KR101451897B1 - Method of preparing catalysts, leaching agent for the same and catalysts thereof - Google Patents

Abstract

The present invention relates to a process for preparing a catalyst, a leaching solution for preparing a catalyst, and a catalyst produced thereby. A method for preparing a catalyst of the present invention comprises: preparing a leach solution containing hydroquinone and a solvent; Wherein the leach solution comprises a first metal containing any one selected from the group consisting of platinum, palladium and combinations thereof and at least one of nickel, cobalt, iron, manganese, chromium, vanadium, titanium, scandium, silver, rhodium, ruthenium, molybdenum A catalyst dispersion step of dispersing an alloy catalyst comprising a second metal containing any one selected from the group consisting of niobium, zirconium, yttrium, tungsten, tantalum, hafnium, and combinations thereof to produce a catalyst dispersion solution; And a leaching step of leaching the second metal in an alloy catalyst in the catalyst dispersion solution.
According to the catalyst prepared according to the production method of the present invention, the second metal present on the surface of the alloy catalyst can be selectively and efficiently removed to improve the electrochemical characteristics of the alloy catalyst.

Description

TECHNICAL FIELD The present invention relates to a catalyst preparation method, a leaching solution for a catalyst preparation, and a catalyst produced by the leaching solution. BACKGROUND ART [0002]

The present invention relates to a process for preparing a catalyst, a leaching solution for a catalyst preparation, and a catalyst produced thereby, and more particularly, to a process for preparing an alloy catalyst having improved electrochemical characteristics as compared with a conventional single- A catalyst leaching solution, and a catalyst prepared thereby.

Typical fuel cells include Proton Exchange Membrane Fuel Cell (PEMFC) and Direct Methanol Fuel Cell (DMFC).

An alloy catalyst of platinum or palladium is used as an anode and a cathode electrode material of such a fuel cell. Specifically, a catalyst material in which platinum alloy nanoparticles are dispersed in a carbon carrier may be used as the electrode material.

Such an alloy catalyst has excellent electrochemical activity, so that it is possible to improve the electrochemical performance of the fuel cell while reducing the amount of platinum or palladium used, as compared with the case of using a platinum or palladium single material as a typical electrode material as a catalyst.

When only a single material of platinum or palladium is applied as the cathode electrode of the fuel cell, the rate of the total oxygen reduction reaction by the slow water formation step may be slowed down. In this case, the electrochemical activity required for the fuel cell can not be satisfied.

However, in the case of using a catalyst containing an alloy containing platinum or palladium, the electronic structure of palladium can be changed in a desired direction through the alloy, and in this case, the rate-determining step of the water- The rate can be increased, and the activity of the catalyst can be increased.

However, such an alloy catalyst has a second metal exposed on its surface except for a platinum (or palladium) metal, and the second metal thus exposed is oxidized or melted in the operating environment of the fuel cell, .

Further, due to the problem that the second metal other than the platinum-based or the palladium-based metal is exposed on the surface of the catalyst, the stability of the catalyst may be lower than that of the pure platinum or palladium catalyst.

Therefore, it is essential to increase the surface concentration of platinum in order to increase the electrochemical activity and stability of the alloy catalyst. Specifically, it is necessary to cause segregation of platinum (or palladium) on the surface of the catalyst, A leaching method is proposed in which the second metal is removed.

The segregation method is a method in which a segregation tendency does not appear in a combination of desired metal elements due to the property of segregation energy depending on the intrinsic properties of the second metal to be alloyed with platinum (or palladium) May occur.

According to the literature (A. Christensen; AV Ruban: KW Jacobsen; HL Skriver; JK Norskov, Phys. Rev. B 1997 56 5822), in the case of nickel, ruthenium and tungsten alloys in which platinum is present as an impurity, , And a segregation energy of -2.06 eV / atom. The larger the negative value of the precipitation energy is, the larger the segregation tendency of the impurity atoms becomes.

Therefore, when a substance to be included in the catalyst is specified to be applied to a specific electrochemical reaction, the segregation energy value may be a fixed value. Although the segregation energy value may be changed by adjusting the ratio of the impurity of the second metal and the specified first metal, it may be difficult to exhibit an intended precipitation effect due to the fixed precipitation energy value.

Since the leaching method has the highest work function value except for gold in the transition metals of platinum or palladium and the standard dissolution potential is also the highest, Only a second metal other than platinum or palladium having a low dissolution potential is selectively dissolved.

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The conventional leaching method is to dissolve the second metal in an aqueous solution of 0.5 M sulfuric acid at about 80 ° C. This method is suitable to be applied when the surface concentration of the second metal is very high, and even this method may exhibit unsatisfactory activity compared with the high activity of a catalyst having a conventional surface platinum layer.

This is because the conventional leaching method is a process of oxidizing and dissolving the second metal of the alloy catalyst in an acidic atmosphere at a high temperature, and therefore, the high metal oxophilicity of the second metal causes the platinum (or palladium) And the degree of alloying can also be lowered at the same time.

The surface of the catalyst particles after the leaching treatment may be a form in which an oxide of a metal and platinum (or palladium) coexist. In order to reduce the proportion of the oxide, a reducing atmosphere , It may lead to undesirable consequences of precipitation of the second metal to the surface.

[Prior Art Literature]

1. Published Korean Patent Application No. 10-2000-0017511 (published on October 31, 2001)

2. Published Korean Patent Application No. 10-2007-0033362 (Publication Date: July 21, 2008)

It is an object of the present invention to provide a production method capable of improving the electrochemical characteristics of an alloy catalyst containing platinum or palladium.

Another object of the present invention is to provide a leach solution used in the above production method.

It is still another object of the present invention to provide an alloy catalyst comprising platinum or palladium produced by the above process.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a process for preparing a leach solution containing hydroquinone and a solvent. A second step of dispersing an alloy catalyst containing a first metal and a second metal in the leaching solution prepared in the first step to prepare a catalyst dispersion solution; And a third step of leaching the second metal in the alloy catalyst in the catalyst dispersion solution prepared in the third step.

The third step may further include washing, filtering and drying.

The drying is preferably performed at a temperature of 30 to 50 DEG C for 10 to 15 hours.

The first metal may include any one selected from the group consisting of platinum, palladium, and combinations thereof.

Wherein the second metal is selected from the group consisting of nickel, cobalt, iron, manganese, chromium, vanadium, titanium, scandium, silver, rhodium, ruthenium, molybdenum, niobium, zirconium, yttrium, tungsten, tantalum, hafnium, And may include any one selected.

The solvent may include any one selected from the group consisting of water, alcohol, and combinations thereof.

The alcohol may be at least one selected from the group consisting of methanol, ethanol, trifluoroethanol, propanol, isopropanol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, oxobutyl alcohol, undecyl alcohol, Methoxyethyl alcohol, 1-methoxy-2-propyl alcohol, benzyl alcohol, phenethyl alcohol, cyclohexyl alcohol, menthyl alcohol, tetrahydrofurfuryl alcohol, tetra 2-butanol, 4-hydroxy-2-butanol, and combinations thereof.

The concentration of the hydroquinone in the leaching solution is preferably 0.001 to 0.5 M.

In the second step, the leaching solution is preferably 0.01 L to 2.0 L per 1 g of the alloy catalyst.

The third step is preferably performed at a temperature of 60 to 78 ° C for 30 minutes to 4 hours.

The present invention also provides an alloy catalyst for a fuel cell produced by the production method of the present invention.

The present invention also provides a leach solution for preparing a catalyst catalyst for a fuel cell comprising hydroquinone and a solvent.

The solvent may include any one selected from the group consisting of water, alcohol, and combinations thereof.

It is preferable that the hydroquinone has an oxidation-reduction potential of 0.5 V to 0.9 V.

The present invention also provides an alloy catalyst for a fuel cell comprising the leaching solution for preparing an alloy catalyst for fuel cells.

According to the method for producing a catalyst of the present invention and the leaching solution for preparing a catalyst, it is possible to efficiently remove a second metal such as nickel, cobalt and iron in an alloy catalyst containing platinum or palladium.

In addition, the catalysts of the present invention have improved electrochemical properties compared to conventional single metal catalysts or catalysts that have not undergone leaching.

1 is a flow chart of a method for producing a catalyst according to an embodiment of the present invention.
2 is a graph showing the results of Ni 2 p 3/2 XPS (X-ray photoelectron spectroscopy) measurement of Comparative Example 1 (pristine Pt 3 Ni 1/1) and Example (leached Pt 3 Ni 1 / C).
3 is a graph comparing the electrochemical activities of catalysts of Comparative Example 1 (pristine Pt3Ni1 / C), Comparative Example 2 (commercial Pt3Ni1 / C), and Example (leached Pt3Ni1 / C).

Hereinafter, the present invention will be described in detail. In the following description of the present invention, a detailed description of known configurations and functions will be omitted.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and should be construed in accordance with the technical meanings and concepts of the present invention.

The embodiments described in the present specification and the configurations shown in the drawings are preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention and thus various equivalents and modifications Can be.

Hereinafter, the present invention will be described in more detail.

The method for producing the catalyst of the present invention includes a leaching solution preparation step, a catalyst dispersion step, and a leaching step.

The method for preparing the catalyst may further include washing, filtering and drying steps after the leaching step.

The leaching solution preparation step includes preparing the leaching solution.

The leaching solution includes hydroquinone (HQ) and a solvent.

Since the hydroquinone has a standard oxidation-reduction potential of -0.3 V in a neutral aqueous solution and has a value between the standard oxidation-reduction potential of nickel, which is a representative second metal, and the standard oxidation-reduction potential of platinum, It is possible to dissolve the second metal while suppressing the oxidation process of the metal.

The solvent may be any solvent selected from the group consisting of water, alcohols, and combinations thereof, and alcohol alone may be used.

The alcohol may be at least one selected from the group consisting of methanol, ethanol, trifluoroethanol, propanol, isopropanol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, oxobutyl alcohol, undecyl alcohol, Methoxyethyl alcohol, 1-methoxy-2-propyl alcohol, benzyl alcohol, phenethyl alcohol, cyclohexyl alcohol, menthyl alcohol, tetrahydrofurfuryl alcohol, tetra Hydroxy-2-butanol, and combinations thereof, and may preferably be ethanol. The solvent may be selected from the group consisting of ethanol, ethanol, propanol, isopropanol, n-butanol,

When ethanol is used alone as the solvent, the oxidation-reduction potential of -0.3 V (vs. NHE) in the neutral water is further increased by the interaction of the solvent and the hydroquinone, so that the standard dissolution potential of the platinum is increased Not only allows the second metal to melt rapidly but also prevents the oxidation of the metal surface atoms as compared to the case of applying the water, thereby effectively leaching the second metal while maintaining the alloy degree.

That is, by inducing the oxidation reaction of hydroquinone in ethanol, it is possible to prevent the deterioration of the catalyst performance and stability due to the oxidation of the surface of the nanoparticles and the decrease of the alloy.

Specifically, in the aqueous solution, hydroquinone on the surface of platinum or palladium exhibits an oxidation-reduction potential of about 0.55 V. That is, the oxidation-reduction potential of the hydroquinone is lower than the standard dissolution potential of the first metal including platinum and palladium, and higher than the standard dissolution potential of the second metal, thereby enabling selective leaching of the second metal.

The concentration of the hydroquinone to be applied to the leaching solution is not particularly limited, but the leaching solution may have a concentration of the hydroquinone of 0.001 to 0.5 M and 0.01 to 0.1 M. When the hydroquinone concentration of the leach solution is in the above range, the second metal can be effectively leached.

The standard dissolution potential of hydroquinone in the leaching solution may be varied depending on the type of the solvent to be applied, the temperature of the leaching solution, etc. In the leaching solution, the standard dissolution potential of the hydroquinone may be 0.5 to 0.9 V, V < / RTI >

In the case of having a standard dissolution potential within the above range, the second metal can be selectively and effectively leached, and most of the remaining transition metals can be dissolved without dissolving Pt, Pd, Ir, Au.

The catalyst dispersing step includes dispersing an alloy catalyst containing a first metal and a second metal in the leaching solution to prepare a catalyst dispersion solution.

Wherein the first metal is one selected from the group consisting of platinum, palladium, and combinations thereof, and the second metal is selected from the group consisting of nickel, cobalt, iron, manganese, chromium, vanadium, titanium, scandium, Ruthenium, molybdenum, niobium, zirconium, yttrium, tungsten, tantalum, hafnium, and the like.

Dispersion in the process of preparing the catalyst dispersion solution may be applied as long as it is capable of sufficiently dispersing the catalyst in the leaching solution, and may include ultrasonic dispersion.

Preferably, the dispersion may include ultrasonic dispersion for 5 to 20 minutes, stirring for 30 minutes to 3 hours, and ultrasonic dispersion for 1 to 10 minutes.

The amount of the leach solution used in the catalyst dispersion step is not particularly limited, but may be adjusted to 0.01 L to 2.0 L per 1 g of the alloy catalyst, and preferably 0.01 to 0.5 L per 1 g of the alloy catalyst. When the amount of the leach solution and the alloy catalyst used is within the above range, the efficiency of the leaching process can be increased.

The leaching step includes leaching the second metal in an alloy catalyst in the catalyst dispersion solution.

The leaching step may be carried out under an argon atmosphere, and the reaction vessel may be filled with argon gas to remove air from the reaction vessel.

The leaching step may be performed by maintaining the temperature in the reaction vessel at 60 to 78 캜 for 30 minutes to 4 hours, preferably at 65 to 75 캜 for 1 to 3 hours.

In the leaching step, when the temperature in the reaction tank exceeds 78 캜, the ethanol solvent may be vaporized and consumed in a large amount. When the temperature is less than 60 캜, the amount of leaching may be insufficient and a long time may be required.

In the leaching step, if the time for maintaining the temperature in the reaction tank is less than 30 minutes, the leaching may not be completed and the amount thereof may be insufficient. If it exceeds 4 hours, the amount of the solvent may be reduced due to vaporization of ethanol.

In the leaching step, the temperature in the reaction tank may be raised to a temperature of about 2 [deg.] C / min using a heater after the air in the reaction tank is removed to reach the temperature of the leaching step. The temperature elevation temperature is to prevent a temperature difference within the catalyst dispersion solution due to rapid overheating, and may be appropriately changed according to the size of the reaction vessel, reaction conditions, and the like.

The catalyst dispersion solution having been subjected to the leaching step may be cooled at room temperature, washed with a solvent, and filtered and dried.

The solvent may be, but is not limited to, solvents used in the preparation of the leach solution.

The drying may be carried out in a vacuum oven at 30 to 50 DEG C for 10 to 15 hours and under an argon atmosphere.

When the method for producing the catalyst is applied, the oxidation of the hydroquinone in the leaching solution containing the hydroquinone and the high binding energy between the hydroquinone and the first metal is used to form the second metal Can be selectively dissolved.

Further, by using hydroquinone in which platinum (or palladium) atoms on the surface of the alloy catalyst are adsorbed and desorbed in the oxidation reaction, the concentration of H + on the catalyst surface as a result of the oxidation reaction can be increased, It is possible to efficiently dissolve the second metal on the surface.

The alloy catalyst may be an alloy catalyst containing a first metal such as platinum or palladium and a second metal such as nickel, cobalt or iron on the surface of the catalyst. The alloy catalyst satisfies the above-mentioned condition A method of producing a catalyst may be applied.

The alloy catalyst may be a nanocatalyst of a first metal including platinum, palladium, and combinations thereof using a carbon carrier, and may be selected from the group consisting of nickel, cobalt, iron, manganese, chromium, vanadium, titanium, scandium, A second metal comprising any one selected from the group consisting of ruthenium, molybdenum, niobium, zirconium, yttrium, tungsten, tantalum, hafnium, and combinations thereof.

The alloy catalyst may be used as an electrochemical catalyst, and specifically, it may be used as an electrode material of a fuel cell including a proton exchange membrane fuel cell and a direct methanol fuel cell.

In particular, in the case of using an alloy catalyst that has undergone a leaching process according to the production method of the present invention as an electrode material of a fuel cell, the electrochemical characteristics of the fuel cell can be improved and the problem .

In addition, since the oxidation of the second metal present on the surface of the catalyst can be reduced, a heat treatment in a reducing atmosphere can be avoided, and the problem of precipitation of the second metal on the surface of the alloy catalyst can be solved .

In another embodiment of the present invention, the leaching solution for catalyst preparation comprises hydroquinone and a solvent.

Details of the composition and effect of the leaching solution containing the hydroquinone, the solvent and the composition of the leaching solution and the oxidation-reduction potential value are the same as those of the method for producing the catalyst, do.

A catalyst, which is another embodiment of the present invention, is produced by the method for producing the catalyst. The content of the catalyst is the same as that described in the above-mentioned production method of the catalyst, so that the description thereof will be omitted.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for describing the present invention in more detail and that the scope of the present invention is not limited by these embodiments in accordance with the gist of the present invention .

Manufacturing example : Pt3Ni1 / C catalyst

40 wt% Pt3Ni1 / C alloy electrode material was manufactured and the process is as follows.

First, 0.15 g of Vulcan XC-72R (carbon) was added to 100 mL of anhydrous ethanol, followed by 30 minutes of stirring, 20 minutes of ultrasonic dispersion, and 30 minutes of stirring. 0.1570 g of a platinum precursor (PtCl ₄ ) and 0.0369 g of a nickel precursor (NiCl ₂ .H ₂ O) were dissolved in 80 mL of anhydrous ethanol, and the solution was added to the carbon-dispersed solution to prepare a synthesis solution.

1.455 g of sodium acetate was added to the above synthesis solution and stirring was continued. The duration of the stirring was at least 4 hours to allow sodium acetate to bind to the metal precursors while being dissolved in ethanol.

0.112 g of sodium borohydride (NaBH ₄ ) was added to a 20 mL vial, and then 20 mL of absolute ethanol was added and dissolved by external vibration for 1 minute.

On the other hand, before the sodium borohydride was added, the synthesis solution was subjected to ultrasonic dispersion for about 15 seconds and the stirring speed was maximized. In this state, 20 mL of sodium borohydride dissolved in ethanol solution was injected into the synthesis solution containing the metal precursors.

The sodium borohydride-impregnated synthesis solution was allowed to undergo rapid stirring for about 30 minutes, followed by appropriately lowering the stirring speed and maintaining stirring for at least 1 hour and 30 minutes.

It has been reported in the literature that all metal precursor compounds are reduced in the shortest time of about 2 hours in a metal reduction condition not including water. Thereafter, the catalyst nanoparticles supported on carbon were obtained through a washing process using DI water and a drying process at 70 ° C.

The Pt3Ni1 / C catalyst (pristine Pt3Ni1 / C) prepared according to the above Preparation Example was used as a comparative example 1, and its physical properties were evaluated.

Example : Ni Leached Pt3Ni1 / C catalyst

Hydroquinone (1,4-benzohydroquinone) was dissolved in 200 mL of ethanol to a concentration of 18 mM and stirred for about 30 minutes to prepare a leaching solution.

0.2 g of a catalyst (Pt3Ni1 / C, electrode material having a metal content of 40% by weight) in which a platinum-nickel alloy was dispersed in the carbon carrier prepared in the above Preparation Example was added to the above leaching solution, The dispersion was sonicated for 10 minutes and stirred for another 2 hours to prepare a catalyst dispersion solution.

The catalyst dispersion solution was placed in a reaction vessel and argon gas was injected for about 10 minutes.

In the argon atmosphere, the temperature of the reaction vessel was gradually raised to 70 ° C for 40 minutes using a heater, and maintained at 70 ° C for 1 hour to carry out the leaching step.

After the leaching step was completed, the heater was turned off, and the catalyst dispersion solution in which the leaching step was completed was naturally cooled. The leached catalyst dispersion solution was washed with ethanol and filtered to obtain a leached catalyst.

The filtered catalyst was dried for about 12 hours at 40 DEG C in a vacuum oven in which air in the oven was removed by first injecting argon gas for about 10 minutes to obtain the catalyst of the embodiment of the present invention.

Experimental Example  1: of the catalyst before and after leaching XPS  compare

2 is a graph showing the results of Ni 2 p 3/2 XPS (X-ray photoelectron spectroscopy) measurement of Comparative Example 1 and Example.

Referring to FIG. 2, the broad shake-up peak near 854.5 eV was the largest in the case of pristine Pt3Ni1 / C (Comparative Example 1), but the leached Pt3Ni1 / Shows that the peak of the metallic phase near 852 eV is clearly visible as the main peak.

This means that the shake-up peak due to nickel oxides disappeared and that the metallic Ni phase was increased.

That is, on the surface of the alloy catalyst after the leaching process, a metallic nickel phase free from oxygen existing in the core of the catalyst nanoparticles was confirmed as a main peak, and nickel oxides It was confirmed that many of them were removed.

Experimental Example  2: The rotating electrode  Comparison of Oxygen Reduction Reaction Result

FIG. 3 is a graph comparing the electrochemical activities of catalysts of Comparative Example 1 (pristine Pt3Ni1 / C) with Comparative Example 2 (commercial Pt3Ni1 / C), and Example (leached Pt3Ni1 / C).

Referring to FIG. 3, a pure platinum catalyst (Pt / C, 40 wt%, Johnson-Matthey Company, Comparative Example 2) indicated by a gray line in the case of the embodiment shown in red line (leached Pt3Ni1 / C) When compared, it showed superior low overvoltage.

In addition, the overvoltage was much lower than in the case of Comparative Example 1 (Pt3Ni1 / C before leaching) in which the example was shown in black line, so that the embodiment of the present invention having been subjected to the leaching process was compared with a pure platinum catalyst or a leached platinum catalyst And thus it has been confirmed that it has excellent activity as an electrode of a fuel cell.

As described above, preferred embodiments of the present invention have been disclosed in the present specification and drawings, and although specific terms have been used, they have been used only in a general sense to easily describe the technical contents of the present invention and to facilitate understanding of the invention , And are not intended to limit the scope of the present invention.

It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

Claims (15)

A first step of preparing a leaching solution containing hydroquinone and a solvent;
A second step of dispersing an alloy catalyst containing a first metal and a second metal in the leaching solution prepared in the first step to prepare a catalyst dispersion solution; And a third step of leaching the second metal from the alloy catalyst in the catalyst dispersion solution prepared in the second step.
The method according to claim 1,
Wherein the third step further comprises washing, filtering and drying.
3. The method of claim 2,
Wherein the drying is performed at a temperature of 30 to 50 DEG C for 10 to 15 hours.
The method according to claim 1,
Wherein the first metal comprises any one selected from the group consisting of platinum, palladium, and combinations thereof.
The method according to claim 1,
Wherein the second metal is selected from the group consisting of nickel, cobalt, iron, manganese, chromium, vanadium, titanium, scandium, silver, rhodium, ruthenium, molybdenum, niobium, zirconium, yttrium, tungsten, tantalum, hafnium, Wherein the catalyst is selected from the group consisting of Al 2 O 3 and Al 2 O 3.
The method according to claim 1,
Wherein the solvent comprises any one selected from the group consisting of water, alcohol, and combinations thereof.
The method according to claim 6,
The alcohol may be at least one selected from the group consisting of methanol, ethanol, trifluoroethanol, propanol, isopropanol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, oxobutyl alcohol, undecyl alcohol, Methoxyethyl alcohol, 1-methoxy-2-propyl alcohol, benzyl alcohol, phenethyl alcohol, cyclohexyl alcohol, menthyl alcohol, tetrahydroperfuryl alcohol, Wherein the catalyst comprises any one selected from the group consisting of tetrahydropyranyl alcohol, cyanobutyl alcohol, 4-hydroxy-2-butanol, and combinations thereof.
The method according to claim 1,
Wherein the leaching solution has a hydroquinone concentration of 0.001 to 0.5 M. 2. The method of claim 1,
The method according to claim 1,
Wherein the leaching solution in the second step is 0.01 L to 2.0 L per 1 g of the alloy catalyst.
The method according to claim 1,
Wherein the third step is performed at a temperature of 60 to 78 ° C for 30 minutes to 4 hours.
11. An alloy catalyst for a fuel cell produced by the method of any one of claims 1 to 10.
A leaching solution for preparing a catalyst for a fuel cell comprising hydroquinone and a solvent.
13. The method of claim 12,
Wherein the solvent comprises any one selected from the group consisting of water, alcohol, and combinations thereof.
13. The method of claim 12,
Wherein the hydroquinone has an oxidation-reduction potential of 0.5 V to 0.9 V.
An alloy catalyst for a fuel cell comprising the leaching solution for a catalyst preparation according to claim 12.

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