JP2003109610A - Method of manufacturing electrode for high molecular electrolyte fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode for a high molecular electrolyte fuel cell capable of stabilizing the water management of a catalyst layer for a long period by preparing the water repellent carbon powder by uniformly bonding carbon powder with a small amount of water repellent material without largely aggregating the water repellent material. SOLUTION: The water repellent carbon powder granulated to a constant particle size is prepared by spraying the dispersion liquid of the water repellent material to flowing carbon powder, and drying the same to attach the water repellent material to the carbon powder, and crushing and granulating the carbon powder with the water repellent material. By mixing the water repellent carbon powder with the catalyst layer, the water repellency of the catalyst layer can be stabilized for a long period, and the durability of the cell can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a water-repellent carbon powder used in a polymer electrolyte fuel cell electrode, particularly in a catalyst layer thereof.

[0002]

2. Description of the Related Art In a fuel cell using a polymer electrolyte, a fuel gas containing hydrogen and a fuel gas containing oxygen such as air are electrochemically reacted to simultaneously generate electric power and heat. It is what makes me. This fuel cell is basically a polymer electrolyte membrane that selectively transports hydrogen ions,
And a pair of electrodes arranged on both sides thereof. The electrode is a catalyst layer prepared by mixing a hydrogen ion conductive polymer electrolyte with a carbon powder carrying a platinum group metal catalyst, and is formed on the outer surface of this catalyst layer and has both air permeability and electron conductivity. It is composed of a gas diffusion layer made of carbon paper. In order to prevent the supplied fuel gas from leaking to the outside and the fuel gas and the oxidant gas from mixing with each other, a gas sealing material or a gasket is arranged around the electrode with a polymer electrolyte membrane sandwiched therebetween. The sealing material and the gasket are integrated with the electrode and the polymer electrolyte membrane, and this is called MEA (electrolyte membrane electrode assembly). The MEA is mechanically fixed to the outside of the MEA and
A conductive separator plate for electrically connecting the two to each other in series is disposed. A gas flow path for supplying the reaction gas to the electrode surface and carrying away the generated gas and the surplus gas is formed in a portion of the separator plate that is in contact with the MEA. The gas channel may be provided separately from the separator plate, but a method of forming a groove on the surface of the separator plate to form the gas channel is common.

The gas diffusion layer of the electrode of the polymer electrolyte fuel cell is generally composed of a porous carbon layer such as a carbon non-woven fabric which has been subjected to a water repellent treatment. In addition, a water repellent carbon layer may be provided at the interface between the catalyst layer and the gas diffusion layer for the purpose of retaining the moisture of the catalyst layer or the polymer electrolyte membrane. The water repellent carbon layer is formed as follows. First, carbon particles are mixed with a dispersion of a water repellent material represented by particles of polytetrafluoroethylene containing a surfactant, and the mixture is dried or filtered to mix the carbon particles and the water repellent material. A body water repellent carbon powder is obtained. Next, water or an organic solvent is added to the water repellent carbon powder to form an ink. This ink is applied to one surface of carbon paper, which is a gas diffusion layer, by a screen printing method, a spray coating method, a doctor blade method, a roll coater method, etc., and is baked at a temperature of about 275 ° C to 380 ° C to form an interface. Burn off the activator. In this way, the water repellent carbon layer is generally formed. At this time, the water-repellent carbon layer is arranged so as to be adjacent to the electrode catalyst layer.

On the other hand, the catalyst layer is generally formed from a mixture of carbon powder carrying a platinum group metal catalyst, a hydrogen ion conductive polymer electrolyte, and the water repellent carbon powder used in the water repellent carbon layer. At present, perfluorocarbon sulfonic acid is generally used as the hydrogen ion conductive polymer electrolyte. To form the catalyst layer, first, the catalyst powder and the water repellent carbon powder are dry-mixed, and the hydrogen ion conductive polymer electrolyte solution is prepared by dissolving the hydrogen ion conductive polymer electrolyte in an alcohol solvent such as ethanol. And are mixed, and an organic solvent having a relatively high boiling point such as isopropyl alcohol or butyl alcohol is added to form an ink, and this ink is used by a screen printing method, a spray coating method, a doctor blade method, a roll coater method, or the like. It is carried out by a method of coating and drying.

[0005]

In order to put the fuel cell into practical use, it is necessary to further improve the efficiency. For that purpose, it is important to optimize water management in the catalyst layer. The optimization of water management means that the water necessary to maintain the hydrogen ion conductivity of the polymer electrolyte in the electrode can be retained, and excessive water impedes the diffusion supply of the fuel gas that is the active material. In order not to do so, it is necessary to have a structure in which it is quickly discharged to the outside of the electrode. In the conventional method, carbon powder and a dispersion of a water repellent material are wet mixed,
A water-repellent carbon powder was prepared from this by a technique such as drying or filtration, and this was introduced into the catalyst layer. As a result, the water-repellent carbon powder provided a diffusion supply path for the fuel gas, and it was possible to suppress excessive evaporation of water from the catalyst layer.

However, in the filtration / drying process when preparing the water repellent carbon powder, the water repellent material agglomerates and adheres to the carbon powder, which causes microscopic water repellency distribution. There has been a problem that the water repellency of the catalyst layer is lowered, the gas diffusion supply path is gradually closed, and the output voltage of the battery is lowered. In addition, when the amount of the water repellent material added is increased to make the entire carbon powder uniformly water repellent, the water repellency increases, but the gas diffusion supply path is hindered, and the initial voltage also decreases. The present invention solves the above-mentioned problems, and when coating the water repellent material on the carbon powder, the water repellent material does not form a large aggregate, and the carbon powder is evenly bonded with a small amount of the water repellent material. Thus, it is an object of the present invention to provide an electrode in which the water management of the catalyst layer is stabilized in the long term and a stable battery voltage is provided in the long term.

[0007]

The present invention provides a polymer having a catalyst layer composed of a carbon powder carrying a noble metal catalyst, a hydrogen ion conductive polymer electrolyte and a water repellent carbon powder coated with a water repellent material. In the method for manufacturing an electrode for an electrolyte fuel cell, the step of manufacturing the water repellent carbon powder includes spraying a dispersion of a water repellent material on flowing carbon powder and drying the carbon powder to attach the water repellent material to the carbon powder. And a step of pulverizing the carbon powder to which the water repellent material is attached, and a step of granulating the carbon powder to which the water repellent material is attached. In the step of manufacturing the water repellent carbon powder, the water repellent carbon powder is heated to 275 ° C.
It is preferable to include a step of firing at 380 ° C. or lower.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a water-repellent carbon powder uniformly coated with a small amount of a water-repellent material. The water-repellent material powder is sprayed with a dispersion of the water-repellent material and dried. Then, a water repellent material is attached to the carbon powder, and the carbon powder to which the water repellent material is attached is crushed and granulated to obtain a water repellent carbon powder granulated to preferably about 0.3 to 40 μm. In the step of attaching the water repellent material, it is preferable to spray the dispersion liquid of the water repellent material in a dry atmosphere in which carbon powder flows. In addition, the steps of crushing and granulating the carbon powder to which the water repellent material adheres should be repeated. By burning the water-repellent carbon powder at 275 ° C. to 380 ° C., impurities such as a surfactant are removed. Therefore, a battery that gives high output from the beginning is provided.

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a conceptual diagram of a spray dry type apparatus used for producing the water repellent carbon powder of the present invention. Above the lower cylindrical container 1, a cylindrical portion 2 and an upper cylindrical container 3 which are tapered so that the diameter of the upper part is increased are connected to form an outer container. A gas introduction port 5 with a heater is provided in the lower part of the container 1, and an inert gas, for example, nitrogen gas, which is controlled at a constant temperature, is introduced from here to make the inside of the container a dry atmosphere. The lower container 1 is provided with a granulation plate 6, a stirring blade 7 having a collision target 10 in the center, a compressed gas injection nozzle 9 for injecting compressed gas toward the collision target 10, and a high-pressure spray 11. The upper container 3 has a bag filter 4 and a gas outlet 12.

In order to manufacture the water repellent carbon powder with this apparatus, first, the carbon powder is put in the lower cylindrical container 1 and the dispersion liquid of the water repellent material is sprayed from the high pressure spray 11.
The speed of the water repellent material dispersion liquid supplied from the high pressure spray 11 into the container can be appropriately adjusted. The carbon powder in the container 1 is blown up above the container by the inert gas at a constant temperature supplied from the gas inlet 5. The gas introduced from the gas inlet 5 is indicated by the arrow 5 indicating the gas flow direction.
According to a and 5b, it blows upward from the granulation plate 6 in the container. The granulating plate 6 has ventilation slits that are opened so that the amount of flowing air increases toward the outer periphery in order to uniformly flow the powder inside the container. Due to the flowing air of the gas that has passed through the granulation plate 6, the carbon powder introduced into the lower cylindrical container 1 flows from the cylindrical portion 2 spread in the shape of an inverted cone into the upper cylindrical container 3, where the water repellent material is placed. The dispersion of is attached and dried.

The carbon powder having the water-repellent material attached thereto and settled on the upper part of the granulating plate 6 is granulated into a particle size corresponding to the gap 8 between the granulating plate 6 and the stirring blade 7. The stirring blade 7 has a function of stirring and flowing the carbon powder to which the water repellent material is attached, and a function of crushing it. The pulse jet intermittently jetted from the compressed gas jet nozzle 9 toward the collision target 10 pulverizes the fluidized carbon powder into primary particles by jet pulverization. The gas introduced into the system is subjected to filtration of carbon powder by the bag filter 4 arranged in the upper cylindrical container portion 3, and only the inert gas is discharged from the gas outlet 12 to the outside of the system. The inert gas discharged to the outside of the system should be cooled by a heat exchanger separately provided outside to recover only the evaporated solvent in the water repellent material dispersion liquid, and be introduced again from the inert gas introduction port 5. Thus, the inert gas can be recycled.

With this apparatus, while the carbon powder is being flown, stirred, and crushed, the dispersion liquid of the water repellent material is sprayed to adhere to the carbon powder and dried, and at the same time, the particle size can be granulated to an appropriate particle size. That is, the sprayed dispersion liquid of the water-repellent material adheres to the surface of the carbon powder, and the dispersion medium is dried and the dispersion medium volatilizes. Therefore, the water-repellent material can be uniformly adhered to the surface of the carbon powder. Further, by adding the crushing step, it becomes possible to finely crush and uniformly attach the water repellent material.

The water-repellent carbon powder obtained by repeating the pulverizing step and the granulating step by the above-mentioned apparatus is a carbon powder having a water-repellent material 22 thinly adhered to its surface as shown in the model of FIG. 2 (a). It is a secondary particle consisting of 21. Figure 2
(B) is obtained by wet mixing, and the water-repellent material 22 is unevenly distributed. Thus, by mixing the water repellent carbon powder prepared according to the present invention with the catalyst layer, the water repellency of the catalyst layer is stabilized for a long period of time, and the durability of the battery can be improved.

[0014]

EXAMPLES Next, specific examples of the present invention will be described. Example 1 In this example, first, the gap between the granulation plate and the stirring blade was adjusted using the apparatus shown in FIG. 1, and then a water repellent material was sprayed on the carbon powder in an inert gas, The carbon powder was coated with a water-repellent material by drying and bonding, and simultaneously performing a granulation step and a pulverization step.
Then, thereafter, this water repellent carbon powder was used to prepare an electrolyte membrane electrode assembly.

First, a water repellent carbon powder was prepared as follows. As the carbon powder, acetylene black (Denka Black manufactured by Denki Kagaku Kogyo Co., Ltd.) was used.
Aqueous dispersion of fluororesin as dispersion of water repellent material (Polyflon PTFE D- from Daikin Industries, Ltd.)
The product obtained by diluting 1) 10 times with water was used. Using the apparatus shown in FIG. 1, while flowing 40 g of acetylene black in a container, spraying 450 g of an aqueous dispersion of diluted fluororesin, drying, pulverizing, and granulating,
Water-repellent carbon powder of acetylene black having a fluororesin attached to its surface was obtained. The surface of the water-repellent carbon thus obtained is uniformly coated with a water-repellent material, the thickness thereof is 0.1 to 0.3 μm, and the average particle diameter of the granulated water-repellent carbon is Was about 10 μm. The operating conditions of the device are as follows. The high-pressure spray 11 sprayed the water-repellent material dispersion liquid at a rate of 2 g / min. Nitrogen was used as the dry gas, the nitrogen gas inlet temperature was 100 ° C., and the nitrogen gas air flow rate was 0.06 m ³ / min. The rotation speed of the stirring blade 7 is 3
The on / off interval of the pulse jet ejected from the nozzle 9 was 12 seconds.

Next, 50:50 weight ratio of platinum particles having an average particle size of about 30Å to Ketjen Black EC (made by AKZO Chemie, Netherlands) which is a conductive carbon particle having an average primary particle size of 30 nm. The powder supported by was used as the noble metal-supported catalyst powder on the air electrode side. Further, a catalyst powder on the fuel electrode side was prepared by supporting platinum particles and ruthenium particles having an average particle diameter of about 30Å on Ketjen Black EC in a weight ratio of 50:25:25. These catalyst powders and the above water-repellent carbon powder were dry-mixed in a weight ratio of 97: 3, and this was mixed with ethylene glycol in a nitrogen atmosphere to prepare a paste-like ink for an electrode catalyst layer. . A hydrogen ion conductive polymer electrolyte membrane (Nafion 112 manufactured by DuPont) having an outer size of 20 cm × 32 cm has an electrode catalyst layer paste containing catalyst powder on the air electrode side on one surface, and a fuel electrode side paste on the other surface. Each of the electrode catalyst layer pastes containing the catalyst powder was applied by a screen printing method to form a catalyst layer. The amount of the catalyst metal contained in the catalyst layer is 0.5 mg /
cm ² and so as to prepare, the average thickness of the catalyst layer is 20μm
I adjusted it to be.

On the other hand, the carbon paper, which serves as the gas diffusion layer of the electrode, was treated for water repellency. Carbon paper with external dimensions of 16 cm x 20 cm and a thickness of 360 μm (TGP, ToGP)
-H-120) was immersed in an aqueous dispersion of a fluororesin (Neotron ND1 manufactured by Daikin Industries, Ltd.), dried, and heated at 400 ° C for 30 minutes to impart water repellency. An ink obtained by mixing conductive carbon powder and an aqueous dispersion of fine polytetrafluoroethylene (PTFE) powder on one surface of this carbon paper,
A water-repellent layer was formed by applying using a screen printing method. At this time, a part of the water repellent layer was embedded in the carbon paper.

This carbon paper is joined by hot pressing to the polymer electrolyte membrane having the above catalyst layer so that the surface of the water repellent layer is in contact with the side of the catalyst layer to form an electrolyte membrane electrode assembly (MEA). It was made. Further, a rubber gasket plate was joined to the outer peripheral portion of the hydrogen ion conductive polymer electrolyte membrane of the MEA to form a manifold hole for circulating cooling water, fuel gas and oxidant gas. On the other hand, the outer size is 20 cm
A separator plate composed of a resin-impregnated graphite plate having a size of 32 cm, a thickness of 1.3 mm, and a gas flow passage and a cooling water flow passage having a depth of 0.5 mm was prepared. A separator plate having an oxidant gas flow channel on one surface of the MEA and a separator plate having a fuel gas flow channel on the other surface were overlaid to form a single cell. A cell stack was assembled by stacking 100 cells of this unit cell. A separator plate having a cooling water channel groove formed on the back surface was inserted every two cells. At both ends of the battery stack, end plates were stacked via a stainless steel collector plate and an insulating plate and fixed with fastening rods. The fastening pressure at this time was 15 kgf / cm ² per area of the separator plate.
This battery is designated as A.

Example 2 Batteries B to G were assembled in the same manner as in Example 1 except that the water-repellent carbon powder and the catalyst powder were dry-mixed at the ratio shown in Table 1.

Example 3 Water repellent carbon powder 380
A battery D ′ was assembled in the same manner as the battery D of Example 2 except that the baking was performed at 30 ° C. for 30 minutes.

Comparative Example 1 First, a water repellent carbon powder was prepared as follows. As the carbon powder, acetylene black (Denka Black manufactured by Denki Kagaku Kogyo Co., Ltd.) was used. An aqueous dispersion of fluororesin (Polyflon PTFE D-1 manufactured by Daikin Industries, Ltd.) was used as a dispersion of the water-repellent resin. Using a colloid mill, ion-exchanged water 1200g and surfactant Triton
8 g of X-100 was mixed at 10000 rpm for 1 minute, and 40 g of acetylene black was gradually added thereto, 1
The mixture was mixed and dispersed at 0000 rpm for 5 minutes. Next, 45 g of fluororesin dispersion was added to this dispersion, and 10
The mixture was mixed and dispersed at 000 rpm for 10 minutes. Then, this dispersion is frozen for 8 hours or more and then thawed and filtered to obtain 380
Baking was performed at 30 ° C. for 30 minutes. Catalyst powder was dry-mixed with the water-repellent carbon powder thus prepared in a ratio shown in Table 1.
Using this mixture, a catalyst layer was formed in the same manner as in Example 1, and batteries H to O were assembled.

[0022]

[Table 1]

Each of the above fuel cells was maintained at 80 ° C., and the hydrogen gas that had been humidified and heated to a dew point of 75 ° C. on the fuel electrode side was humidified and heated to have a dew point of 60 ° C. on the air electrode side. Each warm air was supplied. As a result, a battery open circuit voltage of 98 V was obtained when no load was applied and the current was not output to the outside.
In addition, the fuel utilization rate of this battery is 85%, the oxygen utilization rate is 60%.
%, The continuous power generation test under conditions of a current density of 0.3 A / cm ^2, to measure the time variation of the output characteristics.

FIG. 3 shows the voltages of the batteries A to O after a continuous discharge test for 50 hours at a current density of 0.3 A / cm ² plotted against the ratio of the water repellent carbon powder.
Even after 50 hours from the start of power generation, which is a relatively early stage, the batteries I to O of Comparative Examples using the water-repellent carbon powder prepared by the conventional wet method and the battery H to which the water-repellent carbon powder was not added were used. In comparison, the batteries A to G of the examples using the water repellent carbon powder according to the present invention showed a high voltage in all regions. This is because the water-repellent carbon powder according to this example is thinly and uniformly coated with the water-repellent material, so that the water-repellent carbon powder has a water management effect even in a battery with a small amount of addition. This is because even a large amount of batteries does not hinder the gas diffusion and supply.

FIG. 4 shows the voltages of batteries A to O after a continuous discharge test for 8000 hours at a current density of 0.3 A / cm ² plotted against the ratio of the water repellent carbon powder. The voltage of the battery H to battery O of the comparative example after 8000 hours from the start of power generation was 3 to 12 V lower than the voltage after 50 hours. The degree of decrease in voltage was greater in batteries having a smaller proportion of water-repellent carbon. On the other hand, in the batteries A to G of the example, the voltage of the battery A was reduced by 3 V, and no voltage reduction was observed in the other batteries B to G.
From this, it is considered that the water-repellent carbon powder of the comparative example had a large distribution of the coating of the water-repellent material, so that there were many uncoated carbon surfaces, and in the battery with a small addition amount, the catalyst layer flooded over time. To be Since the water-repellent carbon powder of the batteries of Examples was uniformly coated with the water-repellent material without agglomeration, it is considered that the high voltage was maintained without decreasing the water repellency even with a small addition amount. From these results, the ratio of water repellent carbon powder / catalyst powder was 3/97.
To 50/50 are effective, and 5/95 to 40/60 are more effective.

FIG. 5 shows the current densities of the batteries D and L of 0.3 A.
The voltage change in the continuous discharge test at / cm ² was plotted.
Both the example and the comparative example have the highest characteristics and the water-repellent carbon powder ratio is 20%, but the voltage of the battery L of the comparative example decreases with time, and the rate of voltage decrease increases with time. . This is because when flooding starts, flooding will start in a chain from there and accelerate. On the other hand, since the battery D of the example has no voltage drop at all, it is considered that a catalyst layer which is extremely hard to flood is realized. FIG. 6 is a plot showing changes over time in voltage when a continuous discharge test was performed at a current density of 0.3 A / cm ² of the batteries D and D ′. Immediately after the start of the continuous discharge test, the voltage of the battery D is about 2V compared with the battery D ′.
Although it was low, the same voltage was obtained after about 50 hours, and thereafter the voltage was constant until 8000 hours. This is because the water-repellent carbon powder of the battery D'was baked at 380 ° C to remove impurities such as surfactants before the battery was manufactured, whereas the battery D had impurities remaining and the test was started. This is because the water repellency immediately after is insufficient. However, since these impurities are discharged to the outside of the battery system by the generated water and the like as the battery operates, the voltage becomes the same after about 50 hours.

Although platinum is used as the cathode catalyst and platinum and ruthenium are used as the anode catalyst in the examples, the present invention is based on the structure of the catalyst layer, and similar effects can be obtained even when the catalyst species are different. Further, although polytetrafluoroethylene is adopted as the water repellent material, the same effect can be obtained if the resin has water repellency and is acid resistant, and tetrafluoroethylene / hexafluoropropylene copolymer or tetrafluoroethylene / A perfluoroalkyl vinyl ether copolymer, a tetrafluoroethylene / ethylene copolymer, etc. can be used. In the examples, the water repellent / carbon powder ratio was 4/6, but similar effects can be obtained within the range of 3/7 to 6/4.
In the examples, the method of directly coating the catalyst layer on the polymer electrolyte membrane was adopted, but the catalyst layer was formed on carbon paper, or once the catalyst layer was formed on the polymer base material, and the polymer electrolyte was used. Similar effects can be obtained by transferring to a film.

[0028]

As described above, according to the present invention, it is possible to obtain a water-repellent carbon powder in which carbon powder is thinly and uniformly bonded to a water-repellent material within a certain particle diameter range. By mixing the water repellent carbon powder with the catalyst layer, the water repellency of the catalyst layer is stabilized for a long period of time, and the durability of the battery can be improved. Further, by firing this water-repellent carbon powder at 275 ° C. to 380 ° C., impurities such as a surfactant are removed, and a battery that can obtain a high output immediately after the continuous discharge test can be provided.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a schematic configuration of an apparatus for producing a water-repellent carbon powder used in an example of the present invention.

FIG. 2 is a diagram showing a model of water-repellent carbon powder,
(A) shows a water repellent carbon powder according to the present invention, and (b) shows a conventional water repellent carbon powder.

FIG. 3 is a diagram showing a relationship between a battery voltage after 50 hours of a continuous discharge test and a ratio of water-repellent carbon powder in a catalyst layer.

FIG. 4 is a diagram showing a relationship between a battery voltage after a continuous discharge test for 8000 hours and a ratio of water-repellent carbon powder in a catalyst layer.

FIG. 5 is a diagram showing changes over time in voltage in a continuous discharge test of batteries D and L.

FIG. 6 is a diagram showing changes over time in voltage in a continuous discharge test of batteries D and D ′.

[Explanation of symbols]

1 Lower cylindrical container 2 tube 3 Upper cylindrical container 4 Bug filter 5 gas inlet 6 granulation plate 7 stirring blades 8 Gap between granulation plate and stirring blade 9 Compressed gas injection nozzle 10 collision target 11 high pressure spray 12 gas outlet 21 carbon powder 22 Water repellent

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihiro Hori             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Akihiko Yoshida             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Osamu Sakai             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Takeshi Yonamine             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 5H018 AA06 AS01 BB01 BB06 BB11                       DD06 EE03 EE05 EE08 EE17                       EE18 EE19 HH08                 5H026 AA06 CX05 EE02 EE05 EE18                       EE19 HH08

Claims (2)

[Claims] 1. A method for producing an electrode having a catalyst layer comprising a carbon powder carrying a noble metal catalyst, a hydrogen ion conductive polymer electrolyte and a water repellent carbon powder coated with a water repellent material. The step of producing hydrated carbon powder includes spraying a dispersion of a water repellent material on flowing carbon powder and drying it to attach the water repellent material to the carbon powder, and crushing the carbon powder to which the water repellent material is attached. And a step of granulating a carbon powder having a water repellent material attached thereto, the method for producing an electrode for a polymer electrolyte fuel cell. 2. The electrode for a polymer electrolyte fuel cell according to claim 1, wherein the step of producing the water repellent carbon powder includes the step of firing the water repellent carbon powder at 275 ° C. or higher and 380 ° C. or lower. Production method.