KR20040088288A - Preparation methods of platinum electrode catalyst for fuel cell - Google Patents

Abstract

PURPOSE: A platinum catalyst for the electrode of a fuel cell, its preparation method and a fuel cell containing the platinum catalyst as an electrode catalyst are provided, to improve the reaction active region and the support amount of platinum particles even without heating. CONSTITUTION: The platinum catalyst comprises a supporter where 10-80 wt% platinum is supporter, and the supported platinum has a size of 5 nm or less. Preferably the supporter is a carbon supporter comprising a carbon nanotube or fiber, or a metal oxide. The method comprises the steps of dispersing a supporter in a solvent into colloid state to prepare a slurry, and making the slurry be basic by using a pH controlling material to prepare a supporter slurry; adding a platinum precursor solution and a pH controlling material to prepare a platinum-supported platinum/supporter; and adding a reducing agent to the platinum/supporter.

Description

Manufacturing method of platinum electrode catalyst for fuel cell {PREPARATION METHODS OF PLATINUM ELECTRODE CATALYST FOR FUEL CELL}

The present invention relates to a method for producing a catalyst for oxidation or reduction electrode containing platinum used in a fuel cell, and more particularly, even when platinum is supported in the platinum / support powder in which platinum particles are supported on a support. The present invention relates to a method for producing a platinum electrode catalyst for fuel cell, which can reduce the thickness of the electrode and increase the reaction area in the fuel cell, thereby reducing the total catalyst usage by forming fine particles thereon.

A fuel cell is a power generation device that converts chemical energy of a fuel into electric energy, and is an alternative energy technology of the future having the advantages of being more efficient than existing internal combustion engines and generating little pollution. Applications of fuel cells include 3C (computers, camcorders, mobile phones) markets, power sources for cars, trains, ships, submarines, household power supplies and heating, and medium and large power plants. In recent years, intensive research has been conducted as a power source for automobiles, and has received a lot of attention toward portable power sources.

The fuel cell is composed of an anode, a cathode, and an electrolyte, and generates electrical energy by catalytic reaction between the anode and the cathode and ion permeation from the electrolyte. The classification of fuel cell is mainly classified according to the electrolyte used, and is divided into low temperature type and high temperature type. In the case of a low temperature fuel cell, in order to obtain a desired amount of energy, it is necessary to have high catalytic reactivity and ion permeability at low temperature, and therefore, an electrode catalyst together with an electrolyte is an important factor for determining overall performance. Currently, platinum supported on a support is most used as an electrode catalyst of a low temperature fuel cell. However, while platinum is the only catalyst capable of promoting oxidation of fuel (hydrogen or alcohol) and reduction of oxygen from room temperature to around 100 ° C, the cost of platinum itself is high, thus reducing the amount of platinum used or per unit weight. It is very important to maximize the activity. In order to achieve the above object, it is necessary to control the particle size on the support of platinum within the nano-size range to increase the reaction active area as much as possible. In addition, since the decrease in the performance due to the diffusion decreases as the thickness of the catalyst layer is reduced in the fuel cell, a high supported catalyst having a small amount of support is required. Therefore, there is an urgent need for the production of platinum / support catalysts with platinum microparticles in the high supported area.

The method of preparing the platinum / support powder in which the existing platinum particles are supported on a support is largely divided into a precipitation method and a colloid method. U.S. Patent No. 4,186,110 proposes a precipitation method for basifying a slurry of a carbon support and water, injecting an aqueous solution of chloroplatinic acid, and then liquid-reducing platinum by adding a reducing agent such as formaldehyde (United Technologies Corporation of United States). ). In addition, US Pat. No. 5,068,161 proposes a method for preparing a catalyst having a platinum loading of up to 60% by weight based on the total catalyst weight using the method (Johnson Matthey, UK). Recently, U.S. Patent No. 6,165,635 (Degussa-Huls, Germany) proposes a method of correcting and securing the problem of European Patent No. 0 665 985 (International Fuel Cell, USA), which is platinum in a slurry of carbon support and water. Precipitation method is used to produce a platinum alloy / support powder of 10 nm or less using a method of injecting chloride, using a strong base, and then reducing the liquid phase.

In addition, U.S. Patent No. 3,033,193 (Prototech Company) discloses a platinum oxide-type particle obtained by adding a carbon support to an aqueous platinum sulfite acid solution and adding H ₂ O ₂ to form a platinum oxide, followed by filtering the solution with hydrogen. The colloidal method of reducing was presented. Recently, Matsushita Electric Corporation of Japan puts hydrogen into platinum chloride and polyacrylic acid aqueous solution in Japanese Patent Application Laid-Open No. 2002-42825 to form a platinum colloid, adds a carbon support to it, and then removes polyacrylate from the nitrogen atmosphere. Here's how.

In addition to these methods, there is a method of adding platinum chloride and carbon support in a water-immiscible organic solvent, liquid-free reduction, and freeze-drying to obtain platinum / support (Korea Patent Publication No. 2001-0094086), platinum chloride and hydrogen sulfite A method of depositing platinum / carbon powder by gradually adding an aqueous solution of sodium and a reducing solution to a slurry of carbon and water (Korean Patent Publication No. 1999-0017134) has been proposed.

In the precipitation method (US Patent Nos. 4,186,110, 5,068,161), which is a general catalyst manufacturing method, the manufacturing process is relatively simple and the process scale-up since most of the processes are performed in the liquid phase and the influence of the process variables is not large. On the other hand, it is easy to disperse platinum, and the particle size is large. Recently, the method proposed in US Pat. No. 6,165,635 said that it is possible to reduce the particle size of the total platinum alloy by adjusting the pH to 9 or more using a strong base sodium hydroxide as a pH adjusting material. By adjusting the pH, platinum particles have particles that are twice as large as those treated with weak bases.

The colloidal method has the advantage that fine platinum particles of 1.5-3 nm can be obtained when 20-40% of the total weight of platinum is supported, and the particles are evenly dispersed, but the particle size increases (more than 50%). Is rapidly growing. In addition, there is a disadvantage in that an additional hydrogen reduction process is required and the reactor size increases when starting from economical chloroplatinic acid rather than chlorosulfide acid, since 10 times more water is required to reduce platinum loss compared to the precipitation method. . According to Japanese Patent Laid-Open No. 2002-42825, finer platinum particles can be obtained by addition of carboxylic acid such as polyacrylic acid, but due to the additional procedure of removing the carboxylic acid, the process is complicated and the agglomeration of particles by heat treatment The particle size can be increased.

Republic of Korea Patent Publication No. 2001-0094086 has the advantage that the fine particles can be controlled significantly and the law of precursor selection is expanded by using a water immiscible solvent such as THF, but it is not easy to apply to actual mass production because the process is not simple. There is something wrong. Korean Patent Publication No. 1999-017134 has the advantage of making nano-sized platinum particles by a relatively simple method, while injecting two solutions with more than 3-4 times more water than the precipitation method in the platinum salt and reducing solution. Platinum particles change sensitively with speed and have a long process life.

Therefore, there is a need for an optimized manufacturing method capable of solving the problems of the conventional platinum catalyst and obtaining a fine platinum particle with a simple manufacturing process.

SUMMARY OF THE INVENTION In order to solve the problems in the prior art as described above, an object of the present invention is to provide a platinum catalyst for a fuel cell in which a reactive active region is increased even when the amount of platinum supported on the support is high.

Another object of the present invention is to provide a method for producing a platinum catalyst for fuel cells, in which uniform and small platinum particles are supported, the particle size can be easily adjusted by adjustment of process variables, and the process is simple.

Still another object of the present invention is to provide a high output fuel cell having improved performance by using a platinum catalyst prepared by the above method as an electrode catalyst.

1 is a diagram illustrating a manufacturing process of the platinum catalyst of the present invention,

Figure 2 shows a comparison of the current / voltage curve in the unit cell showing the output from the fuel cell of the platinum catalyst and the conventional catalyst of the present invention.

In order to achieve the above object, the present invention provides a platinum catalyst for a fuel cell having 10 to 80% by weight of platinum supported on the support, the size of the supported platinum particles up to 5 nm.

In addition, the present invention provides a method for producing a platinum catalyst,

a) preparing a slurry by dispersing the support in a colloidal state in a solvent and basifying with a pH adjuster to prepare a support slurry;

b) a step of preparing a platinum / support on which platinum is supported by basifying the support slurry prepared in step a) by adding a platinum precursor solution and a pH adjusting material; And

c) liquid phase reduction by adding a reducing agent to the platinum / support obtained in step b);

It provides a method for producing a platinum catalyst for a fuel cell comprising a.

At this time, step b) is carried out by repeating the process of adjusting the pH value to the base range by adding a pH adjusting material after the platinum precursor solution dispersed in 1 / N of the total platinum solution to the support slurry, It is preferable that the value of said N is at least 2. In addition, step b) may be carried out simultaneously with the addition of the platinum precursor solution to the support slurry and the adjustment of the pH value.

The present invention also provides a high output fuel cell comprising the platinum catalyst described above as an electrode catalyst.

Hereinafter, the present invention will be described in detail.

The present invention relates to a method for producing a catalyst for an oxidation or reduction electrode containing platinum, which is used in a fuel cell in which platinum forms fine particles on a support to provide a wide reaction region even when the supporting amount is high.

The present invention is an economical and simple process of heat-free treatment in which a platinum chloride solution and a pH adjusting material are dispersed or added at the same time and then liquid-reduced after basicizing a slurry of a support and a solvent. Highly dispersed platinum catalyst can be prepared.

The highly dispersed platinum catalyst of the present invention has a platinum content of 10 to 80% by weight supported on the support, and the platinum particles are preferably at most 5 nm. More preferably, the present invention provides a platinum catalyst having a reactive active region in the range of 1.5 to 4.0 nm of platinum particle size in a high support region of up to 20 to 70 wt% platinum content.

In the present invention, in the preparation of the platinum / support powder used for the catalytic reaction in which platinum particles are supported on a support, after the base and the slurry of the solvent are basicized, a platinum chloride solution and a pH adjusting material dissolved in platinum in the solvent are supported. This is done by adding to the slurry and adding the reducing agent to finish the whole process in the liquid phase.

In this case, the method of adding the platinum chloride solution and the pH adjusting material may be used in two ways. The first method is to disperse the platinum chloride solution in the slurry, and then add the pH adjusting material to adjust the pH value. In the second method, a method of continuously adjusting the pH value to the base range by adding a pH adjuster at the same time as the addition of the platinum chloride solution may be used.

That is, the present invention is added to the platinum chloride solution and the pH adjusting material dissolved in the solvent to the support slurry, the content is 1 / N of the total platinum solution, and then the process of raising the pH value to the base range N times It has the characteristic of disperse | distributing and adding repeatedly. It is preferable that the value of N which is the said dispersion frequency is at least 2. Such dispersion addition minimizes the phenomenon of rapid aggregation due to the formation of platinum compound due to hydrolysis when the platinum solution and the pH adjusting material are added all at once, resulting in a catalyst having fine platinum particles. .

In addition, the present invention can adjust the pH value to the base range by the addition of the platinum precursor solution and the addition of the pH adjusting material at the same time. This method has the effect of repeating the addition procedure N times (N> 100), and even when the supporting amount is high, platinum may form fine particles on the support to provide a wide reaction region.

Hereinafter, the catalyst production method of the present invention will be described in more detail. Figure 1 is a simplified illustration of the manufacturing method of the present invention.

First, the present invention performs a process of dispersing the support in a solvent. The solvent and the support are preferably used in a weight ratio of 100: 1 or less. The dispersion method may be used by selecting ultrasonic dispersion, mechanical stirring, magnetic stirring and the like. When the support is not evenly dispersed, since the support of platinum becomes uneven, it is preferable to disperse the support in a colloidal form. The support is preferably a carbon black support, and carbon supports or general metals and metal oxides including carbon nanotubes or fibers are also applicable. The kind of the solvent is not particularly limited, and it is preferable to use distilled water or an alcohol diluent.

Thereafter, the support slurry is prepared by basifying with a pH adjusting material. The support slurry temperature is 80 ° C. or higher, and the pH of this solution is adjusted to 7 or more bases. At this time, when the support is already at pH 7 or more by basicity, there is no need to adjust and the range of pH is preferably adjusted to 8 to 10. The pH adjusting material is preferably injected in the state of an aqueous solution dissolved in a solvent.

Next, a process of dispersing or simultaneously adding a platinum chloride solution and a pH adjusting material in which platinum is dissolved in a solvent is added to the support slurry.

In the present invention, platinum chloride calculated by the desired loading amount is added to a solvent to obtain a platinum solution which is strongly acidic at pH 1-2. Preferably, the platinum chloride is preferably used to be supported by 10 to 80% by weight, more preferably 20 to 70% by weight.

The platinum solution is then added to the support slurry, which amount is 1 / N of the total platinum solution. It is preferable that the value of N which is the said dispersion frequency is at least 2. Thereafter, the pH value is raised to the base range by adjusting the pH value. Once the pH value is stable, add 1 / N of platinum solution and raise the pH value to the base range. Repeat the above procedure until N times to add all the platinum solution, basicize the final pH, and then add the reducing agent to complete the reaction in the liquid phase. In this case, according to the present invention, the platinum solution and the pH adjusting material may be added and basified at the same time. The basicization is preferably carried out in the range of pH 12 above pH 7.

Finally, when the platinum / support slurry, which has been subjected to liquid reduction, is dried by filtration, a platinum / support powder catalyst having fine platinum particles is obtained.

In this case, the platinum precursor is preferably a cheap platinum chloride, may be used platinum nitrate or platinum sulfite acid. Although it does not specifically limit as said pH adjuster, Sodium bicarbonate, sodium hydroxide, ammonium hydroxide, etc. can be used, Preferably, using sodium bicarbonate can obtain finer metal particle. The pH adjusting material is preferably used in an aqueous solution state. The reducing agent includes hydrazine, formaldehyde, sodium borohydride, sodium formate and the like.

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

After 1 g of carbon powder (Vulcan XC-72R) used as a support was put in 100 ml of distilled water, a colloidal solution was obtained by vigorous stirring, which was heated to a temperature of 90 ° C. 1 M sodium bicarbonate solution was added to the colloidal solution to adjust the pH in the range of 8-9. When the pH value was stabilized, 2 ml of 0.214 g aqueous solution of platinum chloride (H ₂ PtCl ₆ .xH ₂ O), one third of the weight corresponding to 20 wt% of the desired platinum loading, was added to the colloidal solution. The pH value dropped by chloroplatinic acid was adjusted again by adding 1 M sodium bicarbonate solution to adjust the pH value in the range of 8-9. Thus, the addition procedure of the chloroplatinic acid solution (0.214 g of solvent, 2 ml) and the sodium bicarbonate solution was repeated two more times. Formaldehyde solution was added to this solution to reduce platinum in the liquid phase. The powder obtained by filtering the solution was washed and then vacuum dried at 80 deg. C to finally obtain a platinum / carbon powder. Elemental analysis showed that 19.1 wt% platinum was supported on carbon.

Example 2

After 1 g of carbon powder (Vulcan XC-72R) used as a support was put in 100 ml of distilled water, a colloidal solution was obtained by vigorous stirring, which was heated to a temperature of 90 ° C. 1 M sodium bicarbonate solution was added to the colloidal solution to adjust the pH in the range of 8-9. When the pH value was stabilized, 4 ml of an aqueous solution of 0.428 g of chloroplatinic acid (H ₂ PtCl ₆ .xH ₂ O), one fourth of the weight corresponding to 40 wt% of the desired platinum loading was added to the colloidal solution. The pH value dropped by chloroplatinic acid was adjusted again by adding 1 M sodium bicarbonate solution to adjust the pH value in the range of 8-9. Thus, the addition procedure of the chloroplatinic acid solution (0.428 g of solvent, 4 ml) and the sodium bicarbonate solution was repeated three more times. Formaldehyde solution was added to this solution to reduce platinum in the liquid phase. The powder obtained by filtration of the solution was washed and then vacuum dried at 80 deg. C to finally obtain a platinum / carbon powder. Elemental analysis showed that 38.5 wt% of platinum was supported on carbon.

Example 3

After 1 g of carbon powder (Vulcan XC-72R) used as a support was put in 100 ml of distilled water, a colloidal solution was obtained by vigorous stirring, which was heated to a temperature of 90 ° C. 1 M sodium bicarbonate solution was added to the colloidal solution to adjust the pH in the range of 8-9. When the pH value was stabilized, 7 ml of an aqueous solution of 0.771 g of chloroplatinic acid (H ₂ PtCl ₆ .xH ₂ O), one fifth of the weight corresponding to 60 wt% of the desired platinum loading was added to the colloidal solution. The pH value dropped by chloroplatinic acid was adjusted again by adding 1 M sodium bicarbonate solution to adjust the pH value in the range of 8-9. Thus, the addition procedure of the chloroplatinic acid solution (0.771 g of solvent, 7 ml) and the sodium bicarbonate solution was repeated four more times. Formaldehyde solution was added to this solution to reduce platinum in the liquid phase. The powder obtained by filtration of the solution was washed and then vacuum dried at 80 deg. C to finally obtain a platinum / carbon powder. Elemental analysis showed that 58.6% by weight of platinum was supported on carbon.

Example 4

After 1 g of carbon powder (Vulcan XC-72R) used as a support was put in 100 ml of distilled water, a colloidal solution was obtained by vigorous stirring, which was heated to 90 ° C. 1 M sodium bicarbonate solution was added to the colloidal solution to adjust the pH in the range of 8-9. When the pH value is stabilized, 16 ml of an aqueous solution of 1.712 g of chloroplatinic acid (H ₂ PtCl ₆ .xH ₂ O), which is equivalent to 40 wt% of platinum, is injected into a colloidal solution of carbon powder (1 g of carbon) at a rate of 0.5 ml / min. , 100 ml), and at the same time by adding a 1 M sodium bicarbonate solution to continuously adjust the pH value in the range of 8 to 9, the effect was repeated N times (N> 100). Formaldehyde solution was added to this solution to reduce platinum in the liquid phase. The powder obtained by filtration of the solution was washed and then vacuum dried at 80 deg. C to finally obtain a platinum / carbon powder. Elemental analysis showed that 38.7 wt% platinum was supported on carbon.

Comparative Example 1

A platinum / carbon powder was prepared according to the precipitation method shown in US Pat. No. 4,186,110, and the process is as follows.

After 1 g of carbon powder (Vulcan XC-72R) used as a support was put in 100 ml of distilled water, a colloidal solution was obtained by vigorous stirring, which was heated to a temperature of 90 ° C. 1 M sodium hydroxide solution was added to the colloidal solution to adjust the pH in the range of 8-9. When the pH value was stabilized, 16 ml of 1.712 g of chloroplatinic acid (H ₂ PtCl ₆ .xH ₂ O) aqueous solution corresponding to the desired platinum loading of 40 wt% was added to the colloidal solution. The pH value dropped by chloroplatinic acid was adjusted again by adding 1 M sodium hydroxide solution to adjust the pH value in the range of 8-9. Formaldehyde solution was added to this solution to reduce platinum in the liquid phase. The powder obtained by filtration of the solution was washed and then vacuum dried at 80 deg. C to finally obtain a platinum / carbon powder. Elemental analysis showed that 37.1 wt% platinum was supported on carbon.

Comparative Example 2

A platinum / carbon powder was obtained in the same manner as in Comparative Example 1, except that 1 M sodium bicarbonate solution was used as the pH adjusting material. Elemental analysis shows that 37.8 wt% platinum is supported on carbon.

Comparative Example 3

A platinum / carbon powder was prepared according to the colloidal method shown in U.S. Patent No. 3,033,193, and the process is as follows.

4.44 g of platinum sulfite acid (H ₃ Pt (SO ₃ ) ₂ OH) was dissolved in 260 ml of distilled water. 1 g of carbon powder (Vulcan XC-72R) was added thereto and stirred, and the pH was adjusted to 3 with 2.5% sodium hydroxide solution. 13.2 ml of 28% H ₂ O ₂ solution was injected into the solution, followed by stirring for 1 hour. pH was adjusted back to 3. The mixture was stirred at 100 ° C. for 1 hour with continued stirring. After cooling the solution, the resulting powder was filtered and washed to dry at 105 ℃. Platinum / carbon powder was obtained after reduction for 1 hour with 50% H ₂ / N ₂ at 200 ° C. Elemental analysis showed that 37.9 wt% platinum was supported on carbon.

Comparative Example 4

A platinum / carbon powder was prepared according to the colloidal method shown in U.S. Patent No. 3,033,193, and the process is as follows.

10.0 g of platinum sulfite acid (H ₃ Pt (SO ₃ ) ₂ OH) was dissolved in 600 ml of distilled water. 1 g of carbon powder (Vulcan XC-72R) was added thereto and stirred, and then the pH was adjusted to 3 with 2.5% sodium hydroxide solution. 30.0 ml of 28% H ₂ O ₂ solution was injected into the solution, followed by stirring for 1 hour. pH was adjusted back to 3. The mixture was stirred at 100 ° C. for 1 hour with continued stirring. After cooling the solution, the resulting powder was filtered and washed to dry at 105 ℃. Platinum / carbon powder was obtained after reduction for 1 hour with 50% H ₂ / N ₂ at 200 ° C. Elemental analysis showed that 59.0 wt% of platinum was supported on carbon.

The platinum particle size in the platinum / carbon powders calculated using the platinum (111) peak widths of the XRD patterns of Examples 1 to 4 and Comparative Examples 1 to 4 are shown in Table 1 below. In addition, the platinum surface area was measured assuming the shape of the platinum particles as a sphere, the results are shown in Table 1 below.

Platinum loading (% by weight) Pt size (nm) Pt surface area (㎡ / g) Example 1 20 1.7 164 Example 2 40 2.6 107 Example 3 60 3.5 80 Example 4 40 2.7 103 Comparative Example 1 40 8.2 34 Comparative Example 2 40 3.6 77 Comparative Example 3 40 3.7 75 Comparative Example 4 60 8.5 33

In the results of Table 1, the platinum / carbon powder of the present invention had a small particle size of about 40-70% at the same platinum loading as compared to the catalysts of Comparative Examples 1 to 4, and the surface area was 1.3-3.0 times higher. It can be seen that the increase. In particular, the surface area of the 60% by weight platinum / carbon powder catalyst of Example 3 is greater than the 40% by weight platinum / carbon powder surface area of Comparative Examples 1 to 3, and the present invention provides platinum / with finely dispersed fine platinum particles in the high supported area. It can be confirmed that the support is provided.

Example 5

(Manufacture of Fuel Cell)

60 wt% platinum / carbon powder obtained in Example 3 was mixed with isopropyl alcohol and Nafion solution to prepare a catalyst slurry, and then it was introduced between carbon paper and Nafion membrane. The amount used was 0.5 mg of platinum per square cm. A polymer electrolyte fuel cell was assembled using this electrolyte membrane-electrode assembly, and the performance of the battery was evaluated by blowing hydrogen into the anode and oxygen into the cathode at a temperature of 70 ° C.

Comparative Example 5

A fuel cell was manufactured in the same manner as in Example 5, except that the catalyst of Comparative Example 4 was used instead of the platinum catalyst of Example 3.

The voltage and current curves of the fuel cell using the catalysts of Example 3 and Comparative Example 4 are shown in FIG. 2.

Referring to FIG. 2, the current density at 0.7 V is excellent when the catalyst of the present invention is 0.8 mA / cm 2, whereas the voltage current of the fuel cell obtained by preparing the 60 wt% platinum / carbon powder of Comparative Example 4 in the same manner The curve showed a lower current density of 0.6 mA / cm 2 at 0.7 V.

As described above, according to the present invention, a simple, economical, uniform, and small platinum particle-supported platinum / support catalyst is prepared without the addition and removal of additives (surfactants or carboxylic acids) and without additional hydrogen reduction. can do. Therefore, the present invention increases the dispersion degree of platinum in the platinum / support powder compared to the general precipitation method and the colloidal method, thereby increasing the reaction active area of platinum. In particular, according to the present invention, even when the supporting amount is high, platinum forms fine particles on the support to form a wide reaction region, and when the catalyst prepared by the above method is used as an electrode catalyst in the fuel cell, the thickness of the electrode in the fuel cell Reduction effect, excellent electric activity increase effect by increasing the reaction zone and platinum consumption compared to the same activity.

Claims (11)

10 to 80% by weight of platinum supported on the support, the platinum catalyst for the fuel cell having a size of the supported platinum particles up to 5 nm. The method of claim 1, A platinum catalyst for a fuel cell in which 20 to 70 wt% of platinum is supported on a support, and the size of the supported platinum particles is 1.5 to 4.0 nm. The method of claim 1, The support is a carbon support comprising a carbon nanotube or fiber, or a metal oxide platinum catalyst. In the manufacturing method of the platinum catalyst, a) preparing a slurry by dispersing the support in a colloidal state in a solvent and basifying with a pH adjuster to prepare a support slurry; b) a step of preparing a platinum / support on which platinum is supported by basifying the support slurry prepared in step a) by adding a platinum precursor solution and a pH adjusting material; And c) liquid phase reduction by adding a reducing agent to the platinum / support obtained in step b); Method for producing a platinum catalyst for a fuel cell comprising a. The method of claim 4, wherein In step b), the platinum precursor solution is added to the support slurry at 1 / N of the total platinum solution, followed by N steps of adjusting the pH value to the base range by adding a pH adjusting material. The value of is at least 2, a method for producing a platinum catalyst for fuel cells. The method of claim 4, wherein The step b) is a method of producing a platinum catalyst for a fuel cell is carried out at the same time the addition of the platinum precursor solution to the support slurry and the adjustment of the pH value. The method of claim 4, wherein The basicization of step b) is a method of producing a platinum catalyst is carried out in the range of pH 12 in excess of pH 7. The method of claim 4, wherein Platinum catalyst production method of the platinum loading of the platinum / support of step b) is 10 to 80% by weight. The method of claim 4, wherein Method for producing a platinum catalyst having a particle size of the platinum of the platinum / support of step b) up to 5 nm. The method of claim 4, wherein The method for producing a platinum catalyst wherein the pH adjusting material is an aqueous solution of sodium bicarbonate, sodium hydroxide, or ammonium hydroxide. A high power fuel cell comprising the platinum catalyst according to claim 1 as an electrode catalyst.