WO2019031792A1 - Method for producing catalyst for fuel cell - Google Patents

Abstract

The present invention relates to a method for producing a catalyst for a fuel cell and, more specifically, to a production process that can stably obtain a two-component or three-component platinum-transition metal alloy catalyst whose the particle size distribution is uniform and a composition controls in large quantities for a short time by projection of an electron beam.

Description

Method for producing catalyst for fuel cell

The present invention relates to a method for producing a catalyst for a two-component or three-component fuel cell, and more particularly, to a method for producing a catalyst for a two-component or three-component fuel cell capable of mass production in a simple process using an electron beam.

Fuel cell is a power generation system that directly converts the chemical reaction energy of hydrogen and oxygen contained in a hydrocarbon-based material such as methanol, ethanol, and natural gas into electric energy. It is a clean energy that can replace fossil energy As a source, it has the advantage of outputting a wide range of output by stacking of unit cells by stacking. It has energy density 4 ~ 10 times higher than that of small lithium battery, Mobile portable power supply.

The principle of generating electricity in such a fuel cell is that the fuel is supplied to the anode electrode as the fuel electrode and adsorbed to the catalyst of the anode electrode and the fuel is oxidized to generate hydrogen ions and electrons, Reaches the cathode electrode, and the hydrogen ions pass through the polymer electrolyte membrane and are transferred to the cathode electrode. At this time, as a catalyst acting on the anode electrode in the oxidation process, conventionally, a platinum-based nano-particle is supported on a carbon material, and such a platinum-based catalyst has not been developed as a completely replaceable commercial catalyst in terms of high reactivity and durability It is not.

In addition, the platinum catalyst has a limited amount of the platinum catalyst, and is a major obstacle to commercialization of the fuel cell due to its high cost. In order to commercialize the fuel cell, the platinum catalyst, which is a fuel cell electrode catalyst, Efforts are being made to lower it.

As a conventional technique for lowering the content of the fuel cell catalyst, Korean Patent No. 10-1163060 discloses a fuel cell including a platinum-yttrium alloy catalyst. More particularly, the present invention relates to a platinum and yttrium alloy catalyst in which the activity and stability of an oxygen reduction reaction are remarkably improved, a method for producing the same, and a fuel cell comprising the catalyst, wherein the catalyst has an atomic composition of yttrium in the platinum and yttrium alloy , More than 0% but not more than 41%, particularly 30%, and can be usefully used in fuel cells, especially polymer electrolyte membrane fuel cells. However, when the fuel cell is manufactured by a sputtering method or the like, the manufacturing process is difficult, Have.

Recently, as a prior art using the electron beam, Korean Patent No. 10-1287104 discloses a method for preparing a metal nanoparticle using an electron beam, wherein a catalyst precursor and a solvent are mixed and the mixture has an energy of 1 MeV or less And a step of irradiating an electron beam to the catalyst layer.

When such an electron beam is used, the electron beam itself can provide reduction energy. Therefore, the nanopowder can be produced at a high yield in a short time without using any reducing agent and the particle size can be uniformly controlled. However, The present invention relates to a method for producing a catalyst for a fuel cell using an electron beam, and more particularly, to a method for producing a catalyst for a fuel cell using an electron beam, Is not known.

Therefore, there is a need to develop a manufacturing technique of a multicomponent alloy catalyst for a fuel cell, which can be produced easily and economically while having high activity and high durability of the catalyst by using an electron beam having a specific power range without using a separate reducing agent Is continuously demanded.

The main object of the present invention is to solve the above-mentioned problems and to provide a catalyst for a fuel cell capable of stably mass-producing a two-component or three-component platinum-transition metal alloy catalyst whose composition is controlled with uniform particle size distribution within a short period of time Method.

Another object of the present invention is to provide a fuel cell capable of reducing platinum content in a platinum-based catalyst which can be used as a catalyst for a fuel cell without requiring a chemical reductant, And a method for producing the catalyst.

According to an aspect of the present invention, there is provided a process for preparing a metal precursor mixture, comprising: (a) mixing a platinum group precursor, a second metal precursor and a solvent to obtain a metal precursor mixture; And (b) irradiating the metal precursor mixture with an electron beam at a power of 0.2 kW to 7.5 kW to produce a two-component platinum-transition metal alloy catalyst.

Another embodiment of the present invention is a process for preparing a metal precursor mixture comprising: (i) mixing a platinum based precursor, a second metal precursor, a third metal precursor and a solvent to obtain a metal precursor mixture; And (ii) irradiating the metal precursor mixture with an electron beam having an applied current of 0.5 mA to 15 mA to produce a three-component platinum-transition metal alloy catalyst.

In the preferred or another embodiment of the invention, the platinum-based precursor is _{H 2 PtCl 6, H 6 Cl} 2 N 2 Pt, PtCl 2, PtBr 2, acetylacetonate _{(platinum acetylacetonate), K 2 (} PtCl 4), H _{2 Pt (OH) 6, Pt} (NO 3) 2, [Pt (NH 3) 4] Cl 2, [Pt (NH 3) 4] (HCO 3) 2, [Pt (NH 3) 4] (OAc) ₂ , (NH ₄ ) ₂ PtBr ₆ , (NH ₃ ) ₂ PtCl ₆ , hydrates thereof, and mixtures thereof.

In one or other embodiments of the present invention, the solvent may be selected from the group consisting of water, alcohols having 1 to 8 carbon atoms, and mixtures thereof.

In one or other embodiments of the present invention, the solvent may be characterized by using a mixed solvent of water and a polyhydric alcohol.

In a preferred embodiment of the present invention, the second metal precursor is selected from the group consisting of Y, Ru, Os, Ga, Ti, V, Cr, (Mn), Fe (Fe), Co, Ni, Cu, Sn, Mo, W, Rh, Ir, Is a metal element-containing precursor selected from scandium (Sc), lanthanum (La), tantalum (Ta), Bi (bismuth) and palladium (Pd).

In a preferred embodiment of the present invention, the second metal precursor is a metal element-containing precursor selected from the group consisting of yttrium (Y), ruthenium (Ru), cobalt (Co), nickel (Ni) and iridium . ≪ / RTI >

In one preferred embodiment of the present invention, the platinum group precursor and the second metal precursor in the step (a) are mixed in a weight ratio of 40: 1 to 1: 5 based on the metal content.

In a preferred embodiment of the present invention, the electron beam irradiation in the step (b) may be characterized by irradiating an electron beam having an applied current of 0.5 mA to 15 mA.

In another preferred embodiment of the present invention, the second metal precursor is selected from the group consisting of Ru, Os, Pd, Ga, Ti, V, Cr, (Mn), Fe (Fe), Co, Ni, Cu, Sn, Mo, W, Ta, Bi, , Ir (iridium), and rhodium (Rh).

In another preferred embodiment of the present invention, the second metal precursor is a metal element-containing precursor including nickel (Ni).

In another preferred embodiment of the present invention, the second metal precursor is a metal element-containing precursor containing cobalt (Co).

In another preferred embodiment of the present invention, the second metal precursor is a metal element-containing precursor containing ruthenium (Ru).

In another preferred embodiment of the present invention, the third metal precursor is a metal element-containing precursor including yttrium (Y) or iridium (IR).

In another preferred embodiment of the present invention, the metal component of the catalyst for a fuel cell obtained by the above production method comprises 15 to 85% by weight of platinum, 5 to 65% by weight of the second metal and 1 to 60% By weight, based on the total weight of the composition.

In another preferred embodiment of the present invention, the metal component of the catalyst for a fuel cell obtained by the above production method comprises 15 to 70% by weight of platinum, 15 to 65% by weight of the second metal and 10 to 60% By weight, based on the total weight of the composition.

In another preferred embodiment of the present invention, the three-component platinum-transition metal alloy catalyst comprises Pt-Co-Y, Pt-Ni-Y, Pt-Ir-Y, Pt-Pd- Transition metal alloy catalyst selected from the group consisting of platinum-transition metal alloy catalysts.

In a preferred or other embodiment of the present invention, the carbon-containing carrier may be further mixed with the step (a) or the step (i) to obtain a metal precursor-carbon-containing support mixture.

In a preferred or other embodiment of the present invention, after the step (a) or (i), the basicity of the metal precursor mixture obtained before irradiation with the electron beam is adjusted to a basic compound, The method comprising the steps of:

In another preferred embodiment of the present invention, the basic compound is at least one selected from the group consisting of NaOH, Na ₂ CO ₃ , KOH and K ₂ CO ₃ .

In a preferred or other embodiment of the present invention, the method for preparing a catalyst for a fuel cell comprises the steps of adjusting the acidity of a metal precursor mixture obtained before irradiation of an electron beam with a basic compound to provide a basic solution of pH 8 to pH 13 ; And then further adding formic acid to the basic solution.

The method for producing a catalyst for a fuel cell according to the present invention not only simplifies the process and shortens the process time by using an electron beam instead of using a chemical reducing agent, but also can be used as a two-component or three- By controlling the electron beam at a specific amount of power, it is possible to control the composition of the two-component or three-component platinum-transition metal alloy catalyst to a desired level while maintaining uniform particle size distribution within a short period of time, There are advantages to be able to.

1A) is an image of TEM (Transmission Electron Microcopy), EDX and XRD analysis results of a catalyst for a fuel cell in which PtY is supported on a carbon carrier in the present invention, and Fig. 1B) (Transmission Electron Microcopy), EDX, and XRD analysis results of a catalyst for a fuel cell catalyst for a fuel cell.

2A) is an image of TEM (Transmission Electron Microcopy), EDX and XRD analysis of a catalyst for a fuel cell in which PtNi is supported on a carbon support in the present invention, and FIG. 2B is an image of PtCo in the present invention (Transmission Electron Microcopy), EDX, and XRD analysis results of a catalyst for a fuel cell catalyst for a fuel cell.

3 is an image of TEM (Transmission Electron Microcopy), EDX and XRD analysis results of a catalyst for a fuel cell of a catalyst for a fuel cell in which PtRu is supported on a carbon carrier according to the present invention.

FIG. 4A is a graph showing the results of an oxygen reduction reaction (ORR) performance evaluation in the case where the catalyst for a fuel cell in which PtY is supported on a carbon carrier and only Pt are supported on a carbon carrier in the present invention, and FIG. FIG. 5 is a graph showing the performance evaluation results of a unit cell in the case where PtY is carried on a carbon carrier and Pt alone is carried on a carbon carrier. FIG.

FIG. 5A is a graph showing the results of an oxygen reduction reaction (ORR) performance evaluation when PtNi is supported on a carbon carrier and Pt alone is supported on a carbon carrier in the present invention, and FIG. 5B) FIG. 5 is a graph showing the performance evaluation results of a unit cell in the case where PtNi is supported on a carbon carrier and only Pt and Pt are carried on a carbon carrier. FIG.

FIG. 6A is a graph showing the results of an oxygen reduction reaction (ORR) performance evaluation in the case where the Pt catalyst for a fuel cell and Pt alone are supported on a carbon support in the present invention, and FIG. 6B) (ORR) performance evaluation when PtCo is supported on a carbon carrier and Pt alone is supported on a carbon carrier.

FIG. 7 is a graph showing the results of the performance evaluation of methanol catalyst (MOR) of a catalyst for a fuel cell in which PtRu is supported on a carbon carrier in the present invention.

8 is a TEM (Transmission Electron Microcopy) image of a catalyst for a fuel cell according to the present invention, wherein a) is a catalyst of Example 1-11, b) is a catalyst of Example 1-12, c) -13, d) is the catalyst of Example 1-14, and e) is the catalyst of Example 1-15.

9 is a TEM (Transmission Electron Microcopy) image of a catalyst for a fuel cell according to the present invention, wherein a) is a catalyst of Example 1-16, b) is a catalyst of Example 1-17, c) -18, and d) is the catalyst of Example 1-19.

10 is a TEM (Transmission Electron Microcopy) image of a catalyst for a fuel cell according to the present invention, wherein a) is a catalyst of Example 1-20, b) is a catalyst of Example 1-21, and c) -22, and d) is the catalyst of Examples 1-23.

11 is an image diagram of TEM (Transmission Electron Microcopy) and EDX showing a catalyst for a fuel cell according to an embodiment of the present invention.

12 is a graph showing XRD analysis results of a catalyst for a fuel cell according to an embodiment of the present invention.

13 is a graph for explaining a graph of results obtained by performing the oxygen reduction reaction (ORR: Oxygen Reduction Reaction) of the embodiments of the present invention and the catalyst for a fuel cell of Comparative Example 1. Fig.

14 is a graph showing a result of performance evaluation of a unit cell of a catalyst for a fuel cell according to an embodiment of the present invention.

15 is a TEM (Transmission Electron Microcopy) image of a catalyst for a fuel cell according to the present invention, wherein a) is a catalyst of Example 2-8, b) is a catalyst of Example 2-9, c) 2-10, and d) is the catalyst of Examples 2-11.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

Throughout this specification, when an element is referred to as " including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

In one aspect, the present invention provides a process for preparing a metal precursor, comprising: (a) mixing a platinum-based precursor, a second metal precursor and a solvent to obtain a metal precursor mixture; And (b) irradiating the metal precursor mixture with an electron beam at an electric power of 0.2 kW to 7.5 kW to produce a two-component platinum-transition metal alloy catalyst.

The present invention also relates, in another aspect, to a process for preparing a metal precursor mixture comprising: (i) mixing a platinum group precursor, a second metal precursor, a third metal precursor and a solvent to obtain a metal precursor mixture; And (ii) irradiating the metal precursor mixture with an electron beam having an applied current of 0.5 mA to 15 mA to produce a three-component platinum-transition metal alloy catalyst.

A conventional method for producing a catalyst for a fuel cell includes a chemical method and an irradiation method. Among these, chemical methods include NaBH ₄ , hydrazine, ethylene glycol, H ₂ SO ₃ , LiAlH ₄ Is the most common method and is optimized by many variables such as the temperature, pH, and reaction rate (time) between the catalyst precursor and the reactant, and therefore, it is difficult to mass-produce the catalyst precursor . On the other hand, the irradiation method is a method using light instead of a reducing agent. In general, gamma rays, electron beams and UV rays are used, and among them, gamma rays and electron beams are most widely used. However, gamma rays are disadvantageous due to size and harmfulness It has been reported that a catalyst for a fuel cell is produced using an electron beam as a single component of a platinum precursor in the case of an electron beam. However, in this case, the content of platinum used in this case is high, It is known that no method for producing a two-component or three-component platinum-transition metal alloy catalyst as a composite component has ever been reported.

Further, in the case of an electron beam, since an electron beam having a high energy of 2 MeV to 10 MeV is used, the manufacturing facility is inevitably enlarged, and the manufacturing process cost is high and mass production is difficult. In addition, such high energy is difficult to apply to real industry because it emits a lot of regulated X-rays.

Thus, in the present invention, as a catalyst for a fuel cell, an electron beam is irradiated with a specific range of applied current or a specific range of power, and uniformity of particle size distribution is controlled without containing a metal composite component in which a single metal component is partially incorporated Component or three-component platinum-transition metal alloy catalyst having one type of alloy.

Hereinafter, the method for producing a catalyst for a fuel cell according to the present invention will be described in more detail in two-component system or three-component system.

< Two-component system  Platinum-transition metal alloy catalyst preparation>

First, a method for producing a catalyst for a fuel cell in which a two-component platinum-transition metal alloy catalyst according to the present invention is prepared comprises mixing a platinum-based precursor, a second metal precursor and a solvent to obtain a metal precursor mixture [step (a)].

The first metal precursor is a platinum based precursor selected from the group consisting of H ₂ PtCl ₆ , H ₆ Cl ₂ N ₂ Pt, PtCl ₂ , PtBr ₂ , platinum acetylacetonate, K ₂ (PtCl ₄ ), H ₂ Pt _{) 6, Pt (NO 3)} 2, [Pt (NH 3) 4] Cl 2, [Pt (NH 3) 4] (HCO 3) 2, [Pt (NH 3) 4] (OAc) 2, (NH ₄ ) ₂ PtBr ₆ , (NH ₃ ) ₂ PtCl ₆ , hydrates thereof, and mixtures thereof, but the present invention is not limited thereto.

Platinum has high reactivity and durability as a catalyst, and catalysts that can not be completely replaced at present are not developed. However, as described above, platinum is limited not only in its reserves but also as a major obstacle to the commercialization of a device using a platinum catalyst due to its high cost. In order to commercialize a device using a platinum catalyst, Efforts have been made to improve the activity or physical properties of a specific application field such as a fuel cell catalyst field while remarkably lowering the amount of platinum used. To prepare a platinum-containing two-component platinum-transition metal alloy catalyst.

The second metal precursor for alloying with the platinum group precursor may include yttrium (Y), ruthenium (Ru), osmium (Os), gallium (Ga), titanium (Ti), vanadium (V) (Mn), Fe (Fe), Co, Ni, Cu, Sn, Mo, W, Rh, Ir, Is a metal element-containing precursor selected from the group consisting of scandium (Sc), lanthanum (La), tantalum (Ta), bismuth (Bi) and palladium (Pd). Examples of the precursor include nitrate, hydroxide, Compounds of any type such as halides such as cargo, iodide, organic acid salts such as sulfate and acetate, and alkoxide salts can be used, and it is preferable to use a precursor which is soluble in a solvent described later.

At this time, the content ratio of the platinum group precursor and the second metal precursor can be mixed in a weight ratio of 40: 1 to 1: 5 based on the metal content, preferably 10: 1 to 1: 5. If the content of platinum is less than the above range, the activity of the catalyst may be lowered. If the content of platinum is higher than the above range, a binary alloy may not be produced, or the content of platinum may be too high, If the content of the other components is higher than the indicated range, the content of platinum is lowered, which may cause a problem in the activity of the catalyst. If the content is lower than the above range, the content of platinum is increased So that the economical efficiency may be deteriorated or a two-component system alloy may not be produced, and it is preferable that the above range is satisfied.

On the other hand, the solvent for uniformly dissolving the platinum group precursor and the second metal precursor may be water, an alcohol having 1 to 8 carbon atoms, and a mixture thereof. Preferably, a mixture of water and alcohols And more preferably, a mixed solvent of water and a polyhydric alcohol can be used.

This is because alcohol acts as a scavenger for removing an oxidizing agent (OH radical), and electrons (hydration electrons) and radicals generated by decomposition of water when electrons or electron beams generated from electron beams collide with water The OH radical, which is a strong oxidizing agent, reacts with the reduced metal nanoparticles to prevent OH radicals, which are strong oxidants, from reacting with the reduced metal nanoparticles and oxidizing the metal nanoparticles prior to causing the reduction reaction of the catalyst precursor. In addition, when polyhydric alcohols are used in the alcohols, the catalyst precursor can be more uniformly dispersed so that the overall reaction can be uniformly performed, thereby improving the uniformity of the product.

When a mixture of water and alcohol is used as the solvent, the mixing ratio of water to alcohols is preferably 20: 1 to 1: 4, more preferably 10: 1 to 1: 2, May be in a weight ratio of 8: 1 to 1: 1.

That is, when the content of the alcohols is less than 5 wt%, the role of the scavenger of the alcohols is insufficient. When the content of the alcohols is more than 80 wt%, the reduction reaction of the catalyst precursor does not occur. I do not. The alcohols may be selected from the group consisting of isopropyl alcohol, methanol, ethanol, n-propyl alcohol, butanol, ethylene glycol, glycerol and combinations thereof. Preferably, a mixture of ethylene glycol and water Or a mixture of glycerol and water, or a mixture of ethylene glycol, glycerol and water. The solvent in the present invention may be a mixture of monohydric alcohols in addition to a mixture of polyhydric alcohol and water.

 On the other hand, the total molar concentration of the two-component precursor is preferably 30 mM to 1 mM, more preferably 20 mM to 5 mM. When the molarity of the catalyst precursor is more than 30 mM, the amount of the catalyst precursor becomes excessively large and coagulation occurs to increase the particle size. When the concentration is less than 1 mM, the amount of the solvent is excessively large, .

In order to make the dispersion of the platinum group precursor and the second metal precursor more uniform, a dispersant may be further used. As the dispersant, polyvinyl pyrrolidone, polyvinyl alcohol, glycerol, sodium dodecylsulfonate and the like may be used One type of dispersant may be used, or two or more types of dispersants may be used in combination.

In this case, the mixing order of the metal precursor mixture is not defined, and the order of introduction of the respective components for the preparation of the metal precursor mixture including the platinum group precursor, the second metal precursor, And the like. For example, a solvent, a dispersant, and the like can be mixed with the platinum group precursor and the second metal precursor, and the platinum group precursor and the second metal precursor are added to the solvent and the dispersant, Or a mixture of the platinum group precursor and the second metal precursor may be added to the solvent, followed by adding a dispersant.

As described above, when the platinum group precursor, the second metal precursor and the solvent are mixed, it is more preferable to form a solution of a uniform composition by further stirring. The stirring time is required to be 5 minutes or more for sufficient agitation to be performed, and the stirring effect is saturated when the agitation time exceeds 1 hour, so that the agitation time is more preferably limited to 5 minutes to 1 hour.

Next, step (b) according to the present invention comprises irradiating the metal precursor mixture with an electron beam at a power of 0.2 kW to 7.5 kW, preferably 0.4 kW to 5 kW, to prepare a two-component platinum-transition metal alloy catalyst .

The electron beam serves to supply electrons or energy necessary to reduce metal ions contained in the platinum-based precursor and the second metal precursor. That is, water is decomposed by the energy of the electron beam of 0.2 kW to 7.5 kW to generate hydrated electrons and various radicals, and electrons generated by dissociation of cations (Mn ⁺ ) of the ionized metal precursor mixture in the reaction solution are supplied metal (M ⁰⁾ as there is to form a metal alloy as reduction, reduction of the alloy can be formed into nano-sized alloy fine because it occurs in aqueous solution, this one having a mean particle size of 1 nm ~ 5 nm uniformly through the catalyst Can be produced.

If the amount of power of the electron beam is less than 0.2 kW, the reaction does not occur, or the reaction speed is too slow to produce alloy nanoparticles, or the productivity decreases. When the electric power exceeds 7,5 kW, There is a risk that the alloy nanoparticles are excessively coarse, the spacing between the formed particles is narrow and the particles are aggregated, and the facility of the electron beam generating device is not economical, and the energy is wasted in terms of energy .

In this case, the amount of power may be expressed as a product of an applied current for driving an electron beam, more specifically, an applied current measured in an electron accelerator for driving an electron beam, and an energy value (keV or MeV) of the electron beam, In the case of the applied current, 0.5 mA to 15 mA can be used, preferably 0.7 mA to 15 mA, more preferably 1 mA to 14 mA can be used.

In relation to the energy of the electron beam, it is preferable to irradiate an electron beam having an energy of 0.1 MeV to 5 MeV, more preferably an electron beam having an energy of 0.2 MeV to 2 MeV in terms of alloy nanoparticle formation And more preferably an electron beam having an energy of 0.2 MeV to 1 MeV can be irradiated.

The electron beam irradiation may be directly irradiated to the metal precursor mixture, or may be irradiated through a window made of a polymer material and Ti foil. In the case of irradiation through a window made of a polymer material, it is possible to conduct mass production without limit to the direction of irradiation using the presently developed irradiation apparatus. As the polymer material, polyimide (capton), porous polytetrafluoroethylene or polyurethane can be used, and it is appropriate that the thickness is 10 占 퐉 to 100 占 퐉 in the case of Ti foil and 4 占 퐉 to 50 占 퐉 in case of Ti foil.

The two-component alloy catalyst for fuel cells formed as described above can be used while being dispersed in a solvent. After removing only the solvent by a filter, a centrifugal separation method, or the like, the alloy nanoparticles are separated or the alcohol or the like is washed, Can be used.

The catalyst for a fuel cell according to the production method of the present invention can not only maintain a high activity but also can add a second metal capable of reducing the content of platinum to produce a catalyst for a fuel cell more economically, When used as a catalyst for a fuel cell, since the particle size and distribution are uniform, it can have uniform particle size distribution, high reactivity and electromagnetic characteristics.

In addition, it is possible to obtain fine particles having an average particle size of about 1 nm to 5 nm, and the surface area that is an actual reaction area is widened, so that the same effect can be obtained with a smaller amount, The reaction rate is also faster.

Meanwhile, in the method for producing a catalyst for a fuel cell according to the present invention, a metal precursor-carbon containing support mixture can be obtained by additionally mixing the carbon-containing support in the step (a).

This is because, in the above production process, step (a) is performed by mixing a platinum group precursor, a second metal precursor, a carbon-containing carrier and a solvent to obtain a metal precursor-carrier mixture, A catalyst for a fuel cell which is economical, highly active, and highly durable can be produced.

As the carbon-containing support used in the mixing step, a carbon-based material such as graphite, denka black, ketjen black, acetylene black, carbon nanotube, carbon nanofiber, carbon nanowire, carbon nano-ball or activated carbon may be used. When the carrier is added, the amount of the carrier to be added is set to 100 wt% based on the total catalyst composition (the total amount of the carrier and the metal nanoparticles), and when the content of the two-component platinum-transition metal alloy nanoparticles in the catalyst for a polymer electrolyte fuel cell is 20 wt% To 80 wt%, and in the case of a catalyst for a direct oxidation type fuel cell, the content of the alloy nanoparticles is preferably 40 wt% to 80 wt%, and it is also possible to form a black catalyst which does not use a carbon carrier have.

In addition, the method for preparing a catalyst for a fuel cell according to the present invention can further improve the reactivity and dispersibility of the metal precursor mixture by controlling the reduction rate of the metal precursor mixture similarly before irradiating the metal precursor mixture with the electron beam, After step (a), the acidity of the metal precursor obtained may be adjusted to a basic compound to provide a basic solution of pH 8 to pH 13, preferably pH 10 to pH 13.

The step (a) may be carried out after the step (a) by adding a basic compound to the metal precursor mixture obtained before irradiation of the electron beam. The basic compound may be, for example, at least one selected from the group consisting of NaOH, Na ₂ CO ₃ , KOH and K ₂ CO ₃ , but is not limited thereto.

Further, the method for producing a catalyst for a fuel cell according to the present invention comprises the steps of: controlling the acidity of a metal precursor mixture obtained before irradiation of an electron beam with a basic compound as described above to provide a basic solution having a pH of 8 to 13; And then adding an additional formic acid to the basic solution.

The formic acid serves as a scavenger for removing OH radicals of a metal precursor mixture having a controlled acidity with a basic compound, and can prevent the metal precursor mixture from being oxidized to metal cations, thereby forming metal alloy particles well. At this time, the formic acid content can be added within a range in which the acidity of the metal precursor mixture whose acidity is controlled is maintained within the range of pH 4 to pH 13.

< Three-component system  Platinum-transition metal alloy catalyst preparation>

The method for preparing a catalyst for a fuel cell for producing a three-component platinum-transition metal alloy catalyst according to the present invention comprises first mixing a platinum group precursor, a second metal precursor, a third metal precursor and a solvent to obtain a metal precursor mixture i) step].

The first metal precursor is a platinum based precursor selected from the group consisting of H ₂ PtCl ₆ , H ₆ Cl ₂ N ₂ Pt, PtCl ₂ , PtBr ₂ , platinum acetylacetonate, K ₂ (PtCl ₄ ), H ₂ Pt _{) 6, Pt (NO 3)} 2, [Pt (NH 3) 4] Cl 2, [Pt (NH 3) 4] (HCO 3) 2, [Pt (NH 3) 4] (OAc) 2, (NH ₄ ) ₂ PtBr ₆ , (NH ₃ ) ₂ PtCl ₆ , hydrates thereof, and mixtures thereof, but the present invention is not limited thereto.

Platinum has high reactivity and durability as a catalyst, and catalysts that can not be completely replaced at present are not developed. However, as described above, platinum is limited not only in its reserves but also as a major obstacle to the commercialization of a device using a platinum catalyst due to its high cost. In order to commercialize a device using a platinum catalyst, Efforts have been made to improve the activity or physical properties of a specific application field such as a fuel cell catalyst field while remarkably lowering the amount of platinum used. The following components are presented as components of a platinum-containing three-component platinum-transition metal alloy catalyst.

The second metal precursor for use with the platinum group precursor may include ruthenium (Ru), osmium (Os), palladium (Pd), gallium (Ga), titanium (Ti), vanadium (V) (Mn), Fe (Fe), Co, Ni, Cu, Sn, Mo, W, Ta, , Iridium (IR), and rhodium (Rh) may be used. Preferably, the transition metal-containing precursor may be selected from the group consisting of cobalt (Co), nickel (Ni), iridium (IR), and ruthenium &Lt; / RTI &gt; may be used.

Also, the third metal precursor may be a transition metal-containing precursor including yttrium (Y) or iridium (Ir).

Examples of the precursors that can be used for the second metal precursor and the third metal precursor include any compounds such as nitrates, hydroxides, halides such as chlorides, bromides and iodides, organic acid salts such as sulfates and acetates, and alkoxide salts And it is preferable to use a precursor which is soluble in a solvent described later.

On the other hand, the metal component of the three-component platinum-transition metal alloy catalyst obtained by the above production method can be obtained at a content ratio of 15 to 85% by weight of platinum, 5 to 65% by weight of the second metal and 1 to 60% by weight of the third metal Preferably 15 to 70% by weight of platinum, 15 to 65% by weight of a second metal, and 10 to 60% by weight of a third metal. If the content of platinum is less than the above range, the activity of the catalyst may be lowered. If the content of platinum is higher than the above range, the ternary alloy may not be partially formed. If the content of the other components is higher than the above range, the content of platinum is lowered, which may cause a problem in the activity of the catalyst. If the content is lower than the above range, the content of platinum becomes higher, A three-component system alloy may not be produced, and it is preferable that the above range is satisfied.

Accordingly, the platinum precursor, the second metal precursor and the third metal precursor in the step (i) may be mixed with the solvent described below suitably according to the molecular weight of the precursor so as to satisfy the range of the metal content of the alloy nanoparticles.

On the other hand, the solvent for uniformly dissolving the platinum precursor, the second metal precursor and the third metal precursor may be water, an alcohol having 1 to 8 carbon atoms, and a mixture thereof. Preferably, A mixed solvent of water and a polyhydric alcohol may be used, and more preferably, a mixed solvent of water and a polyhydric alcohol may be used.

This is because alcohol acts as a scavenger for removing an oxidizing agent (OH radical), and electrons (hydration electrons) and radicals generated by decomposition of water when electrons or electron beams generated from electron beams collide with water Prior to causing a reduction reaction of the catalyst precursor, OH radicals, a strong oxidizing agent, are prevented from reacting with the reduced metal nanoparticles to oxidize. In addition, when polyhydric alcohols are used in the alcohols, the catalyst precursor can be more uniformly dispersed so that the overall reaction can be uniformly performed, thereby improving the uniformity of the product.

When a mixture of water and alcohol is used as the solvent, the mixing ratio of water to alcohols is preferably from 19: 1 to 1: 4 by weight, more preferably from 10: 1 to 1: 2 by weight, May be in a weight ratio of 8: 1 to 1: 1.

That is, if the content of the alcohol is less than 5 wt%, the role of the scavenger of the alcohol is insufficient, and if it is used in excess of 80 wt%, the reduction reaction of the catalyst precursor does not occur . The alcohols may be selected from the group consisting of isopropyl alcohol, methanol, ethanol, n-propyl alcohol, butanol, ethylene glycol, glycerol and combinations thereof. Preferably, a mixture of ethylene glycol and water Or a mixture of glycerol and water, or a mixture of ethylene glycol, glycerol and water. The solvent in the present invention may be a mixture of monohydric alcohols in addition to a mixture of polyhydric alcohol and water.

On the other hand, the total molar concentration of the three-component precursor is preferably 30 mM to 1 mM, more preferably 20 mM to 5 mM. When the molarity of the catalyst precursor is more than 30 mM, the amount of the catalyst precursor becomes excessively large, aggregation occurs, and particles become large. When the concentration is less than 1 mM, the amount of the solvent is excessively large, Which is undesirable.

Further, in order to more uniformly disperse the platinum-based precursor, the second metal precursor and the third metal precursor, the present invention may optionally use a dispersing agent, and examples of the dispersing agent include polyvinylpyrrolidone, polyvinyl alcohol , Glycerol, sodium dodecylsulfonate, and the like. One kind of dispersant may be used, or two or more kinds of dispersants may be used in combination.

In this case, the mixing order of the metal precursor mixture is not defined, and the order of introduction of the respective components for manufacturing the metal precursor mixture including the respective metal precursors and the solvent is suitably adjusted according to the operator's selection, .

Accordingly, when the platinum group precursor, the second metal precursor, the third metal precursor, and the solvent are added, it is more preferable to form a solution having a uniform composition by further stirring. The stirring time is required to be 5 minutes or more for sufficient agitation to be performed, and the stirring effect is saturated when the agitation time exceeds 1 hour, so that the agitation time is more preferably limited to 5 minutes to 1 hour.

Next, step (ii) according to the present invention is a step of producing a three-component alloy catalyst by irradiating the metal precursor mixture with an electron beam having an applied current of 0.5 mA to 15 mA.

The electron beam serves to supply electrons necessary for reducing the metal ions contained in the platinum-based precursor, the second and third metal precursors. For this purpose, it is preferable to use an electron beam having an applied current of 0.5 mA to 15 mA , Whereby a uniform fine particle catalyst having an average particle size of 1 nm to 5 nm can be produced.

Here, the applied current means an applied current measured in an electron acceleration tube for driving an electron beam, preferably 0.7 mA to 14 mA, more preferably 1 mA to 14 mA. have.

When the applied current is in the above range, the electron beams irradiated from the electron beam irradiating device can sufficiently ionize the metal precursor mixture, and the anion of the ionized metal precursor mixture can be combined with the metal ions to form a reduced alloy catalyst, A fine nano-sized catalyst can be produced.

At this time, when the electron beam applied current is less than 0.1 mA, the reaction does not occur or the reaction speed is slow, so that the ternary alloy nanoparticles are not produced or the productivity is lowered. When the current is more than 15 mA, the driving force for reducing the ternary alloy There is a problem that the alloy nanoparticles are excessively aggregated, the spacing between the formed particles is narrow and the particles are aggregated, and there is also a problem in that it is wasted in terms of energy.

With respect to the energy of the electron beam, in the present invention, it is preferable to irradiate an electron beam having an energy of 0.1 MeV to 5 MeV, more preferably an electron beam having an energy of 0.2 MeV to 2 MeV , And more preferably an electron beam having an energy of 0.2 MeV to 1 MeV can be irradiated.

The electron beam irradiation may be directly irradiated to the metal precursor mixture, or may be irradiated through a window made of a polymer material and Ti foil. In the case of irradiation through a window made of a polymer material, it is possible to conduct mass production without limit to the direction of irradiation using the presently developed irradiation apparatus. As the polymer material, polyimide (capton), porous polytetrafluoroethylene or polyurethane can be used, and it is appropriate that the thickness is 10 占 퐉 to 100 占 퐉 in the case of Ti foil and 4 占 퐉 to 50 占 퐉 in case of Ti foil.

The three-component platinum-transition metal alloy catalyst formed as described above can be used while being dispersed in a solvent. After removing only the solvent by a filter, a centrifugal separation method or the like, the three-component alloy nanoparticles are separated or the alcohol You can then use it to suit your needs.

The three-component alloy catalyst thus prepared is preferably a platinum-transition metal selected from the group consisting of Pt-Co-Y, Pt-Ni-Y, Pt-Ir-Y, Pt- Alloy catalyst.

Meanwhile, in the method for producing a catalyst for a fuel cell according to the present invention, a metal precursor-carbon containing support mixture can be obtained by additionally mixing the carbon-containing support in the step (a). This is because, in step (a), the carbon-containing support is added to the step of obtaining the metal precursor-support mixture by mixing the platinum group precursor, the second metal precursor, the third metal precursor, the carbon- As a result, it is possible to manufacture a catalyst for a fuel cell that is more economical, highly active, and highly durable.

As the carbon-containing support used in the mixing step, a carbon-based material such as graphite, denka black, ketjen black, acetylene black, carbon nanotube, carbon nanofiber, carbon nanowire, carbon nano-ball or activated carbon may be used. When the carrier is added, the amount of the carrier to be added is set to 100 wt% based on the total catalyst composition (the total amount of the carrier and the metal nano-particles), and when the catalyst for a polymer electrolyte fuel cell is used, the content of the three-component platinum-transition metal alloy nano- wt., and in the case of a catalyst for a direct oxidation type fuel cell, the content of the alloy nanoparticles is preferably 40 to 80 wt%, and a black catalyst which does not use a carbon carrier at times may be prepared.

In addition, the method for preparing a catalyst for a fuel cell according to the present invention can further improve the reactivity and dispersibility of the metal precursor mixture by controlling the reduction rate of the metal precursor mixture similarly before irradiating the metal precursor mixture with the electron beam, After step (a), the acidity of the metal precursor obtained may be adjusted to a basic compound to provide a basic solution of pH 8 to pH 13, preferably pH 10 to pH 13.

This step can be carried out after (i) by adding a basic compound to the metal precursor mixture obtained before irradiation of the electron beam. The basic compound may be, for example, at least one selected from the group consisting of NaOH, Na ₂ CO ₃ , KOH and K ₂ CO ₃ , but is not limited thereto.

Further, the method for producing a catalyst for a fuel cell according to the present invention comprises the steps of: controlling the acidity of a metal precursor mixture obtained before irradiation of an electron beam with a basic compound as described above to provide a basic solution having a pH of 8 to 13; And then adding an additional formic acid to the basic solution.

The formic acid serves as a scavenger for removing OH radicals of a metal precursor mixture having a controlled acidity with a basic compound, and can prevent the metal precursor mixture from being oxidized to metal cations, thereby forming metal alloy particles well. At this time, the formic acid content can be added within a range in which the acidity of the metal precursor mixture whose acidity is controlled is maintained within the range of pH 4 to pH 13.

<Fuel Cell Manufacturing>

The two-component or three-component platinum-transition metal alloy catalyst produced by the method of the present invention may be used for one or both of the anode electrode and the cathode electrode of the fuel cell. In general, this is not distinguished by the type of catalyst of the anode electrode and the cathode electrode in the case of a fuel cell, and thus can be easily understood by those skilled in the art.

The electrode comprising the catalyst of the present invention comprises an electrode substrate and a catalyst layer. The catalyst layer comprises a catalyst prepared by the process of the present invention. The catalyst layer may further include a binder resin for improving adhesion of the catalyst layer and transferring hydrogen ions.

As the binder resin, it is preferable to use a polymer resin having hydrogen ion conductivity. More preferably, a cation exchanger selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, a phosphonic acid group, Any polymer resin may be used. Preferable examples include fluorine-based polymers, benzimidazole polymers, polyimide polymers, polyetherimide polymers, polyphenylene sulfide polymers, polysulfone polymers, polyether sulfone polymers, (Perfluorosulfonic acid), poly (perfluorocarboxylic acid), poly (perfluorocarboxylic acid), poly (perfluorocarboxylic acid), and poly (perfluorocarboxylic acid) Copolymers of tetrafluoroethylene and fluorovinyl ethers containing sulfonic acid groups, dehydrofluorinated sulfated polyether ketones, aryl ketones, poly (2,2'-m-phenylene) -5,5'-bibenzimidazole and at least one proton conductive polymer selected from poly (2,2 '- (m-phenylene) -5,5'-bibenzimidazole) or poly (2,5-benzimidazole).

The hydrogen-ion conductive polymer may be substituted with Na, K, Li, Cs or tetrabutylammonium in the ion exchange group at the side chain terminal. In the case of replacing H with Na in the ion exchange group at the side chain terminal, NaOH is used in the preparation of the catalyst composition and tetrabutylammonium hydroxide is used in the case of replacing tetrabutylammonium, and K, Li or Cs is also appropriately substituted . &Lt; / RTI &gt; Since this substitution method is well known in the art, a detailed description thereof will be omitted in this specification.

The binder resin may be used singly or in the form of a mixture, and may also optionally be used together with a nonconductive polymer for the purpose of further improving adhesion to a polymer electrolyte membrane. It is preferable to adjust the amount thereof to suit the purpose of use.

Examples of the nonconductive polymer include polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene / tetrafluoroethylene (PVdF-HFP), dodecyltrimethoxysilane (DMSO), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene copolymer (ECTFE), polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer At least one member selected from the group consisting of silbenzenesulfonic acid and sorbitol is more preferable.

The electrode substrate plays a role of supporting the electrode and diffusing the fuel and the oxidant into the catalyst layer so that the fuel and the oxidant can easily access the catalyst layer. As the electrode substrate, a conductive substrate is used. Typical examples of the electrode substrate include a carbon paper, a carbon cloth, a carbon felt, or a metal cloth (a porous film or polymer fiber composed of a metal cloth in a fiber state) A metal film is formed on the surface of the cloth formed with the metal film), but the present invention is not limited thereto.

In addition, it is preferable to use a water repellent treatment of the electrode substrate with a fluorine-based resin, because it is possible to prevent the reactant diffusion efficiency from being lowered due to water generated when the fuel cell is driven. Examples of the fluorine-based resin include polytetrafluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, polyperfluoroalkyl vinyl ether, polyperfluorosulfonyl fluoride alkoxyvinyl ether, fluorinated ethylene propylene ( Fluorinated ethylene propylene), polychlorotrifluoroethylene, and copolymers thereof.

The microporous layer may further include a microporous layer for promoting diffusion of reactant in the electrode substrate. The microporous layer is generally composed of a conductive powder having a small particle diameter such as carbon powder, carbon black, acetylene black, activated carbon, carbon fiber, fullerene, carbon nanotube, carbon nanowire, carbon nano -horn) or a carbon nano ring.

The microporous layer is prepared by coating a composition comprising conductive powder, a binder resin and a solvent on the electrode substrate. Examples of the binder resin include polytetrafluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, polyperfluoroalkyl vinyl ether, polyperfluorosulfonyl fluoride, alkoxyvinyl ether, polyvinyl alcohol, cellulose acetate Or a copolymer thereof, and the like can be preferably used. Examples of the solvent include alcohols such as ethanol, isopropyl alcohol, n-propyl alcohol and butyl alcohol, water, dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone and tetrahydrofuran. The coating process may be performed by a screen printing method, a spray coating method or a coating method using a doctor blade, depending on the viscosity of the composition, but is not limited thereto.

In the membrane-electrode assembly for a fuel cell including the electrode having such a structure as a cathode electrode and an anode electrode, the cathode electrode and the anode electrode are located opposite to each other, and the polymer electrolyte membrane is positioned between the cathode electrode and the anode electrode.

The polymer electrolyte membrane is generally used as a polymer electrolyte membrane in a fuel cell, and any polymer electrolyte membrane having hydrogen ion conductivity may be used. Representative examples thereof include a polymer resin having a cation-exchange group selected from the group consisting of a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, a phosphonic acid group and derivatives thereof in the side chain.

Typical examples of the polymer resin include fluorine-based polymers, benzimidazole-based polymers, polyimide-based polymers, polyetherimide-based polymers, polyphenylene sulfide-based polymers, polysulfone-based polymers, polyether sulfone- (Perfluorosulfonic acid) (generally commercially available as Nafion), poly (methyl methacrylate), poly (methyl methacrylate), poly (Perfluorocarboxylic acid), a copolymer of tetrafluoroethylene and fluorovinyl ether containing a sulfonic acid group, a dehydrofluorinated sulfated polyether ketone, an aryl ketone, a poly (2,2'-m-phenylene) - At least one selected from the group consisting of poly (2,2 '- (m-phenylene) -5,5'-bibenzimidazole) and poly (2,5-benzimidazole) have.

Further, H may be replaced with Na, K, Li, Cs or tetrabutylammonium in the proton conductive group of the proton conductive polymer. In the hydrogen-ion conductive group of the proton conductive polymer, NaOH is substituted for H with Na and tetrabutylammonium hydroxide is substituted for tetrabutylammonium, and K, Li or Cs is substituted with a suitable compound . &Lt; / RTI &gt; Since the above-described replacement method is well known in the art, detailed description thereof will be omitted herein.

Hereinafter, the present invention will be described in more detail by way of examples according to the present invention. However, the following examples are only illustrative of the present invention, and the claims of the present invention are not limited thereto.

[Example: Preparation of two-component platinum-transition metal alloy catalyst]

Example  1-1 to 1-10 and Comparative Example  1-1 and 1-2

A mixture of a metal precursor, a solvent and a carrier was prepared under the conditions shown in Table 1 below, and then irradiated with an electron beam to obtain a two-component platinum-transition metal alloy catalyst. Here, the second metal precursor used in Examples 1-1 to 1-2 was Ni (NO ₃ ) _2, and the second metal precursor used in Examples 1-3 to 1-5 was Co (NO ₃ ) ₂ , Y (NO ₃ ) ₃ was used as the second metal precursor used in Examples 1-6 to 1-8, RuCl ₃ was used as the second metal precursor used in Examples 1-9, IrCl ₃ was used as the second metal precursor used in Example 1-10.

As Exemplary Embodiment 1-1, H ₂ PtCl ₆ as a platinum precursor, Ni (NO ₃ ) _{2 as} a second metal precursor, and graphitized carbon black carrier were mixed with a mixture of water and isopropyl alcohol (9: 1, v / v) and 540 g of glycerol and dispersed by stirring for 20 minutes to obtain a metal precursor mixture, and then an electron beam having an energy of 0.2 MeV was irradiated thereto to prepare a catalyst for a fuel cell. At this time, the irradiation time was 20 minutes, and the applied current was 5 mA.

At this time, a 5-liter batch metal reactor having a height of 7 cm × width × 23 cm × thickness of 10 μm and having a Ti foil window was used as a transmission window in the reactor so that the electron beam could be transmitted. The recovered catalyst was recovered by centrifugal separator Were used.

In Comparative Examples 1-1 and 1-2, catalysts for fuel cells were prepared under the same conditions as those in Example 1, except that the applied current and voltage were different.

Example  1-11 to 1-15

A catalyst for a fuel cell was prepared in the same manner as in Example 1-1, and an electron beam was irradiated under the conditions shown in Table 1 below to prepare a catalyst for a fuel cell. At this time, NaOH (0.1 M) was added to the metal precursor mixture before the electron beam irradiation to adjust the pH to the value shown in Table 1.

Example  1-16 to 1-23

A catalyst for a fuel cell was prepared in the same manner as in Example 1-11, and an electron beam was irradiated under the conditions shown in Table 1 below to prepare a catalyst for a fuel cell. At this time, formic acid was added by adjusting so that the pH of the NaOH-added metal precursor mixture finally reached the pH shown in Table 1.

division Platinum precursor: second metal precursor content ratio (g, based on the metal content contained in the precursor) menstruum The carrier (g) Presence or absence of NaOH Presence or absence of formic acid PH of metal precursor mixture Electron beam Water (g) Glycerol (g) Applied current (mA) Applied voltage (MeV) Power (kW) Example 1-1 Pt 0.80: Ni 0.38 2500 (IPA 10% v / v) 540 2.5 - - One 5 0.2 One Examples 1-2 Pt 0.80: Ni 0.38 2500 400 2.5 - - One 5 0.2 One Example 1-3 Pt 0.72: Co 0.59 2500 (IPA 10% v / v) 540 2.5 - - One 5 0.2 One Examples 1-4 Pt 0.72: Co 0.59 2500 400 2.5 - - One 10 0.5 5 Examples 1-5 Pt 0.72: Co 0.59 2500 (IPA 10% v / v) - 2.5 - - One 10 0.5 5 Examples 1-6 Pt 0.79: Y 0.47 2500 (IPA 10% v / v) 540 2.5 - - One 5 0.4 2 Examples 1-7 Pt 0.79: Y 0.47 2500 400 2.5 - - One 5 0.2 One Examples 1-8 Pt 0.79: Y 0.47 2500 (IPA 10% v / v) 540 2.5 - - One 2 0.2 0.4 Examples 1-9 Pt 0.58: Ru 0.46 2500 400 2.5 - - One 5 0.4 2 Example 1-10 Pt 0.64: Ir 0.39 2500 (IPA 10% v / v) 540 2.5 - - One 5 0.4 2 Example 1-11 Pt 66.22: Ru 33.78 2500 (IPA 10% v / v) 540 2.5 U - 4 13.5 0.2 2.7 Examples 1-12 Pt 66.22: Ru 33.78 2500 (IPA 10% v / v) 540 2.5 U - 8 13.5 0.2 2.7 Examples 1-13 Pt 66.22: Ru 33.78 2500 (IPA 10% v / v) 540 2.5 U - 10 13.5 0.2 2.7 Examples 1-14 Pt 66.22: Ru 33.78 2500 (IPA 10% v / v) 540 2.5 U - 12 13.5 0.2 2.7 Examples 1-15 Pt 66.22: Ru 33.78 2500 (IPA 10% v / v) 540 2.5 U - 14 13.5 0.2 2.7 Examples 1-16 Pt 66.22: Ru 33.78 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 0.2 2.7 Examples 1-17 Pt 97.29: Sc 2.71 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 0.2 2.7 Example 1-18 Pt 94.70: La 5.30 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 0.2 2.7 Example 1-19 Pt 95.76: W 4.24 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 0.2 2.7 Examples 1-20 Pt 73.32: Ir 26.68 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 0.2 2.7 Examples 1-21 Pt 83.78: Co 16.22 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 0.2 2.7 Examples 1-22 Pt 94.84: Ni 5.16 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 0.2 2.7 Examples 1-23 Pt 87.11: Y 12.89 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 0.2 2.7 Comparative Example 1-1 Pt 0.80: Ni 0.38 2500 (IPA 10% v / v) 540 2.5 - - One 0.5 0.1 0.05 Comparative Example 1-2 Pt 0.80: Ni 0.38 2500 (IPA 10% v / v) 540 2.5 - - One 10 One 10

In addition, FIGS. 1 to 3 and Table 2 show TEM (Transmission Electron Microcopy), EDX and XRD analysis results of the two-component platinum-transition metal alloy catalyst according to the present invention.

division  Analysis Example 1-1 Good, uniform alloy preparation, small amount of unreacted Ni Examples 1-2 Good, uniform alloy preparation, small amount of unreacted Ni Example 1-3 Good, uniform alloy manufacture, small amount of unreacted Co Examples 1-4 Good, uniform alloy manufacture, small amount of unreacted Co Examples 1-5 Size distribution and dispersibility Usually, homogeneous alloy manufacture, small amount of unreacted Co Examples 1-6 Good, uniform alloy preparation, small amount of unreacted Y Examples 1-7 Good, uniform alloy preparation, small amount of unreacted Y Examples 1-8 Good, uniform alloy preparation, small amount of unreacted Y Examples 1-9 Good, uniform alloy preparation, small amount of unreacted Ru Example 1-10 Good, uniform alloy preparation, small amount of unreacted Ir Example 1-11 Good, uniform alloy preparation, small amount of unreacted Ru Examples 1-12 Good, uniform alloy manufacture, unreacted Ru Examples 1-13 Good, uniform alloy manufacture, unreacted Ru Examples 1-14 Good, uniform alloy manufacture, unreacted Ru Examples 1-15 Size Distribution and Dispersion Normally, uniform alloy manufacture, unreacted Ru Examples 1-16 Excellent, uniform alloy manufacture, unreacted Ru Examples 1-17 Excellent, uniform alloy manufacture, unreacted Sc No Example 1-18 Excellent, uniform alloy manufacture, unreacted La Example 1-19 Excellent, uniform alloy manufacture, unreacted W None Examples 1-20 Excellent, uniform alloy manufacture, unreacted Ir No Examples 1-21 Excellent, uniform alloy manufacture, unreacted Co Examples 1-22 Excellent, uniform alloy manufacture, no unreacted Ni Examples 1-23 Excellent, uniform alloy manufacture, unreacted Y None Comparative Example 1-1 Trace production of catalyst Comparative Example 1-2 Particle agglomeration, production of partially heterogeneous alloys, large amounts of unreacted Ni

1A), PtNi (Example 1-1) in PtIr (Example 1-10), PtCo (Example 1-3) in PtNi (Example 1-1) ) And FIG. 3 shows TEM (Transmission Electron Microcopy), EDX and XRD analysis results of a catalyst for a fuel cell obtained according to PtRu (Example 1-9), wherein the TEM image and EDX were obtained from Korea Basic Science Institute Respectively.

As shown in Figs. 1 to 3 and Table 2, the two-component catalysts obtained in Examples 1-1 to 1-10 according to the present invention had an average particle size in the range of 1 nm to 5 nm, and platinum- The catalysts were uniformly produced. However, in the case of Examples 1-5, it was found that the catalyst particle size distribution was not uniform and the dispersibility of the catalyst in the carrier was poorer than the other embodiments of the present invention .

On the other hand, in the case of Comparative Example 1-1, a two-component platinum-transition metal catalyst was hardly produced due to a low electric power. In Comparative Example 1-2, An alloy catalyst in which the composition of the two-component system was not uniform was prepared.

More specifically, FIG. 4A shows a catalyst for fuel cell (dotted line) in which PtY is supported on a carbon carrier according to Example 1-8 of the present invention and oxygen (solid line) in the case where only Pt is supported on a carbon carrier (ORR) performance evaluation results are shown in FIG. 4B. In FIG. 4B, a catalyst for fuel cell (dotted line) in which PtY is supported on a carbon carrier and Pt alone are supported on a carbon carrier according to Example 1-8 of the present invention (Solid line). In FIG. 5A, the catalyst for fuel cell (dotted line) in which PtNi is supported on a carbon support according to Example 1-1 of the present invention and Pt alone are carbon (ORR) performance evaluation when the catalyst was supported on a carrier (solid line). FIG. 5B shows the result of evaluation of the ORR performance of the catalyst for fuel cell in which PtNi was supported on a carbon carrier Dotted line) and Pt alone are supported on the carbon carrier When it shows the performance evaluation results of the unit cell of a).

6A), a catalyst for fuel cell (shown by a dotted line) in which PtIr is supported on a carbon carrier and an oxygen reduction reaction (solid line) in the case where only Pt is supported on a carbon carrier (ORR) performance evaluation results. FIG. 6B shows the results of the performance evaluation of the catalyst for fuel cell (dotted line) in which PtCo is supported on a carbon carrier and Pt only on a carbon carrier according to Example 1-3 of the present invention 7 shows the results of the performance evaluation of the unit cell of Example 1. In FIG. 7, a catalyst for fuel cells (dotted line) in which PtRu was supported on a carbon carrier and Pt alone were supported on a carbon carrier (Solid line) shows the results of the performance evaluation for the methanol oxidation reaction (MOR).

As shown in the results of FIGS. 3 to 7, the two-component platinum-transition metal alloy catalyst according to the present invention shows that the existing platinum alone is at least equivalent to or superior to the catalyst supported on the carrier, Catalyst for a two-component fuel cell shows a high possibility of being used as a catalyst for a fuel cell by securing a performance and stability higher than that of a conventional catalyst while reducing the amount of platinum used by 30% or more.

Meanwhile, in the production of the catalyst for a fuel cell according to the present invention, in order to control the acidity of the metal precursor mixture under the same conditions and to measure the dispersibility of the particles and uniformity of the particle size according to the addition of formic acid, in Examples 1-11 to 1-23 TEM (Transmission Electron Microcopy) of the prepared catalyst for fuel cell was measured, and the results are shown in Figs. 8 to 10.

Figs. 8A to 8E are the catalysts for each fuel cell prepared in Examples 1-11 to 1-15, and Figs. 9A to 9D are graphs showing the relationship between the amount of each fuel produced in Examples 1-16 to 1-19 10a) to 10d are the catalysts for each fuel cell prepared in Examples 1-20 to 1-23.

8, in which the pH of the metal precursor mixture is 8 to 12 as compared to the catalyst of Example 1-11 in which the pH of the metal precursor mixture is 4 (FIG. 8A), as shown in FIG. 8) -14 catalyst (FIG. 8b), FIG. 8c) and FIG. 8d)] showed uniform particle size and improved particle dispersibility. Particularly, the catalyst of Example 1-14, in which the pH of the metal precursor mixture was 12, 8 c)], the particle dispersibility was further improved, and the Ru reaction proceeded smoothly, indicating that unreacted Ru did not remain. On the other hand, in the case of the catalyst of Example 1-15 in which the pH of the metal precursor mixture was 14 (Fig. 8E)), it was confirmed that the particle dispersibility was rather lowered.

Further, as shown in Fig. 9 and Fig. 10, the catalyst of Example 1-16 in which formic acid was added before the electron beam irradiation (Fig. 9A)) exhibited higher particle dispersibility than Example 8c in which formic acid was not added under the same conditions And the particle size is also uniform. Also, when the second metal precursor is Sc, La, W, Ir, Co, Ni and Y in addition to Ru, the particle dispersibility is improved and the particle size becomes uniform I could confirm.

[Example: Preparation of a three-component platinum-transition metal alloy catalyst]

Examples 2-1 to 2-7 and Comparative Examples 2-1 and 2-2

A mixture of a metal precursor, a solvent and a carrier was prepared under the conditions shown in Table 3 below and then irradiated with an electron beam to obtain a three-component platinum-transition metal alloy catalyst. Here, the electron beam energy is a second metal precursor used in Examples 2-1 to 2-3 were irradiated with an electron beam having an energy of 0.2 MeV is Ni (NO _{3) 2,} the third metal precursor is Y (NO ₃ ) ₃ , the second metal precursor used in Examples 2-4 to 2-7 was Co (NO ₃ ) ₂ , and the third metal precursor was Y (NO ₃ ) ₃ .

As Example 2-1, platinum precursor H ₂ PtCl ₆ , a second metal precursor Ni (NO ₃ ) ₂ , a third metal precursor Y (NO ₃ ) _3, and a carbon support were mixed with water and isopropyl alcohol 2500 g of a mixed solution (9: 1, v / v) and 540 g of glycerol, and dispersed by stirring for 30 minutes to obtain a metal precursor mixture. Then, an electron beam having an energy of 0.2 MeV was irradiated thereto, . At this time, the irradiation time was 40 minutes, and the applied current was 5 mA.

At this time, a 5-liter batch metal reactor having a height of 7 cm × width × 23 cm × thickness of 10 μm and having a Ti foil window was used as a transmission window in the reactor so that the electron beam could be transmitted. The recovered catalyst was recovered by centrifugal separator Were used.

On the other hand, in Comparative Examples 2-1 and 2-2, catalysts for fuel cells were produced under the same conditions as in Example 2-1, except that the applied current was different.

Examples 2-8

A catalyst for a fuel cell was prepared in the same manner as in Example 2-1, and an electron beam was irradiated under the conditions shown in Table 3 below to prepare a catalyst for a fuel cell. At this time, NaOH was added to the metal precursor mixture before the electron beam irradiation to adjust the pH to the value shown in Table 3.

Examples 2-9 to 2-11

A catalyst for a fuel cell was prepared in the same manner as in Example 2-8, and an electron beam was irradiated under the conditions shown in Table 3 below to prepare a catalyst for a fuel cell. At this time, formic acid was added by adjusting so that the pH of the NaOH-added metal precursor mixture finally reached the pH shown in Table 3.

division Platinum precursor: second metal precursor: third metal precursor content ratio (g, based on the metal content contained in the precursor) menstruum The carbon nanotube carrier (g) Presence or absence of NaOH Presence or absence of formic acid PH of metal precursor mixture Electron beam Water (g) Glycerol (g) Applied current (mA) Example 2-1 Pt 0.68: Ni 0.41: Y 0.34 2500 (IPA 10% v / v) 540 2.5 - - One 5 Example 2-2 Pt 0.83: Ni 0.50: Y 0.40 2500 540 2 - - One 5 Example 2-3 Pt 0.41: Ni 0.25: Y 0.20 2500 (IPA 10% v / v) 540 3.5 - - One 2 Examples 2-4 Pt 0.59: Co 0.36: Y 0.59 2500 400 2.5 - - One 8 Example 2-5 Pt 0.71: Co 0.43: Y 0.71 2500 (IPA 10% v / v) 540 2 - - One 5 Examples 2-6 Pt 0.35: Co 0.22: Y 0.35 2500 540 3.5 - - One 5 Examples 2-7 Pt 0.59: Co 0.36: Y 0.59 2500 (IPA 10% v / v) - 2.5 - - One 5 Examples 2-8 Pt 78.85: Co 9.35: Y 11.80 2500 (IPA 10% v / v) 540 2.5 U - 12 13.5 Examples 2-9 Pt 79.97: Co 11.95: Y 8.08 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 Examples 2-10 Pt 78.32: Ir 20.61: Y 1.07 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 Examples 2-11 Pt 83.28: Ni 7.31: Y 9.41 2500 (IPA 10% v / v) 540 2.5 U U 12 13.5 Comparative Example 2-1 Pt 0.68: Ni 0.41: Y 0.34 2500 (IPA 10% v / v) 540 2.5 - - One 20 Comparative Example 2-2 Pt 0.68: Ni 0.41: Y 0.34 2500 (IPA 10% v / v) 540 2.5 - - One 0.3

 11 to 15 and Table 4 show TEM (Transmission Electron Microcopy), EDX and XRD analysis results of the three-component platinum-transition metal alloy catalyst according to the present invention.

division  Analysis Example 2-1 Good, uniform alloy production, small amount of unreacted metal Example 2-2 Good, uniform alloy production, small amount of unreacted metal Example 2-3 Good, uniform alloy production, small amount of unreacted metal Examples 2-4 Good, uniform alloy production, small amount of unreacted metal Example 2-5 Good, uniform alloy production, small amount of unreacted metal Examples 2-6 Good, uniform alloy production, small amount of unreacted metal Examples 2-7 Size distribution and dispersibility Usually, homogeneous alloy manufacture, small amount of unreacted metal Examples 2-8 Good, uniform alloy manufacture, no unreacted metal Examples 2-9 Excellent, uniform alloy manufacture, no unreacted metal Examples 2-10 Excellent, uniform alloy manufacture, no unreacted metal Examples 2-11 Excellent, uniform alloy manufacture, no unreacted metal Comparative Example 2-1 Particle aggregation, production of partially heterogeneous alloys, large amounts of unreacted metal Comparative Example 2-2 Trace production of catalyst

FIGS. 11 and 14 show TEM (Transmission Electron Microcopy) and EDX images of the catalysts for fuel cells prepared according to Example 2-1 (PtNiY / C) and Example 2-4 (PtCoY / C) The TEM image and EDX were analyzed at Jeonju Center, Korea Basic Science Institute.

 As shown in FIG. 11, it can be seen that the three-component system particles according to the present invention have an average particle size in the range of 1 nm to 5 nm and that a three-component platinum-transition metal catalyst is uniformly produced, This shows that uniform catalyst particles were similarly prepared in the other examples. However, in the case of Example 2-7, the catalyst particle size distribution was not uniform than that of Examples 2-1 to 2-6, The dispersibility in the carrier was not good.

On the other hand, in the case of Comparative Example 2-1, particles were aggregated due to a high current amount, or an alloy catalyst in which the composition of the three-component system was not uniform was partially produced. In Comparative Example 2-2, - transition metal catalysts were found to be hardly produced.

On the other hand, as Comparative Example 3, the performance of a conventional Pt / C (carbon bearing platinum) catalyst and a catalyst for a fuel cell according to an embodiment of the present invention was evaluated using a commercially available Pt / C catalyst as a fuel cell catalyst. 13 and Fig.

More specifically, Fig. 13 shows the results of measurement of the catalyst activity of the fuel cell catalyst prepared according to Example 2-1 (PtNiY / C) and Example 2-4 (PtCoY / C) of the present invention and commercially available Pt black (ORR: Oxygen Reduction Reaction) of a catalyst for a fuel cell of a Pt / C (carbon-bearing platinum) catalyst obtained by the above-described method of the present invention and a commercially available Pt black And the results of MEA performance evaluation in the case where the catalyst was used as a fuel cell catalyst.

As shown in the results of FIG. 13 and FIG. 14, the ternary platinum-transition metal alloy catalyst according to the present invention shows improved performance as compared with the conventional platinum catalyst, and the ternary platinum- The catalyst shows a high possibility of being used as a catalyst for a fuel cell by reducing the use amount of platinum by 30% or more and securing higher performance and stability than existing catalysts.

On the other hand, in the production of the catalyst for a fuel cell according to the present invention, in order to control the acidity of the metal precursor mixture under the same conditions and to measure the dispersibility of the particles and the uniformity of the particle size according to the addition of formic acid, The TEM (Transmission Electron Microcopy) of the prepared catalyst for fuel cell was measured and the results are shown in Fig.

As shown in Fig. 15, the catalyst of Example 2-8 (Fig. 15A), in which the pH of the metal precursor mixture was pH 12 compared to the catalyst of Examples 2-1 and 2-4 (Fig. 11) , It was confirmed that the addition of formic acid under the same conditions, that is, in the case of the catalysts of Examples 2-9 to 2-11 (Figs. 15B to 15D), unreacted It was confirmed that there is no metal, the particle dispersibility is improved, and the particle size becomes more uniform.

According to the method for producing a catalyst for a fuel cell of the present invention, it is possible to produce a catalyst for a fuel cell having excellent performance and stability while remarkably reducing the amount of Pt used. In addition, the use amount of the chemical reducing agent is reduced and the production of by-products is reduced, and the production at a room temperature can be performed in a short time without heat treatment and an additional post-treatment process, thereby remarkably improving productivity at the time of production and is suitable for mass production.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments, It will be apparent that the scope is not limited. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (22)

(a) mixing a platinum based precursor, a second metal precursor and a solvent to obtain a metal precursor mixture; And (b) irradiating the metal precursor mixture with an electron beam at a power of 0.2 kW to 7.5 kW to produce a two-component platinum-transition metal alloy catalyst. (i) mixing a platinum-based precursor, a second metal precursor, a third metal precursor, and a solvent to obtain a metal precursor mixture; And (ii) irradiating the metal precursor mixture with an electron beam having an applied current of 0.5 mA to 15 mA to produce a three-component platinum-transition metal alloy catalyst. 3. The method according to claim 1 or 2, The platinum-based precursor is _{H 2 PtCl 6, H 6 Cl} 2 N 2 Pt, PtCl 2, PtBr 2, acetylacetonate _{(platinum acetylacetonate), K 2 (} PtCl 4), H 2 Pt (OH) 6, Pt (NO _{3) 2, [Pt (NH} 3) 4] Cl 2, [Pt (NH 3) 4] (HCO 3) 2, [Pt (NH 3) 4] (OAc) 2, (NH 4) 2 PtBr 6, (NH ₃ ) ₂ PtCl ₆ , a hydrate thereof, and a mixture thereof. 3. The method according to claim 1 or 2, Wherein the solvent is selected from the group consisting of water, alcohols having 1 to 8 carbon atoms, and mixtures thereof. 5. The method of claim 4, Wherein the solvent is a mixed solvent of water and a polyhydric alcohol. The method according to claim 1, The second metal precursor may be at least one selected from the group consisting of yttrium, ruthenium, osmium, gallium, titanium, vanadium, chromium, manganese, iron, Co, Ni, Cu, Sn, Mo, W, Rh, Ir, Sc, La, Wherein the precursor is a metal element-containing precursor selected from tantalum (Ta), bismuth (Bi), and palladium (Pd). The method according to claim 6, Wherein the second metal precursor is a metal element-containing precursor selected from the group consisting of yttrium (Y), ruthenium (Ru), cobalt (Co), nickel (Ni), and iridium (Ir) Way. The method according to claim 1, Wherein the platinum group precursor and the second metal precursor in the step (a) are mixed at a weight ratio of 40: 1 to 1: 5 based on the metal content. The method according to claim 1, Wherein the electron beam irradiation in the step (b) irradiates an electron beam having an applied current of 0.5 mA to 15 mA. 3. The method of claim 2, The second metal precursor may be at least one selected from the group consisting of Ru, Os, Pd, Ga, Ti, V, Cr, Mn, (Co), nickel (Ni), copper (Cu), tin (Sn), molybdenum (Mo), tungsten Wherein the metal element-containing precursor is a metal element-containing precursor. 11. The method of claim 10, Wherein the second metal precursor is a metal element-containing precursor containing nickel (Ni). 11. The method of claim 10, Wherein the second metal precursor is a metal element-containing precursor containing cobalt (Co). 11. The method of claim 10, Wherein the second metal precursor is a metal element-containing precursor containing ruthenium (Ru). 11. The method of claim 10, Wherein the second metal precursor is a metal element-containing precursor containing iridium (Ir). 3. The method of claim 2, Wherein the third metal precursor is a metal element-containing precursor including yttrium (Y) or iridium (Ir). 3. The method of claim 2, The metal component of the catalyst for a fuel cell obtained by the above production method is obtained in a content ratio of 15 wt% to 85 wt% of platinum, 5 wt% to 65 wt% of the second metal and 1 wt% to 60 wt% of the third metal Wherein the catalyst layer is formed on the surface of the catalyst layer. 17. The method of claim 16, The metal component of the catalyst for a fuel cell obtained by the above production method is characterized by a content ratio of 15 to 70% by weight of platinum, 15 to 65% by weight of the second metal and 10 to 60% by weight of the third metal Wherein the catalyst layer is formed on the surface of the catalyst layer. 3. The method of claim 2, Wherein the three-component platinum-transition metal alloy catalyst comprises a platinum-transition metal alloy selected from the group consisting of Pt-Co-Y, Pt-Ni-Y, Pt-Ir-Y, Pt- Wherein the catalyst is a catalyst. 3. The method according to claim 1 or 2, Wherein the metal-containing carrier mixture is obtained by further mixing the carbon-containing carrier in the step (a) or the step (i). 3. The method according to claim 1 or 2, (A) or (i), providing a basic solution having a pH of 8 to pH 13 by adjusting the acidity of the metal precursor mixture obtained before the irradiation of the electron beam with a basic compound By weight based on the total weight of the catalyst. 21. The method of claim 20, Wherein the basic compound is at least one selected from the group consisting of NaOH, Na ₂ CO ₃ , KOH and K ₂ CO ₃ . 21. The method of claim 20, The method for producing a catalyst for a fuel cell comprises the steps of: controlling the acidity of a metal precursor mixture obtained before irradiation of an electron beam with a basic compound to provide a basic solution having a pH of 8 to 13; And then adding formic acid to the basic solution. &Lt; Desc / Clms Page number 19 &gt;

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