JP2017168192A - Method for manufacturing electrolyte membrane-electrode assembly and electrolyte membrane-electrode assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-performance electrolyte membrane-electrode assembly in which a catalyst layer does not has a defect such as peeling or a crack.SOLUTION: A method for manufacturing an electrolyte membrane-electrode assembly comprises: a first catalyst composition coating step (S11) for coating one face of an electrolyte membrane with a first catalyst composition; a first catalyst layer formation step (S12) for removing a dispersant from the first catalyst composition to form a first catalyst layer; an electrolyte membrane humidification step (S13) for humidifying the electrolyte membrane; a second catalyst composition coating step (S14) for coating the other face of the electrolyte membrane with a second catalyst composition; and a second catalyst layer formation step (S15) for removing a dispersant from the second catalyst composition to form a second catalyst layer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for producing an electrolyte membrane-electrode assembly and an electrolyte membrane-electrode assembly for fuel cells used for household cogeneration systems, power sources for electric vehicles, portable power sources, and the like.

  2. Description of the Related Art As a fuel cell that generates power by an electrochemical reaction between a fuel gas and an oxidant gas, a fuel cell that includes an electrolyte membrane-electrode assembly is known. Conventionally, this type of electrolyte membrane-electrode assembly is configured by bonding a catalyst layer to both surfaces of an electrolyte membrane.

  FIG. 13 is a configuration diagram showing a conventional electrolyte membrane-electrode assembly. As shown in FIG. 13, the electrolyte membrane-electrode assembly 130 includes an electrolyte membrane 131 having hydrogen ion conductivity, and a catalyst layer 132 formed on both surfaces of the electrolyte membrane 131.

  Here, the catalyst layer 132 is composed mainly of catalyst powder containing a catalyst such as platinum supported on carbon powder, and has a function of oxidizing and reducing fuel gas and oxidant gas to promote electrochemical reaction, Since it has a great influence on the power generation performance of the fuel cell, it is a particularly important component in the fuel cell.

  In order to improve the performance of such an electrolyte membrane-electrode assembly, various methods for producing an electrolyte membrane-electrode assembly have been proposed so far.

  Among them, a method for producing an electrolyte membrane-electrode assembly without crushing the catalyst layer is disclosed in order to maintain the performance of the electrolyte membrane-electrode assembly when the catalyst layer is formed on the electrolyte membrane. (For example, refer to Patent Document 1).

  In the method disclosed in Patent Document 1, a catalyst composition containing a catalyst powder and a dispersion medium is directly applied to one surface of an electrolyte membrane, and the catalyst layer is removed by heating the catalyst composition to remove the dispersion medium. After the formation, an electrolyte membrane-electrode assembly is prepared by directly applying a catalyst composition containing catalyst powder and a dispersion medium to the other surface of the electrolyte membrane, and heating the catalyst composition to remove the dispersion medium. ing.

JP 2002-063911 A

  Here, the inventor applied the catalyst composition to one surface of the electrolyte membrane in the method for producing the electrolyte membrane-electrode assembly described in Patent Document 1 described above, and then applied the dispersion medium from the catalyst composition. In the removing step, the test was performed while changing the temperature at which the catalyst composition was heated.

  As a result, when the catalyst composition is heated at a temperature equal to or higher than the boiling point of water, the electrolyte membrane becomes a high temperature state, and moisture is evaporated from the electrolyte membrane, so that the critical surface tension of the other surface of the electrolyte membrane is reduced. And it discovered that the wettability of the catalyst composition with respect to the said surface deteriorated.

In the case where the wettability of the catalyst composition with respect to the other surface of the electrolyte membrane is deteriorated, the catalyst layer formed on the other surface of the electrolyte membrane by removing the dispersion medium contained in the catalyst composition in the subsequent step. It was found that many defects such as peeling and cracks occur.

  In addition, it has been found that the power generation performance is lowered in a fuel cell using an electrolyte membrane-electrode assembly having a catalyst layer in which defects such as peeling and cracking occur.

  Therefore, in particular, in the method of manufacturing an electrolyte membrane-electrode assembly in which a catalyst layer is formed on the electrolyte membrane by removing the dispersion medium by heating the catalyst composition at a temperature equal to or higher than the boiling point of water, peeling or cracks in the catalyst layer Therefore, the formation of the catalyst layer while suppressing the decrease in the critical surface tension of the electrolyte membrane is an important issue because the defects such as the above cause the performance of the catalyst layer to be lowered and consequently the power generation performance of the fuel cell. It was.

  The present invention solves the above-mentioned conventional problems, and in the method for producing an electrolyte membrane-electrode assembly, the critical surface tension of the electrolyte membrane is prevented from being lowered and the wettability of the catalyst composition with respect to the electrolyte membrane is improved. Thus, an object of the present invention is to provide a method for producing an electrolyte membrane-electrode assembly in which the catalyst layer has no defects such as peeling and cracking.

  Another object of the present invention is to provide an electrolyte membrane-electrode assembly having high quality and high performance using this production method.

  In order to solve the above-mentioned conventional problems, the method for producing an electrolyte membrane-electrode assembly of the present invention comprises applying a catalyst composition containing a catalyst powder and a dispersion medium to one surface of an electrolyte membrane, and using the catalyst composition. This is a method for producing an electrolyte membrane-electrode assembly including a step of humidifying the electrolyte membrane after removing the dispersion medium and forming a catalyst layer.

  As a result, the electrolyte membrane with the catalyst layer formed on one surface is humidified, so that the electrolyte membrane contains moisture, so that the critical surface tension of the electrolyte membrane does not decrease, so the catalyst layer was formed on one surface. The wettability of the catalyst composition with respect to the other surface of the electrolyte membrane is not deteriorated, and it is possible to form a catalyst layer free from defects such as peeling and cracks on both surfaces of the electrolyte membrane, which is excellent in quality and high A high performance electrolyte membrane-electrode assembly can be produced.

  In another method of manufacturing an electrolyte membrane-electrode assembly according to the present invention, after applying a catalyst composition including a catalyst powder and a dispersion medium having a boiling point equal to or higher than the boiling point of water to one surface of the electrolyte membrane, A step of forming a solvent-substituted catalyst composition by replacing the dispersion medium of the catalyst composition with a solvent having a boiling point less than that of water, or forming a catalyst layer by replacing the dispersion medium of the catalyst composition with water It is a manufacturing method of the electrolyte membrane electrode assembly including the process to do.

  Thereby, since the dispersion medium contained in the catalyst composition can be removed without heating at a temperature equal to or higher than the boiling point of water, the moisture of the electrolyte membrane does not evaporate, and the critical surface tension of the electrolyte membrane does not change. The wettability of the catalyst composition with respect to the other side of the electrolyte membrane with the catalyst layer formed on one side is not deteriorated, and it is possible to form a catalyst layer that is free from defects such as peeling and cracking on both sides of the electrolyte membrane Thus, an electrolyte membrane-electrode assembly having excellent quality and high performance can be manufactured.

  In another method of manufacturing an electrolyte membrane-electrode assembly according to the present invention, a catalyst composition containing a dispersion medium having a boiling point less than the boiling point of catalyst powder and water is applied to one surface of the electrolyte membrane. Thereafter, the catalyst composition is heated at a temperature equal to or higher than the boiling point of the dispersion medium and lower than the boiling point of water to remove the dispersion medium, thereby forming a catalyst layer. It is a manufacturing method of a body.

  This allows the dispersion medium contained in the catalyst composition to be removed by heating at a temperature below the boiling point of water, so that the moisture in the electrolyte membrane does not evaporate and the critical surface tension of the electrolyte membrane does not change. The wettability of the catalyst composition with respect to the other surface of the electrolyte membrane in which the catalyst layer is formed on the surface of the electrolyte membrane is not deteriorated, and it is possible to form a catalyst layer free from defects such as peeling and cracking on both surfaces of the electrolyte membrane Therefore, an electrolyte membrane-electrode assembly having excellent quality and high performance can be manufactured.

  Moreover, since the electrolyte membrane-electrode assembly of the present invention is an electrolyte membrane-electrode assembly produced by the above production method, it is possible to provide an electrolyte membrane-electrode assembly having excellent quality and high performance.

  The method for producing an electrolyte membrane-electrode assembly and the electrolyte membrane-electrode assembly according to the present invention are such that the wettability of the catalyst composition with respect to the electrolyte membrane is remarkably improved, so that the catalyst layer has no defects such as peeling and cracking. -A manufacturing method of an electrode assembly and an electrolyte membrane-electrode assembly excellent in quality and high performance can be provided, and by using this, a high performance fuel cell can be provided.

The block diagram which shows the electrolyte membrane-electrode assembly manufactured by the manufacturing method in Embodiment 1 of this invention The flowchart which shows the manufacturing process of the manufacturing method of the electrolyte membrane electrode assembly in Embodiment 1 of this invention. (A) Schematic diagram showing a first catalyst composition application step in the method for producing an electrolyte membrane-electrode assembly in Embodiment 1 of the present invention (b) Electrolyte membrane-electrode in Embodiment 1 of the present invention Schematic diagram showing the first catalyst layer forming step in the method for producing the joined body (c) Schematic diagram showing the electrolyte membrane humidifying step in the method for producing the electrolyte membrane-electrode assembly in the first embodiment of the present invention. (D) Schematic diagram showing a second catalyst composition application step in the method for producing an electrolyte membrane-electrode assembly in Embodiment 1 of the present invention (e) Electrolyte membrane-electrode in Embodiment 1 of the present invention The schematic diagram which shows the 2nd catalyst layer formation process of the manufacturing method of a conjugate | zygote. The block diagram which shows the electrolyte membrane-electrode assembly manufactured by the manufacturing method in Embodiment 2 of this invention The flowchart which shows the manufacturing process of the manufacturing method of the electrolyte membrane-electrode assembly in Embodiment 2 of this invention. (A) Schematic diagram showing a first catalyst composition application step in the method for producing an electrolyte membrane-electrode assembly in Embodiment 2 of the present invention (b) Electrolyte membrane-electrode in Embodiment 2 of the present invention Schematic diagram showing the solvent displacement catalyst composition forming step in the method for producing the joined body (c) The first catalyst layer forming step in the method for producing the electrolyte membrane-electrode assembly in the second embodiment of the present invention. Schematic diagram showing (d) Schematic diagram showing a second catalyst composition coating step in the method for producing an electrolyte membrane-electrode assembly in Embodiment 2 of the present invention (e) Electrolyte in Embodiment 2 of the present invention The schematic diagram which shows the 2nd catalyst layer formation process in the manufacturing method of a membrane-electrode assembly. The block diagram which shows the electrolyte membrane-electrode assembly manufactured by the manufacturing method in Embodiment 3 of this invention The flowchart which shows the manufacturing process of the manufacturing method of the electrolyte membrane electrode assembly in Embodiment 3 of this invention. (A) Schematic diagram showing the first catalyst composition application step in the method for producing an electrolyte membrane-electrode assembly in Embodiment 3 of the present invention (b) Electrolyte membrane-electrode in Embodiment 3 of the present invention Schematic diagram showing the step of immersing the first catalyst composition applied to the electrolyte membrane in water in the method for producing the joined body (c) of the method for producing the electrolyte membrane-electrode assembly in the third embodiment of the present invention Schematic diagram showing the first catalyst layer forming step (d) Schematic diagram showing the second catalyst composition coating step in the method for producing an electrolyte membrane-electrode assembly in the third embodiment of the present invention (e) ) Schematic diagram showing the second catalyst layer forming step in the method of manufacturing the electrolyte membrane-electrode assembly in the third embodiment of the present invention. The block diagram which shows the electrolyte membrane electrode assembly manufactured by the manufacturing method in Embodiment 4 of this invention The flowchart which shows the manufacturing process of the manufacturing method of the electrolyte membrane electrode assembly in Embodiment 4 of this invention. (A) Schematic diagram showing a first catalyst composition application step in the method for producing an electrolyte membrane-electrode assembly in Embodiment 4 of the present invention (b) Electrolyte membrane-electrode in Embodiment 4 of the present invention Schematic diagram showing the first catalyst layer forming step in the method for producing the joined body (c) Second catalyst composition applying step in the method for producing the electrolyte membrane-electrode assembly in Embodiment 4 of the present invention (D) The schematic diagram which shows the 2nd catalyst layer formation process in the manufacturing method of the electrolyte membrane-electrode assembly in Embodiment 4 of this invention. Configuration diagram showing a conventional electrolyte membrane-electrode assembly

  The first invention is a first catalyst composition coating step in which a first catalyst composition containing a catalyst powder and a dispersion medium is applied to one surface of an electrolyte membrane, and the electrolyte membrane is formed by the first catalyst composition coating step. A first catalyst layer forming step of forming a first catalyst layer on one surface of the electrolyte membrane by removing the dispersion medium from the first catalyst composition applied to the first catalyst layer; and a first catalyst layer forming step An electrolyte membrane humidifying step for humidifying the electrolyte membrane having the first catalyst layer formed on one surface thereof, and a second electrode containing catalyst powder and a dispersion medium on the other surface of the electrolyte membrane humidified in the electrolyte membrane humidifying step. A second catalyst composition applying step for applying the catalyst composition; and removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane by the second catalyst composition applying step, thereby A second catalyst layer forming step of forming a second catalyst layer on the surface of A method of manufacturing an electrode assembly - the electrolyte membrane.

  By the above manufacturing method, the electrolyte membrane having the catalyst layer formed on one surface is humidified, and the electrolyte membrane contains moisture. Therefore, the decrease in the critical surface tension of the electrolyte membrane is suppressed, and the wettability of the catalyst composition with respect to the electrolyte membrane is reduced. It is possible to improve, and it is possible to manufacture an electrolyte membrane-electrode assembly in which the catalyst layer has no defects such as peeling or cracking.

  According to a second aspect of the invention, there is provided a first catalyst composition coating step in which a first catalyst composition including a dispersion medium having a boiling point equal to or higher than that of catalyst powder and water is applied to one surface of the electrolyte membrane; Solvent replacement catalyst composition on one surface of the electrolyte membrane by replacing the dispersion medium of the first catalyst composition applied to the electrolyte membrane by the catalyst composition application step with a solvent having a boiling point less than the boiling point of water A solvent replacement catalyst composition forming step for forming the solvent replacement catalyst composition formed on one surface of the electrolyte membrane by the solvent replacement catalyst composition forming step at a temperature equal to or higher than the boiling point of the solvent and the boiling point of water A first catalyst layer forming step of forming a first catalyst layer on one surface of the electrolyte membrane by removing the solvent from the solvent replacement catalyst composition by heating at a temperature lower than The first catalyst layer is formed on one side by the process A second catalyst composition applying step of applying a second catalyst composition containing catalyst powder and a dispersion medium to the other surface of the electrolyte membrane, and a second catalyst composition applying step applied to the electrolyte membrane by the second catalyst composition applying step. 2 is a method for producing an electrolyte membrane-electrode assembly including a second catalyst layer forming step of forming a second catalyst layer on the other surface of the electrolyte membrane by removing the dispersion medium from the catalyst composition of No. 2.

  By the above production method, the dispersion medium contained in the catalyst composition is solvent-substituted with a solvent having a boiling point lower than the boiling point of water, and the solvent is removed by heating at a temperature lower than the boiling point of water. It is possible to prevent evaporation, suppress a decrease in the critical surface tension of the electrolyte membrane, improve the wettability of the catalyst composition with respect to the electrolyte membrane, and there is no defect such as peeling or cracking in the catalyst layer. The body can be manufactured.

  According to a third aspect of the present invention, there is provided a first catalyst composition coating step in which a first catalyst composition including a dispersion medium having a boiling point equal to or higher than that of catalyst powder and water is applied to one surface of an electrolyte membrane; First catalyst layer formation for forming the first catalyst layer on one surface of the electrolyte membrane by replacing the dispersion medium of the first catalyst composition applied to the electrolyte membrane by the catalyst composition coating step with water And a second catalyst composition containing a catalyst powder and a dispersion medium is applied to the other surface of the electrolyte membrane having the first catalyst layer formed on one surface by the first catalyst layer forming step. By removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane by the catalyst composition application step and the second catalyst composition application step, the second catalyst layer is formed on the other surface of the electrolyte membrane. It is a manufacturing method of the electrolyte membrane electrode assembly including the 2nd catalyst layer formation process to form.

  Since the dispersion medium contained in the catalyst composition is replaced with water by the above production method, the dispersion medium can be removed without heating, so that evaporation of moisture from the electrolyte film is prevented and the criticality of the electrolyte film is reduced. A decrease in surface tension can be suppressed, the wettability of the catalyst composition with respect to the electrolyte membrane can be improved, and an electrolyte membrane-electrode assembly free from defects such as peeling and cracks in the catalyst layer can be produced.

  According to a fourth aspect of the present invention, there is provided a first catalyst composition coating step in which a first catalyst composition including a dispersion medium having a boiling point lower than that of catalyst powder and water is applied to one surface of an electrolyte membrane; The first catalyst composition applied to the electrolyte membrane in the catalyst composition application step is heated at a temperature not lower than the boiling point of the dispersion medium and lower than the boiling point of water to be dispersed from the first catalyst composition. The first catalyst layer forming step of forming the first catalyst layer on one surface of the electrolyte membrane by removing the medium, and the first catalyst layer is formed on one surface by the first catalyst layer forming step A second catalyst composition coating step of applying a second catalyst composition containing a catalyst powder and a dispersion medium to the other surface of the electrolyte membrane, and the electrolyte membrane was coated by the second catalyst composition coating step By removing the dispersion medium from the second catalyst composition, the second surface of the electrolyte membrane is Electrolyte membrane including a second catalyst layer forming step of forming a catalyst layer - is a manufacturing method of the electrode assembly.

  By the above manufacturing method, the dispersion medium contained in the catalyst composition is removed by heating at a temperature lower than the boiling point of water, so that evaporation of moisture from the electrolyte membrane is prevented, and the decrease in the critical surface tension of the electrolyte membrane is suppressed. It becomes possible to improve the wettability of the catalyst composition with respect to the membrane, and it is possible to produce an electrolyte membrane-electrode assembly free from defects such as peeling and cracks in the catalyst layer.

  In particular, the fifth invention is an electrolyte membrane-electrode assembly manufactured by the manufacturing method of the first to fourth inventions.

  Thereby, since the catalyst layers formed on both surfaces of the electrolyte membrane are free from defects such as peeling and cracks, an electrolyte membrane-electrode assembly having excellent quality and high performance can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a configuration diagram of an electrolyte membrane-electrode assembly produced by the method for producing an electrolyte membrane-electrode assembly in Embodiment 1 of the present invention.

  FIG. 2 is a flowchart showing the manufacturing process of the electrolyte membrane-electrode assembly in the first embodiment of the present invention, and FIG. 3 shows the manufacturing method of the electrolyte membrane-electrode assembly in the first embodiment of the present invention. It is a schematic diagram which shows.

  First, the configuration and constituent materials of the electrolyte membrane-electrode assembly according to Embodiment 1 of the present invention will be specifically described with reference to FIG.

  In FIG. 1, an electrolyte membrane-electrode assembly 10 includes an electrolyte membrane 11, a first catalyst layer 12 formed on one surface of the electrolyte membrane 11, and a second surface formed on the other surface of the electrolyte membrane 11. Of the catalyst layer 13.

  The electrolyte membrane 11 is made of a resin having hydrogen ion conductivity. Specifically, the electrolyte membrane 11 is made of a resin having a fluorine-containing polymer as a skeleton and a substituent such as a sulfonic acid group, a carboxyl group, or a phosphoric acid group. Yes.

  The first catalyst layer 12 and the second catalyst layer 13 include a catalyst powder made of carbon particles carrying platinum or a platinum alloy and a polymer electrolyte made of perfluorocarbon sulfonate ionomer.

  Next, the manufacturing method of the electrolyte membrane-electrode assembly in Embodiment 1 of the present invention will be described with reference to FIG.

  As shown in FIG. 2, the manufacturing method of an electrolyte membrane-electrode assembly includes a first catalyst composition application step (S11) for applying a first catalyst composition to one surface of an electrolyte membrane, and an electrolyte membrane. A first catalyst layer forming step (S12) for forming a first catalyst layer on one surface of the electrolyte membrane by removing the dispersion medium from the applied first catalyst composition, and a first catalyst layer forming step on the one surface. An electrolyte membrane humidifying step (S13) for humidifying the electrolyte membrane on which the first catalyst layer is formed, and a second catalyst composition is applied to the other surface of the electrolyte membrane humidified in the electrolyte membrane humidifying step (S13) The second catalyst composition coating step (S14) and a second catalyst layer formed on the other surface of the electrolyte membrane by removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane. The catalyst layer forming step (S15) is included.

  Hereinafter, the manufacturing method of the above-described electrolyte membrane-electrode assembly will be described in detail with reference to FIG. 2 and FIG.

  In the first catalyst composition application step (S11), a first catalyst composition prepared in advance is applied to one surface of the electrolyte membrane.

  Specifically, the electrolyte membrane 32 is fixed, and the first catalyst composition 31 is applied to one surface thereof by a screen printing method ((a) of FIG. 3).

  In the first catalyst layer forming step (S12), the dispersion medium is removed from the first catalyst composition applied to one surface of the electrolyte membrane in the first catalyst composition applying step (S11), and the electrolyte membrane A first catalyst layer is formed on one surface.

  Specifically, the first catalyst composition 31 applied to the electrolyte membrane 32 is heated under predetermined conditions to remove the dispersion medium from the first catalyst composition 31, so that one surface of the electrolyte membrane 32 is formed. The first catalyst layer 33 is formed (FIG. 3B).

  In the electrolyte membrane humidification step (S13), the other surface of the electrolyte membrane in which the first catalyst layer is formed on one surface in the first catalyst layer formation step (S12) is humidified.

  Specifically, water vapor is sprayed onto the electrolyte membrane 32 to humidify the electrolyte membrane 32 on which the first catalyst layer 33 is formed ((c) in FIG. 3).

  In the second catalyst composition application step (S14), the second catalyst composition prepared in advance is applied to the other surface of the electrolyte membrane humidified in the electrolyte membrane humidification step (S13).

  Specifically, the electrolyte membrane 32 is fixed so that the humidified other surface of the electrolyte membrane 32 having the first catalyst layer 33 formed on one surface becomes the upper surface, and the second catalyst composition is fixed on the surface. The object 34 is applied by a screen printing method ((d) of FIG. 3).

  In the second catalyst layer forming step (S15), the dispersion medium is removed from the second catalyst composition applied to the electrolyte membrane in the second catalyst composition applying step (S14), and the other surface of the electrolyte membrane is formed. A second catalyst layer is formed.

  Specifically, the second catalyst composition 34 applied to the other surface of the electrolyte membrane 32 having the first catalyst layer 33 formed on one surface is heated under a predetermined condition, whereby the second The dispersion medium is removed from the catalyst composition 34, the second catalyst layer 35 is formed on the other surface of the electrolyte membrane 32, and the electrolyte membrane-electrode assembly 30 is manufactured ((e) of FIG. 3).

  Hereinafter, although the manufacturing method of the electrolyte membrane-electrode assembly according to the present embodiment will be described in more detail based on specific examples, the present invention is not necessarily limited to the contents of the specific raw materials used below. It is not limited.

Example 1
In this embodiment, after the first catalyst layer is formed on one surface of the electrolyte membrane, the electrolyte membrane on which the first catalyst layer is formed is humidified, and the second catalyst layer is formed on the other surface of the electrolyte membrane. An electrolyte membrane-electrode assembly was produced by forming the membrane.

  First, the 1st catalyst composition was produced in the following procedures. That is, 15 parts by weight of platinum-supported carbon powder (manufactured by Tanaka Kikinzoku Co., Ltd., product number: TEC10E50E) as catalyst powder, and 50 parts by weight of Nafion 10% dispersion (manufactured by Sigma-Aldrich, product number: 527114) as polymer electrolyte. As a dispersion medium, 20 parts by weight of pure water and 45 parts by weight of ethyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., boiling point 78.4 ° C.) are collected in a container, and a dispersion machine (manufactured by Seiwa Giken Co., Ltd., product name: RS-05W) and an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho Co., Ltd., product name: US-150E) are kneaded at room temperature for 2 hours and referred to as a first catalyst composition (hereinafter referred to as catalyst composition a). ) Was produced.

  When the surface tension of the catalyst composition a thus prepared was measured using a surface tension meter (model number: DY-300, manufactured by Kyowa Interface Science Co., Ltd.), the surface tension of the catalyst composition a at 20 ° C. was 30.2 mN. / M.

  Next, the 2nd catalyst composition was produced in the following procedures. In other words, 15 parts by weight of a carbon powder carrying platinum and ruthenium (manufactured by Tanaka Kikinzoku Co., Ltd., product number: TEC66E50) as a catalyst powder, and a 10% Nafion dispersion as a polymer electrolyte (manufactured by Sigma Aldrich, product number: 527114) 50 parts by weight, 20 parts by weight of pure water as a dispersion medium and 45 parts by weight of ethyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., boiling point 78.4 ° C.) were collected in a container, and a dispersing machine (manufactured by Seiwa Giken Co., Ltd.) A product name: RS-05W) and an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho, product name: US-150E) were kneaded at room temperature for 2 hours, and a second catalyst composition (hereinafter referred to as catalyst composition). b)).

  When the surface tension of the catalyst composition b produced in this way was measured using a surface tension meter (model number: DY-300, manufactured by Kyowa Interface Science Co., Ltd.), the surface tension at 20 ° C. of the catalyst composition b was 30.2 mN. / M.

  Subsequently, the following steps were performed to produce an electrolyte membrane-electrode assembly.

  The 1st 1st catalyst composition application | coating process is demonstrated.

  First, Nafion 112 (manufactured by DuPont), which is a perfluorocarbon sulfonic acid film, was prepared as an electrolyte membrane, and the critical surface tension of Nafion 112 was determined by the Jisman plot method.

  That is, wetting index standard solutions having various surface tensions (manufactured by Wako Pure Chemical Industries, Ltd., product name: Wet tension test mixed solution) are attached to the surface of Nafion 112, and the respective contact angles θ are measured by contact angle meters. (Kyowa Interface Science Co., Ltd., model number: DM-901).

  Next, cos θ is plotted on the horizontal axis, and surface tensions of various wetting index standard solutions are plotted on the vertical axis to determine the surface tension at which cos θ = 1, and this surface tension is taken as the critical surface tension of Nafion 112.

  As a result, the critical surface tension of Nafion 112 at 20 ° C. was 31.2 mN / m.

  Next, separately from the Nafion 112 whose critical surface tension was measured, three new Nafion 112 were prepared, and a screen printing machine (manufactured by Neurong Seimitsu Kogyo Co., Ltd., product name: DP-) was prepared on one of them. 320), the catalyst composition a was applied by screen printing.

  The second first catalyst layer forming step will be described.

  In the first catalyst composition application process described above, the three Nafion 112 coated with the catalyst composition a are left for 1 hour in a thermostat set to 110 ° C. (manufactured by Yamato Scientific Co., Ltd., model number: DKM300). Thus, after removing the dispersion medium by heating the catalyst composition a, the catalyst composition a was left at room temperature for 2 hours to form a catalyst layer (hereinafter referred to as catalyst layer A-1) on one surface of each Nafion 112. .

  Subsequently, for one of the three Nafions 112 on which the catalyst layer A-1 is formed by the above-described method, the critical surface tension of the other surface of the surface on which the catalyst layer A-1 is formed is expressed as a Jisman plot. Obtained by law.

  That is, a wetting index standard solution having various surface tensions (manufactured by Wako Pure Chemical Industries, Ltd., product name: mixed solution for wetting tension test) on the other side of the surface on which the catalyst layer A-1 of Nafion 112 is formed. Each contact angle θ was measured using a contact angle meter (Kyowa Interface Science Co., Ltd., model number: DM-901).

  Next, cos θ is plotted on the horizontal axis, and surface tensions of various wetting index standard solutions are plotted on the vertical axis to determine the surface tension at which cos θ = 1, and this surface tension is defined as the critical surface tension of the surface.

  As a result, the critical surface tension at 20 ° C. of the other surface of the Nafion 112 on which the catalyst layer A-1 is formed is 29.0 mN / m, and the surface of the Nafion 112 on which the catalyst layer A-1 is formed. It was smaller than the critical surface tension.

The critical surface tension of the other surface of the Nafion 112 on which the catalyst layer A-1 is formed is reduced because the Nafion 112 is exposed to a temperature higher than the boiling point of water in the formation process of the catalyst layer A-1. This is probably because the water contained in the Nafion 112 has evaporated.

  A third electrolyte membrane humidification step will be described.

  Of the three Nafion 112 having the catalyst layer A-1 formed on one surface by the first catalyst layer forming step described above, the critical surface tension of the other surface on which the catalyst layer A-1 is formed is Using the ultrasonic humidifier (made by Wetmaster Co., Ltd .: product name ENA1200), water vapor was sprayed on Nafion 112 to form catalyst layer A-1 for the remaining two sheets different from the measured ones. The Nafion 112 was humidified (hereinafter, the other surface on which the catalyst layer A-1 of the Nafion 112 humidified by the above-described method was formed is referred to as a humidified surface).

  Next, the critical surface tension of the humidified surface of one of the two Nafions 112 humidified by the method described above was determined by the same Zisman plot method.

  As a result, the critical surface tension at 20 ° C. of the humidified surface of Nafion 112 was 31.0 mN / m, which was almost the same as the critical surface tension of the surface of Nafion 112 on which catalyst layer A-1 was formed.

  The critical surface tension of the humidified surface of Nafion 112 was almost the same as the critical surface tension of the surface on which the catalyst layer A-1 was formed because the Nafion 112 on which the catalyst layer A-1 was formed was humidified. It is considered that Nafion 112 contains moisture.

  A fourth second catalyst composition coating step will be described.

  Of the two Nafion 112 humidified by the electrolyte membrane humidification process described above, the screen printer described above was used on the humidified surface of the remaining one other than the one that measured the critical surface tension of the humidified surface. Then, the above-described catalyst composition b was applied by a screen printing method.

  A fifth second catalyst layer forming step will be described.

  By leaving the Nafion 112 coated with the catalyst composition b in the above-mentioned incubator set at 110 ° C. for 1 hour, the catalyst composition b is heated to remove the dispersion medium, and then left at room temperature for 2 hours. A catalyst layer (hereinafter referred to as catalyst layer B-1) is formed on the other surface of the Nafion 112 on which the catalyst layer A-1 is formed, and an electrolyte membrane-electrode assembly (hereinafter, electrolyte membrane-electrode assembly AB) is formed. -1)).

  When the surface of the electrolyte membrane-electrode assembly AB-1 thus produced was observed with the naked eye, the catalyst layer A-1 and the catalyst layer B-1 were free from peeling and cracking.

(Example 2)
In this example, the same manufacturing method as in Example 1 described above, except that the base material was previously disposed on the entire surface of one side of the electrolyte membrane, and that the humidification of the electrolyte membrane was performed after the base material was peeled off. Thus, an electrolyte membrane-electrode assembly was produced.

  First, Nafion 112 is prepared as an electrolyte membrane, catalyst composition a as a first catalyst composition, catalyst composition b as a second catalyst composition, and a sheet made of polyethylene terephthalate having a thickness of 100 μm as a substrate. (Hereinafter referred to as “PET sheet”) was prepared, and the Nafion 112 was placed on the PET sheet so that one whole surface of the Nafion 112 was in close contact with the PET sheet.

  Next, the first first catalyst composition coating step and the second first catalyst layer forming step of Example 1 are performed, and the catalyst layer is formed on the surface opposite to the surface on which the PET sheet of Nafion 112 is disposed. (Hereinafter referred to as catalyst layer A-2).

  Subsequently, after the PET sheet was peeled from the Nafion 112 on which the catalyst layer A-2 was formed, the third electrolyte membrane humidification step of Example 1 was performed to humidify the Nafion 112.

  Thereafter, the fourth second catalyst composition coating step and the fifth second catalyst layer forming step of Example 1 are performed, and the catalyst is formed on the other surface of the Nafion 112 on which the catalyst layer A-2 is formed. A layer (hereinafter referred to as catalyst layer B-2) was formed to produce a polymer electrolyte electrode assembly (hereinafter referred to as electrolyte membrane-electrode assembly AB-2).

  When the surface of the electrolyte membrane-electrode assembly AB-2 produced in this manner was visually observed, the catalyst layer A-2 and the catalyst layer B-2 were free from peeling and cracking.

(Comparative Example 1)
An electrolyte membrane-electrode assembly was produced by the same production method as in Example 1 except that the electrolyte membrane was not humidified.

  First, Nafion 112 is prepared as an electrolyte membrane, catalyst composition a is prepared as a first catalyst composition, and catalyst composition b is prepared as a second catalyst composition, and the first first catalyst composition of Example 1 is prepared. The coating step and the second first catalyst layer forming step were performed to form a catalyst layer (hereinafter referred to as catalyst layer A-3) on one surface of Nafion 112.

  Thereafter, the fourth second catalyst composition coating step and the fifth second catalyst layer forming step of Example 1 are performed, and the catalyst is formed on the other surface of the Nafion 112 on which the catalyst layer A-3 is formed. A layer (hereinafter referred to as catalyst layer B-3) was formed to produce a polymer electrolyte electrode assembly (hereinafter referred to as electrolyte membrane-electrode assembly AB-3).

  When the surface of the electrolyte membrane-electrode assembly AB-3 thus produced was visually observed, the catalyst layer A-3 was free from peeling and cracking, but the catalyst layer B-3 was part of the catalyst layer. Peeling occurred, and many cracks existed even in the portion where the catalyst layer was present.

(Comparative Example 2)
An electrolyte membrane-electrode assembly was produced by the same production method as in Example 2 described above, except that the electrolyte membrane was not humidified.

  First, Nafion 112 is prepared as an electrolyte membrane, catalyst composition a is prepared as a first catalyst composition, catalyst composition b is prepared as a second catalyst composition, and a PET sheet is prepared as a substrate. The Nafion 112 was placed on the PET sheet so that the entire surface of one surface of the 112 was in close contact with the PET sheet.

  Next, the first first catalyst composition coating step and the second first catalyst layer forming step of Example 1 are performed, and the catalyst layer (on the surface opposite to the surface on which the PET sheet of Nafion 112 is disposed) Hereinafter, catalyst layer A-4) was formed.

Thereafter, after peeling the PET sheet from the Nafion 112, the fourth second catalyst composition coating step and the fifth second catalyst layer forming step of Example 1 are performed, and the catalyst layer A-3 of the Nafion 112 is formed. A catalyst layer (hereinafter referred to as catalyst layer B-4) was formed on the other surface of the formed surface to produce a polymer electrolyte electrode assembly (hereinafter referred to as electrolyte membrane-electrode assembly AB-4). .

  When the surface of the electrolyte membrane-electrode assembly AB-4 thus produced was visually observed, the catalyst layer A-4 was free from peeling and cracking, but the catalyst layer B-4 was part of the catalyst layer. Peeling occurred, and many cracks existed even in the portion where the catalyst layer was present.

  The above results are summarized in (Table 1).

電解質膜−電極接合体の触媒層の剥がれやクラックに関し、本実施例に係る電解質膜−電極接合体（電解質膜−電極接合体ＡＢ−１、ＡＢ−２）は、触媒層に剥がれやクラックは無く、品質に優れるものであった。

Regarding the peeling and cracking of the catalyst layer of the electrolyte membrane-electrode assembly, the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly AB-1, AB-2) according to the present example is not peeled or cracked on the catalyst layer. There was no quality.

  This is presumably because the catalyst compositions a and b were wet with the Nafion 112 and a uniform catalyst layer could be formed because the surface tension of the catalyst compositions a and b was smaller than the critical surface tension of the Nafion 112.

  On the other hand, the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly AB-3, AB-4) of Comparative Example 1 and Comparative Example 2 had neither peeling nor cracking in one catalyst layer, but the other catalyst In the layer, peeling and cracking occurred, and the quality was inferior to that of the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly AB-1, AB-2) according to this example.

  This is because in the catalyst layer on the side where there was no peeling or cracking, the surface tension of the catalyst composition a is smaller than the critical surface tension of the application surface of the catalyst composition a of the Nafion 112. This is probably because the catalyst layer on the side where peeling or cracking occurred was generated in the catalyst layer formation process, and Nafion 112 lost water and the critical surface tension was reduced. Therefore, since the surface tension of the catalyst composition b becomes larger than the critical surface tension of the application surface of the catalyst composition b of the Nafion 112, the catalyst composition b does not get wet with the Nafion 112 and a uniform catalyst layer can be formed. It is thought that it was not possible.

  Subsequently, in order to investigate the performance of each of the above-described electrolyte membrane-electrode assemblies and examine the influence on the power generation performance of the fuel cell, a single cell (1) is used by using the electrolyte membrane-electrode assemblies AB-1 to AB-4. ) To (4) were produced and a power generation test was performed.

  Here, in the cells (1) to (4), the gas diffusion layers are arranged on both surfaces of the electrolyte membrane-electrode assemblies AB-1 to AB-4, and then the electrolyte membrane-electrode assemblies AB-1 to AB. -4 and a gas diffusion layer gasket (Kureha Elastomer Co., Ltd., product number: SB50NJP) bonded to the outer periphery of the gas diffusion layer, and a separator composed of a resin-impregnated graphite plate having a gas flow path formed on the surface. The electrolyte membrane-electrode assembly was disposed on both sides.

  The gas diffusion layer is made of carbon paper (manufactured by Toray Industries, Inc., product name: TGP-H-120), a dispersion of acetylene black and polytetrafluoroethylene (manufactured by Daikin Industries, Ltd., product name: D-1) and A mixture of pure water was applied and heated at 350 ° C. for 2 hours.

In addition, the power generation performance of the cells (1) to (4) is such that air is passed through the air electrode, hydrogen gas containing 25% carbon dioxide and 50 ppm carbon monoxide is passed through the fuel electrode, the battery temperature is 80 ° C., air The battery voltage was measured when power was generated at a current density of 0.2 A / cm ² with a utilization rate of 40%, fuel utilization rate of 80%, air dew point of 60 ° C. and hydrogen gas dew point of 75 ° C. . The battery voltages of the cells (1) to (4) are shown in (Table 2).

本実施例に係る触媒層にクラックや剥れが無い電解質膜−電極接合体（電解質膜−電極接合体ＡＢ−１、ＡＢ−２）を用いた単電池（単電池(1)、(2)）は、比較例に係る触媒層にクラックや剥れがある電解質膜−電極接合体（電解質膜−電極接合体ＡＢ−３、ＡＢ−４）を用いた単電池（単電池(3)、(4)）に比べ、電池電圧が高くなった。

Single cell (single cell (1), (2)) using an electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly AB-1, AB-2) having no cracks or peeling in the catalyst layer according to this example ) Is a single cell (unit cell (3), (4)) using an electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly AB-3, AB-4) in which the catalyst layer according to the comparative example has cracks or peeling. Battery voltage is higher than 4)).

  This is because the catalyst compositions a and b get wet with the Nafion 112 to form a uniform catalyst layer without peeling or cracking, and the performance of the electrolyte membrane-electrode assembly is improved. This is probably because the power generation performance of the fuel cell has improved compared to

  From the above power generation test, it is confirmed that the electrolyte membrane-electrode assembly AB-1 and AB-2 produced in the present embodiment can improve the performance of the electrolyte membrane-electrode assembly and improve the power generation performance of the fuel cell. did it.

(Embodiment 2)
FIG. 4 shows a configuration diagram of an electrolyte membrane-electrode assembly produced by the method for producing an electrolyte membrane-electrode assembly in the second embodiment of the present invention.

  FIG. 5 is a flowchart showing a manufacturing process of the electrolyte membrane-electrode assembly in the second embodiment of the present invention, and FIG. 6 is a manufacturing method of the electrolyte membrane-electrode assembly in the second embodiment of the present invention. It is a schematic diagram which shows.

  First, the configuration and constituent materials of the electrolyte membrane-electrode assembly according to Embodiment 2 of the present invention will be specifically described with reference to FIG.

  In FIG. 4, an electrolyte membrane-electrode assembly 40 includes an electrolyte membrane 41, a first catalyst layer 42 formed on one surface of the electrolyte membrane 41, and a second surface formed on the other surface of the electrolyte membrane 41. The catalyst layer 43 is composed of

  The electrolyte membrane 41 is made of a resin having hydrogen ion conductivity. Specifically, the electrolyte membrane 41 is made of a resin having a fluorine-containing polymer as a skeleton and a substituent such as a sulfonic acid group, a carboxyl group, or a phosphoric acid group. Yes.

  The first catalyst layer 42 and the second catalyst layer 43 include a catalyst powder made of carbon particles carrying platinum or a platinum alloy and a polymer electrolyte made of perfluorocarbon sulfonate ionomer.

  Next, a method for manufacturing an electrolyte membrane-electrode assembly in Embodiment 2 of the present invention will be described with reference to FIG.

  As shown in FIG. 5, the manufacturing method of the electrolyte membrane-electrode assembly includes a first catalyst composition application step (S21) in which the first catalyst composition is applied to one surface of the electrolyte membrane, and the electrolyte membrane. Solvent replacement catalyst composition formation in which the dispersion medium contained in the applied first catalyst composition is solvent-substituted with a solvent having a boiling point lower than that of water to form a solvent replacement catalyst composition on one surface of the electrolyte membrane A step (S22), a first catalyst layer forming step (S23) for forming a first catalyst layer on one surface of the electrolyte membrane by removing the solvent from the solvent replacement catalyst composition, A second catalyst composition coating step (S24) in which the second catalyst composition is coated on the other surface of the surface on which the first catalyst layer is formed, and the second catalyst composition coated on the electrolyte membrane is dispersed. The second catalyst layer is formed on the other surface of the electrolyte membrane by removing the medium. It includes a second catalyst layer forming step (S25).

  Hereinafter, the manufacturing method of the above-described electrolyte membrane-electrode assembly will be described in further detail with reference to FIG. 5 and FIG.

  In the first catalyst composition application step (21), a first catalyst composition prepared in advance is applied to one surface of the electrolyte membrane. Specifically, the electrolyte membrane 62 is fixed, and the first catalyst composition 61 is applied to one surface thereof by a screen printing method ((a) of FIG. 6).

  In the solvent replacement catalyst composition formation step (S22), the dispersion medium contained in the first catalyst composition applied to one surface of the electrolyte membrane in the first catalyst composition application step (S21) is less than the boiling point of water. The solvent is replaced with a solvent having a boiling point.

  Specifically, a container storing a solvent 63 having a boiling point less than the boiling point of water is prepared, and the first catalyst composition 61 applied to the electrolyte membrane 62 is immersed in the solvent 63, so that the first catalyst composition is immersed. The dispersion medium contained in 61 is replaced with the solvent 63 to form the solvent replacement catalyst composition 64 on one surface of the electrolyte membrane 62 ((b) of FIG. 6).

  In the first catalyst layer forming step (S23), the first catalyst layer is formed by removing the solvent from the solvent replacement catalyst composition formed on one surface of the electrolyte membrane in the solvent replacement catalyst composition forming step (S22). Form.

  Specifically, the solvent substitution catalyst composition 64 formed on one surface of the electrolyte membrane 62 is heated at a predetermined temperature to remove the solvent from the solvent substitution catalyst composition 64, and one of the electrolyte membranes 62. A first catalyst layer 65 is formed on the surface ((c) of FIG. 6).

  In the second catalyst composition application step (S24), a second catalyst composition prepared in advance is applied to the other surface of the electrolyte membrane.

  Specifically, the electrolyte membrane 62 is fixed so that the other surface of the electrolyte membrane 62 having the first catalyst layer 65 formed on one surface is the upper surface, and the first catalyst layer 65 of the electrolyte membrane 62 is fixed. The second catalyst composition 66 is applied by screen printing to the other surface of the surface on which is formed ((d) of FIG. 6).

  In the second catalyst layer forming step (S25), the dispersion medium is removed from the second catalyst composition applied to the electrolyte membrane in the second catalyst composition applying step (S24) to form the second catalyst layer. .

  Specifically, the second catalyst composition 66 applied to the other surface of the electrolyte membrane 62 having the first catalyst layer 65 formed on one surface is heated under a predetermined condition, whereby the second The dispersion medium is removed from the catalyst composition 66, the second catalyst layer 67 is formed on the other surface of the electrolyte membrane 62, and the electrolyte membrane-electrode assembly 60 is manufactured ((e) of FIG. 6).

  Hereinafter, although the manufacturing method of the electrolyte membrane-electrode assembly according to the present embodiment will be described in more detail based on specific examples, the present invention is not necessarily limited to the contents of the specific raw materials used below. It is not limited.

(Example 3)
In this example, a catalyst composition is applied to one surface of an electrolyte membrane, and the solvent contained in the catalyst composition is replaced with a solvent having a boiling point lower than that of water to form a solvent-substituted catalyst composition. Then, the solvent was removed from the solvent-substituted catalyst composition to form a catalyst layer, and an electrolyte membrane-electrode assembly was manufactured.

  First, the 1st catalyst composition was produced in the following procedures. That is, 15 parts by weight of platinum-supported carbon powder (manufactured by Tanaka Kikinzoku Co., Ltd., product number: TEC10E50E) as catalyst powder, and 50 parts by weight of Nafion 10% dispersion (manufactured by Sigma-Aldrich, product number: 527114) as polymer electrolyte. As a dispersion medium, 20 parts by weight of pure water and 55 parts by weight of n-butanol (manufactured by Wako Pure Chemical Industries, Ltd., boiling point 117 ° C.) are collected in a container, and a disperser (Seiwa Giken Co., Ltd., product name: RS) -05W) and an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho, product name: US-150E), the mixture is kneaded at room temperature for 2 hours, and the first catalyst composition (hereinafter referred to as catalyst composition c). Was made.

  When the surface tension of the catalyst composition c thus prepared was measured using a surface tension meter (model number: DY-300, manufactured by Kyowa Interface Science Co., Ltd.), the surface tension at 20 ° C. of the catalyst composition c was 29.0 mN. / M.

Next, the 2nd catalyst composition was produced in the following procedures. In other words, 15 parts by weight of a carbon powder carrying platinum and ruthenium (manufactured by Tanaka Kikinzoku Co., Ltd., product number: TEC66E50) as a catalyst powder, and a 10% Nafion dispersion as a polymer electrolyte (manufactured by Sigma Aldrich, product number: 527114) 50 parts by weight, 20 parts by weight of pure water as a dispersion medium and 55 parts by weight of ethyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., boiling point 78.4 ° C.) were collected in a container, and a dispersing machine (manufactured by Seiwa Giken Co., Ltd.) A product name: RS-05W) and an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho, product name: US-150E) were kneaded at room temperature for 2 hours, and a second catalyst composition (hereinafter referred to as catalyst composition). d)).

  When the surface tension of the catalyst composition d thus prepared was measured using a surface tension meter (model number: DY-300, manufactured by Kyowa Interface Science Co., Ltd.), the surface tension at 20 ° C. of the catalyst composition d was 28.5 mN. / M.

  Subsequently, the following steps were performed to produce an electrolyte membrane-electrode assembly.

  The 1st 1st catalyst composition application | coating process is demonstrated.

  Two electrolyte membranes, Nafion 112 (manufactured by DuPont, critical surface tension at 20 ° C. of 31.2 mN / m), were prepared. Co., Ltd .: Product name: DP-320) was used to apply the catalyst composition c described above by screen printing.

  The second solvent replacement catalyst composition forming step will be described.

  A container in which pentane (Wako Pure Chemical Industries, Ltd., boiling point: 36.1 ° C.) is stored as two Nafion 112 coated with the catalyst composition c on one side by the first catalyst composition coating step described above. Soaked in.

  At this time, the amount of pentane was set so that the catalyst composition c was soaked so that only the catalyst composition c was immersed in pentane with the Nafion 112 on the upper side and the catalyst composition c on the lower side. After immersing in this state for 30 minutes, Nafion 112 was taken out of the container, and a solvent substitution catalyst composition was formed on one surface of Nafion 112.

  A third first catalyst layer forming step will be described.

  1 in a thermostat (manufactured by Yamato Scientific Co., Ltd., model number: DKM300) in which two Nafion 112 having a solvent substitution catalyst composition formed on one surface by the above-described solvent substitution catalyst composition formation step is set to 50 ° C. By leaving it for a period of time, pentane was removed from the solvent-substituted catalyst composition, and then left at room temperature for 2 hours to form a catalyst layer (hereinafter referred to as catalyst layer C-1) on one surface of Nafion 112.

  Of the two Nafions 112 on which the catalyst layer C-1 is formed by the above-described method, the critical surface tension of the other surface of the surface on which the catalyst layer C-1 is formed is obtained by the Jisman plot method. It was.

  That is, a wetting index standard solution having various surface tensions (manufactured by Wako Pure Chemical Industries, Ltd., product name: mixed solution for wetting tension test) is the other surface of the surface on which the catalyst layer C-1 of Nafion 112 is formed. Each contact angle θ was measured using a contact angle meter (Kyowa Interface Science Co., Ltd., model number: DM-901).

  Next, cos θ is plotted on the horizontal axis, and surface tensions of various wetting index standard solutions are plotted on the vertical axis to determine the surface tension at which cos θ = 1, and this surface tension is defined as the critical surface tension of the surface.

  As a result, the critical surface tension of the surface of Nafion 112 at 20 ° C. was 31.2 mN / m, which was the same as the critical surface tension of the surface of Nafion 112 on which the catalyst layer C-1 was formed.

  The critical surface tension of the other surface of the surface of the Nafion 112 on which the catalyst layer C-1 was formed was the same as the critical surface tension of the surface of the Nafion 112 on which the catalyst layer C-1 was formed. This is probably because the Nafion 112 was not heated to a temperature equal to or higher than the boiling point of water in the C-1 formation process, and the water did not evaporate from the Nafion 112.

  A fourth second catalyst composition coating step will be described.

  Of the two Nafions 112 on which the catalyst layer C-1 is formed by the first catalyst layer forming step described above, the catalyst layer C-1 is the remaining one other than the one that has measured the critical surface tension. On the other side of the formed surface, the above-described catalyst composition d was applied by a screen printing method using the screen printing machine described above.

  A fifth second catalyst layer forming step will be described.

  The dispersion medium is heated from the catalyst composition d by leaving the Nafion 112 coated with the catalyst composition d in a thermostat set to 110 ° C. (manufactured by Yamato Scientific Co., Ltd., model number: DKM300) for 1 hour. After removal, the substrate is left at room temperature for 2 hours to form a catalyst layer (hereinafter referred to as catalyst layer D-1) on the other surface of Nafion 112, and an electrolyte membrane-electrode assembly (hereinafter referred to as electrolyte membrane-electrode junction). Body CD-1).

  When the surface of the thus produced electrolyte membrane-electrode assembly CD-1 was visually observed, the catalyst layer C-1 and the catalyst layer D-1 were free from peeling and cracking.

(Comparative Example 3)
The dispersion medium of the first catalyst composition was not replaced with a solvent, the temperature of the incubator in the first catalyst layer forming step was changed from 50 ° C. to 130 ° C., and the first catalyst composition applied to the electrolyte membrane was changed to An electrolyte membrane-electrode assembly was produced by the same production method as in Example 3 except that the heating temperature was changed from 50 ° C to 130 ° C.

  First, two sheets of Nafion 112 (manufactured by DuPont, whose critical surface tension at 20 ° C. is 31.2 mN / m) are prepared as electrolyte membranes, and the catalyst composition c is used as the first catalyst composition. The catalyst composition d was prepared as the catalyst composition of No. 2, and the first first catalyst composition application step of Example 3 was performed to apply the catalyst composition c to one surface of each Nafion 112.

  Subsequently, the two Nafions coated with the catalyst composition c on one surface were allowed to stand for 1 hour in a thermostat set to 130 ° C. (model number: DKM300, manufactured by Yamato Scientific Co., Ltd.), whereby the catalyst composition c Is heated at 130 ° C., which is equal to or higher than the boiling point of n-butanol, to remove n-butanol, and then left at room temperature for 2 hours to form a catalyst layer (hereinafter referred to as catalyst layer C-2 on one side of Nafion 112). Formed).

  Next, the critical surface tension of the other surface on which the catalyst layer C-2 is formed is the same as the above for one of the two Nafions 112 on which the catalyst layer C-2 is formed by the method described above. It was determined by the Jisman plot method.

As a result, the critical surface tension at 20 ° C. of the other surface of the Nafion 112 on which the catalyst layer C-2 is formed is 28.0 mN / m, and the surface of the Nafion 112 on which the catalyst layer C-1 is formed. It was smaller than the critical surface tension.

  The critical surface tension of the other surface of the Nafion 112 on which the catalyst layer C-2 is formed is reduced because the Nafion 112 is exposed to a temperature higher than the boiling point of water in the formation process of the catalyst layer C-2. This is probably because the water contained in the Nafion 112 has evaporated.

  After that, out of the two Nafion 112 on which the catalyst layer C-2 was formed, one example different from the one on which the critical surface tension of the other surface on which the catalyst layer C-2 was formed was measured 3, the fourth second catalyst composition coating step and the fifth second catalyst layer forming step, and a catalyst layer (hereinafter referred to as “the catalyst layer”) is formed on the other surface of the Nafion 112 on which the catalyst layer C-2 is formed. Catalyst layer D-2) was formed to produce a polymer electrolyte electrode assembly (hereinafter referred to as electrolyte membrane-electrode assembly CD-2).

  When the surface of the thus produced electrolyte membrane-electrode assembly CD-2 was visually observed, the catalyst layer C-2 was free from peeling and cracking, but the catalyst layer D-2 was part of the catalyst layer. Peeling occurred, and many cracks existed even in the portion where the catalyst layer was present.

  The above results are summarized in (Table 3).

電解質膜−電極接合体の触媒層の剥がれやクラックに関し、本実施例に係る電解質膜−電極接合体（電解質膜−電極接合体ＣＤ−１）は、触媒層に剥がれやクラックが無く、品質に優れるものであった。

Regarding the peeling and cracking of the catalyst layer of the electrolyte membrane-electrode assembly, the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly CD-1) according to this example has no peeling or cracking on the catalyst layer, and the quality is improved. It was excellent.

  This is presumably because the catalyst compositions c and d were smaller than the critical surface tension of the Nafion 112, so that the catalyst compositions c and d were wetted by the Nafion 112 and a uniform catalyst layer could be formed.

  On the other hand, the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly CD-2) of Comparative Example 3 did not peel or crack in one catalyst layer, but peeled or cracked in the other catalyst layer. However, compared with the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly CD-1) according to this example, the quality was inferior.

This is because, in the catalyst layer on the side where there was no peeling or cracking, the surface tension of the catalyst composition c is smaller than the critical surface tension of the application surface of the catalyst composition c of the Nafion 112, so that the catalyst composition c becomes the Nafion 112. This is probably because the catalyst layer on the side where peeling or cracking occurred was generated in the catalyst layer formation process, and Nafion 112 lost water and the critical surface tension was reduced. Therefore, since the surface tension of the catalyst composition d becomes larger than the critical surface tension of the application surface of the catalyst composition d of the Nafion 112, the catalyst composition d does not get wet with the Nafion 112, and a uniform catalyst layer can be formed. It is thought that it was not possible.

  Subsequently, in order to investigate the performance of each of the above-described electrolyte membrane-electrode assemblies and examine the influence on the power generation performance of the fuel cell, a single cell (5 ) And (6) were produced and a power generation test was conducted.

  Here, the single cells (5) and (6) are arranged on both surfaces of the electrolyte membrane-electrode assembly (5) and (6), and then the electrolyte membrane-electrode assembly (5), ( 6) and a gasket composed of a resin-impregnated graphite plate having a gas flow path formed on the surface of a gasket (made by Kureha Elastomer Co., Ltd., product number: SB50NJP) made of a silicone resin, is bonded to the outer periphery of the gas diffusion layer. The electrolyte membrane-electrode assembly was disposed on both sides.

  The gas diffusion layer is made of carbon paper (Toray Industries, product name: TGP-H-120), acetylene black and polytetrafluoroethylene dispersion (Daikin Industries, product name: D-). A mixture of 1) and pure water was applied and heated at 350 ° C. for 2 hours.

The power generation performance of the cells (5) and (6) is that air flows through the air electrode, hydrogen gas containing 25% carbon dioxide and 50 ppm carbon monoxide flows through the fuel electrode, the battery temperature is 80 ° C, and air is used. The battery voltage was measured when power was generated at a current density of 0.2 A / cm ² with a rate of 40%, a fuel utilization of 80%, an air dew point of 60 ° C., and a hydrogen gas dew point of 75 ° C.

  The battery voltages of the cells (5) and (6) are shown in (Table 4).

本実施例に係る触媒層にクラックや剥れが無い電解質膜−電極接合体（電解質膜−電極接合体ＣＤ−１）を用いた単電池（単電池(5)）は、比較例に係る触媒層にクラックや剥れがある電解質膜−電極接合体（電解質膜−電極接合体ＣＤ−２）を用いた単電池（単電池(6)）に比べ、電池電圧が高くなった。

A single cell (single cell (5)) using an electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly CD-1) having no cracks or peeling in the catalyst layer according to this example is a catalyst according to a comparative example. The battery voltage was higher than that of the unit cell (unit cell (6)) using the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly CD-2) having cracks or peeling in the layer.

  This is because the catalyst compositions c and d get wet with the Nafion 112 to form a uniform catalyst layer without peeling or cracking, and the performance of the electrolyte membrane-electrode assembly is improved. This is probably because the power generation performance of the fuel cell has improved.

  From the above power generation test, it was confirmed that the electrolyte membrane-electrode assembly CD-1 produced in the present embodiment can improve the performance of the electrolyte membrane-electrode assembly and improve the power generation performance of the fuel cell.

(Embodiment 3)
FIG. 7 shows a configuration diagram of an electrolyte membrane-electrode assembly manufactured by the method of manufacturing an electrolyte membrane-electrode assembly in Embodiment 3 of the present invention.

  FIG. 8 is a flowchart showing a manufacturing process of the electrolyte membrane-electrode assembly in the third embodiment of the present invention, and FIG. 9 shows a manufacturing method of the electrolyte membrane-electrode assembly in the third embodiment of the present invention. It is a schematic diagram which shows.

  First, the configuration and constituent materials of the electrolyte membrane-electrode assembly according to Embodiment 3 of the present invention will be specifically described with reference to FIG.

  In FIG. 7, an electrolyte membrane-electrode assembly 70 includes an electrolyte membrane 71, a first catalyst layer 72 formed on one surface of the electrolyte membrane 71, and a second surface formed on the other surface of the electrolyte membrane 71. Of the catalyst layer 73.

  The electrolyte membrane 71 is made of a resin having hydrogen ion conductivity. Specifically, the electrolyte membrane 71 is made of a resin having a fluorine-containing polymer as a skeleton and a substituent such as a sulfonic acid group, a carboxyl group, or a phosphoric acid group. Yes.

  The first catalyst layer 72 and the second catalyst layer 73 include a catalyst powder made of carbon particles carrying platinum or a platinum alloy and a polymer electrolyte made of perfluorocarbon sulfonate ionomer.

  Next, a method for manufacturing an electrolyte membrane-electrode assembly in Embodiment 3 of the present invention will be described with reference to FIG.

  As shown in FIG. 8, the manufacturing method of the electrolyte membrane-electrode assembly includes a first catalyst composition application step (S31) of applying the first catalyst composition to one surface of the electrolyte membrane, and an electrolyte membrane. A first catalyst layer forming step (S32) for forming a first catalyst layer on one surface of the electrolyte membrane by replacing the dispersion medium contained in the applied first catalyst composition with water; A second catalyst composition application step (S33) for applying the second catalyst composition to the other surface of the membrane, and removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane; A second catalyst layer forming step (S34) for forming a second catalyst layer on the other surface of the membrane is included.

  Hereinafter, the manufacturing method of the electrolyte membrane-electrode assembly described above will be described in more detail with reference to FIG. 8 and FIG.

  In the first catalyst composition application step (S31), a first catalyst composition prepared in advance is applied to one surface of the electrolyte membrane.

  Specifically, the electrolyte membrane 92 is fixed, and the first catalyst composition 91 is applied to one surface thereof by a screen printing method ((a) of FIG. 9).

  In the first catalyst layer forming step (S32), the dispersion medium contained in the first catalyst composition applied to one surface of the electrolyte membrane in the first catalyst composition applying step (S31) is replaced with water. A first catalyst layer is formed.

Specifically, a container storing water 93 is prepared, and the first catalyst composition 91 applied to the electrolyte membrane 92 is immersed in the water 93 ((b) of FIG. 9), and the first catalyst composition is immersed. The dispersion medium contained in 91 is replaced with water 93 to form the first catalyst layer 94 on one surface of the electrolyte membrane 92 ((c) of FIG. 9).

  In the second catalyst composition application step (S33), a second catalyst composition prepared in advance is applied to the other surface of the electrolyte membrane.

  Specifically, the electrolyte membrane 92 was fixed so that the other surface of the electrolyte membrane 92 on which the first catalyst layer 94 was formed was the upper surface, and the first catalyst layer 94 of the electrolyte membrane 92 was formed. The second catalyst composition 95 is applied to the other surface of the surface by a screen printing method ((d) in FIG. 9).

  In the second catalyst layer forming step (S34), the dispersion medium is removed from the second catalyst composition formed in the second catalyst composition coating step (S33) to form the second catalyst layer.

  Specifically, the dispersion medium is removed from the second catalyst composition 95 by heating the second catalyst composition 95 applied to the electrolyte membrane 92 on which the first catalyst layer 94 is formed at a predetermined temperature. Then, the second catalyst layer 96 is formed on the other surface of the electrolyte membrane 92, and the electrolyte membrane-electrode assembly 90 is manufactured ((e) of FIG. 9).

  Hereinafter, although the manufacturing method of the electrolyte membrane-electrode assembly according to the present embodiment will be described in more detail based on specific examples, the present invention is not necessarily limited to the contents of the specific raw materials used below. It is not limited.

Example 4
In this example, an electrolyte membrane-electrode assembly is manufactured by applying a catalyst composition to one surface of an electrolyte membrane and replacing the dispersion medium contained in the catalyst composition with water to form a catalyst layer. did.

  First, the 1st catalyst composition was produced in the following procedures. That is, 15 parts by weight of platinum-supported carbon powder (manufactured by Tanaka Kikinzoku Co., Ltd., product number: TEC10E50E) as catalyst powder, and 50 parts by weight of Nafion 10% dispersion (manufactured by Sigma-Aldrich, product number: 527114) as polymer electrolyte. As a dispersion medium, 20 parts by weight of pure water and 65 parts by weight of isopentyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., boiling point: 131.7 ° C.) are collected in a container, and a dispersion machine (manufactured by Seiwa Giken Co., Ltd., product name) is collected. : RS-05W) and an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho Co., Ltd., product name: US-150E), kneading at room temperature for 2 hours, and the first catalyst composition (hereinafter referred to as catalyst composition e) .) Was produced.

  When the surface tension of the catalyst composition e thus prepared was measured using a surface tension meter (model number: DY-300, manufactured by Kyowa Interface Science Co., Ltd.), the surface tension at 20 ° C. of the catalyst composition e was 29.0 mN. / M.

  Next, the 2nd catalyst composition was produced in the following procedures. In other words, 15 parts by weight of a carbon powder carrying platinum and ruthenium (manufactured by Tanaka Kikinzoku Co., Ltd., product number: TEC66E50) as a catalyst powder, and a 10% Nafion dispersion as a polymer electrolyte (manufactured by Sigma Aldrich, product number: 527114) 50 parts by weight, 20 parts by weight of pure water as a dispersion medium and 65 parts by weight of ethyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., boiling point: 78.4 ° C.) are collected in a container, and a dispersing machine (manufactured by Seiwa Giken Co., Ltd.) A product name: RS-05W) and an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho, product name: US-150E) were kneaded at room temperature for 2 hours, and a second catalyst composition (hereinafter referred to as catalyst composition). f)).

When the surface tension of the catalyst composition f thus prepared was measured using a surface tension meter (model number: DY-300, manufactured by Kyowa Interface Science Co., Ltd.), the surface tension of the catalyst composition f at 20 ° C. was 2.
It was 8.0 mN / m.

  Subsequently, the following steps were performed to produce an electrolyte membrane-electrode assembly.

  The 1st 1st catalyst composition application | coating process is demonstrated.

  As the electrolyte membrane, Nafion 112 (manufactured by DuPont Co., Ltd., critical surface tension at 20 ° C. is 31.2 mN / m) is prepared. Object e was applied by screen printing.

  The second first catalyst layer forming step will be described.

  In the first catalyst composition application step described above, Nafion 112 having one surface coated with the catalyst composition e was immersed in a container storing distilled water.

  At this time, the electrolyte membrane was on the upper side and the catalyst composition e was on the lower side, and the amount of distilled water was set until the catalyst composition e was soaked so that only the catalyst composition e was immersed in distilled water.

  After soaking for 30 minutes in this state, Nafion 112 was taken out of the container, and a catalyst layer (hereinafter referred to as catalyst layer E-1) was formed on one surface of Nafion 112.

  A third second catalyst composition coating step will be described.

  For the Nafion 112 on which the catalyst layer E-1 was formed by the first catalyst layer formation step described above, a screen printing machine (Neurong Seimitsu Kogyo Co., Ltd.) was formed on the other surface of the surface on which the catalyst layer E-1 was formed. The above-mentioned catalyst composition f was applied by a screen printing method using a product name: DP-320).

  A fourth second catalyst layer forming step will be described.

  By leaving the Nafion 112 coated with the catalyst composition f in a thermostat set to 110 ° C. (manufactured by Yamato Scientific Co., Ltd., model number: DKM300) for 1 hour, the catalyst composition f is heated to remove the dispersion medium. And then left at room temperature for 2 hours to form a catalyst layer (hereinafter referred to as catalyst layer F-1) on the other surface of Nafion 112, and an electrolyte membrane-electrode assembly (hereinafter referred to as electrolyte membrane-electrode assembly). EF-1).

  When the surface of the electrolyte membrane-electrode assembly EF-1 thus produced was visually observed, the catalyst layer E-1 and the catalyst layer F-1 were free from peeling and cracking.

(Comparative Example 4)
Except that the dispersion medium of the first catalyst composition was not replaced with water, and the first catalyst composition applied to the electrolyte membrane was heated to 150 ° C. after the first catalyst composition application step, An electrolyte membrane-electrode assembly was produced by the same production method as in Example 4 described above.

  First, two sheets of Nafion 112 (manufactured by DuPont Co., Ltd., with a critical surface tension of 31.2 mN / m at 20 ° C.) were prepared as the electrolyte membrane, and the catalyst composition e was used as the first catalyst composition. The catalyst composition f was prepared as the catalyst composition of No. 2, and the first first catalyst composition application step of Example 4 was performed to apply the catalyst composition e to one surface of each Nafion 112.

Subsequently, the two Nafion 112 coated with the catalyst composition e on one side were left for 1 hour in a thermostat set to 150 ° C. (model number: DKM300, manufactured by Yamato Scientific Co., Ltd.) for 1 hour. e was heated at 150 ° C., which is a temperature equal to or higher than the boiling point of isopentyl alcohol, to remove the dispersion medium, and then allowed to stand at room temperature for 2 hours to form a catalyst layer (hereinafter referred to as catalyst layer E-2) on one surface of Nafion 112. Formed).

  Of the two Nafion 112 on which the catalyst layer E-2 is formed by the above-described method, the critical surface tension of the other surface of the surface on which the catalyst layer E-2 is formed is obtained by the Jisman plot method. It was.

  That is, a wetting index standard solution having various surface tensions (manufactured by Wako Pure Chemical Industries, Ltd., product name: mixed solution for wetting tension test) is the other surface of the surface on which the catalyst layer E-2 of Nafion 112 is formed. Each contact angle θ was measured using a contact angle meter (Kyowa Interface Science Co., Ltd., model number: DM-901).

  Next, cos θ is plotted on the horizontal axis, and surface tensions of various wetting index standard solutions are plotted on the vertical axis to determine the surface tension at which cos θ = 1, and this surface tension is defined as the critical surface tension of the surface.

  As a result, the critical surface tension at 20 ° C. of the other surface of the Nafion 112 on which the catalyst layer E-2 is formed is 27.5 mN / m, and the surface of the Nafion 112 on which the catalyst layer E-1 is formed. It was smaller than the critical surface tension.

  The critical surface tension of the other surface of the Nafion 112 on which the catalyst layer E-2 is formed is reduced because the Nafion 112 is exposed to a temperature higher than the boiling point of water in the formation process of the catalyst layer E-2. This is probably because the water contained in the Nafion 112 has evaporated.

  After that, of the two Nafion 112 on which the catalyst layer E-2 was formed, one of the Nafion 112 other than the one on which the critical surface tension of the surface on which the catalyst layer E-2 was formed was measured. The second catalyst composition coating step and the fourth second catalyst layer forming step are performed, and a catalyst layer (hereinafter referred to as catalyst layer F-2) is formed on the other surface of the Nafion 112 on which the catalyst layer E-2 is formed. And a polymer electrolyte electrode assembly (hereinafter referred to as an electrolyte membrane-electrode assembly EF-2) was produced.

  When the surface of the electrolyte membrane-electrode assembly EF-2 produced in this way was visually observed, the catalyst layer E-2 was free from peeling and cracking, but the catalyst layer F-2 was part of the catalyst layer. Peeling occurred, and many cracks existed even in the portion where the catalyst layer was present.

  The above results are summarized in (Table 5).

電解質膜−電極接合体の触媒層の剥がれやクラックに関し、本実施例に係る電解質膜−
電極接合体（電解質膜−電極接合体ＥＦ−１）は、触媒層に剥がれやクラックは無く、品質に優れるものであった。

Electrolyte Membrane-Electrolyte Membrane according to this Example Regarding Peeling and Cracking of Catalyst Layer of Electrode Assembly-
The electrode assembly (electrolyte membrane-electrode assembly EF-1) was excellent in quality without peeling or cracking in the catalyst layer.

  This is presumably because the catalyst compositions e and f were smaller than the critical surface tension of the Nafion 112, so that the catalyst compositions e and f were wetted with the Nafion 112 and a uniform catalyst layer could be formed.

  On the other hand, the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly EF-2) of Comparative Example 4 had no peeling or cracking in one catalyst layer, but peeling or cracking occurred in the other catalyst layer. However, compared with the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly EF-1) according to this example, the quality was inferior.

  This is because in the catalyst layer on the side where there is no peeling or cracking, the surface tension of the catalyst composition e is smaller than the critical surface tension of the application surface of the catalyst composition e of the Nafion 112, so This is probably because the catalyst layer on the side where peeling or cracking occurred was generated in the catalyst layer formation process, and Nafion 112 lost water and the critical surface tension was reduced. Therefore, since the surface tension of the catalyst composition f becomes larger than the critical surface tension of the application surface of the catalyst composition f of the Nafion 112, the catalyst composition f does not get wet with the Nafion 112, and a uniform catalyst layer can be formed. It is thought that it was not possible.

  Subsequently, in order to investigate the performance of each of the above-described electrolyte membrane-electrode assemblies and examine the influence on the power generation performance of the fuel cell, the cell (7) is used by using the electrolyte membrane-electrode assemblies EF-1 and EF-2. ) And (8) were produced and a power generation test was conducted.

  Here, the unit cells (7) and (8) are formed by disposing gas diffusion layers on both surfaces of the electrolyte membrane-electrode assembly EF-1 and EF-2, and then the electrolyte membrane-electrode assembly (7), ( 8) and a gasket composed of a resin-impregnated graphite plate having a gas flow path formed on the surface thereof by bonding a gasket (made by Kureha Elastomer Co., Ltd., product number: SB50NJP) made of silicone resin to the outer periphery of the gas diffusion layer. The electrolyte membrane-electrode assembly was disposed on both sides.

  The gas diffusion layer was made of carbon paper (manufactured by Toray Industries, Inc., product name: TGP-H-120) and a dispersion of acetylene black and polytetrafluoroethylene (manufactured by Daikin Industries, Ltd., product name: D-1). ) And pure water mixture and heated at 350 ° C. for 2 hours.

The power generation performance of the cells (7) and (8) is as follows: air flows through the air electrode, hydrogen gas containing 25% carbon dioxide and 50 ppm carbon monoxide flows through the fuel electrode, the battery temperature is 80 ° C, and the air utilization rate Was set to 40%, the fuel utilization rate was set to 80%, the dew point of air was set to 60 ° C., the dew point of hydrogen gas was set to 75 ° C., and the battery voltage was measured at a current density of 0.2 A / cm ² .

  The battery voltages of the cells (7) and (8) are shown in (Table 6).

本実施例に係る触媒層にクラックや剥れが無い電解質膜−電極接合体（電解質膜−電極接合体ＥＦ−１）を用いた単電池（単電池(7)）は、比較例に係る触媒層にクラックや剥れがある電解質膜−電極接合体（電解質膜−電極接合体ＥＦ−２）を用いた単電池（単電池(8)）に比べ、電池電圧が高くなった。

A single cell (single cell (7)) using an electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly EF-1) having no cracks or peeling in the catalyst layer according to this example is a catalyst according to a comparative example. The battery voltage was higher than that of the unit cell (unit cell (8)) using the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly EF-2) having a crack or peeling in the layer.

  This is because the catalyst compositions e and f get wet with the Nafion 112 to form a uniform catalyst layer without peeling or cracking, and the performance of the electrolyte membrane-electrode assembly is improved. Compared with the unit cell (8). This is probably because the power generation performance of the fuel cell has improved.

  From the above power generation test, it was confirmed that the electrolyte membrane-electrode assembly EF-1 produced in the present embodiment can improve the performance of the electrolyte membrane-electrode assembly and improve the power generation performance of the fuel cell.

(Embodiment 4)
FIG. 10 shows a configuration diagram of an electrolyte membrane-electrode assembly produced by the method for producing an electrolyte membrane-electrode assembly in Embodiment 4 of the present invention.

  Moreover, FIG. 11 is a flowchart which shows the manufacturing process of the electrolyte membrane-electrode assembly in Embodiment 4 of this invention, FIG. 12 is the manufacturing method of the electrolyte membrane-electrode assembly in Embodiment 4 of this invention. It is a schematic diagram which shows.

  First, the configuration and constituent materials of the electrolyte membrane-electrode assembly according to Embodiment 4 of the present invention will be specifically described with reference to FIG.

  In FIG. 10, an electrolyte membrane-electrode assembly 100 includes an electrolyte membrane 101, a first catalyst layer 102 formed on one surface of the electrolyte membrane 101, and a second surface formed on the other surface of the electrolyte membrane 101. Of the catalyst layer 103.

  The electrolyte membrane 101 is made of a resin having hydrogen ion conductivity. Specifically, the electrolyte membrane 101 is made of a resin having a fluorine-containing polymer as a skeleton and a substituent such as a sulfonic acid group, a carboxyl group, or a phosphoric acid group. Yes.

  The first catalyst layer 102 and the second catalyst layer 103 include a catalyst powder made of carbon particles carrying platinum or a platinum alloy and a polymer electrolyte made of perfluorocarbon sulfonate ionomer.

  Next, the manufacturing method of the electrolyte membrane electrode assembly in Embodiment 4 of this invention is demonstrated, referring FIG.

  As shown in FIG. 11, the manufacturing method of the electrolyte membrane-electrode assembly includes a first catalyst composition application step (S41) in which the first catalyst composition is applied to one surface of the electrolyte membrane, and the electrolyte membrane. The applied first catalyst composition is heated at a temperature not lower than the boiling point of the dispersion medium and lower than the boiling point of water to remove the dispersion medium, whereby the first catalyst composition is formed on one surface of the electrolyte membrane. A first catalyst layer forming step (S42) for forming a catalyst layer, and a second catalyst composition in which a second catalyst composition is applied to the other surface of the electrolyte membrane on which the first catalyst layer is formed Application step (S43) and a second catalyst layer forming step of forming a second catalyst layer on the other surface of the electrolyte membrane by removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane ( S44).

  Hereinafter, the manufacturing method of the above-described electrolyte membrane-electrode assembly will be described in detail step by step with reference to FIGS. 11 and 12.

  In the first catalyst composition application step (S41), a first catalyst composition prepared in advance is applied to one surface of the electrolyte membrane.

  Specifically, the electrolyte membrane 122 is fixed, and the first catalyst composition 121 is applied to one surface thereof by a screen printing method ((a) of FIG. 12).

  In the first catalyst layer forming step (S42), the dispersion medium is removed from the first catalyst composition applied to one surface of the electrolyte membrane in the first catalyst composition applying step (S41), thereby A catalyst layer is formed.

  Specifically, the first catalyst composition 121 applied to the electrolyte membrane 122 is heated at a temperature not lower than the boiling point of the dispersion medium and lower than the boiling point of water, whereby the first catalyst composition 121 is heated. Then, the dispersion medium is removed, and the first catalyst layer 123 is formed on one surface of the electrolyte membrane 122 ((b) of FIG. 12).

  In the second catalyst composition application step (S43), a second catalyst composition prepared in advance is applied to the other surface of the electrolyte membrane.

  Specifically, the electrolyte membrane 122 is fixed so that the other surface of the electrolyte membrane 122 on which the first catalyst layer 123 is formed is an upper surface, and the surface of the electrolyte membrane 122 on which the first catalyst layer 123 is formed. The second catalyst composition 124 is applied to the other surface by screen printing (FIG. 12 (c)).

  In the second catalyst layer forming step (S44), the second catalyst layer is formed by removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane in the second catalyst composition applying step (S43). Form.

  Specifically, the dispersion medium is removed from the second catalyst composition 124 by heating the second catalyst composition 124 applied to the electrolyte membrane 122 formed with the first catalyst layer 123 at a predetermined temperature. Then, the second catalyst layer 125 is formed on the other surface of the electrolyte membrane 122 to manufacture the electrolyte membrane-electrode assembly 120 ((d) in FIG. 12).

  Hereinafter, although the manufacturing method of the electrolyte membrane-electrode assembly according to the present embodiment will be described in more detail based on specific examples, the present invention is not necessarily limited to the contents of the specific raw materials used below. It is not limited.

(Example 5)
In this example, after applying the first catalyst composition to one surface of the electrolyte membrane, removing the dispersion medium from the first catalyst composition to form the first catalyst layer, the other side of the electrolyte membrane A second catalyst layer was formed on this surface to produce an electrolyte membrane-electrode assembly.

  First, the 1st catalyst composition was produced in the following procedures. That is, 15 parts by weight of platinum-supported carbon powder (manufactured by Tanaka Kikinzoku Co., Ltd., product number: TEC10E50E) as catalyst powder, and 50 parts by weight of Nafion 10% dispersion (manufactured by Sigma-Aldrich, product number: 527114) as polymer electrolyte. As a dispersion medium, 20 parts by weight of pure water and 45 parts by weight of methyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., boiling point 64.7 ° C.) are collected in a container, and a dispersion machine (manufactured by Seiwa Giken Co., Ltd., product name: RS-05W) and an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho, product name: US-150E) are kneaded at room temperature for 2 hours, and are referred to as a first catalyst composition (hereinafter referred to as catalyst composition g). ) Was produced.

  When the surface tension of the catalyst composition g thus prepared was measured using a surface tension meter (model number: DY-300, manufactured by Kyowa Interface Science Co., Ltd.), the surface tension of the catalyst composition g at 20 ° C. was 30.5 mN. / M.

  Next, the 2nd catalyst composition was produced in the following procedures. In other words, 15 parts by weight of a carbon powder carrying platinum and ruthenium (manufactured by Tanaka Kikinzoku Co., Ltd., product number: TEC66E50) as a catalyst powder, and a 10% Nafion dispersion as a polymer electrolyte (manufactured by Sigma Aldrich, product number: 527114) 50 parts by weight, 20 parts by weight of pure water as a dispersion medium and 45 parts by weight of methyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., boiling point 64.7 ° C.) were collected in a container, and a dispersing machine (manufactured by Seiwa Giken Co., Ltd.) A product name: RS-05W) and an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho, product name: US-150E) were kneaded at room temperature for 2 hours, and a second catalyst composition (hereinafter referred to as catalyst composition). h)).

  When the surface tension of the catalyst composition h thus prepared was measured using a surface tension meter (model number: DY-300, manufactured by Kyowa Interface Science Co., Ltd.), the surface tension of the catalyst composition h at 20 ° C. was 30.5 mN. / M.

  Subsequently, the following steps were performed to produce an electrolyte membrane-electrode assembly.

  The 1st 1st catalyst composition application | coating process is demonstrated.

  As the electrolyte membrane, Nafion 112 (manufactured by DuPont Co., Ltd., critical surface tension at 20 ° C. is 31.2 mN / m) is prepared. Product g was applied by screen printing.

  The second first catalyst layer forming step will be described.

  Two Nafion 112 coated with the catalyst composition g are prepared in the first catalyst composition coating step described above, and the temperature is set to 80 ° C. (manufactured by Yamato Scientific Co., Ltd., model number: DKM300) for 1 hour. By leaving it to stand, the catalyst composition g was heated at 80 ° C. to remove the dispersion medium, and then left at room temperature for 2 hours. ) Was formed.

  The critical surface tension of the other surface of the Nafion 112 on which the catalyst layer G-1 was formed by the above-described method was determined by the Jisman plot method.

  That is, wetting index standard solutions having various surface tensions (manufactured by Wako Pure Chemical Industries, Ltd., product name: mixed liquid for wet tension test) on the opposite side of the surface on which the catalyst layer G-1 of Nafion 112 was formed. Each contact angle θ was measured by using a contact angle meter (Kyowa Interface Science Co., Ltd., model number: DM-901).

  Next, cos θ is plotted on the horizontal axis, and surface tensions of various wetting index standard solutions are plotted on the vertical axis to determine the surface tension at which cos θ = 1, and this surface tension is defined as the critical surface tension of the surface.

  As a result, the critical surface tension at 20 ° C. of the surface of Nafion 112 was 31.2 mN / m, which was the same as the critical surface tension of the surface on which the catalyst layer G-1 was formed.

  The critical surface tension of the other surface of the Nafion 112 on which the catalyst layer G-1 was formed was the same as the critical surface tension of the surface on which the catalyst layer G-1 of the Nafion 112 was formed. This is probably because the Nafion 112 was not exposed to a temperature equal to or higher than the boiling point of water in the formation process of -1, and water was not lost from the Nafion 112.

  A third second catalyst composition coating step will be described.

  Of the two Nafions 112 on which the catalyst layer G-1 is formed by the first catalyst layer forming step described above, the catalyst layer G-1 is the remaining one other than the one that has measured the critical surface tension. The catalyst composition h described above was applied to the other surface of the formed surface by a screen printing method using a screen printer (manufactured by Neurong Seimitsu Kogyo Co., Ltd., product name: DP-320).

  A fourth second catalyst layer forming step will be described.

  The dispersion medium is heated from the catalyst composition h by leaving the Nafion 112 coated with the catalyst composition h described above in a thermostat set to 80 ° C. (model number: DKM300, manufactured by Yamato Scientific Co., Ltd.) for 1 hour. And then left at room temperature for 2 hours to form a catalyst layer (hereinafter referred to as catalyst layer H-1) on the other surface of Nafion 112, and an electrolyte membrane-electrode assembly (hereinafter referred to as electrolyte membrane-electrode). A zygote GH-1) was produced.

  When the surface of the electrolyte membrane-electrode assembly GH-1 produced in this way was visually observed, the catalyst layer G-1 and the catalyst layer H-1 were free from peeling and cracking.

(Comparative Example 5)
Except that the temperature of the incubator in the first catalyst layer forming step is changed from 80 ° C. to 110 ° C., and the temperature for heating the first catalyst composition applied to the electrolyte membrane is changed from 80 ° C. to 110 ° C. An electrolyte membrane-electrode assembly was produced by the same production method as in Example 5.

  First, two sheets of Nafion 112 (manufactured by DuPont, whose critical surface tension at 20 ° C. is 31.2 mN / m) are prepared as the electrolyte membrane, and the catalyst composition g is used as the first catalyst composition. The catalyst composition h was prepared as the catalyst composition of No. 2, and the first first catalyst composition application step of Example 5 was performed to apply the catalyst composition g to one surface of each Nafion 112.

  Subsequently, the temperature of the thermostatic chamber was set to 110 ° C., and the heating temperature of the catalyst composition g was changed from 80 ° C. to 110 ° C., which was the same as the second first catalyst layer forming step of Example 5. By this method, a catalyst layer (hereinafter referred to as catalyst layer G-2) was formed on one surface of the Nafion 112.

Of the two Nafion 112 on which the catalyst layer G-2 is formed by the method described above, the critical surface tension of the other surface of the surface on which the catalyst layer G-2 is formed is the same Zisman plot as described above. Obtained by law.

  As a result, the critical surface tension at 20 ° C. of the other surface of the Nafion 112 on which the catalyst layer G-2 is formed is 29.0 mN / m, and the surface of the Nafion 112 on which the catalyst layer G-2 is formed. It was smaller than the critical surface tension.

  The critical surface tension of the other surface of the Nafion 112 on which the catalyst layer G-2 is formed is reduced because the Nafion 112 is exposed to a temperature higher than the boiling point of water in the formation process of the catalyst layer G-2. This is probably because the water contained in the Nafion 112 has evaporated.

  Thereafter, of the two Nafions 112 on which the catalyst layer G-2 was formed, one other than the one on which the critical surface tension of the surface on which the catalyst layer G-2 was formed was measured. The second catalyst composition coating step and the fourth second catalyst layer forming step are performed, and a catalyst layer (hereinafter referred to as catalyst layer H-) is formed on the other surface of the Nafion 112 on which the catalyst layer G-2 is formed. 2) to produce a polymer electrolyte electrode assembly (hereinafter referred to as an electrolyte membrane-electrode assembly GH-2).

  When the surface of the electrolyte membrane-electrode assembly GH-2 produced in this way was visually observed, the catalyst layer G-2 was free from peeling and cracking, but the catalyst layer H-2 was part of the catalyst layer. Peeling occurred, and many cracks existed even in the portion where the catalyst layer was present.

  The above results are summarized in (Table 7).

電解質膜−電極接合体の触媒層の剥がれやクラックに関し、本実施例に係る電解質膜−電極接合体（電解質膜−電極接合体ＧＨ−１）は、触媒層に剥がれやクラックは無く、品質に優れるものであった。

Regarding the peeling and cracking of the catalyst layer of the electrolyte membrane-electrode assembly, the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly GH-1) according to this example has no peeling or cracking on the catalyst layer, and the quality It was excellent.

  This is considered to be because the catalyst compositions g and h were wet with the Nafion 112 and a uniform catalyst layer could be formed because the surface tension of the catalyst compositions g and h was smaller than the critical surface tension of the Nafion 112.

  On the other hand, in the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly GH-2) of Comparative Example 5, there was no peeling or cracking in one catalyst layer, but peeling or cracking occurred in the other catalyst layer. However, compared with the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly GH-1) according to this example, the quality was inferior.

This is because in the catalyst layer on the side where there was no peeling or cracking, the surface tension of the catalyst composition g was smaller than the critical surface tension of the application surface of the catalyst composition g of the Nafion 112. This is probably because the catalyst layer on the side where peeling or cracking occurred was generated in the catalyst layer formation process, and Nafion 112 lost water and the critical surface tension was reduced. Therefore, since the surface tension of the catalyst composition h is larger than the critical surface tension of the application surface of the catalyst composition f of the Nafion 112, the catalyst composition h does not get wet with the Nafion 112, and a uniform catalyst layer can be formed. It is thought that it was not possible.

  Subsequently, in order to investigate the performance of each of the above-described electrolyte membrane-electrode assemblies and examine the influence on the power generation performance of the fuel cell, the cell (9) was used by using the electrolyte membrane-electrode assemblies GH-1, GH-2. ) And (10) were produced and a power generation test was performed.

  Here, the single cells (9) and (10) are arranged on both surfaces of the electrolyte membrane-electrode assembly (9), (10), and after the gas diffusion layers are disposed, the electrolyte membrane-electrode assembly (9), ( 10) and a gasket composed of a resin-impregnated graphite plate with a silicone resin gasket (Kureha Elastomer Co., Ltd., product number: SB50NJP) joined to the outer periphery of the gas diffusion layer The electrolyte membrane-electrode assembly was disposed on both sides.

  The gas diffusion layer is made of carbon paper (manufactured by Toray Industries, Inc., product name: TGP-H-120), a dispersion of acetylene black and polytetrafluoroethylene (manufactured by Daikin Industries, Ltd., product name: D-1) and A mixture of pure water was applied and heated at 350 ° C. for 2 hours.

The power generation performance of the cells (9) and (10) is that air is passed through the air electrode, hydrogen gas containing 25% carbon dioxide and 50 ppm carbon monoxide is passed through the fuel electrode, the battery temperature is 80 ° C, and the air utilization rate. Was set to 40%, the fuel utilization rate was set to 80%, the dew point of air was set to 60 ° C., the dew point of hydrogen gas was set to 75 ° C., and the battery voltage was measured at a current density of 0.2 A / cm ² .

  The battery voltages of the cells (9) and (10) are shown in (Table 8).

本実施例に係る触媒層にクラックや剥れが無い電解質膜−電極接合体（電解質膜−電極接合体ＧＨ−１）を用いた単電池（単電池(9)）は、比較例に係る触媒層にクラックや剥れがある電解質膜−電極接合体（電解質膜−電極接合体ＧＨ−２）を用いた単電池（単電池(10)）に比べ、電池電圧が高くなった。

A single cell (single cell (9)) using an electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly GH-1) having no cracks or peeling in the catalyst layer according to this example is a catalyst according to a comparative example. The battery voltage was higher than that of the unit cell (unit cell (10)) using the electrolyte membrane-electrode assembly (electrolyte membrane-electrode assembly GH-2) having cracks or peeling in the layer.

  This is because the catalyst compositions g and h get wet with the Nafion 112 to form a uniform catalyst layer without peeling or cracking, and the performance of the electrolyte membrane-electrode assembly is improved. Compared with the unit cell (10). This is probably because the power generation performance of the fuel cell has improved.

  From the above power generation test, it was confirmed that the electrolyte membrane-electrode assembly GH-1 produced in the present embodiment improved the performance of the electrolyte membrane-electrode assembly and improved the power generation performance of the fuel cell.

(Modification)
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to such Embodiment, A various structure can be taken in the range which does not deviate from the meaning.

(Modification 1)
In each of the above-described embodiments, Nafion 112 is used as the electrolyte membrane. As the electrolyte membrane, hydrogen ions having a fluorine-containing polymer as a skeleton and having substituents such as a sulfonic acid group, a carboxyl group, and a phosphoric acid group are used. A conductive resin can be used. For example, other electrolyte membranes such as Aciplex (registered trademark) and Flemion (registered trademark) can be used.

(Modification 2)
In each of the embodiments described above, platinum and ruthenium are used as the catalyst. Examples of the catalyst include noble metals such as gold, silver, rhodium, palladium, osmium, iridium, iron, nickel, manganese, cobalt, chromium, Base metals such as copper, zinc, molybdenum, tungsten, germanium, and tin, alloys of these noble metals and base metals, and compounds such as metal oxides and metal complexes can be used.

(Modification 3)
In each of the embodiments described above, acetylene black, Vulcan or Ketjen black can be used as the carbon powder supporting platinum as a catalyst, and instead of carbon powder, for example, carbon nanotube, carbon In addition to carbon materials such as nanofibers, carbon compounds such as silicon carbide can be used.

(Modification 4)
In each of the above-described embodiments, a Nafion 10% dispersion is used as the polymer electrolyte. As the polymer electrolyte, a polymer having an acidic functional group having excellent heat resistance and chemical resistance is used. For example, perfluorocarbon sulfonic acid ionomers such as Nafion (registered trademark) and Flemion (registered trademark) dispersed in an organic solvent such as ethyl alcohol or water can be used.

  Further, in each of the above-described embodiments, the catalyst composition is configured using the catalyst powder, the polymer electrolyte, and the dispersion medium. However, without using the polymer electrolyte, the catalyst composition is formed from the catalyst powder and the dispersion medium. You may comprise a composition.

(Modification 5)
In each of the above-described embodiments, a mixed solvent of pure water and ethyl alcohol or n-butanol, isopentyl alcohol, and methyl alcohol is used as a dispersion medium for the catalyst composition. Besides these, alcohols such as 2-methylpropyl alcohol and 2-ethylhexanol, glycols such as ethylene glycol and propylene glycol, or a mixed solvent using at least two or more of these can be used.

(Modification 6)
In the first embodiment described above, a PET sheet is used as the base material to be disposed on the electrolyte membrane, but as the base material, various sheets made of polypropylene, polyethylene, polytetrafluoroethylene, etc. are used in addition to the PET sheet. be able to.

(Modification 7)
In the electrolyte membrane humidification step (S13) in Example 2 of the first embodiment described above, the surface of the electrolyte membrane that is in close contact with the PET sheet is humidified after peeling off the PET sheet. Even if the electrolyte membrane is humidified without peeling off, the same effect can be obtained.

(Modification 8)
In the catalyst composition application step (S11, S14, S21, S24, S31, S34, S41, S43) in each of the above-described embodiments, the catalyst composition is applied to the electrolyte membrane by a screen printing method. In addition to the screen printing method, the composition may be applied to the electrolyte membrane by a doctor blade method, a spray method, a bar coating method, a die coating method, or the like.

(Modification 9)
In the solvent replacement catalyst composition forming step (S23) in the above-described second embodiment, pentane is used as a solvent for replacing the dispersion medium contained in the catalyst composition, but as a solvent for replacing the dispersion medium, Various solvents having a boiling point lower than that of water can be used. For example, instead of pentane, a solvent such as hexane, diethyl ether, acetone, methyl alcohol, or ethyl alcohol can be used.

(Modification 10)
In each of the above-described embodiments, the first catalyst composition and the second catalyst composition are produced at the beginning of the production process of the electrolyte membrane-electrode assembly, but the first catalyst composition is produced in each production. Before the first catalyst composition coating step (S1, S21, S31, S41) in the process, the second catalyst composition is the second catalyst composition coating step (S14, S24, S34, S43). It may be produced before.

  As described above, according to the method for producing an electrolyte membrane-electrode assembly according to the present invention, there is no defect such as peeling or cracking in the catalyst layer, an excellent quality, and a high-performance electrolyte membrane-electrode assembly is obtained. When used by being incorporated in a fuel cell, a high battery voltage can be developed, so that it can be applied to the use of a fuel cell used in a home cogeneration system, a power source for an electric vehicle, a portable power source and the like.

10, 30, 40, 60, 70, 90, 100, 120 Electrolyte membrane-electrode assembly 31, 61, 91, 121 First catalyst composition 11, 32, 41, 62, 71, 92, 101, 122 Electrolyte Membrane 12, 33, 42, 65, 72, 94, 102, 123 First catalyst layer 34, 66, 95, 124 Second catalyst composition 13, 35, 43, 67, 73, 96, 103, 125 First 2 catalyst layer 63 solvent 64 solvent displacement catalyst composition 93 water

Claims (5)

In the method for producing an electrolyte membrane-electrode assembly, a catalyst composition containing a catalyst powder and a dispersion medium is applied to both surfaces of an electrolyte membrane, and the dispersion medium is removed to form catalyst layers on both surfaces of the electrolyte membrane.
A first catalyst composition coating step of coating a first catalyst composition containing a catalyst powder and a dispersion medium on one surface of the electrolyte membrane;
A first catalyst layer is formed on one surface of the electrolyte membrane by removing the dispersion medium from the first catalyst composition applied to the electrolyte membrane in the first catalyst composition application step. 1 catalyst layer forming step;
An electrolyte membrane humidifying step of humidifying the electrolyte membrane in which the first catalyst layer is formed on one surface by the first catalyst layer forming step;
A second catalyst composition application step of applying a second catalyst composition containing a catalyst powder and a dispersion medium to the other surface of the electrolyte membrane humidified in the electrolyte membrane humidification step;
A second catalyst layer is formed on the other surface of the electrolyte membrane by removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane in the second catalyst composition coating step. 2 catalyst layer forming step;
The manufacturing method of the electrolyte membrane electrode assembly containing this. In the method for producing an electrolyte membrane-electrode assembly, a catalyst composition containing a catalyst powder and a dispersion medium is applied to both surfaces of an electrolyte membrane, and the dispersion medium is removed to form catalyst layers on both surfaces of the electrolyte membrane.
A first catalyst composition application step of applying a first catalyst composition containing a dispersion medium having a boiling point equal to or higher than the boiling point of catalyst powder and water to one surface of the electrolyte membrane;
By replacing the dispersion medium of the first catalyst composition applied to the electrolyte membrane by the first catalyst composition application step with a solvent having a boiling point less than the boiling point of water, one of the electrolyte membranes A solvent replacement catalyst composition forming step for forming a solvent replacement catalyst composition on the surface;
The solvent replacement catalyst composition formed on one surface of the electrolyte membrane by the solvent replacement catalyst composition formation step is heated at a temperature not lower than the boiling point of the solvent and lower than the boiling point of water. A first catalyst layer forming step of forming a first catalyst layer on one surface of the electrolyte membrane by removing the solvent from the solvent replacement catalyst composition;
A second catalyst composition containing a catalyst powder and a dispersion medium is applied to the other surface of the electrolyte membrane having the first catalyst layer formed on one surface by the first catalyst layer forming step. A catalyst composition coating step;
A second catalyst layer is formed on the other surface of the electrolyte membrane by removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane in the second catalyst composition coating step. 2 catalyst layer forming step;
The manufacturing method of the electrolyte membrane electrode assembly containing this. In the method for producing an electrolyte membrane-electrode assembly, a catalyst composition containing a catalyst powder and a dispersion medium is applied to both surfaces of an electrolyte membrane, and the dispersion medium is removed to form catalyst layers on both surfaces of the electrolyte membrane.
A first catalyst composition application step of applying a first catalyst composition containing a dispersion medium having a boiling point equal to or higher than the boiling point of catalyst powder and water to one surface of the electrolyte membrane;
By replacing the dispersion medium of the first catalyst composition applied to the electrolyte membrane in the first catalyst composition application step with water, the first catalyst layer is formed on one surface of the electrolyte membrane. A first catalyst layer forming step to be formed;
A second catalyst composition containing a catalyst powder and a dispersion medium is applied to the other surface of the electrolyte membrane having the first catalyst layer formed on one surface by the first catalyst layer forming step. A catalyst composition coating step;
A second catalyst layer is formed on the other surface of the electrolyte membrane by removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane in the second catalyst composition coating step. 2 catalyst layer forming step;
The manufacturing method of the electrolyte membrane electrode assembly containing this. In the method for producing an electrolyte membrane-electrode assembly, a catalyst composition containing a catalyst powder and a dispersion medium is applied to both surfaces of an electrolyte membrane, and the dispersion medium is removed to form catalyst layers on both surfaces of the electrolyte membrane.
A first catalyst composition application step of applying a first catalyst composition containing a dispersion medium having a boiling point lower than the boiling point of catalyst powder and water on one surface of the electrolyte membrane;
Heating the first catalyst composition applied to the electrolyte membrane by the first catalyst composition application step at a temperature not lower than the boiling point of the dispersion medium and lower than the boiling point of water; A first catalyst layer forming step of forming a first catalyst layer on one surface of the electrolyte membrane by removing the dispersion medium from the first catalyst composition;
A second catalyst composition containing a catalyst powder and a dispersion medium is applied to the other surface of the electrolyte membrane having the first catalyst layer formed on one surface by the first catalyst layer forming step. A catalyst composition coating step;
A second catalyst layer is formed on the other surface of the electrolyte membrane by removing the dispersion medium from the second catalyst composition applied to the electrolyte membrane in the second catalyst composition coating step. 2 catalyst layer forming step;
The manufacturing method of the electrolyte membrane electrode assembly containing this.   An electrolyte membrane-electrode assembly produced by the production method according to claim 1.

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