Abstract: An object of the present disclosure is to provide a membrane electrode assembly excellent in power generation performance and durability. This embodiment is a membrane electrode assembly. The membrane electrode assembly includes a solid polymer electrolyte membrane, an anode catalyst layer, and a cathode catalyst layer. The anode catalyst layer is disposed on one surface of the solid polymer electrolyte membrane. The cathode catalyst layer is disposed on the other surface of the solid polymer electrolyte membrane. The anode catalyst layer at least contains an electrode catalyst, an ionomer, a metal ion, and a host compound. The ionomer has sulfonate group. The metal ion is selected from cerium ion or manganese ion. The host compound allows forming an inclusion compound with the metal ion. The host compound has a molecular weight of 300 or more.

Abstract: To provide a catalyst layer that is low in gas diffusion resistance and proton resistance even when a support having a small specific surface area is used. The catalyst layer is a catalyst layer for fuel cells, wherein the catalyst layer comprises a catalyst metal, a support and a conductive additive; wherein the support supports the catalyst metal; wherein a specific surface area of the support is 600 m2/g-C or less; wherein the conductive additive does not support the catalyst metal and has a larger aspect ratio than the support; wherein the aspect ratio of the conductive additive is more than 10; wherein, when a total mass of the catalyst layer is 100 mass %, a percent of the conductive additive contained in the catalyst layer is more than 2 mass % and less than 20 mass %; and wherein the conductive additive is a non-hydrophilized conductive additive.

Abstract: There is provided a catalyst layer for a fuel cell that can inhibit reduction in water electrolysis function. The catalyst layer for a fuel cell according to this disclosure comprises carbon supports on which Pt particles are supported, and Ir oxide particles, wherein the ratio of the mean primary particle size of the Ir oxide particles with respect to the mean primary particle size of the Pt particles is 20 or greater. The mean primary particle size of the Pt particles may be 20.0 nm or smaller and the mean primary particle size of the Ir oxide particles may be 100.0 nm to 500.0 nm.

Abstract: Mesoporous carbon has a connecting structure in which primary particles made of carbon particles having primary pores with a primary pore diameter of less than 20 nm are connected. In the mesoporous carbon, the pore capacity of secondary pores with secondary pore diameters within a range of 20 nm to 100 nm, which is measured by a mercury intrusion method, is 0.42 cm3/g or more and 1.34 cm3/g or less. In addition, the mesoporous carbon has a linearity of 2.2 or more and 2.6 or less. An electrode catalyst for a fuel cell includes the mesoporous carbon and catalyst particles supported in the primary pores in the mesoporous carbon. Furthermore, a catalyst layer includes the electrode catalyst for the fuel cell and a catalyst layer ionomer.

Abstract: To provide a catalyst layer that is low in gas diffusion resistance and proton resistance even when a support having a small specific surface area is used. The catalyst layer is a catalyst layer for fuel cells, wherein the catalyst layer comprises a catalyst metal, a support and a conductive additive; wherein the support supports the catalyst metal; wherein a specific surface area of the support is 600 m2/g-C or less; wherein the conductive additive does not support the catalyst metal and has a larger aspect ratio than the support; wherein the aspect ratio of the conductive additive is more than 10; wherein, when a total mass of the catalyst layer is 100 mass %, a percent of the conductive additive contained in the catalyst layer is more than 2 mass % and less than 20 mass %; and wherein the conductive additive is a non-hydrophilized conductive additive.

Abstract: A control device for a fuel cell system comprises a hydrogen deficiency judging part configured to judge if a hydrogen deficiency which is a state in which an amount of hydrogen supplied to the fuel cell is insufficient compared with an amount of hydrogen required for power generation has occurred, a hydrogen deficiency elimination judging part configured to judge if the hydrogen deficiency has been eliminated after the hydrogen deficiency judging part judges that the hydrogen deficiency has occurred and a breakage control part configured to make the circuit breaker temporarily break an electrical connection of the fuel cell and the electrical load part when the hydrogen deficiency elimination judging part judges that the hydrogen deficiency has been eliminated.

Abstract: There is provided a catalyst layer for a fuel cell that can inhibit reduction in water electrolysis function. The catalyst layer for a fuel cell according to this disclosure comprises carbon supports on which Pt particles are supported, and Ir oxide particles, wherein the ratio of the mean primary particle size of the Ir oxide particles with respect to the mean primary particle size of the Pt particles is 20 or greater. The mean primary particle size of the Pt particles may be 20.0 nm or smaller and the mean primary particle size of the Ir oxide particles may be 100.0 nm to 500.0 nm.

Abstract: An oxygen evolution catalyst includes a core and a shell covering the surface of the core. The core includes ruthenium oxide or metal ruthenium in at least a surface portion. The shell includes titania or a composite oxide of titanium and ruthenium. Such an oxygen evolution catalyst is obtained by (a) dispersing core particles each including ruthenium oxide or metal ruthenium in at least a surface portion in a solvent to obtain a dispersion, (b) adding a Ti source to the dispersion to produce precursor particles in which the surface of each core particle is covered with a titania precursor, and (c) collecting the precursor particles from the dispersion and heat-treating the precursor particles after drying.

Abstract: A fuel cell includes: an electrolyte membrane; an anode catalyst layer; a cathode catalyst layer; and a cathode gas diffusion layer. The cathode catalyst layer includes an ionomer, the ionomer includes copolymers each of which has a hydrophilic block. The hydrophilic block is positioned at a terminal of a copolymer which includes a hydrophobic portion and a hydrophilic portion having a sulfonic acid group. The hydrophilic block has an aggregated structure of the hydrophilic portion. A gas diffusion resistance coefficient of the cathode gas diffusion layer is 3.2×10?4 m or lower. The gas diffusion resistance coefficient is expressed by “Gas Diffusion Resistance Coefficient=Thickness of Cathode Gas Diffusion Layer/(Porosity of Cathode Gas Diffusion Layer)4”.

Abstract: An oxygen evolution catalyst includes a core and a shell covering the surface of the core. The core includes ruthenium oxide or metal ruthenium in at least a surface portion. The shell includes titania or a composite oxide of titanium and ruthenium. Such an oxygen evolution catalyst is obtained by (a) dispersing core particles each including ruthenium oxide or metal ruthenium in at least a surface portion in a solvent to obtain a dispersion, (b) adding a Ti source to the dispersion to produce precursor particles in which the surface of each core particle is covered with a titania precursor, and (c) collecting the precursor particles from the dispersion and heat-treating the precursor particles after drying.

Abstract: To produce a core-shell catalyst with high catalytic activity for a short period of time. Disclosed is a method for producing a core-shell catalyst comprising a core containing palladium and a shell containing platinum and coating the core, the method comprising: supplying palladium-containing particles and a copper-containing material to an acid solution; stirring the acid solution with introducing an oxygen-containing gas into the acid solution; coating at least a part of a surface of the palladium-containing particles with copper by applying a potential that is nobler than the oxidation reduction potential of copper to the palladium-containing particles in a copper ion-containing electrolyte after the stirring; and then forming the shell by substituting the copper coating at least a part of the surface of the palladium-containing particles with platinum by bringing the palladium-containing particles into contact with a platinum ion-containing solution.

Abstract: A control device for a fuel cell system comprises a hydrogen deficiency judging part configured to judge if a hydrogen deficiency which is a state in which an amount of hydrogen supplied to the fuel cell is insufficient compared with an amount of hydrogen required for power generation has occurred, a hydrogen deficiency elimination judging part configured to judge if the hydrogen deficiency has been eliminated after the hydrogen deficiency judging part judges that the hydrogen deficiency has occurred and a breakage control part configured to make the circuit breaker temporarily break an electrical connection of the fuel cell and the electrical load part when the hydrogen deficiency elimination judging part judges that the hydrogen deficiency has been eliminated.

Abstract: Disclosed is a method for producing a fine catalyst particle comprising a palladium-containing particle and a platinum outermost layer covering the palladium-containing particle, wherein a first composite body containing palladium and platinum is formed by mixing the palladium-containing particle with a first solution in which a platinum compound is dissolved, and then covering at least part of a surface of the palladium-containing particle with platinum; wherein a second composite body containing palladium, platinum and copper is formed by mixing the first composite body with a second solution in which a copper compound is dissolved, and then covering at least part of a surface of the first composite body with copper using copper underpotential deposition; and wherein the copper in the second composite body is substituted with platinum derived from a third solution in which a platinum compound is dissolved.

Abstract: The present invention is to provide fine catalyst particles with better catalytic performance than ever before and a carbon-supported catalyst with better catalytic performance than ever before.

Abstract: The disclosure is to provide a method for producing a core-shell catalyst that is able to increase the power generation performance of a membrane electrode assembly. A dispersion is prepared, in which a palladium-containing particle support, in which palladium-containing particles are supported on an electroconductive support, is dispersed in water; hydrogen gas is bubbled into the dispersion; the palladium-containing particles are acid treated after the bubbling; copper is deposited on the surface of the palladium-containing particles by applying a potential that is nobler than the oxidation reduction potential of copper to the palladium-containing particles in a copper ion-containing electrolyte after the acid treatment; and then a shell is formed by substituting the copper deposited on the surface of the palladium-containing particles with platinum by bringing the copper deposited on the surface of the palladium-containing particles into contact with a platinum ion-containing solution.

Abstract: Disclosed is a method for producing a catalyst, wherein the method comprises: a supplying step of supplying a dispersion containing a palladium-containing fine particle from a supplying part into a reaction container; a preparing step of preparing a copper-palladium-containing complex in which at least part of a surface of the palladium-containing fine particle is covered with copper, by passing the dispersion through a reacting part and bringing the palladium-containing fine particle in the dispersion into contact with a copper-containing member in the reacting part; and a substituting step of substituting the copper in the copper-palladium-containing complex emitted from an emitting part with platinum by bringing the complex into contact with a platinum-containing solution.

Abstract: A fuel cell includes: an electrolyte membrane; an anode catalyst layer; a cathode catalyst layer; and a cathode gas diffusion layer. The cathode catalyst layer includes an ionomer, the ionomer includes copolymers each of which has a hydrophilic block. The hydrophilic block is positioned at a terminal of a copolymer which includes a hydrophobic portion and a hydrophilic portion having a sulfonic acid group. The hydrophilic block has an aggregated structure of the hydrophilic portion. A gas diffusion resistance coefficient of the cathode gas diffusion layer is 3.2×10?4 m or lower. The gas diffusion resistance coefficient is expressed by “Gas Diffusion Resistance Coefficient=Thickness of Cathode Gas Diffusion Layer/(Porosity of Cathode Gas Diffusion Layer)4”.

Abstract: To produce a core-shell catalyst with high catalytic activity for a short period of time. Disclosed is a method for producing a core-shell catalyst comprising a core containing palladium and a shell containing platinum and coating the core, the method comprising: supplying palladium-containing particles and a copper-containing material to an acid solution; stirring the acid solution with introducing an oxygen-containing gas into the acid solution; coating at least a part of a surface of the palladium-containing particles with copper by applying a potential that is nobler than the oxidation reduction potential of copper to the palladium-containing particles in a copper ion-containing electrolyte after the stirring; and then forming the shell by substituting the copper coating at least a part of the surface of the palladium-containing particles with platinum by bringing the palladium-containing particles into contact with a platinum ion-containing solution.

Abstract: The disclosure is to provide a method for producing a core-shell catalyst that is able to increase the power generation performance of a membrane electrode assembly. A dispersion is prepared, in which a palladium-containing particle support, in which palladium-containing particles are supported on an electroconductive support, is dispersed in water; hydrogen gas is bubbled into the dispersion; the palladium-containing particles are acid treated after the bubbling; copper is deposited on the surface of the palladium-containing particles by applying a potential that is nobler than the oxidation reduction potential of copper to the palladium-containing particles in a copper ion-containing electrolyte after the acid treatment; and then a shell is formed by substituting the copper deposited on the surface of the palladium-containing particles with platinum by bringing the copper deposited on the surface of the palladium-containing particles into contact with a platinum ion-containing solution.

Abstract: The present invention is to provide fine catalyst particles with better catalytic performance than ever before and a carbon-supported catalyst with better catalytic performance than ever before.