JP2008016338A - Fuel cell, porous platinum sheet, and manufacturing method of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique of suppressing power generation performance degradation of a fuel cell caused by degradation of a catalytic action of a catalyst metal, in a catalyst electrode layer of a fuel cell. <P>SOLUTION: This fuel cell is provided with an electrolyte membrane, and a catalyst electrode layer formed on the electrolyte membrane. The catalyst electrode layer is provided with at least a plate-like porous platinum sheet, and an electrolyte formed on surfaces of inner holes of the porous platinum sheet. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a catalyst electrode layer that forms a membrane-electrode assembly (MEA) of a fuel cell.

  Conventionally, in a fuel cell, an anode and a cathode, which are catalyst electrode layers, are supplied with a fuel gas containing hydrogen and an oxidizing gas containing oxygen, respectively, to generate an electrochemical reaction and generate power. . This catalyst electrode layer is composed of, for example, carbon particles as a carrier on which particles of a catalyst metal (platinum, palladium, etc.) are supported, a proton conductive electrolyte (fluorine resin, etc.), etc. (patent) Reference 1).

JP 2004-247316 A

  However, in the fuel cell described above, heat is generated as the electrochemical reaction proceeds, but if this exhaust heat is not successful, the catalyst electrode layer becomes high temperature and the catalyst metal particles supported on the carbon particles are solidified. There is a risk that so-called sintering may occur. Further, in the above-described fuel cell, the carbon particles as the carrier are oxidized (corroded) and lost due to the influence of the electric potential, and there is a possibility that sintering may occur. Thus, when sintering occurs, the surface area of the catalytic metal particles is reduced, so that the catalytic action of the catalytic metal is reduced. As a result, the progress of the electrochemical reaction is slowed down, and the power generation performance of the fuel cell is reduced. There was a fear.

  Such a problem is not limited to the case where carbon particles are used as a carrier, but is a common problem when predetermined metal particles (for example, nickel) are used as a carrier.

  The present invention has been made to solve the above-described conventional problems, and provides a technique for suppressing a decrease in power generation performance of a fuel cell due to a decrease in catalytic action of a catalyst metal in a catalyst electrode layer of the fuel cell. With the goal.

In order to achieve at least a part of the above object, in the fuel cell of the present invention,
A fuel cell,
An electrolyte membrane;
A catalyst electrode layer formed on the electrolyte membrane;
With
The catalyst electrode layer is at least
A plate-like porous platinum sheet;
An electrolyte formed on the surface of the inner hole of the porous platinum sheet;
It is a summary to provide.

  According to the fuel cell having the above configuration, the catalyst electrode layer is provided with a porous platinum sheet that has a catalytic action and is not in the form of particles, so that the catalyst electrode layer becomes hot or is affected by potential or the like. Even if it comes under a situation, it can suppress that the surface area of a porous platinum sheet reduces, ie, can suppress that a catalytic action falls. As a result, with the above configuration, it is possible to suppress a decrease in power generation performance of the fuel cell due to a decrease in catalytic action.

In the fuel cell,
It is preferable that the porous platinum sheet is in contact with the electrolyte membrane.

  In this way, it is possible to suppress a decrease in catalytic action, particularly at the interface with the electrolyte membrane, and therefore a decrease in power generation performance is further suppressed.

In the fuel cell,
The electrolyte is preferably formed on the surface of the porous platinum sheet in addition to the inner holes of the porous platinum sheet.

  If it does in this way, power generation efficiency can be raised.

In the fuel cell,
The inner hole of the porous platinum sheet may be a through hole penetrating in the thickness direction.

  If it does in this way, it will become easy to apply electrolyte to the inside (inner hole) of a porous platinum sheet. Moreover, the production | generation of a porous platinum sheet becomes easy.

In the fuel cell,
The through hole is preferably opened using a femtosecond laser.

  If it does in this way, a porous platinum sheet can be easily created from a platinum sheet.

In the fuel cell,
The porous platinum sheet is preferably generated by sintering platinum particles.

  In this way, it is possible to generate a porous platinum sheet having a three-dimensionally expanding fine path.

In the fuel cell,
In the porous platinum sheet, it is preferable that at least the surface opposite to the electrolyte membrane side is formed in an uneven shape.

  In this way, the surface area of the surface opposite to the electrolyte membrane side can be increased in the porous platinum sheet, that is, the reaction supplied from the side opposite to the electrolyte membrane side in the porous platinum sheet. The reaction area with the gas can be increased. As a result, power generation efficiency can be improved.

In the fuel cell,
In the porous platinum sheet, at least the surface opposite to the electrolyte membrane may be etched to form the irregularities.

  In this way, by performing the etching treatment, the surface area of the surface opposite to the electrolyte membrane side can be increased in the porous platinum sheet, that is, in the porous platinum sheet, the surface area of the electrolyte membrane side can be increased. The reaction area with the reaction gas supplied from the opposite side can be increased. As a result, power generation efficiency can be improved.

In order to achieve at least a part of the above object, in the membrane-electrode assembly for a fuel cell of the present invention,
A fuel cell membrane-electrode assembly comprising:
An electrolyte membrane;
A catalyst electrode layer formed on the electrolyte membrane;
With
The catalyst electrode layer is at least
A plate-like porous platinum sheet;
An electrolyte formed on the surface of the inner hole of the porous platinum sheet;
It is a summary to provide.

  According to the membrane-electrode assembly for a fuel cell having the above-described structure, the catalyst electrode layer has a high temperature or is affected by potential or the like because it includes a porous platinum sheet that has a catalytic action and is not particulate. Even if it comes under a situation, it can suppress that the surface area of a porous platinum sheet reduces, ie, can suppress that a catalytic action falls. As a result, when the fuel cell membrane-electrode assembly is used in a fuel cell, the fuel cell can suppress a decrease in power generation performance due to a decrease in catalytic action.

In order to achieve at least a part of the above object, in the method for producing a fuel cell of the present invention,
A fuel cell manufacturing method comprising:
(A) preparing a plate-like porous platinum sheet;
(B) preparing a dispersion containing an electrolyte;
(C) applying the dispersion to the porous platinum sheet;
(D) drying the dispersion applied to the porous platinum sheet;
(E) preparing an electrolyte membrane;
(F) disposing the porous platinum sheet on the electrolyte membrane so that the surface opposite to the surface on which the dispersion is applied and the electrolyte membrane face each other;
(G) joining the electrolyte membrane and the porous platinum sheet;
It is a summary to provide.

  According to the method for manufacturing a fuel cell having the above-described configuration, it becomes possible to manufacture a fuel cell including a porous platinum sheet that has a catalytic action and is not particulate in the catalyst electrode layer. This fuel cell can suppress the reduction of the surface area of the porous platinum sheet even when the catalyst electrode layer is at a high temperature or under the influence of an electric potential or the like. It can suppress that it falls. As a result, in this fuel cell, it is possible to suppress a decrease in power generation performance due to a decrease in catalytic action.

In the fuel cell manufacturing method,
In the step (A),
Preparing a plate-like platinum sheet;
Opening a plurality of through holes in the platinum sheet, and producing the porous platinum sheet;
You may make it provide.

  In this way, it is possible to prepare a porous platinum sheet having a plurality of through holes.

  The present invention is not limited to the above-described aspects such as a fuel cell and a fuel-cell membrane-electrode assembly, and can also be realized, for example, as an aspect such as a fuel-cell catalyst electrode layer or a porous platinum sheet. It is. Further, the present invention is not limited to a method such as a fuel cell manufacturing method, and may be realized as a method such as a method for manufacturing a fuel cell catalyst electrode layer or a fuel cell membrane electrode assembly (MEA). It is.

Next, embodiments of the present invention will be described in the following order based on examples.
A. Fuel cell configuration:
B. Configuration of catalyst electrode layer:
C. Method for producing MEA having catalyst electrode layer:
D. Experimental results of examples and comparative examples:
E. Variation:

A. Fuel cell configuration:
FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a fuel cell according to an embodiment of the present invention. The fuel cell of the present embodiment can be a solid polymer electrolyte fuel cell, for example, and has a stack structure in which a plurality of single cells 10 are stacked. The single cell 10 includes an MEA 24 including an electrolyte membrane 21 and catalyst electrode layers (cathode 22 and anode 23) formed on both surfaces of the electrolyte membrane 21. Further, the single cell 10 includes first gas diffusion layers 31 and 32 outside the MEA 24, and further includes second gas diffusion layers 33 and 34 outside the MEA 24.

  The electrolyte membrane 21 is a proton conductive ion exchange membrane formed of a solid polymer material, for example, a fluororesin, and exhibits good proton conductivity in a wet state. Details of the cathode 22 and the anode 23 which are the catalyst electrode layers will be described later.

  The first gas diffusion layers 31 and 32 are conductive carbon porous members, and are formed of, for example, carbon cloth or carbon paper. In addition, the second gas diffusion layers 33 and 34 are conductive porous members having relatively larger pores than the first gas diffusion layers 31 and 32. For example, a carbon porous material such as carbon paper is used. Or a porous metal body such as a metal mesh or foam metal.

  The gas separators 35 and 36 can be formed of a gas-impermeable conductive member, for example, dense carbon that is compressed by gas and made impermeable to gas, or a press-molded metal plate. On the surfaces of the gas separators 35 and 36, an uneven shape for forming a flow path for the fuel gas or the oxidizing gas supplied to the single cell 10 is formed. That is, between the second gas diffusion layer 33 on the cathode 22 side and the gas separator 35, there is formed an in-single cell oxidizing gas flow path 37 through which oxidizing gas used for an electrochemical reaction at the cathode passes. . Further, between the second gas diffusion layer 34 on the anode 23 side and the gas separator 36, a fuel gas flow path 38 in the single cell is formed through which the fuel gas used for the electrochemical reaction at the anode passes. . The gas separators 35 and 36 in FIG. 1 have an uneven shape including a plurality of parallel grooves. However, the gas separators 35 and 36 may have different shapes, and a gas flow path is provided between the gas separators 35 and 36 and the MEA 24. It suffices if a space for forming can be formed.

  A sealing member (not shown) is provided on the outer peripheral portion of the single cell 10 to ensure gas sealing performance in the single-cell oxidizing gas flow channel 37 and the single-cell fuel gas flow channel 38. In addition, the fuel cell of this embodiment has a stack structure in which a plurality of single cells 10 are stacked. The outer periphery of the stack structure is parallel to the stacking direction of the single cells 10 and is fuel gas or oxidation. A plurality of gas manifolds through which gas flows are provided (not shown). The oxidizing gas flowing through the oxidizing gas supply manifold among the plurality of gas manifolds is distributed to each single cell 10, diffuses through the second gas diffusion layer 33 and the first gas diffusion layer 31, and is subjected to an electrochemical reaction by the MEA. While passing, each single cell passes through the oxidizing gas flow path 37 and then collects in the oxidizing gas discharge manifold. Similarly, the fuel gas flowing through the fuel gas supply manifold is distributed to each single cell 10, diffuses through the second gas diffusion layer 34 and the first gas diffusion layer 32, and is subjected to an electrochemical reaction in the MEA. It passes through the in-cell fuel gas flow path 38 and then gathers in the fuel gas discharge manifold.

  For example, air can be used as the oxidizing gas supplied to the fuel cell. Further, as the fuel gas supplied to the fuel cell, a hydrogen rich gas obtained by reforming a hydrocarbon-based fuel may be used, or a high purity hydrogen gas may be used.

  Although illustration is omitted, in order to adjust the internal temperature of the stack structure, a refrigerant flow path through which the refrigerant passes may be provided between the single cells or every time a predetermined number of single cells are stacked. good. The refrigerant flow path may be provided between the adjacent single cells and between the gas separator 35 provided in one single cell and the gas separator 36 of the other single cell provided adjacent thereto.

B. Configuration of catalyst electrode layer:
FIG. 2 is an enlarged view of the dotted line region X of FIG. 1, and is an explanatory view schematically showing a cross section of the catalyst electrode layer (cathode 22). FIG. 3 is an explanatory diagram showing the AA cross section of FIG. 1. That is, FIG. 3 shows the state of the interface between the cathode 22 and the first gas diffusion layer 31. The cathode 22 that is a catalyst electrode layer includes a platinum sheet 40 and an electrolyte 45.

  The platinum sheet 40 is a rectangular plate material made of platinum. For example, a platinum sheet having a thickness of 5 μm to 50 μm can be used. Further, the surface of the platinum sheet 40 functions as a catalyst metal. 2 and 3, the platinum sheet 40 is a porous body having a plurality of holes 42 penetrating in the thickness direction, and the surface on the first gas diffusion layer 31 side. However, it is etched to be uneven (or jagged).

  Further, the electrolyte 45 is formed on the surface of the hole 42 of the platinum sheet 40 (see FIG. 2) and the surface of the platinum sheet 40 on the first gas diffusion layer 31 side (uneven shape) (see FIGS. 2 and 3). Yes. In particular, on the surface (uneven shape) of the platinum sheet 40 on the first gas diffusion layer 31 side, the electrolyte 45 is formed in a mottle shape as shown in FIG. As a result, the oxidizing gas, the catalyst metal (platinum sheet 40), and the electrolyte 45 can form a three-layer interface. The electrolyte 45 can be made of a material having proton conductivity, such as a fluorine resin.

  As described above, the cathode 22 of the fuel cell of the present embodiment has a catalytic action on the surface, and is composed of a plate-like platinum sheet 40 instead of particles. In this case, the heat generated with the progress of the electrochemical reaction cannot be exhausted well, and even if the cathode 22 is at a high temperature, the platinum sheet 40 is not in the form of particles. It can suppress that it reduces, ie, it can suppress that a catalytic action falls by high temperature. Further, the cathode 22 does not contain a carrier, and platinum is difficult to oxidize, so that it is less likely to be oxidized (corroded) due to the influence of potential or the like. Therefore, it is possible to suppress a decrease in the surface area of the platinum sheet 40 due to the influence of the potential or the like at the cathode 22, that is, it is possible to suppress a decrease in the catalytic action due to the influence of the potential or the like at the cathode 22. As a result, with the above configuration, it is possible to suppress a decrease in power generation performance of the fuel cell due to a decrease in catalytic action at the cathode 22. Although the electrochemical reaction is most active in the vicinity of the interface between the electrolyte membrane 21 and the catalyst electrode layer, the platinum sheet 40 is formed so as to be in contact with the electrolyte membrane 21, and in particular, the interface with the electrolyte membrane 21. In this case, it is possible to suppress the decrease in the catalytic action as described above, and therefore, the decrease in the power generation performance is further suppressed.

  Further, as described above, the surface of the platinum sheet 40 on the first gas diffusion layer 31 side in the cathode 22 is etched so as to be uneven. In this way, the surface area of the platinum sheet 40 on the first gas diffusion layer 31 side can be increased, that is, the reaction area of the platinum sheet 40 with the oxidizing gas supplied from the first gas diffusion layer 31 side. Can be increased. As a result, power generation efficiency can be improved.

  The anode 23 is also composed of a platinum sheet 40 and an electrolyte 45 as with the cathode 22, and can exhibit the same effects as the cathode 22.

C. Method for producing MEA having catalyst electrode layer:
FIG. 4 is an explanatory diagram showing a manufacturing process of the MEA 24 having the catalyst electrode layer (cathode 22 and anode 23) executed at the time of manufacturing the fuel cell. In order to produce the catalyst electrode layer, first, the platinum sheet 40 is prepared (step S100).

  Next, an etching process is performed on one surface of the prepared platinum sheet 40 with an aqua regia solution (sulfuric acid aqueous solution) (step S110).

  Then, the hole part 42 which is a through-hole is produced | generated using the femtosecond laser with respect to the surface which performed the etching process in the platinum sheet 40 (step S120). It is preferable that the hole diameter and the interval of the hole 42 are determined so that the porosity of the platinum sheet 40 is about 5% to 20%. For example, the hole 42 may have a hole diameter of 10 μm, and the interval may be generated every 10 μm. In addition, the porosity represents the volume ratio of the hole portion 42 with respect to the volume of the entire platinum sheet 40.

  Next, a dispersion (electrolytic solution) that is a mixed solution of water and the electrolyte 45 is prepared (step S130).

  Then, the dispersion is applied to the surface on which the platinum sheet 40 is etched and the hole 42 is formed (step S140). In this case, for example, it is preferably performed by spraying or screen printing.

  After the application, the dispersion is dried with the platinum sheet 40 (step S150). In this case, for example, the substrate is dried by being placed in an air atmosphere at 80 ° C. for 10 minutes.

  By repeating the steps S100 to S150, two products (hereinafter also referred to as post-application platinum sheets) in which the electrolyte 45 is formed on the platinum sheet 40 are prepared. And the electrolyte membrane 21 is prepared and a platinum sheet | seat after application | coating is arrange | positioned on both surfaces of the electrolyte membrane 21 (step S160). In this case, the platinum sheet after coating is arranged so that the surface opposite to the electrolyte coating surface (the surface not subjected to the etching process) and the electrolyte membrane 21 face each other.

  Then, the product (the member in which the platinum sheet is applied on both surfaces of the electrolyte membrane 21) generated in the process of step S160 is hot-pressed (step S170) to join the electrolyte membrane 21 and the catalyst electrode layer. Then, the MEA in which the catalyst electrode layers are formed on both surfaces of the electrolyte membrane 21 is completed. In this case, for example, hot pressing is performed at 100 ° C. and 1 MPa.

  If it does as mentioned above, it is possible to produce the catalyst electrode layer provided with the platinum sheet 40 having a plurality of hole portions 42 which are through holes.

D. Experimental results of examples and comparative examples:
FIG. 5 is a diagram showing experimental results comparing the durability of the fuel cell of this example and a fuel cell having a different catalyst electrode layer configuration from the fuel cell of this example. This experimental result shows that the voltage of the fuel cell of this example and the fuel cell of this example having a different catalyst electrode layer configuration (referred to as a fuel cell of the comparative example) immediately after the start of the experiment. The voltage maintenance rate after 3000 hours of operation (power generation) is shown. The fuel cell of the comparative example has a configuration (electrolyte membrane 21, first gas diffusion layer, second gas diffusion layer, gas separator, etc.) other than the catalyst electrode layer (cathode 22). It is the same.

  In the fuel cell of this example used in the experiment, only the cathode 22 in the catalyst electrode layer is composed of the platinum sheet 40 and the electrolyte 45 as described above, and the anode 23 is supported by platinum as in the conventional case. Carbon (hereinafter also referred to as supported carbon) and an electrolyte 45. On the other hand, the fuel cell of Comparative Example 1 is composed of only the supported carbon and the electrolyte 45 for both the cathode and the anode.

  In the cathode 22 of the fuel cell of this example, a platinum sheet 40 having a thickness of 10 μm, a hole diameter of 10 μm, a gap between the holes 42 of 10 μm, a porosity of about 19%, and an electrolyte As 45, 1.1 g of a polymer electrolyte (manufactured by DuPont, SE20092) was used. On the other hand, in the cathode of the fuel cell of the comparative example, 1 g of carbon particles (Ketjen Black International Co., Ltd., Ketjen Black EC) carrying 45% by mass of platinum was used as the supported carbon, and the polymer electrolyte ( 2.2 g of DuPont SE20092) was used.

  Moreover, in the anodes of the fuel cells of the present example and the comparative example, 1 g of carbon particles (Nippon Cabot Co., Ltd., Vulcan XC-72R) supporting 30% by mass of platinum was used as the supporting carbon. 3.5 g of molecular electrolyte (manufactured by DuPont, SE20092) was used. In addition, as an electrolyte membrane, a fluorine-based solid polymer membrane (manufactured by DuPont, Nafion 112) was prepared.

  In the fuel cells of this example and the comparative example, an MEA is manufactured using the above materials (see FIG. 4), and the MEA is sandwiched in the order of the first gas diffusion layer and the second gas diffusion layer. In addition, a single cell was manufactured by sandwiching the laminate with a gas separator.

Although an actual fuel cell has a structure in which a plurality of single cells are stacked, the experimental results shown in FIG. 5 show that the fuel cells of the present example and the comparative example are allowed to generate power in a single cell state. It is a result in the case of. During power generation, a large excess of high purity hydrogen gas was used as the fuel gas, and a large excess of air was used as the oxidizing gas. At this time, the operating temperature of each fuel cell was 90 ° C., and the fuel gas and the oxidizing gas were humidified so that the bubbler temperature was 50 ° C., respectively. The electrode area in each fuel cell was 25 cm ² . Each fuel cell was operated for 3000 hours, during which the load was maintained at 0.5 A / cm ² .

  As shown in FIG. 5, the fuel cell of the present example was able to significantly suppress the voltage drop compared to the fuel cell of the comparative example. From this, the fuel cell of the present embodiment can suppress the reduction of the surface area of the catalytic metal at the cathode 22 and the catalytic action of the catalytic metal can suppress the decrease compared to the fuel cell of the comparative example. It is thought that you can.

E. Variation:
Note that the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the scope of the invention.

E1. Modification 1:
FIG. 6 is a schematic cross-sectional view of an MEA 24A including a platinum sheet 40 as the first modification. The catalyst electrode layer of the fuel cell of the above embodiment is composed of only the platinum sheet 40 and the electrolyte 45 and is provided on the electrolyte membrane 21, but the present invention is not limited to this. For example, the catalyst electrode layer (cathode 22 or anode 23) may be composed of a supported carbon layer made of supported carbon and an electrolyte, and a platinum sheet 40. In this case, as shown in FIG. 6, a supported carbon layer may be disposed on the electrolyte membrane 21, and further, a platinum sheet 40 may be disposed on the laminate, or the platinum sheet 40 may be disposed on the electrolyte membrane 21. And a supported carbon layer may be disposed on the laminate. If it does in this way, in the catalyst electrode layer, the thickness of the platinum sheet 40 can be suppressed, that is, the amount of platinum used for the catalyst electrode layer can be suppressed.

E2. Modification 2:
Although the platinum sheet 40 used in the fuel cell of the above embodiment includes a plurality of holes 42 that are through holes, the present invention is not limited to this. For example, the platinum sheet 40 may be a platinum sheet having a fine path that extends three-dimensionally. In this case, the platinum sheet 40 is produced, for example, by sintering platinum powder, and a dispersion containing the electrolyte 45 is applied to the surface and inner holes of the platinum sheet 40 by spraying. Even if the platinum sheet 40 thus produced is used, the same effect as described above can be obtained. Moreover, since this platinum sheet | seat 40 is provided with the fine path which expands three-dimensionally, it can improve the reaction area with a reactive gas.

It is a cross-sectional schematic diagram showing the schematic structure of the fuel cell which is an Example of this invention. FIG. 2 is an enlarged view of a dotted area X in FIG. 1. It is explanatory drawing showing the AA cross section of FIG. It is explanatory drawing showing the manufacturing process of MEA24 which has a catalyst electrode layer (cathode 22 and anode 23) performed at the time of manufacture of a fuel cell. It is a figure which shows the experimental result which compared the durability of the fuel cell of a present Example, and the fuel cell from which the structure of a catalyst electrode layer differs with respect to the fuel cell of a present Example. FIG. 6 is a schematic cross-sectional view of an MEA 24A including a platinum sheet 40 as a first modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Single cell 21 ... Electrolyte membrane 22 ... Cathode 23 ... Anode 31 ... 1st gas diffusion layer 32 ... 1st gas diffusion layer 33 ... 2nd gas diffusion layer 34 ... second gas diffusion layer 35 ... gas separator 36 ... gas separator 37 ... single cell oxidizing gas flow path 38 ... single cell fuel gas flow path 40 ... platinum sheet 42. .. Hole 45 ... Electrolyte

Claims (11)

A fuel cell,
An electrolyte membrane;
A catalyst electrode layer formed on the electrolyte membrane;
With
The catalyst electrode layer is at least
A plate-like porous platinum sheet;
An electrolyte formed on the surface of the inner hole of the porous platinum sheet;
A fuel cell comprising: The fuel cell according to claim 1, wherein
The fuel cell, wherein the porous platinum sheet is in contact with the electrolyte membrane. The fuel cell according to claim 1 or 2,
The fuel cell is characterized in that the electrolyte is formed not only on the inner hole of the porous platinum sheet but also on the surface of the porous platinum sheet. The fuel cell according to any one of claims 1 to 3,
An inner hole of the porous platinum sheet is a through hole penetrating in a thickness direction. The fuel cell according to claim 4, wherein
The fuel cell, wherein the through-hole is opened using a femtosecond laser The fuel cell according to any one of claims 1 to 3,
The porous platinum sheet is produced by sintering platinum particles. The fuel cell according to any one of claims 1 to 6,
In the porous platinum sheet, at least a surface opposite to the electrolyte membrane side is formed in a concavo-convex shape. The fuel cell according to claim 7, wherein
In the porous platinum sheet, at least a surface opposite to the electrolyte membrane side is etched to form the irregularity in the fuel cell. A fuel cell membrane-electrode assembly comprising:
An electrolyte membrane;
A catalyst electrode layer formed on the electrolyte membrane;
With
The catalyst electrode layer is at least
A plate-like porous platinum sheet;
An electrolyte formed on the surface of the inner hole of the porous platinum sheet;
A membrane-electrode assembly for a fuel cell, comprising: A fuel cell manufacturing method comprising:
(A) preparing a plate-like porous platinum sheet;
(B) preparing a dispersion containing an electrolyte;
(C) applying the dispersion to the porous platinum sheet;
(D) drying the dispersion applied to the porous platinum sheet;
(E) preparing an electrolyte membrane;
(F) disposing the porous platinum sheet on the electrolyte membrane so that the surface opposite to the surface on which the dispersion is applied and the electrolyte membrane face each other;
(G) joining the electrolyte membrane and the porous platinum sheet;
A method of manufacturing a fuel cell comprising: The method of manufacturing a fuel cell according to claim 10,
In the step (A),
Preparing a plate-like platinum sheet;
Opening a plurality of through holes in the platinum sheet, and producing the porous platinum sheet;
A method of manufacturing a fuel cell comprising:

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