JP2009238638A - Electrolyte membrane-catalyst layer assembly and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolyte membrane-catalyst layer assembly having a high output and inexpensive catalyst layer, and a fuel cell using the same. <P>SOLUTION: The electrolyte membrane-catalyst layer assembly having a catalyst layer comprising at least catalyst fine particles, fine particles with ion exchange function and a binder, and an electrolyte membrane, and a fuel cell using the same, are provided. The binder preferably includes ion exchange function. At least either the fine particles with ion exchange function or the binder preferably comprises a hydrocarbon system material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrolyte membrane-catalyst layer assembly and a fuel cell, and more particularly to an electrolyte membrane-catalyst layer assembly and a polymer electrolyte fuel cell having an electrode catalyst layer for a polymer electrolyte fuel cell.

  A fuel cell is an electrochemical oxidation of a fuel composed of a reducing agent such as hydrogen, methanol, or reformed hydrogen from fossil fuels using an oxidant such as oxygen or air, thereby converting the chemical energy of the fuel into electricity. It is converted into energy and extracted.

  Among these, the polymer electrolyte fuel cell has the first advantage that the operation temperature is low, and the second advantage that the internal resistance can be reduced by thinning the electrolyte part, so that the current can be taken out with high efficiency. It is suitable for reducing the battery size.

  The membrane electrode assembly used in this polymer electrolyte fuel cell has a structure in which an anode (fuel electrode) and a cathode (air electrode) are joined with a solid polymer electrolyte membrane interposed therebetween. The polymer electrolyte fuel cell is formed into a cell by stacking the membrane electrode assembly with a separator interposed therebetween.

  Usually, the anode or cathode and the solid polymer electrolyte membrane are joined via a catalyst-carrying conductive material made of a mixture of a catalyst and conductive carbon, and a diffusion layer that allows gas or liquid to permeate non-linearly. The fuel supplied to the anode side passes through the pores in the diffusion layer, reaches the catalyst, releases electrons by the catalyst, and becomes hydrogen ions. Hydrogen ions pass through the solid polymer electrolyte membrane and reach the cathode side, and react with oxygen supplied to the diffusion layer on the cathode side and electrons flowing from the external circuit to generate water. Electrons emitted from the fuel pass through the catalyst in the electrode and the conductive carbon on which the catalyst is supported, are led from the anode to the external circuit, and flow from the external circuit to the cathode. As a result, in the external circuit, electrons flow from the anode to the cathode and electric power is taken out.

  At this time, if the solid polymer electrolyte membrane and the electrode (anode and cathode) are insufficiently bonded, the movement of hydrogen ions is inhibited at the interface between the electrode and the polymer electrolyte membrane. As a result, the internal resistance of the whole membrane electrode assembly increases. Further, the joining interface between the solid polymer electrolyte and the electrode is also a three-phase interface where a catalytic reaction occurs. The larger the area of this three-phase interface, the more hydrogen ions are generated. That is, the joining state of the polymer electrolyte membrane and the electrode in the membrane electrode assembly greatly affects the characteristics of the polymer electrolyte fuel cell.

  In general, the electrode catalyst layer described above is applied to a polymer electrolyte membrane, a porous carbon electrode, or a support by applying a paste prepared by mixing a solution in which a catalyst body and a polymer electrolyte are dispersed in an organic solvent. Or by applying a paste prepared by mixing a catalyst body and an arbitrary organic solvent to a polymer electrolyte membrane, a porous carbon electrode, or a support, and then dispersing a polymer electrolyte in an organic solvent. It is produced by a method of impregnation. Further, the polymer electrolyte membrane is sandwiched between the pair of electrode catalyst layers obtained in this manner, and thermocompression bonded with a hot press or the like to produce an electrolyte membrane-catalyst layer assembly (MEA) (patent) Reference 1).

In addition, as another method for producing a membrane electrode assembly, a method for applying and drying a catalyst layer forming paste to an electrolyte membrane obtained by filling a porous membrane mainly composed of polyimide with an electrolyte component is described. (See Patent Document 2).
JP-A-8-106915 Japanese Patent Laid-Open No. 2004-247152

  However, the electrolyte membrane-catalyst layer assembly according to the conventional manufacturing method still has insufficient three-dimensionalization of the three-phase interface inside the catalyst layer. This means an increase in the internal resistance of the battery and a decrease in the utilization rate of the catalyst. Therefore, sufficient output characteristics of the polymer electrolyte fuel cell are not obtained from the electrolyte membrane-catalyst layer assembly according to the conventional manufacturing method.

In addition, the fluororesin used as an electrolyte or a catalyst layer binder is expensive, and further cost reduction is required.
The present invention has been made in view of such a background art, and provides an electrolyte membrane-catalyst layer assembly having a high-power and inexpensive catalyst layer and a fuel cell using the same.

  An electrolyte membrane-catalyst layer assembly for solving the above-mentioned problems is characterized by having at least catalyst fine particles, a catalyst layer comprising fine particles having ion exchange ability and a binder, and an electrolyte membrane.

  In addition, a fuel cell for solving the above-described problems is characterized by using the above electrolyte membrane-catalyst layer assembly.

  According to the present invention, it is possible to provide an electrolyte membrane-catalyst layer assembly having a high-power and inexpensive catalyst layer and a fuel cell using the same.

Hereinafter, the present invention will be described in detail.
The electrolyte membrane-catalyst layer assembly according to the present invention is characterized by having an electrolyte membrane and a catalyst layer comprising at least catalyst fine particles, fine particles having ion exchange ability, and a binder.

The binder preferably has an ion exchange capacity.
It is preferable that at least one of the fine particles having an ion exchange capacity and the binder is made of a hydrocarbon material.

It is preferable that the electrolyte membrane is a hydrocarbon electrolyte membrane.
Moreover, the fuel cell according to the present invention is characterized by using the electrolyte membrane-catalyst layer assembly.

  In the present invention, it is considered that by dispersing fine particles in the catalyst-carrying conductive layer, fuel diffusion in the catalyst-carrying conductive layer is facilitated, thereby contributing to an increase in the three-phase interface region.

Further, since the fine particles have ion exchange ability, it is possible to efficiently transport hydrogen ions generated in the three-phase interface region, and power generation efficiency is improved.
Furthermore, in addition to fine particles with ion exchange capacity, it is possible to further increase the three-phase interface region by increasing the probability of contact with the catalyst at the three-phase interface part and fine particles with ion exchange ability by using a binder. Become.

Next, the form for implementing this invention is demonstrated.
Hereinafter, the present invention will be described with reference to FIG. 1, but the configurations and shapes of the membrane electrode assembly and the polymer electrolyte fuel cell of the present invention are not limited to those shown in FIG.

  The configuration of one embodiment of the polymer electrolyte fuel cell according to the present invention is schematically shown in FIG. 101 is a solid polymer electrolyte membrane, 102 is a catalyst layer, 103 is a diffusion layer, 2 is an anode, 3 is a cathode, and 4 is a solid polymer electrolyte membrane.

  In the present invention, a joined body composed of the solid polymer electrolyte membrane 101, the catalyst layer 102, and the diffusion layer 103 is referred to as a membrane electrode assembly 1. The assembly comprising the solid polymer electrolyte membrane 101 and the catalyst layer 102 is the electrolyte membrane-catalyst layer assembly 4.

  The catalyst layer 102 will be described in detail with reference to FIG. FIG. 2 is a schematic cross-sectional view showing the configuration of a part of the catalyst layer in the present invention. The catalyst layer includes catalyst fine particles 201, fine particles 202 having ion exchange ability, and a binder 203.

Examples of the fine particles having ion exchange ability in the present invention include organic substances or inorganic substances such as various ion exchange resins and resins having ion conductive groups.
Ion exchange resins are classified into cation exchange resins and anion exchange resins. When utilizing the movement of hydrogen ions in power generation, a cation exchange resin is preferable, and a strongly acidic cation exchange resin is more preferable.

  The ion exchange capacity in the present invention refers to having a functional group having ion conductivity. For example, as a hydrogen ion conductive group, a sulfonic acid group, a sulfinic acid group, a carboxylic acid group, a phosphonic acid group, phosphorus An acid group, a phosphinic acid group, and a boronic acid group are mentioned.

When the material having ion exchange capacity is a cured product and is provided in the form of pellets or beads, it can be used by dispersing or crushing it into fine particles.
The fine particles having ion exchange capacity are preferably made of a hydrocarbon material.

  The average particle size of the fine particles having ion exchange ability in the present invention is preferably 0.1 μm or more and 50 μm or less, more preferably 1 μm or more and 10 μm or less.

  As the catalyst fine particles used in the present invention, a catalyst alone or a catalyst having a catalyst supported on the surface of conductive carbon can be used. The average particle diameter of the supported catalyst is preferably small, and specifically, it is preferably in the range of 0.5 nm to 20 nm, more preferably 1 nm to 10 nm. If it is less than 0.5 nm, the activity of the catalyst particles alone is too high, making handling difficult. On the other hand, if the thickness exceeds 20 nm, the surface area of the catalyst decreases and the number of reaction sites decreases, which may reduce the activity.

  As the catalyst, a platinum group metal such as platinum, rhodium, ruthenium, iridium, palladium, and osmium, or an alloy of platinum and these metals may be used. In particular, when methanol is used as the fuel, it is preferable to use an alloy of platinum and ruthenium.

The conductive carbon can be selected from carbon black, carbon fiber, graphite, carbon nanotube, and the like. The average particle diameter of the conductive carbon is preferably 5 nm or more and 1000 nm or less, and more preferably 10 nm or more and 100 nm or less. In order to support the metal catalyst, the specific surface area is preferably large to some extent, and is preferably 50 m ² / g or more and 3000 m ² / g or less, more preferably 100 m ² / g or more and 2000 m ² / g or less.

  A known method can be widely used as a method for supporting the catalyst on the conductive carbon surface. For example, a method of impregnating conductive carbon in a solution of platinum and other metals and then reducing these noble metal ions and supporting them on the surface of the conductive carbon is known. JP-A-2-111440, JP-A-2000- No. 003712 and the like. Alternatively, a noble metal to be supported may be used as a target and supported on conductive carbon by a vacuum film forming method such as sputtering.

  The catalyst fine particles used in the present invention are composed of the catalyst alone or conductive carbon as described above. The average particle diameter of the catalyst fine particles is preferably 0.5 nm or more and 20 nm or less, more preferably 1 nm or more. 10 nm or less. If it is less than 0.5 nm, the activity of the catalyst particles alone is too high, and handling becomes difficult. On the other hand, if it exceeds 20 nm, the surface area of the catalyst decreases and the number of reaction sites decreases, which may reduce the activity.

  As the binder used in the present invention, a known resin can be used. Since the binder also has ion exchange capacity, the power generation efficiency is improved as a whole. Examples of binders having ion exchange ability include sulfonic acid group-containing fluororesins represented by Dufone Nafion (registered trademark), sulfonic acid fluoro-oligomers, sulfonated polyimides, sulfonated polystyrene, sulfonated oligomers, and the like.

The binder having ion exchange capacity is preferably made of a hydrocarbon material.
In order to produce a catalyst layer in the present invention, at least the above catalyst fine particles, fine particles having ion exchange ability and a binder, a polymer electrolyte, a water repellent, conductive carbon, a solvent, etc. are mixed and pasted, It is formed by adhering to a molecular electrolyte membrane and a diffusion layer described later.

  The paste application method is not particularly limited, for example, bar coater method, spin coating method, screen printing method, air doctor coater method, blade coater method, rod coater method, knife coater method, squeeze coater method, impregnation coater method, comma coater method, Examples include a die coater method, a reverse roll coater method, a transfer roll coater method, a gravure coater method, a kiss roll coater method, a cast coater method, a spray coater method, a curtain coater method, a calendar coater method, and an extrusion coater method.

  Regarding the content ratio of the catalyst fine particles forming the catalyst layer, the fine particles having ion exchange ability, and the binder, if the ratio of the catalyst fine particles is small, conversion to protons and reduction to oxygen are not sufficiently performed, and power generation characteristics deteriorate. On the other hand, if the amount of catalyst fine particles is too large, the amount of catalyst that is effectively used is not increased with respect to the amount of catalyst added, resulting in a lot of waste.

  Further, both the fine particles having ion exchange ability and the catalyst fine particles are particles, and these fine particles alone cannot maintain a sufficient mechanical strength as a catalyst layer, and therefore a binder is required in addition to the fine particles.

  At this time, if the ratio of the binder is too large with respect to the fine particle component that does not have a binding ability alone, the fuel permeability is lowered, so that proton transfer is not sufficiently performed, and the power generation characteristics are lowered. On the other hand, when the ratio of the binder is small, the film formation is not sufficient and the mechanical strength of the catalyst layer is insufficient.

  For these reasons, the mass ratio of the catalyst fine particles (A) to the fine particles (B) having ion exchange capacity and the binder (C) is (A + B): C = 1: 10 to 10: 1 and A: B = 1: A range of 10 to 10: 1 is preferred. In calculating the mass ratio, the mass at the time of drying in a material containing a volatile component such as water is used.

The amount of catalyst in the catalyst layer is preferably from 0.01 mg / cm ² to 10 mg / cm ² , more preferably from 0.1 mg / cm ² to 5 mg / cm ² .
By using at least one of the fine particles having ion exchange ability and the binder forming the catalyst layer as a hydrocarbon material, the binding property inside the catalyst layer and the adhesion to the solid polymer electrolyte membrane described later can be improved. Is possible.

  The hydrocarbon-based material in the present invention is an electrolyte material that does not contain at least fluorine. You may have elements, such as sulfur and phosphorus contained in the group which has ion exchange ability, such as a sulfonic acid group and a phosphoric acid group. Specific examples of the hydrocarbon material include sulfonated polystyrene.

  The diffusion layer 103 can efficiently and uniformly introduce hydrogen, reformed hydrogen, methanol, dimethyl ether, and air and oxygen, which are fuels, into the electrode catalyst layer and contact the electrodes to transfer electrons. In general, a conductive porous film is preferable, and carbon paper, carbon cloth, a composite sheet of carbon and polytetrafluoroethylene, or the like is used.

The surface and the inside of the diffusion layer may be coated with a fluorine-based paint and subjected to a water repellent treatment.
The thickness of the diffusion layer 103 is preferably 0.1 μm or more and 500 μm or less. When the thickness of the diffusion layer 103 is less than 0.1 μm, gas diffusibility and water repellency are insufficient. Conversely, if the thickness of the diffusion layer 103 is greater than 500 μm, the electrical resistance of the diffusion layer 103 increases and ohmic loss increases, which is not preferable. A more preferable thickness of the diffusion layer 103 is 1 μm or more and 300 μm or less.

  As the solid polymer electrolyte membrane 101, a perfluorosulfonic acid polymer having a structure in which a side chain having a sulfonic acid group at the end is bonded to a fluorocarbon skeleton, or a porous polymer membrane impregnated with an electrolyte is used. Can do.

  The thickness of the solid polymer electrolyte membrane is selected from the material, the strength of the target membrane electrode assembly, the characteristics of the target solid polymer fuel cell, etc., and is not particularly limited. However, a suitable film thickness considered from the use of a general polymer electrolyte fuel cell is 15 μm or more and 150 μm or less, preferably 30 μm or more and 100 μm or less. If the thickness of the solid polymer electrolyte membrane 101 is less than 15 μm, the strength during assembly of the membrane electrode assembly or use as a solid polymer fuel cell is difficult. Since it becomes too long, power generation efficiency decreases.

  The anode 2 and the cathode 3 are electrodes for taking out the current generated in the membrane electrode assembly 1 to the outside, and are preferably made of a conductive material. Each of the anode 2 and the cathode 3 may also serve as a flow path plate for supplying fuel and oxidant gas to the diffusion layer 103. That is, the anode 2 and the cathode 3 do not need to be flat plates, and may have a shape patterned in the current extraction portion and the flow channel.

  The polymer electrolyte fuel cell of the present invention can be obtained by using the membrane electrode assembly. The solid polymer type fuel cell of the present invention shown in FIG. 1 shows one example of the minimum configuration, but the actual shape is arbitrary, and a plurality of membrane electrode assemblies are combined in series or in parallel. Also good.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
Example 1
As a resin having ion exchange capacity, 0.2 part by mass of a strongly acidic cation exchange resin (Amberlite IR118, Organo Co., Ltd.) is crushed in 1 part by mass of 2,4-pentanedione, and an ion having an average particle diameter of 10 μm. A fine particle mixture having exchange ability was prepared.

Next, 1 part by mass of a binder (ESREC BM-2, Sekisui Chemical Co., Ltd., compound name butyral resin) was dissolved in 19 parts by mass of 2,4-pentanedione to prepare a binder solution.
To the fine particle mixture, 0.6 parts by mass of platinum catalyst fine particles (AY-1020, Tanaka Kikinzoku Kogyo Co., Ltd.) and 1.5 parts by mass of the binder solution are mixed to prepare a catalyst paste.

The catalyst paste was applied on carbon paper (TGP-H-060, thickness 200 μm, manufactured by Toray Industries, Inc.) with a bar coater and dried with a vacuum dryer to form a catalyst layer.
^Two carbon papers with a catalyst layer are cut out to a size of 10 cm ² , and sandwiched with an electrolyte membrane (Nafion (registered trademark)) sandwiched between the coating surfaces of the catalyst for the fuel electrode and the air electrode, a heating press Was subjected to press treatment under the conditions of 95 ° C. and 2 kN (catalyst layer area 10 cm ² ) to prepare an electrolyte membrane-catalyst layer assembly.

The amount of platinum catalyst fine particles supported on the carbon paper was 3.0 mg / cm ² .
The prepared electrolyte membrane-catalyst layer assembly is mounted on a fuel cell (DFC-012, manufactured by Kemix Co., Ltd., catalyst layer area 10 cm ² , operating temperature 60 ° C.). Air was allowed to flow as an oxidant on the pole side, a load was applied by a fuel cell test system (manufactured by Scribner, 890B), and the output (mW / cm ² ) was measured. The results are shown in Table 1.

Example 2
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 1 except that the binder solution was replaced with a Nafion (registered trademark) solution (Aldrich, concentration: 5 wt%), and the output was measured.

Example 3
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 1 except that the binder solution was replaced with a sulfonated polystyrene solution (manufactured by Aldrich, concentration: 5 wt%, represented by PSS in the table), and the output was measured.

Example 4
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 3 except that the ion exchange resin was replaced with a weakly acidic cation exchange resin (Amberlite IRC76, Organo Corp.), and the output was measured.

Example 5
Styrene monomer 80 parts by mass, n-butyl acrylate 20 parts by mass, divinylbenzene 5 parts by mass, V-65 (initiator) 2 parts by mass, 10% PVA aqueous solution 50 parts by mass, sodium lauryl sulfate 0.05 part by mass, water 360 The mass parts were emulsified with a homomixer and stirred at 80 ° C. for 2 hours to prepare polystyrene fine particles having a diameter of 5 μm.

  After washing and filtration, 130 parts by mass of concentrated sulfuric acid was added to 40 parts by mass of the obtained polystyrene fine particles, and the mixture was reacted at 80 ° C. for 8 hours. After the reaction, the resin component was separated by filtration and washed with water to prepare sulfonated polystyrene fine particles.

  0.2 parts by mass of the sulfonated polystyrene fine particles (expressed as PSS in the table), 0.6 parts by mass of the platinum catalyst fine particles, 1 part by mass of 2,4-pentanedione, and a binder solution (ESREC BM-2, Sekisui Chemical Co., Ltd.) Co., Ltd.) An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 1 except that 1.5 parts by mass of a 2,4-pentanedione 5 wt% solution was mixed to prepare a catalyst paste, and the output was measured. .

Example 6
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 5 except that the binder solution was replaced with a Nafion solution (Aldrich, concentration: 5 wt%), and the output was measured.

Example 7
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 5 except that the binder solution was replaced with a sulfonated polystyrene solution (Aldrich, concentration: 5 wt%), and the output was measured.

Examples 8, 9, 10
Example 1 (Example 8), 4 (Example 9), 5 (Example 10) except that the binder solution was replaced with a sulfonated benzene-hexamethylene polysulfonamide 5 wt% methanol solution (indicated by PAS in the table). Similarly, an electrolyte membrane-catalyst layer assembly was prepared, and the output was measured.

Example 11
A hydrocarbon-based electrolyte membrane was prepared by the following method.
An electrolyte solution was prepared by mixing 28 parts by mass of vinyl sulfonic acid, 10 parts by mass of acryloylmorpholine, and 3 parts by mass of methacryloyloxyethyl phosphate in a plastic container. A polyimide film having a thickness of 30 μm and an average pore diameter of 0.1 μm as a porous polymer film was immersed in this solution, and the container was subjected to ultrasonic treatment for 5 minutes. The polyimide film taken out from the container was transferred onto a smooth SUS plate and irradiated with an electron beam having an acceleration voltage of 200 kV and a dose of 50 kGy using an electron beam irradiation apparatus (EC250 / 15 / 180L manufactured by Iwasaki Electric Co., Ltd.).

  The electrolyte membrane comprising the hydrocarbon-based compound thus obtained was joined to the catalyst layer prepared in Example 1 to produce an electrolyte membrane-catalyst layer assembly, and the output was measured in the same manner as in Example 1. did.

Example 12
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 2 except that the electrolyte membrane was replaced with the hydrocarbon-based electrolyte membrane prepared in Example 11, and the output was measured.

Example 13
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 3 except that the electrolyte membrane was replaced with the hydrocarbon-based electrolyte membrane prepared in Example 11, and the output was measured.

Example 14
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 4 except that the electrolyte membrane was replaced with the hydrocarbon-based electrolyte membrane prepared in Example 11, and the output was measured.

Example 15
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 2 except that Pt-Ru (TEC90110, Tanaka Kikinzoku Co., Ltd.) was used as the fuel electrode catalyst, and the output was measured.

Example 16
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 3 except that the fuel electrode catalyst was replaced with Pt-Ru (TEC90110, Tanaka Kikinzoku Co., Ltd.), and the output was measured. The measurement results are shown in FIG.

Comparative Example 1
A catalyst paste is prepared by mixing 1 part by mass of a binder (ESREC BM-2, Sekisui Chemical Co., Ltd.) and 3 parts by mass of a binder solution consisting of 19 parts by mass of 2,4-pentanedione and 0.6 parts by mass of platinum catalyst fine particles. Except that, an electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 1, and the output was measured.

Comparative Example 2
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Comparative Example 1 except that the binder solution was replaced with a Nafion solution (Aldrich, concentration: 5 wt%), and the output was measured. The measurement results are shown in FIG.

Comparative Example 3
An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Comparative Example 1 except that the binder solution was replaced with a sulfonated polystyrene solution (Aldrich, concentration: 5 wt%), and the output was measured.

Comparative Example 4
As a resin having ion exchange capacity, 0.4 part by mass of strongly acidic cation exchange resin (Amberlite IR118, Organo Co., Ltd.) is crushed in 1 part by mass of 2,4-pentanedione, and ion exchange with a particle size of 10 μm. An electrolyte membrane-catalyst layer assembly was prepared in the same manner as in Example 1 except that a fine particle mixture having a function was prepared, 0.6 parts by mass of platinum catalyst fine particles were mixed, and a catalyst paste was prepared. However, the electrolyte membrane and the catalyst layer were peeled off during the measurement, and the output was not measured.

  Since the electrolyte membrane-catalyst layer assembly of the present invention can be provided with high output and low cost, it can be used for a polymer electrolyte fuel cell.

It is a cross-sectional schematic diagram which shows the structure of one embodiment of the polymer electrolyte fuel cell which concerns on this invention. It is a cross-sectional schematic diagram which shows the structure of a part of catalyst layer in this invention. It is a figure which shows the output measurement result of the fuel cell in Example 16. It is a figure which shows the output measurement result of the fuel cell in the comparative example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Membrane electrode assembly 2 Anode 3 Cathode 4 Electrolyte membrane-catalyst layer assembly 101 Solid polymer electrolyte membrane 102 Catalyst layer 103 Diffusion layer 201 Catalyst fine particle 202 Fine particle having ion exchange ability 203 Binder

Claims (5)

  An electrolyte membrane-catalyst layer assembly comprising at least catalyst fine particles, a catalyst layer comprising fine particles having ion exchange ability and a binder, and an electrolyte membrane.   2. The electrolyte membrane-catalyst layer assembly according to claim 1, wherein the binder has an ion exchange ability.   The electrolyte membrane-catalyst layer assembly according to claim 1 or 2, wherein the fine particles having an ion exchange capacity and the binder are made of a hydrocarbon material.   The electrolyte membrane-catalyst layer assembly according to any one of claims 1 to 3, wherein the electrolyte membrane is a hydrocarbon electrolyte membrane.   A fuel cell using the electrolyte membrane-catalyst layer assembly according to any one of claims 1 to 4.

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