JP2008027685A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell capable of restraining degradation of functions of catalyst even in case hydrocarbon-based electrolyte is contained in an MEA. <P>SOLUTION: The fuel cell 100 is provided with a membrane electrode assembly 4 equipped with an electrolyte membrane 1, an anode catalyst layer 2a arranged on one face of the electrolyte membrane 1, and a cathode catalyst layer 3a arranged on the other face of the electrolyte membrane 1. The membrane electrode assembly 4 contains hydrocarbon-based electrolyte in at least one out of the electrolyte membrane 1, the anode catalyst layer 2a, and the cathode catalyst layer 3a, and the anode catalyst layer 2a and/or the cathode catalyst layer 3a contains alloy catalyst containing platinum and at least one kind or more of transition metal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more particularly, to a fuel cell capable of suppressing a decrease in catalyst function even when a MEA contains a hydrocarbon-based electrolyte.

  A fuel cell has a membrane electrode assembly (hereinafter referred to as “MEA (Membrane Electrode)” comprising an electrolyte layer (hereinafter referred to as “electrolyte membrane”) and electrodes (anode and cathode) respectively disposed on both sides of the electrolyte membrane. The electrical energy generated by the electrochemical reaction in “) is taken out to the outside through current collectors (for example, separators) respectively disposed on both sides of the MEA. Among fuel cells, polymer electrolyte fuel cells (hereinafter sometimes referred to as “PEFC (Polymer Electrolyte Fuel Cell)”) used in household cogeneration systems and automobiles, etc., are used at low temperatures. Is possible. In addition, PEFC has attracted attention as an optimal power source for electric vehicles and portable power sources because of its high energy conversion efficiency, short start-up time, and small and lightweight system.

  A single cell of PEFC includes an electrolyte membrane, a cathode and an anode including at least a catalyst layer, and a theoretical electromotive force thereof is 1.23V. In PEFC, a hydrogen-containing gas is supplied to the anode, and an oxygen-containing gas is supplied to the cathode. The hydrogen supplied to the anode is separated into protons and electrons on the catalyst contained in the catalyst layer of the anode (hereinafter referred to as “anode catalyst layer”), and the protons generated from the hydrogen are separated into the anode catalyst layer and the electrolyte membrane. To the cathode catalyst layer (hereinafter referred to as “cathode catalyst layer”). On the other hand, electrons reach the cathode catalyst layer through an external circuit, and through such a process, electric energy can be extracted. Then, the protons and electrons that have reached the cathode catalyst layer react with oxygen supplied to the cathode catalyst layer, thereby generating water.

  That is, in order to extract electric energy, it is necessary that protons can be conducted through the anode catalyst layer, the electrolyte membrane, and the cathode catalyst layer. From this viewpoint, the electrolyte membrane, the anode catalyst layer, and the cathode catalyst layer are provided with an electrolyte resin having an ion exchange group that can be a passage for protons. In addition to the electrolyte resin, the anode catalyst layer and the cathode catalyst layer are further provided with metal particles (for example, Pt) that function as an electrochemical reaction catalyst.

  As a technology related to PEFC, for example, Patent Document 1 discloses a step of producing a catalyst layer forming composition by mixing a polymer ionomer, an alcohol solvent, and a polar organic solvent having a boiling point of 30 to 200 ° C. with a metal catalyst, A fuel cell unit comprising the steps of coating the catalyst layer forming composition on both surfaces of a molecular electrolyte membrane to form electrode catalyst layers, and disposing an electrode support on the electrode catalyst layer. Techniques relating to a method for manufacturing a body are disclosed. According to this technique, the composition for forming the electrode catalyst layer can be directly coated on the polymer electrolyte membrane regardless of the material of the polymer electrolyte membrane, so that the manufacturing process is easy and the number of manufacturing processes is reduced. Production costs and time can be saved.

Patent Document 2 discloses a technique related to an electrode catalyst for a polymer electrolyte fuel cell that does not cause a significant decrease in the polymer electrolyte fuel cell even when used for a long time. 2 exemplifies a solid polymer type fuel cell having Nafion as an electrolyte membrane (“Nafion” is a registered trademark of DuPont, USA; hereinafter, may be simply referred to as “Nafion”). . In addition, Patent Document 3 discloses a technique relating to a method for producing a fuel cell electrode catalyst in which high catalytic activity is stably obtained. As the fuel cell electrode catalyst, Pt, Pd, Ru, Os, Examples include one or two or more kinds of noble metals selected from Ir, Rh and Au and one or more kinds of base metals selected from Fe, Ni, Cr, Mn and Co.
JP 2004-146367 A JP 2004-335328 A JP 2001-68120 A

  As disclosed in Patent Document 1, an organic solvent is often used in producing the catalyst layer. However, in a fuel cell in which a hydrocarbon electrolyte is provided in the electrolyte membrane, the anode catalyst layer, and / or the cathode catalyst layer, the function of the catalyst is impaired by the organic solvent during the operation of the fuel cell, There was a problem that the power generation performance deteriorated. However, Patent Documents 1 to 3 do not describe this problem, and no means for solving this problem is disclosed. For this reason, it has been difficult to suppress a decrease in the function of the catalyst depending on the techniques according to Patent Documents 1 to 3.

  Accordingly, an object of the present invention is to provide a fuel cell capable of suppressing a decrease in the function of the catalyst even when the MEA contains a hydrocarbon-based electrolyte.

In order to solve the above problems, the present invention takes the following means. That is,
The invention according to claim 1 is a membrane electrode assembly comprising an electrolyte membrane, an anode catalyst layer disposed on one surface of the electrolyte membrane, and a cathode catalyst layer disposed on the other surface of the electrolyte membrane. The membrane electrode assembly includes a hydrocarbon-based electrolyte in at least one of the electrolyte membrane, the anode catalyst layer, and the cathode catalyst layer, and platinum and the anode catalyst layer and / or cathode catalyst layer, The above problem is solved by a fuel cell comprising an alloy catalyst containing at least one transition metal.

  Specific examples of the hydrocarbon electrolyte include S-PEEK represented by the following formula 1, S-PEES represented by the following formula 2, S-PPBP represented by the following formula 3, and sulfonated polyether. Examples include ketone (S-PEK), polybenzimidazole (PBI), and sulfonated polyimide (SPI). The locations where the hydrocarbon-based electrolyte can be provided include an electrolyte membrane, an anode catalyst layer, a cathode catalyst layer, an electrolyte membrane and an anode catalyst layer, an electrolyte membrane and a cathode catalyst layer, an anode catalyst layer and a cathode catalyst layer, and an electrolyte membrane, An anode catalyst layer and a cathode catalyst layer can be mentioned. Furthermore, specific examples of transition metals as components of alloy catalysts include Co, Ru, Ir, Au, Ag, Cu, Ni, Fe, Cr, Mn, V, Ti, Mo, Pd, Rh, and W. Can do. In addition, perfluorosulfonic acid type electrolyte can be illustrated as an electrolyte component with which a hydrocarbon type electrolyte is not provided in MEA, and Nafion etc. are illustrated as the perfluorosulfonic acid type electrolyte. can do.

  According to a second aspect of the present invention, in the fuel cell of the first aspect, the anode catalyst layer and / or the cathode catalyst layer contains a hydrocarbon-based electrolyte.

  The invention according to claim 3 is the fuel cell according to claim 1 or 2, wherein the alloy catalyst contains platinum and cobalt.

  According to the first aspect of the present invention, the MEA contains a hydrocarbon electrolyte, and the anode catalyst layer and / or the cathode catalyst layer contains an alloy catalyst containing platinum and a transition metal. Since the alloy catalyst is unlikely to deteriorate in function due to an organic solvent, a fuel cell capable of suppressing the deterioration in the function of the catalyst even when the MEA contains a hydrocarbon-based electrolyte is provided. Can provide.

  According to the second aspect of the present invention, the anode catalyst layer and / or the cathode catalyst layer contains a hydrocarbon-based electrolyte, and the catalyst layer contains an alloy catalyst that is unlikely to deteriorate in function due to an organic solvent. Therefore, by adopting such a configuration, it is possible to provide a fuel cell capable of suppressing a decrease in the function of the catalyst even when a hydrocarbon-based electrolyte is contained in the MEA catalyst layer.

  According to the invention described in claim 3, the alloy catalyst contains platinum and cobalt (hereinafter, an alloy containing platinum and cobalt may be described as “PtCo alloy”. “PtCo alloy” An alloy consisting of platinum and cobalt and inevitable impurities, or at least selected from the group consisting of Ru, Ir, Au, Ag, Cu, Ni, Fe, Cr, Mn, V, Ti, Mo, Pd, Rh, W It means an alloy composed of one or more transition metals, platinum and cobalt, and inevitable impurities). Since the PtCo alloy is unlikely to deteriorate in function due to an organic solvent, such a configuration can provide a fuel cell that can easily suppress deterioration in the function of the catalyst.

  The PEFC catalyst layer is prepared by a method such as applying an ink-like substance (hereinafter referred to as “catalyst ink”) prepared by dispersing a catalyst in a dissolved electrolyte resin to the electrolyte membrane and drying. As the electrolyte resin (hereinafter referred to as “electrolyte”) used in PEFC, perfluorosulfonic acid-based electrolytes and hydrocarbon-based electrolytes are known. In particular, PEFCs equipped with hydrocarbon-based electrolytes have such It is known that the catalyst activity is reduced during operation and the power generation performance is reduced. As a result of diligent research, the present inventor has found that an organic solvent used in the above-described catalyst ink production and the like and remaining in the MEA contributes to a decrease in catalyst activity. In order to prevent a decrease in catalytic activity, it is important to use a catalyst that is unlikely to deteriorate in function due to an organic solvent. If a catalyst with such properties is used, the power generation performance of a PEFC having a hydrocarbon electrolyte is improved. It will be possible to make it.

  The present invention has been made from such a viewpoint, and the gist of the present invention is that an alloy containing platinum and at least one transition metal is used as a catalyst for a fuel cell containing a hydrocarbon electrolyte in MEA. An object of the present invention is to provide a fuel cell capable of suppressing a decrease in the function of the catalyst.

  Hereinafter, the fuel cell of the present invention will be specifically described with reference to the drawings. In the following description, the anode catalyst layer and the cathode catalyst layer may be collectively referred to simply as “catalyst layer”.

1. First Embodiment FIG. 1 is a cross-sectional view schematically showing a partial configuration example of a fuel cell of the present invention according to a first embodiment.
As shown in FIG. 1, the fuel cell 100 of the present invention according to the first embodiment includes an electrolyte membrane 1, an anode catalyst layer 2a provided on one side of the electrolyte membrane 1, and a cathode provided on the other side. An MEA 4 including a catalyst layer 3a, an anode diffusion layer 2b disposed on one side of the MEA 4, a cathode diffusion layer 3b disposed on the other side, and an anode diffusion layer 2b side. Separator 5 and a separator 6 disposed on the cathode diffusion layer 3b side. The anode 2 of the fuel cell 100 includes an anode catalyst layer 2a and an anode diffusion layer 2b, and the cathode 3 includes a cathode catalyst layer 3a and a cathode diffusion layer 3b. The anode diffusion layer 2b and the cathode diffusion layer 3b are made of, for example, carbon paper, and the separator 5 and the separator 6 are made of a metal material, a carbon material, or the like. The separator 5 disposed on the anode diffusion layer 2b side is provided with flow paths 7, 7,... Through which the hydrogen-containing gas flows, and the separator 6 disposed on the cathode diffusion layer 3b side includes an oxygen-containing layer. The flow path 8,8 ... which gas should distribute | circulate is provided. When the fuel cell 100 is operated, the MEA 4 is maintained at a predetermined temperature or lower (for example, 90 ° C. or lower) by a heat medium that flows in a heat medium flow path (not shown) provided in the separators 5 and 6.

  In the fuel cell 100, the electrolyte constituting the electrolyte membrane 1 is a hydrocarbon-based electrolyte (for example, S-PEEK), and the anode catalyst layer 2a and the cathode catalyst layer 3a are alloy catalysts (for example, PtCo alloys). ) And a hydrocarbon electrolyte (for example, S-PEEK) that functions as a proton conductor. In such a form, even if an organic solvent (for example, alcohol) remains in the MEA 4, the function of the alloy catalyst is difficult to be impaired by the organic solvent. Therefore, a conventional electrolyte containing a hydrocarbon-based electrolyte is included. The fuel cell 100 can have a power generation performance better than that of the fuel cell.

2. Second Embodiment FIG. 2 is a cross-sectional view schematically showing an example of a partial configuration of a fuel cell according to a second embodiment of the present invention. 2, components having the same configuration as in FIG. 1 are denoted by the same reference numerals as those used in FIG. 1, and description thereof is omitted as appropriate.
As shown in FIG. 2, the fuel cell 200 of the present invention according to the second embodiment includes an electrolyte membrane 1, an anode catalyst layer 22a provided on one side of the electrolyte membrane 1, and a cathode provided on the other side. An MEA 24 having a catalyst layer 23a, an anode diffusion layer 2b disposed on one side of the MEA 24, a cathode diffusion layer 3b disposed on the other side, and an anode diffusion layer 2b side. Separator 5 and a separator 6 disposed on the cathode diffusion layer 3b side. The anode 22 of the fuel cell 200 includes an anode catalyst layer 22a and an anode diffusion layer 2b, and the cathode 23 includes a cathode catalyst layer 23a and a cathode diffusion layer 3b. The separator 5 is provided with channels 7, 7,..., And the separator 6 is provided with channels 8, 8,. When the fuel cell 200 is operated, the MEA 24 is maintained at a predetermined temperature or lower (for example, 90 ° C. or lower) by a heat medium that flows in a heat medium flow path (not shown) provided in the separators 5 and 6.

  In the fuel cell 200, the anode catalyst layer 22a and the cathode catalyst layer 23a contain an alloy catalyst (for example, a PtCo alloy) as a catalyst and Nafion that functions as a proton conductor. By the way, an organic solvent may be used also in the production of the electrolyte membrane, and if the organic solvent remains in the produced electrolyte membrane, the organic solvent may be used when the fuel cell is operated. It moves to the cathode catalyst layer and the like, and there is a risk that the function of the catalyst is lowered. Therefore, even when the hydrocarbon electrolyte is provided only in the electrolyte membrane in the MEA, there is a concern that the function of the catalyst is deteriorated. Here, in the fuel cell 200, the anode catalyst layer 22a and the cathode catalyst layer 23a contain an alloy catalyst that is unlikely to deteriorate in function due to an organic solvent. Therefore, according to the fuel cell 200, the functional degradation of the catalyst can be suppressed.

  In the above description, the electrolyte membrane, the anode catalyst layer, and the cathode catalyst layer contain a hydrocarbon electrolyte (first embodiment), and the electrolyte membrane contains a hydrocarbon electrolyte (second embodiment). Embodiment) is illustrated, but the form that the fuel cell of the present invention can take is not limited to the above form. As other forms that the fuel cell of the present invention can adopt, the hydrocarbon-based electrolyte is contained in the anode catalyst layer, the cathode catalyst layer, the anode catalyst layer and the cathode catalyst layer. And the form contained in the anode catalyst layer and the electrolyte membrane, and the form contained in the electrolyte membrane and the cathode catalyst layer. Among these, in the present invention, since the alloy catalyst is contained in the anode catalyst layer and / or the cathode catalyst layer, when the hydrocarbon-based electrolyte is contained in the anode catalyst layer and / or the cathode catalyst layer, It is easy to get an effect.

  Furthermore, in the above description, the anode catalyst layer and the cathode catalyst layer have been illustrated as having an alloy catalyst (first embodiment, second embodiment). However, the fuel cell of the present invention has the anode catalyst layer or cathode. An alloy catalyst may be contained only in the catalyst layer. However, from the standpoint of improving the power generation performance of the fuel cell by suppressing the decrease in the function of the catalyst, it is preferable that the anode catalyst layer and the cathode catalyst layer contain an alloy catalyst.

  Moreover, although S-PEEK was illustrated as a hydrocarbon type electrolyte, the hydrocarbon type electrolyte which can be contained in the fuel cell of this invention is not limited to S-PEEK. Other specific examples of the hydrocarbon electrolyte include S-PES, S-PPBP, S-PEK, PBI, and SPI.

  Moreover, although PtCo alloy was illustrated as an alloy catalyst contained in a catalyst layer, in this invention, the alloy catalyst contained in a catalyst layer is not limited to a PtCo alloy. Other specific examples of the alloy catalyst contained in the catalyst layer of the fuel cell according to the present invention include Ru, Ir, Au, Ag, Cu, Ni, Fe, Cr, Mn, V, Ti, Mo, Pd, and Rh. And an alloy catalyst containing at least one transition metal selected from the group consisting of W and Pt.

  Moreover, although alcohol was illustrated as an organic solvent, the organic solvent used when producing an electrolyte membrane and a catalyst layer is not limited to alcohol. Other specific examples of the organic solvent include dimethyl sulfoxide (DMSO), an ethanol solution containing water, a mixed solution of water, methanol and 2-propanol, N-methyl-2-pyrrolidone (NMP), N, Examples thereof include N-dimethylacetamide (DMAC), dimethyl ether (DME), and acetone.

1 and 2 exemplify a fuel cell in which a diffusion layer is provided on the anode and the cathode. However, the fuel cell according to the present invention is not limited to this mode, and the anode and / or the cathode is not limited thereto. The form in which a diffusion layer is not provided may be sufficient.
1 and 2 exemplify the fuel cell in which the anode-side separator and the cathode-side separator are provided with the flow path, the fuel cell according to the present invention is not limited to this mode, and the anode-side separator is not limited to the anode-side separator. The separator and / or the cathode-side separator may not be provided with a flow path. When the separator is not provided with a flow path, the fuel cell is provided with a diffusion layer, and the hydrogen-containing gas or oxygen-containing gas is supplied to the diffusion layer made of foam metal, sintered metal, or the like. As long as the diffusion layer is not provided, a hydrogen-containing gas or an oxygen-containing gas can be supplied to the catalyst layer.
Furthermore, in the above description, a so-called flat plate type fuel cell has been exemplified. However, the form of the fuel cell according to the present invention is not limited to the flat plate type, and the fuel has a dimple shape, a cylindrical shape (tube type) or the like. The present invention can be applied even to a battery.

<Example 1>
(1) Preparation of Sample After a dispersion liquid in which carbon carrying PtCo alloy (hereinafter referred to as “PtCo / C catalyst”) was dispersed in an ethanol solution containing water was dropped onto a glassy carbon electrode, The electrode according to Example 1 was produced by drying for 10 minutes. On the other hand, in place of the PtCo / C catalyst, Pt-supported carbon (hereinafter referred to as “Pt / C catalyst”) was dispersed in the same procedure as that of the electrode according to Example 1, except that carbon was dispersed. 1 was produced. In the PtCo / C catalyst according to Example 1, when the mass of the PtCo / C catalyst is 100 parts by mass, PtCo is 51 parts by mass, and the breakdown of the 51 parts by mass is that 48 parts by mass of Pt, Co Was 3 parts by mass.

(2) CV measurement Using a glass tripolar electrochemical measurement cell (hereinafter referred to as "electrochemical cell") and a rotating device, CV (Cyclic Voltammetry) measurement is performed to determine the oxidation-reduction characteristics of the catalyst. Examined. The electrode according to Example 1 or the electrode according to Comparative Example 1 produced by the above procedure was used as the working electrode of the electrochemical cell, the Pt line was the counter electrode, and the hydrogen reversible electrode (RHE) was the reference electrode.
After all electrodes (working electrode, counter electrode, and reference electrode) are set in an electrochemical cell containing a 0.1 [mol / l] sulfuric acid aqueous solution, the electrolyte is removed by bubbling with N ₂ gas. Careful and CV measurements were taken. In the CV measurement, the potential was repeatedly scanned so that the potential of the working electrode was 0.05 to 1.4 [V] with respect to the reference electrode. Here, the potential scanning speed is 100 [mV / sec], the working electrode rotation speed is 400 [rpm], and the potential of the working electrode with respect to the reference electrode is 0.5 [V]. It was judged that deaeration was completed when | reduction current | Then, bubbling was performed by switching the bubbling gas to O ₂ gas. After the CV waveform was stabilized, the potential was scanned from 1.2 [V] to 0.4 [V] at a scanning speed of 10 [mV / sec], and the oxygen reduction current was measured. Thereafter, DMSO is added to a 0.1 [mol / l] sulfuric acid aqueous solution so that the concentration becomes 10 [ppm]. Similarly, the scanning speed is changed from 1.2 [V] to 0.4 [V]. The potential was scanned at 10 [mV / sec], and the oxygen reduction current was measured. The relationship between the potential and the oxygen reduction current when the electrode according to Example 1 is used as the working electrode, and the relationship between the potential and the oxygen reduction current when the electrode according to Comparative Example 1 is used as the working electrode. This is also shown in FIG. 3 represents the potential of the working electrode with respect to the reference electrode [V vs. RHE], the horizontal axis of FIG. 3 represents the oxygen reduction current [A / g] per gram of catalyst. If DMSO remains in the MEA, the function of the catalyst is deteriorated when the fuel cell is operated.

(3) Results From FIG. 3, the electrode according to Example 1 exhibited superior oxygen reduction characteristics than the electrode according to Comparative Example 1. Therefore, it was confirmed that the use of a PtCo alloy as a catalyst can suppress a decrease in the function of the catalyst.

<Example 2>
(1) Production of test cell When the mass of the PtCo / C catalyst is 100 parts by mass, PtCo is 51 parts by mass, and the breakdown of the 51 parts by mass is 48 parts by mass of Pt and 3 parts by mass of Co. While mixing 1 g of a PtCo / C catalyst with 1.5 g of water and kneading, 1.84 g of DMSO containing 10% by mass of a hydrocarbon electrolyte (S-PEEK) and 20 g of ethanol were mixed to prepare a mixed solution. And the catalyst ink which concerns on Example 2 was prepared by disperse | distributing the kneaded said PtCo / C catalyst to a mixed solution using a homogenizer. The catalyst ink thus prepared is applied to an electrolyte membrane containing a hydrocarbon-based electrolyte with an anode-side catalyst ink weight of 0.2 mg / cm ² and a cathode-side catalyst ink weight of 0.4 mg / cm ^2. The MEA according to Example 2 was produced by directly coating and drying with a vacuum dryer set at 100 ° C. for 12 hours. Thereafter, the MEA is disposed between a pair of diffusion layers (carbon paper) and thermocompression bonded to produce a laminate including the anode diffusion layer, the MEA, and the cathode diffusion layer. A cell according to Example 2 was produced by disposing carbon separators on both sides.

On the other hand, when the mass of the Pt / C catalyst is 100 parts by mass, 1.5 g of water is added to 1 g of the Pt / C catalyst having 45 parts by mass of Pt and kneaded, while 10 mass% of S-PEEK is contained. A mixed solution was prepared by mixing 2.06 g of DMSO and 20 g of ethanol. And the catalyst ink which concerns on the comparative example 2 was prepared by disperse | distributing the kneaded said Pt / C catalyst to a mixed solution using a homogenizer. The catalyst ink thus prepared was applied to an electrolyte membrane made of a hydrocarbon-based electrolyte with a catalyst ink basis weight of 0.2 mg / cm ² on the anode side and a catalyst ink basis weight of 0.4 mg / cm ² on the cathode side. The MEA according to Comparative Example 2 was produced by directly coating the film and drying it with a vacuum dryer set at 100 ° C. for 12 hours. Thereafter, the MEA is disposed between a pair of diffusion layers (carbon paper) and thermocompression bonded to produce a laminate including the anode diffusion layer, the MEA, and the cathode diffusion layer. A cell according to Comparative Example 2 was produced by disposing carbon separators on both sides.

(2) IV Measurement Using the cell according to Example 2 and the cell according to Comparative Example 2, IV measurement was performed and the resistance of each cell was examined. In each cell, the cell temperature was set to 80 ° C., a fully humidified H ₂ gas was supplied to the anode, and a fully humidified air was supplied to the cathode. The results of IV measurement and cell resistance are also shown in FIG. The vertical axis in FIG. 4 is voltage [V] and resistance [mΩ], and the horizontal axis in FIG. 4 is current density [A / cm ² ].

(3) Results FIG. 4 shows that the current density of the cell according to Comparative Example 2 at a voltage of 0.2 V was a value smaller than 1.0 [A / cm ² ], whereas The current density of the cell at a voltage of 0.2 V was a value larger than 1.4 [A / cm ² ]. 4, the resistance of the cell according to Example 2 was lower than the resistance of the cell according to Comparative Example 2. Therefore, it was confirmed that the power generation performance of the fuel cell can be improved by using a PtCo alloy as the catalyst.

It is sectional drawing which shows roughly the example of a partial structure of the fuel cell of this invention concerning 1st Embodiment. It is sectional drawing which shows roughly the example of a partial structure of the fuel cell of this invention concerning 2nd Embodiment. It is a figure which shows the relationship between an electric potential and oxygen reduction current. It is a figure which shows the relationship between an electric potential and resistance, and a current density.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrolyte membrane 2, 22 Anode 2a, 22a Anode catalyst layer 2b, 22b Anode diffusion layer 3, 23 Cathode 3a, 23a Cathode catalyst layer 3b, 23b Cathode diffusion layer 4, 24 MEA (membrane electrode assembly)
5, 6 Separator 100, 200 Fuel cell

Claims (3)

A membrane electrode assembly comprising: an electrolyte membrane; an anode catalyst layer disposed on one surface of the electrolyte membrane; and a cathode catalyst layer disposed on the other surface of the electrolyte membrane;
The membrane electrode assembly contains a hydrocarbon electrolyte in at least one of the electrolyte membrane, the anode catalyst layer, and the cathode catalyst layer,
The fuel cell, wherein the anode catalyst layer and / or the cathode catalyst layer contains an alloy catalyst containing platinum and at least one transition metal. The fuel cell according to claim 1, wherein the anode catalyst layer and / or the cathode catalyst layer contains a hydrocarbon-based electrolyte. The fuel cell according to claim 1 or 2, wherein the alloy catalyst contains platinum and cobalt.

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