thereof. The electrocatalytic electrode comprises a conductive non-catalytic active support member and a plurality of electrocatalytic active units, each electrocatalytic active unit is arranged on the surface of the conductive non-catalytic active support member, and distributed in a periodic array. The electrocatalytic active units on the electrocatalyst are distributed in a periodic array, so that when an external voltage is applied to the electrocatalyst, the electrocatalytic active units can spontaneously generate an electric field enhancement effect, thereby improving the electrocatalytic performance and reducing the electrocatalytic activity. amount of material.

Description

A kind of electrocatalyst and its preparation method and application

technical field

The invention relates to the technical field of electrochemistry, in particular to an electrocatalytic electrode and a preparation method and application thereof.

Background technique

Under the background of the global realization of carbon neutrality, in order to solve the problems of environmental pollution and energy shortages currently facing the world, the current energy system dominated by fossil fuels needs to be transformed. Electrochemical energy technology is considered to be the main technology of the future energy system because of its cleanliness and high efficiency. Electrochemical energy technologies such as electrochemical hydrogen production, electrochemical nitrogen reduction and electrochemical carbon dioxide reduction can be coupled with new energy technologies such as wind energy and solar energy, and then convert clean electrical energy into chemical energy and store it in hydrogen, ammonia and organic compounds to realize energy clean conversion and large-scale transportation and application, avoiding energy waste. At the same time, the efficiency of electrochemical energy technologies such as fuel cells is not limited by the Carnot cycle, and can achieve efficient conversion of chemical energy stored in compounds into electrical energy. However, current electrochemical energy technologies are inefficient due to the high kinetic energy barrier of electrochemical reactions, which hinders their large-scale applications. The use of electrocatalysts to reduce the energy barrier of electrochemical reactions and thereby improve the energy conversion efficiency is the premise for the large-scale application of various electrochemical technologies. Currently, improving the efficiency of electrocatalysts and reducing the amount of electrocatalytically active materials containing expensive metals is one of the core issues to be solved in electrochemical energy technology.

In recent years, researchers have improved the catalytic performance of electrocatalysts by changing the chemical properties and electronic structures of electrocatalysts through chemical composition regulation, defect regulation, stress regulation, and substrate regulation. By precisely controlling the synthesis conditions of materials, using relatively complex technical means such as plasma treatment and high-temperature sintering, and adopting different strategies for different electrocatalysts and electrochemical reaction systems, the performance of electrocatalysts can be effectively improved and the reduction of electrocatalysts can be reduced. Cost and amount of electrocatalytic active components.

For example, the patent application reports a method for regulating the electrocatalytic hydrogen evolution performance of nickel-iron-based hydroxides by cadmium doping, and the patent application reports a method for improving the electrocatalytic performance of metal oxides by quenching modification. However, these methods based on chemical regulation require precise control of reaction conditions, and the technical means to achieve these chemical regulation are relatively complex, and these methods have poor versatility for different electrocatalysts and electrochemical reactions, so they are difficult to implement.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an electrocatalyst and its preparation method and application.

In a first aspect of the present invention, an electrocatalyst is proposed, comprising:

Conductive non-catalytically active supports,

A plurality of electrocatalytic active units, each of which is arranged on the conductive non-catalytic active support member, is distributed in a periodic array.

The electrocatalytic electrode according to the embodiment of the present invention has at least the following beneficial effects: the electrocatalyst has a number of electrocatalytic active units arranged in a periodic array on the conductive non-catalytic active support, wherein by arranging the electrocatalytic active units in a periodic array , so that when an external voltage is applied to the electrocatalyst, the electric field strength on the surface of the electrocatalytic active unit can be spontaneously enhanced, and the electrocatalytic performance can be improved; while the amount of electrocatalytic active material on the electrocatalytic active unit can be reduced, the electrocatalyst can Excellent catalytic performance in electrochemical reaction; no need to control harsh reaction conditions, loose requirements for reaction conditions, which is conducive to large-scale production and application; and its simple structure, easy preparation, good versatility, can be used according to the needs of electrochemical reaction. The electrocatalytic active material is processed to prepare the corresponding electrocatalyst; and in the service state, the current density of the electrocatalyst can be adjusted between 1 and 5000 mA/cm ² , which is suitable for various industrial-grade electrochemical applications.

In some embodiments of the present invention, the periodic array distribution is at least one of N-fold rotational axis symmetry distribution, inversion centrosymmetric distribution, mirror symmetry distribution, and slip plane symmetry distribution; wherein, N is 3 Integer in ~6. Among them, the symmetrical distribution of the N-th rotation axis specifically means that there is an N-th rotation axis in the electrocatalytic active units arranged in a periodic array, and the electrocatalytic active units arranged in a periodic array as a whole rotate around this axis every 360°/ N will coincide with the figure before the rotation; the symmetrical distribution of the N rotation axis may specifically be the symmetrical distribution of the third rotation axis (C ₃ ), the symmetrical distribution of the fourth rotation axis (C ₄ ), and the symmetrical distribution of the fifth rotation axis (C ₅ ) Or 6 times of rotation axis (C ₆ ) symmetrical distribution. Slip plane symmetry means that the electrocatalytic active units arranged in a periodic array are reflected by a mirror surface and slip parallel to the mirror surface for a certain distance. The position, that is, through the transformation of the slip plane, the electrocatalytic active units arranged in a periodic array can self-coincide.

In some embodiments of the present invention, the distance between adjacent electrocatalytic active units is 10 nm˜20 cm. For example, the spacing between adjacent electrocatalytically active units can be set to 500 nm, 0.005 cm, 0.006 cm, 0.008 cm, 0.01 cm, 0.015 cm, 0.02 cm, 0.025 cm, 0.03 cm, 0.05 cm, 0.06 cm, 0.08 cm , 0.1cm, 0.15cm, 0.2cm, 0.25cm, 0.3cm, 0.4cm, 0.5cm, 0.8cm, 1cm, 2cm, 2.5cm, 5cm, etc.

In some embodiments of the present invention, the electrocatalytically active unit is provided on the surface of the conductive non-catalytically active support; and/or, the electrocatalytically active unit is embedded in the conductive non-catalytically active support .

In some embodiments of the present invention, the conductive and non-catalytic supporting member includes a plurality of conductive and non-catalytically active supporting sub-members, the electrocatalytic active unit is sandwiched between the conductive and non-catalytically active supporting sub-members, and each The electrocatalytic active units are distributed in a periodic array on the conductive non-catalytic active support.

In some embodiments of the present invention, the material of the electrocatalytic active unit is an electrocatalytic active material; or, the electrocatalytic active unit includes a template unit and an electrocatalytic active material layer composed of an electrocatalytic active material. The electrocatalytic active material layer is provided on the surface of the template unit.

The electrocatalytically active unit can be used to catalyze electrochemical reactions, especially the electrochemical reactions of solid-liquid-gas three-phase. In some embodiments of the present invention, the electrocatalytic active material comprises at least one of an element, a compound and a composition having electrocatalytic activity; the electrocatalytic activity includes electrochemical hydrogen evolution reaction catalytic activity, electrochemical oxygen evolution reaction At least one of reaction catalytic activity, electrochemical hydrogen oxidation reaction catalytic activity, electrochemical methanol oxidation reaction catalytic activity, electrochemical formic acid oxidation reaction catalytic activity, electrochemical carbon dioxide reduction reaction catalytic activity and electrochemical nitrogen reduction reaction catalytic activity.

In some embodiments of the present invention, the electrocatalytically active material is selected from any one of a metal element, a metal compound and a carbon material having the electrocatalytic activity; preferably, the metal element and the metal compound The metal element is selected from aluminum, titanium, vanadium, chromium, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, rhodium, palladium, silver, antimony, hafnium, tantalum, tungsten, iridium, platinum, gold, At least one of bismuth, lanthanum, and cerium. The carbon material may be a pure carbon material or a carbon material containing a dopant.

In addition, the total projected area of each electrocatalytic active unit on the conductive substrate is generally smaller than the area (θ _c ) of the conductive substrate, preferably, the total projected area of each electrocatalytic active unit on the conductive substrate accounts for 0.5% of the area of the conductive substrate ~85%; for example, it can be 1%, 2.5%, 5%, 6.25%, 10%, 12.5%, 20%, 25%, 50%, 75%, etc.

In some embodiments of the present invention, the material of the conductive and non-catalytically active support member is a conductive electrochemically inert material, and the electrochemically inert material is specifically a material that has no catalytic activity for the electrochemical reaction catalyzed by the electrocatalytically active unit. Preferably, the conductive electrochemically inert material is selected from at least one of graphite, glassy carbon, titanium, copper, nickel, gold, and stainless steel. The conductive and non-catalytically active support member can be in the shape of a flat plate, foam, fabric or mesh, etc. For example, glassy carbon sheets, titanium sheets, titanium meshes, titanium foams, etc. can be used.

In the second aspect of the present invention, a method for preparing any electrocatalyst proposed in the first aspect of the present invention is proposed, comprising: constructing template units distributed in a periodic array on a conductive and non-catalytic active support, and then The surface of the template unit is provided with an electrocatalytic active material layer; specifically, template units that are periodically arranged in rows can be constructed on the conductive and non-catalytic active support by means of mask assistance, 3D printing, etc., and then the conductive and non-catalytic active A mask plate with a periodic array of through holes is correspondingly arranged on the support, and the through holes correspond to the template units; At least one is provided with an electrocatalytically active material layer on the template unit;

Alternatively, the preparation method of the electrocatalytic electrode includes: using an electrocatalytic active material to directly arrange electrocatalytic active units distributed in a periodic array on a conductive non-catalytic active support; specifically, the electrocatalytic active material may be used to directly print, Electrocatalytic active units distributed in periodic arrays are directly arranged on the conductive non-catalytic active support by laser cutting, screen printing, electrostatic inkjet printing, etc.;

Alternatively, the preparation method of the electrocatalyst includes: constructing electrocatalytically active units distributed in a periodic array on a conductive substrate; and then disposing a conductive non-catalytically active support member between adjacent electrocatalytically active units.

The above preparation method of electrocatalyst is suitable for the preparation of various electrochemical reaction catalysts, especially suitable for the electrochemical reaction of solid-liquid-gas three-phase. electrocatalyst.

The third aspect of the present invention proposes an application of any of the electrocatalysts proposed in the first aspect of the present invention in catalytic electrochemical reactions, the electrochemical reactions include electrochemical hydrogen evolution reaction, electrochemical oxygen evolution reaction, At least one of electrochemical hydrogen oxidation reaction, electrochemical methanol oxidation reaction, electrochemical formic acid oxidation reaction, electrochemical carbon dioxide reduction reaction and electrochemical nitrogen reduction reaction.

In a fourth aspect of the present invention, an electrocatalytic electrode is provided, including any electrocatalyst proposed in the first aspect of the present invention. In addition, the electrocatalytic electrode may further include a conductive substrate, and the electrocatalyst is disposed on the surface of the conductive substrate. The electrocatalytic electrode is suitable for catalyzing alkaline electrochemical reactions.

The fifth aspect of the present invention provides an electrochemical reactor, comprising any electrocatalytic electrode proposed in the fourth aspect of the present invention; or, comprising a membrane layer and any electrocatalytic electrode proposed in the first aspect of the present invention A catalyst, the electrocatalyst is arranged on the membrane layer, and the membrane layer is selected from ion exchange membrane or gas membrane. The ion exchange membrane can be a cation exchange membrane or an anion exchange membrane. Among them, the electrochemical reactor including the membrane layer is suitable for acid electrochemical reaction.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, wherein:

1 is a photo of the electrocatalytic electrode prepared in Example 1;

Fig. 2 is the structural representation of the electrocatalytic electrode of Example 1;

Fig. 3 is the current density-electrode potential curve diagram of embodiment 1 and comparative example 1 electrocatalytic electrode in electrochemical hydrogen evolution reaction;

Fig. 4 is the reaction principle comparison diagram of embodiment 1 and comparative example 1 electrocatalytic electrode in electrochemical hydrogen evolution reaction;

5 is a photo of the electrocatalytic electrode prepared in Example 2;

Fig. 6 is the current density-electrode potential curve diagram of embodiment 2 and comparative example 4 electrocatalytic electrode in electrochemical hydrogen evolution reaction;

Fig. 7 is the photo of embodiment 2 electrocatalytic electrode under the service state of electrochemical hydrogen evolution reaction process;

8 is a photo of the electrocatalytic electrode prepared in Example 3;

Fig. 9 is the current density-electrode potential curve diagram of embodiment 3 electrocatalytic electrode in electrochemical oxygen evolution reaction;

Figure 10 is a photo of the electrocatalytic electrode prepared in Example 4;

Fig. 11 is the current density-electrode potential curve diagram of embodiment 4 and comparative example 2 electrocatalytic electrode in electrochemical hydrogen evolution reaction;

12 is a front view of the electrocatalytic electrode prepared in Example 5;

13 is a side view of the electrocatalytic electrode prepared in Example 5;

Fig. 14 is the current density-electrode potential curve diagram of embodiment 5 and comparative example 3 electrocatalytic electrode in electrochemical hydrogen evolution reaction;

FIG. 15 is a photograph of the electrocatalytic electrode of Example 5 in the service state during the electrochemical hydrogen evolution reaction process.

Reference numerals: conductive non-catalytically active support 100 , electrocatalytically active unit 200 .

Detailed ways

The concept of the present invention and the technical effects produced will be clearly and completely described below with reference to the embodiments, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative efforts are all within the scope of The scope of protection of the present invention.

Example 1

This embodiment prepares an electrocatalyst, and the specific process includes the following steps:

(1) A mask plate corresponding to the electrocatalyst shown in Fig. 1 is constructed by laser cutting, wherein the mask plate has several square through holes with a side length of 0.0125 cm, and each through hole is periodic according to the point group of the 4th rotation axis (C4). In the array arrangement, the spacing between adjacent through holes is 0.025 cm; the area of the through holes accounts for 25% of the total area of the mask plate (θ _c =25%).

(2) Select a glassy carbon sheet with no electrocatalytic activity in the electrochemical hydrogen production reaction as a conductive and non-catalytic active support, and at the same time as a conductive substrate, cover the mask plate constructed in step (1) on the glassy carbon sheet, and sputtering The deposition method sputters the electrocatalytic active material platinum (Pt) on the glassy carbon, and the electrocatalytic active material platinum is deposited on the glassy carbon sheet through each through hole on the mask to form an electrocatalytic active unit, and then the mask is peeled off, as shown in Figure 1 As shown, electrocatalytically active units arranged periodically according to the C4 point group are loaded on the glassy carbon sheet to prepare a platinum/glassy carbon electrocatalyst, which can be used as an electrocatalytic electrode at the same time. As shown in FIG. 2 , the electrocatalyst includes a conductive and non-catalytic active support 100 , and a plurality of electro-catalytic active units 200 distributed on the surface of the conductive and non-active support 100 in a spaced and periodic array. The material of the electro-catalytic active units 200 is electro- The catalytically active material platinum, which is specifically distributed on the conductive non-catalytically active support 100 in a 4-fold rotational axis symmetry.

Comparative Example 1

An electrocatalyst was prepared in this comparative example, and the difference from Example 1 is that in this comparative example, the setting of the mask plate was cancelled, and Pt was directly deposited on the glassy carbon sheet by sputtering according to the operation similar to step (2) in Example 1. , forming a continuous electrocatalytic active material layer platinum sheet on the glassy carbon sheet to prepare an electrocatalyst, which can be used as an electrocatalytic electrode at the same time.

The electrocatalysts (that is, electrocatalytic electrodes) prepared in Example 1 and Comparative Example 1 were respectively used to carry out the hydrogen evolution reaction of water electrolysis in a 0.5 mol/L sulfuric acid aqueous solution. The current density-electrode potential curve of each electrocatalytic electrode in the hydrogen evolution reaction is as follows: shown in Figure 3. It can be seen from FIG. 3 that the electrocatalytic active units on the electrocatalytic electrode in Example 1 are arranged in a periodic array on the conductive non-catalytic active support, so that the electrocatalytic electrode has strong electrochemical hydrogen evolution reaction catalytic activity. In addition, a comparison diagram of the reaction principle of the electrocatalytic electrode in the electrolytic water electrolysis hydrogen evolution reaction of Example 1 and Comparative Example 1 is shown in Figure 4, and (a) in Figure 4 represents the reaction of the electrocatalytic electrode in Comparative Example 1 in the electrolytic water hydrogen evolution reaction. Schematic diagram of the principle; (b) represents the schematic diagram of the reaction principle of the electrocatalytic electrode in Example 1 in the hydrogen evolution reaction of water electrolysis. It can be seen from Figure 4 that the electrocatalytic electrode in Example 1 spontaneously produces an electric field enhancement effect on the surface of the electrocatalytic active unit during the hydrogen evolution reaction of electrolysis of water, while the surface of the electrocatalytic active material layer of the electrocatalytic electrode in Comparative Example 1 has no electric field enhancement effect. . 3 and 4, it can be seen that in the electrocatalytic electrode in Example 1, the electrocatalytic active units are periodically arrayed on the conductive non-catalytic active support, and in the service state, the electrocatalytic active units can spontaneously generate an electric field enhancement effect, Therefore, the electrocatalytic performance can be improved, and the amount of electrocatalytic active materials can be reduced at the same time.

Example 2

This embodiment prepares an electrocatalyst, and the specific process includes the following steps:

(1) A mask plate corresponding to the shape of the electrocatalyst shown in Fig. 5 is constructed by laser cutting, wherein the mask plate has a plurality of isosceles triangle-shaped through holes with a base length of 0.03 cm and a height of 0.6 cm. The bottom edge direction is lined up periodically, and the minimum distance between adjacent through holes is 0.074 cm; the area of the through holes accounts for 25% of the mask area (θ _c =25%).

(2) Covering the mask plate constructed in step (1) on the conductive substrate of the glassy carbon sheet, sputtering electrocatalytic active material platinum (Pt) onto the glassy carbon sheet by the method of sputtering deposition, and the electrocatalytic active material platinum passes through the mask plate Each of the through holes was deposited on the glassy carbon sheet to form electrocatalytically active units, and then soluble PMMA was coated on these electrocatalytically active units, and then the mask was peeled off; a layer of amorphous carbon film was sputtered again, and acetone was used to remove PMMA and electrocatalytic activity. The amorphous carbon on the catalytically active unit and the amorphous carbon between the adjacent electrocatalytically active units constitute the conductive non-catalytically active support, thereby preparing the platinum/amorphous carbon catalyst on the conductive substrate glassy carbon sheet, as shown in Figure 5 Periodically arranged electrocatalytic active units are supported on the conductive substrate glassy carbon sheet, and surrounding the electrocatalytic active units are amorphous carbon conductive and non-catalytic active supports, which can constitute an electrocatalytic electrode as a whole.

The electrocatalytic electrode prepared in this example is used for electrolysis of water and hydrogen evolution reaction in 0.5mol/L sulfuric acid aqueous solution. The current density-electrode potential curve of the electrocatalytic electrode in the hydrogen evolution reaction is shown in Figure 6. The electrocatalytic electrode is in service. The photo of the state is shown in Figure 7. It can be seen from FIG. 6 that the electrocatalytic electrode of this embodiment has strong catalytic activity for the electrochemical hydrogen evolution reaction; it can be seen from FIG. 7 that during the service process, the bubbles are easily desorbed on the surface of the electrocatalytic electrode with electrocatalytic active units, It is proved that the electrocatalytic electrode has good mass transfer for hydrogen evolution reaction.

Example 3

This embodiment prepares an electrocatalyst, and the specific process includes the following steps:

(1) A mask plate corresponding to the shape of the electrocatalyst shown in Fig. 8 is constructed by laser cutting, wherein the mask plate has several square through holes with a side length of 0.0125 cm, and each through hole rotates 4 times according to the point group period of the axis (C4) The space between adjacent through holes is 0.05cm; the area of the through holes accounts for 6.25% of the area of the mask plate (θ _c =6.25%).

(2) The mask plate constructed in step (1) is covered on the glassy carbon conductive substrate, and the electrocatalytic active material ruthenium (Ru) is evaporated onto the glassy carbon sheet by the method of electron beam-assisted evaporation, and the electrocatalytic active material ruthenium is passed through the mask. Each through hole on the template is supported on the glassy carbon sheet to form electrocatalytically active units, then soluble PMMA is coated on these electrocatalytically active units, and then the mask is peeled off; a layer of amorphous carbon is sputtered again, and acetone is used to remove PMMA and The gold film on the electrocatalytic active unit and the amorphous carbon between the adjacent electrocatalytic active units constitute the conductive non-catalytic active support member, so that the ruthenium/amorphous carbon catalyst is prepared on the conductive substrate glassy carbon sheet, as shown in the figure 8 shows that periodically arranged electrocatalytically active units are supported on the glassy carbon substrate, and surrounding the electrocatalytically active units are amorphous carbon conductive and non-catalytically active support components, which can constitute an electrocatalytic electrode as a whole. That is, the electrocatalyst in this embodiment includes a conductive and non-catalytic active support member and several electro-catalytic active units. The conductive and non-catalytic active support member includes a number of conductive and non-catalytic active support sub-members, and the electro-catalytic active unit is sandwiched between the conductive and non-catalytic active support sub-members. and each electrocatalytic active unit is distributed in a periodic array on the conductive non-catalytic active support.

The electrocatalytic electrode prepared in this example is used for electrolysis of water and oxygen evolution reaction in 1 mol/L potassium hydroxide aqueous solution, and the current density-electrode potential curve of the electrocatalytic electrode in the oxygen evolution reaction is shown in Figure 9. It can be seen from FIG. 9 that the electrocatalytic electrode of this embodiment has strong catalytic activity for the electrochemical oxygen evolution reaction.

Example 4

This embodiment prepares an electrocatalyst, and the specific process includes the following steps:

(1) A mask plate corresponding to the shape of the electrocatalyst shown in Fig. 10 is constructed by laser cutting, wherein the mask plate has a number of isosceles triangle-shaped through holes with a base length of 0.03 cm and a height of 0.6 cm. The bottom edge direction is lined up periodically, and the minimum spacing between adjacent through holes is 0.074 cm; the area of the through holes accounts for 15% of the mask area (θ _c =15%).

(2) Covering the mask plate constructed in step (1) on the conductive non-catalytically active support glassy carbon sheet (at the same time as a conductive substrate), and evaporating the electrocatalytic active material platinum (Pt) onto the glassy carbon sheet by sputtering deposition ), then place the whole material on the tube furnace, under the atmosphere of H ₂ S gas with a flow rate of 30 sccm and Ar gas with a flow rate of 500 sccm, at 750 ° C for 30 min, and then take out and peel off the mask plate, such as As shown in FIG. 10 , periodically arranged electrocatalytically active units (containing a charged catalytically active material PtS ₂ ) are supported on a glassy carbon substrate to form a PtS ₂ /glassy carbon electrocatalyst, which can be used as an electrocatalytic electrode at the same time.

Comparative Example 2

An electrocatalyst was prepared in this comparative example, and the difference from Example 4 is that: in this comparative example, the mask plate was omitted, and Pt was directly sputtered on the glassy carbon sheet according to the operation similar to step (2) in Example 4, and then The prepared material was placed on a tube furnace as a whole, and treated at 750° C. for 30 min under the atmosphere of H ₂ S gas with a flow rate of 30 sccm and Ar gas with a flow rate of 500 sccm to obtain an electrocatalyst, which can be used as an electrocatalyst at the same time. electrode.

The electrocatalytic electrodes prepared in Example 4 and Comparative Example 2 were used to conduct water electrolysis and oxygen evolution reaction in a 0.5 mol/L sulfuric acid aqueous solution. The current density-electrode potential curve of the electrocatalytic electrode in the hydrogen evolution reaction is shown in Figure 11. . It can be seen from FIG. 11 that the electrocatalytic electrode of Example 4 has strong catalytic activity for the electrochemical hydrogen evolution reaction.

Example 5

This embodiment prepares an electrocatalyst, and the specific process includes the following steps:

(1) The front view is corresponding to Fig. 12 and the top view is as shown in Fig. 13 on the resin/platinum composite conductive non-catalytic active support (which can also be used as a conductive substrate) by 3D printing. Template unit, the bottom cross-section diameter of each template unit attached to the conductive substrate is 0.125cm, and the height is 0.1cm, and each template unit is specifically arranged in a periodic array of point groups of three rotation axes (C ₃ ), adjacent templates The spacing between the units was 0.025 cm, and the projected area of each template unit on the conductive substrate accounted for 15.1% of the area of the conductive substrate.

(2) A mask plate with C3 periodic array through holes is correspondingly arranged on the conductive and non-catalytic active support, and the through holes correspond to the template units; The electrocatalytic active material platinum (Pt) is sputtered on the side with the template unit, and then the electrocatalytic active units periodically arranged according to the C3 point group are formed on the conductive non-catalytic active support corresponding to the template unit, as shown in Figure 12 and Figure 13. As shown, electrocatalysts were prepared, which can also be used as electrocatalytic electrodes. The electrocatalyst includes a conductive non-catalytic active support and a plurality of electrocatalytic active units periodically arranged on the surface of the conductive non-catalytic active support, the electrocatalytic active unit includes a template unit and an electrocatalytic active material layer disposed on the surface of the template unit, Each electrocatalytic active unit is specifically distributed on the conductive substrate in three rotational axes symmetrically.

Comparative Example 3

An electrocatalyst was prepared in this comparative example, and the difference from Example 5 is that in this comparative example, the setting of the template unit and the mask plate is canceled, and directly following step (2) in Example 5, the resin is deposited on the resin by the sputtering deposition method. The electrocatalytic active material layer (platinum layer) is sputter-deposited on the platinum/platinum composite conductive non-catalytic active support to obtain an electrocatalyst, which can also be used as an electrocatalytic electrode.

The electrocatalytic electrodes obtained in Example 5 and Comparative Example 3 were respectively used to carry out water electrolysis and hydrogen evolution reaction in a 0.5 mol/L sulfuric acid aqueous solution. The current density-electrode potential curve of the electrocatalytic electrode in the hydrogen evolution reaction is shown in Figure 14. The photo of the electrocatalytic electrode in Example 5 in the service state is shown in Fig. 15. The fine and fuzzy trailing region in Fig. 15 is the bubble. It can be seen from Figure 14 that the electrocatalytic electrode of Example 5 has strong electrochemical hydrogen evolution reaction catalytic activity; it can be seen from Figure 15 that during the service process, it is easy for the bubbles to be provided with the surface of the electrocatalytic active unit on the electrocatalytic electrode of Example 5. desorption, which proves that the electrocatalytic electrode has good mass transfer for hydrogen evolution reaction.

Example 6

This embodiment prepares an electrocatalyst, and the specific process includes the following steps:

(1) Construct truncated spherical template units distributed in a periodic array on a resin/platinum composite conductive non-catalytic active support (which can also be used as a conductive substrate) by 3D printing. The diameter of the bottom section of each template unit that is attached to the conductive substrate It is 0.125cm, the height is 0.1cm, and each template unit is specifically arranged in a periodic array of 6 rotation axis (C ₆ ) point groups, and the spacing between adjacent template units is 0.025cm.

(2) A mask plate with C6 periodic array through holes is correspondingly arranged on the conductive non-catalytic active support, by corresponding to the template unit; and then the conductive substrate obtained in step (1) is provided with a One side of the template unit is sputtered electrocatalytically active material platinum (Pt), and then corresponding to the template unit on the conductive non-catalytic active support to form an electrocatalytically active unit periodically arranged according to the C ₆ point group to obtain an electrocatalyst. as an electrocatalytic electrode.

Comparative Example 4

An electrocatalyst was prepared in this comparative example, and the difference from Example 1 is that in this comparative example, the mask plate is removed, and the same operation as step (2) in Example 1 is directly followed, and the sputtering deposition method is used on the glassy carbon sheet. The electrocatalytic active material platinum is sputtered to form an electrocatalytic active material layer (platinum layer) uniformly supported on the conductive non-catalytic active support glassy carbon sheet to obtain an electrocatalyst, which can also be used as an electrocatalytic electrode.

According to the same method in Example 2, the electrocatalytic electrode of this comparative example was used to carry out the hydrogen evolution reaction of water electrolysis in a 0.5 mol/L sulfuric acid aqueous solution. The current density-electrode potential curve of the electrocatalytic electrode in the hydrogen evolution reaction is shown in Figure 6. .

Comparative Example 5

An electrocatalyst was prepared in this comparative example, and the specific process includes the following steps:

(1) Electrodeposition of cobalt hydroxide was carried out directly on the titanium sheet by the electrochemical deposition method, using the titanium sheet as the working electrode (conductive non-catalytic active support) and 1 mol/L cobalt nitrate solution as the electrolyte, to obtain a uniformly loaded Cobalt hydroxide thin films arranged in aperiodic arrays on titanium sheets;

(2) put the titanium sheet loaded with cobalt hydroxide prepared in step (1) in a tube furnace, and calcined at 300° C. for 2 hours in an air atmosphere, so that the cobalt hydroxide supported on the titanium sheet is converted into cobalt tetroxide to form an electrocatalyst .

Comparative Example 6

An electrocatalyst was prepared in this comparative example, and the specific process includes the following steps:

(1) iridium dioxide powder is dispersed in isopropanol by ultrasonic wave to obtain iridium dioxide dispersion;

(2) coating the iridium dioxide dispersion droplets prepared in step (1) on the carbon cloth, and then drying, to form an iridium dioxide coating on the carbon cloth to prepare an electrocatalyst.

From the above, the electrocatalyst prepared in the above embodiments includes a conductive non-catalytic active support and electrocatalytic active units arranged in a periodic array on the conductive non-catalytic active support. The electrocatalyst is in the form of a film, wherein the electrocatalytic activity By adopting a periodic array distribution of the cells, when an external voltage is applied to the electrocatalyst, the electrocatalytic active cells can spontaneously generate an electric field enhancement effect, thereby improving the electrocatalytic performance and reducing the amount of electrocatalytic active materials. The above preparation method of electrocatalyst is suitable for the preparation of various electrochemical reaction catalysts. In the specific production and preparation process, corresponding electrocatalyst active materials can be used to process and prepare corresponding electrocatalysts according to the needs of electrochemical reaction, and then the prepared electrocatalyst The catalyst can be applied to catalyze corresponding electrochemical reactions, including electrochemical hydrogen evolution reaction, electrochemical oxygen evolution reaction, electrochemical hydrogenation reaction, electrochemical methanol oxidation reaction, electrochemical formic acid oxidation reaction, electrochemical carbon dioxide reduction reaction and electrochemical reaction. Nitrogen reduction reaction, etc. The above electrocatalyst can be used as an electrocatalytic electrode or further prepare an electrocatalytic electrode. Therefore, the present invention also provides an electrocatalytic electrode, which includes any electrocatalyst provided by the present invention, and can also include a conductive substrate, an electrocatalyst, and an electrocatalyst. The catalyst is arranged on the surface of the conductive substrate; the electrocatalytic electrode is suitable for catalyzing alkaline electrochemical reactions. In addition, the above electrocatalytic electrode can also be applied to prepare an electrochemical reactor, and further, the present invention also provides an electrochemical reactor, the electrochemical reactor includes any electrocatalytic electrode provided by the present invention, the electrochemical reactor The reactor is suitable for alkaline electrochemical reaction; in addition, the present invention also provides an electrochemical reactor, comprising a membrane layer and any electrocatalyst provided by the present invention, the electrocatalyst is arranged on the membrane layer, and the membrane layer can be Selected from ion exchange membrane or gas membrane, the ion exchange membrane can specifically be a cation exchange membrane or an anion exchange membrane, and the electrochemical reactor is especially suitable for acidic electrochemical reaction.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the patent of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention.

Claims (16)

1. An electrocatalyst, comprising:

an electrically conductive non-catalytically active support member,

the electrocatalytic activity units are arranged on the surface of the conductive non-catalytic activity support and are distributed in a periodic array.

2. The electrocatalyst according to claim 1, wherein the periodic array distribution is at least one of N-fold rotationally symmetric distribution, inverted centrosymmetric distribution, mirror symmetric distribution, slip plane symmetric distribution, wherein N is an integer from 3 to 6.

3. The electrocatalyst according to claim 2, wherein the spacing between adjacent electrocatalytically active cells is in the range of 10nm to 20 cm.

4. The electrocatalyst according to claim 1, wherein the material of the electrocatalytically active element is an electrocatalytically active material; or, the electrocatalytic active unit comprises a template unit and an electrocatalytic active material layer composed of electrocatalytic active materials, wherein the electrocatalytic active material layer is arranged on the surface of the template unit, and the template unit is arranged on the surface of the conductive non-catalytic active support.

5. The electrocatalyst according to claim 4, wherein the electrocatalytically-active material comprises at least one of elements, compounds and compositions having electrocatalytic activity; the electrocatalytic activity includes at least one of electrochemical hydrogen evolution reaction catalytic activity, electrochemical oxygen evolution reaction catalytic activity, electrochemical hydrogen oxidation reaction catalytic activity, electrochemical methanol oxidation reaction catalytic activity, electrochemical formic acid oxidation reaction catalytic activity, electrochemical carbon dioxide reduction reaction catalytic activity and electrochemical nitrogen reduction reaction catalytic activity.

6. The electrocatalyst according to claim 5, wherein the electrocatalytically-active material is selected from any one of elemental metals, metal compounds and carbon materials having the electrocatalytic activity.

7. The electrocatalyst according to claim 6, wherein the elemental metal and the metal element in the metal compound are selected from at least one of aluminum, titanium, vanadium, chromium, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, rhodium, palladium, silver, antimony, hafnium, tantalum, tungsten, iridium, platinum, gold, bismuth, lanthanum, and cerium.

8. Electrocatalyst according to any one of claims 1 to 7, wherein the electrically conductive, non-catalytically active support is made of an electrically conductive, electrochemically inert material.

9. Electrocatalyst according to claim 8, characterized in that the electrically conductive, electrochemically inert material is selected from at least one of graphite, glassy carbon, titanium, copper, nickel, gold, stainless steel.

10. An electrocatalyst, comprising:

an electrically conductive non-catalytically active support;

the electrocatalytic activity units are embedded in the conductive non-catalytic activity support and are distributed in a periodic array, and the electrocatalytic activity units are solid electrocatalytic activity units formed by sputtering deposition by means of a mask plate.

11. The electrocatalyst according to claim 10 wherein the electrically conductive non-catalyst support members comprise electrically conductive non-catalytically active support sub-members, the electrocatalytically active cells being sandwiched between the electrically conductive non-catalytically active support sub-members.

12. A method of preparing an electrocatalyst according to any one of claims 1 to 9, comprising: constructing template units distributed in a periodic array on the surface of the conductive non-catalytic active support, and then arranging an electrocatalytic active material layer on the surface of each template unit;

alternatively, the method of preparing the electrocatalyst comprises: the method comprises the following steps that an electrocatalytic active material is adopted to directly arrange electrocatalytic active units distributed in a periodic array on the surface of a conductive non-catalytic active support;

alternatively, the method of preparing the electrocatalyst comprises: the method comprises the steps of constructing electrocatalytically-active cells distributed in a periodic array on an electrically-conductive substrate, and then arranging an electrically-conductive non-catalytically-active support member between adjacent electrocatalytically-active cells.

13. A method of preparing an electrocatalyst according to any one of claims 7 to 9, comprising: solid electrocatalytic active units distributed in a periodic array are constructed on a conductive substrate through sputtering deposition by means of a mask plate, and then a conductive non-catalytic active support is arranged between the adjacent solid electrocatalytic active units.

14. Use of the electrocatalyst of any one of claims 1 to 9 to catalyse an electrochemical reaction comprising at least one of an electrochemical hydrogen evolution reaction, an electrochemical oxygen evolution reaction, an electrochemical hydrogen oxidation reaction, an electrochemical methanol oxidation reaction, an electrochemical formic acid oxidation reaction, an electrochemical carbon dioxide reduction reaction and an electrochemical nitrogen reduction reaction.

15. An electrocatalytic electrode comprising the electrocatalyst according to any one of claims 1 to 9.

16. An electrochemical reactor comprising the electrocatalytic electrode of claim 15; alternatively, comprising a membrane layer on which the electrocatalyst according to any one of claims 1 to 9 is disposed and an electrocatalyst selected from an ion exchange membrane or a gas membrane.

Images