Abstract: A method for producing an electrode catalyst for a fuel cell is provided. The electrode catalyst includes a carbon support and a catalyst supported on the carbon support. The catalyst is one of platinum and a platinum-alloy. The method includes supporting the catalyst on the carbon support; and treating the carbon support carrying the catalyst with a nitric acid and cleaning the treated carbon support, such that an amount of an acid present on the carbon support becomes in a range from 0.7 mmol to 1.31 mmol of the acid per gram of the electrode catalyst.

Abstract: A technique for producing a membrane electrode assembly with high quality is provided. In a method for producing a membrane electrode assembly, a first catalyst layer of a first catalyst layer sheet is bonded to a surface of an electrolyte film on which an electrolyte film base sheet is not formed. A first catalyst layer base sheet is separated from the first catalyst layer. The electrolyte film base sheet has been separated from the electrolyte film. A second catalyst layer of a second catalyst layer sheet is bonded to a surface of the electrolyte film from which the electrolyte film base sheet has been separated. The method for producing a membrane electrode assembly further includes a preliminary step of bonding either the second catalyst layer formed on the second catalyst layer base sheet or the second catalyst layer base sheet to a portion of the electrolyte film that has been fed prior to a position at which bonding of the first catalyst layer starts.

Abstract: An electrolyte membrane roll body to be used in a manufacturing apparatus for membrane electrode assemblies allows effective use of an electrolyte membrane in the manufacturing apparatus. A first end of a lead film and a first end of a lead film supporting base that is peelably bonded to the lead film are connected to a roll core around which an electrolyte membrane sheet and a back sheet for supporting the electrolyte membrane sheet are rolled. A terminal end of the electrolyte membrane sheet and a terminal end of the back sheet are connected to a second end of the lead film and a second end of the lead film supporting base, respectively.

Abstract: A catalyst ink for improving the performance of catalyst electrodes in a fuel cell is produced by the following procedure. A catalyst dispersion is prepared by dispersing catalyst-supported particles as conductive particles with a catalyst supported thereon in a solvent. A gel material having viscoelasticity is prepared by mixing an ionomer with a volatile solvent. A catalyst ink having a desired viscosity is produced by stirring and mixing the catalyst dispersion with the gel material.

Abstract: A method for producing an electrode catalyst for a fuel cell is provided. The electrode catalyst includes a carbon support and a catalyst supported on the carbon support. The catalyst is one of platinum and a platinum-alloy. The method includes supporting the catalyst on the carbon support; and treating the carbon support carrying the catalyst with a nitric acid and cleaning the treated carbon support, such that an amount of an acid present on the carbon support becomes in a range from 0.7 mmol to 1.31 mmol of the acid per gram of the electrode catalyst.

Abstract: The present invention provides an electrolyte membrane roll body to be used in a manufacturing apparatus for membrane electrode assemblies which allows effective use of an electrolyte membrane in the manufacturing apparatus.

Abstract: A technique for producing a membrane electrode assembly with high quality is provided. In a method for producing a membrane electrode assembly, a first catalyst layer of a first catalyst layer sheet is bonded to a surface of an electrolyte film on which an electrolyte film base sheet is not formed. A first catalyst layer base sheet is separated from the first catalyst layer. The electrolyte film base sheet has been separated from the electrolyte film. A second catalyst layer of a second catalyst layer sheet is bonded to a surface of the electrolyte film from which the electrolyte film base sheet has been separated. The method for producing a membrane electrode assembly further includes a preliminary step of bonding either the second catalyst layer formed on the second catalyst layer base sheet or the second catalyst layer base sheet to a portion of the electrolyte film that has been fed prior to a position at which bonding of the first catalyst layer starts.

Abstract: A catalyst ink for improving the performance of catalyst electrodes in a fuel cell is produced by the following procedure. A catalyst dispersion is prepared by dispersing catalyst-supported particles as conductive particles with a catalyst supported thereon in a solvent. A gel material having viscoelasticity is prepared by mixing an ionomer with a volatile solvent. A catalyst ink having a desired viscosity is produced by stirring and mixing the catalyst dispersion with the gel material.

Abstract: The present invention specifies the physical property valves of a catalytic layer correlating with the performance of a fuel cell, and provides the catalytic layer having the physical proper values and a fuel cell. Specifically, in a fuel cell having a membrane-electrode assembly provided with a catalytic layer 13 on each side of an electrolyte membrane 10, an electrode powder constituting the catalytic layer 13 shall have an amount of adsorbed water vapor in a range of 52 to 70 cm3(STP)/g by a value measured when the water-vapor partial pressure is 0.6, which is determined from the adsorption isotherm of water. The fuel cell having the catalytic layer with the use of the electrode powder having the amount of adsorbed water vapor in this range has the output performance of 0.6 A/cm2 or higher by current density at 0.6 V, in a less humidified condition and a more humidified condition.

Abstract: An electrode catalyst for a fuel cell consists principally of a carbon support, and a platinum catalyst or a platinum-alloy catalyst supported on the carbon support. In the electrode catalyst, at least 0.7 mmol of an acid per gram of the electrode catalyst is present on the carbon support.

Abstract: An object of the present invention is to optimize an anode catalyst layer such that high output performance can be achieved even under low-humidity conditions. In addition, another object of the present invention is to provide a polymer electrolyte fuel cell having such an anode catalyst layer. The following is obtained: an anode catalyst layer for a polymer electrolyte fuel cell, which comprises a carbon support on which a catalyst is carried and a hydrogen ion-conductive polyelectrolyte, and wherein the catalyst is carried by a carbon support for which the hydrophilic characteristic value specified based on a value representing the amount of adsorbed water vapor/the amount of adsorbed nitrogen is 0.02 or less, or the hydrophilic characteristic value for the catalyst-carrying carbon support is 0.30 or less.

Abstract: To provide a production process of an electrode catalyst for fuel cell whose initial voltage is high and whose endurance characteristics, especially, whose voltage drop being caused by high-potential application is less. A production process according to the present invention of an electrode catalyst for fuel cell is characterized in that: it includes: a dispersing step of dispersing a conductive support in a solution; a loading step of dropping a platinum-salt solution, a base-metal-salt solution and an iridium-salt solution to the resulting dispersion liquid, thereby loading respective metallic salts on the conductive support as hydroxides under an alkaline condition; and an alloying step of heating the conductive support with metallic hydroxides loaded in a reducing atmosphere to reduce them, thereby alloying them.

Abstract: The present invention specifies the physical property valves of a catalytic layer correlating with the performance of a fuel cell, and provides the catalytic layer having the physical proper values and a fuel cell. Specifically, in a fuel cell having a membrane-electrode assembly provided with a catalytic layer 13 on each side of an electrolyte membrane 10, an electrode powder constituting the catalytic layer 13 shall have an amount of adsorbed water vapor in a range of 52 to 70 cm3(STP)/g by a value measured when the water-vapor partial pressure is 0.6, which is determined from the adsorption isotherm of water. The fuel cell having the catalytic layer with the use of the electrode powder having the amount of adsorbed water vapor in this range has the output performance of 0.6 A/cm2 or higher by current density at 0.6 V, in a less humidified condition and a more humidified condition.

Abstract: In a membrane electrode assembly 1 of a fuel cell, the porosity of a hydrogen electrode-side catalyst layer 11a is made to be lower than that of an air electrode-side catalyst layer 11b. Specifically, the weight ratio of ion-exchange resin to carbon carriers of the hydrogen electrode-side catalyst layer is made to be larger than such ratio of the air electrode-side catalyst layer, the hydrogen electrode-side catalyst layer is allowed to contain an additive having a certain particle diameter or less, or the hydrogen electrode-side catalyst layer is formed by spraying a catalyst ink and the air electrode-side catalyst layer is formed by a transfer method. According to the present invention, the amount of hydrogen that permeates from the hydrogen electrode-side catalyst layer to the air electrode-side catalyst layer via an electrolyte membrane is reduced to suppress a direct hydrogen combustion reaction in the air electrode-side catalyst layer, thereby improving the fuel cell durability.

Abstract: To provide a production process of an electrode catalyst for fuel cell whose initial voltage is high and whose endurance characteristics, especially, whose voltage drop being caused by high-potential application is less. A production process according to the present invention of an electrode catalyst for fuel cell is characterized in that: it includes: a dispersing step of dispersing a conductive support in a solution; a loading step of dropping a platinum-salt solution, a base-metal-salt solution and an iridium-salt solution to the resulting dispersion liquid, thereby loading respective metallic salts on the conductive support as hydroxides under an alkaline condition; and an alloying step of heating the conductive support with metallic hydroxides loaded in a reducing atmosphere to reduce them, thereby alloying them.

Abstract: To enhance the activation of a catalyst comprising an alloy of platinum and cobalt, thereby providing an electrode catalyst for fuel cell whose battery output and fuel efficiency are high, and thereby providing a production process of the same. An electrode catalyst according to the present invention for fuel cell is an electrode catalyst for fuel cell in which catalytic particles comprising platinum and cobalt are loaded on a conductive support, and is characterized in that a compositional (molar) ratio of said catalytic particles is platinum:cobalt=3:1-5:1: In the range of platinum:cobalt=3:1-5:1, a high battery voltage is obtainable. When the proportion of platinum is less than platinum: cobalt=3:1, the elution of cobalt from out of catalyst increases. On the contrarily, when the proportion of platinum is more than platinum: cobalt=5:1, the catalytic activities become low.

Abstract: In a membrane electrode assembly 1 of a fuel cell, the porosity of a hydrogen electrode-side catalyst layer 11a is made to be lower than that of an air electrode-side catalyst layer 11b. Specifically, the weight ratio of ion-exchange resin to carbon carriers of the hydrogen electrode-side catalyst layer is made to be larger than such ratio of the air electrode-side catalyst layer, the hydrogen electrode-side catalyst layer is allowed to contain an additive having a certain particle diameter or less, or the hydrogen electrode-side catalyst layer is formed by spraying a catalyst ink and the air electrode-side catalyst layer is formed by a transfer method. According to the present invention, the amount of hydrogen that permeates from the hydrogen electrode-side catalyst layer to the air electrode-side catalyst layer via an electrolyte membrane is reduced to suppress a direct hydrogen combustion reaction in the air electrode-side catalyst layer, thereby improving the fuel cell durability.