Abstract: Porous oxide semiconductor particles have a connected structure in which porous primary particles having an aggregate of crystallites composed of an oxide semiconductor are connected to each other and have a specific surface area of 60 m2/g or more. The porous oxide semiconductor particles have preferably a pore diameter of 1 nm or more and 20 nm or less. The porous oxide semiconductor particles have preferably a tap density of 0.005 g/cm3 or more and 1.0 g/cm3 or less. The oxide semiconductor is preferably SnO2 or SnO2 doped with at least one element selected from the group consisting of Nb, Sb, W, Ta, and Al.

Abstract: A catalyst layer includes an electrode catalyst and an ionomer. The electrode catalyst includes: tin oxide-based particles having a structure (connected structure) in which porous primary particles are connected to each other in a bead shape and having a specific surface area of 30 m2/g or more; and Pt-based fine particles supported on the surface of the tin oxide-based particles. The conductivity of a green compact composed of the tin oxide-based particles is desirably 1×10?3 S/cm or more. As the tin oxide-based particles, those composed of Sb-doped SnO2 and having a specific surface area of 90 m2/g or more and a pore diameter of 5 nm or more and 8 nm or less are desired.

Abstract: The present disclosure provides a method of shortening an aging period of a polymer electrolyte fuel cell immediately after production to increase shipping inspection speed and production speed of the polymer electrolyte fuel cell. The present disclosure relates to an aging method of a fuel cell which comprises a membrane electrode assembly comprising a fuel electrode, an electrolyte membrane, and an oxidant electrode, wherein the method comprises applying a potential cycle, wherein the lowest cell potential when a load is applied and OCV are alternately repeated between the fuel electrode and the oxidant electrode, and in the potential cycle, fuel gas is supplied to the fuel electrode, and oxidant gas and carbon monoxide gas are supplied to the oxidant electrode.

Abstract: First, a reaction gas is supplied to a fuel cell stack including a laminate of solid polymer electrolyte fuel cells and power generation is performed so that a temperature of the fuel cell stack reaches 65° C. or higher (heating power generation step). Next, the reaction gas is supplied to the fuel cell stack and the power generation is performed under a condition in which relative humidity is 100% or more (cleaning power generation step). Cooling water of room temperature may be supplied to the fuel cell stack from the outside before the cleaning power generation step is performed after the heating power generation step is completed, or after the cleaning power generation step is completed (quenching step).

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: The present disclosure provides a method of shortening an aging period of a polymer electrolyte fuel cell immediately after production to increase shipping inspection speed and production speed of the polymer electrolyte fuel cell. The present disclosure relates to an aging method of a fuel cell which comprises a membrane electrode assembly comprising a fuel electrode, an electrolyte membrane, and an oxidant electrode, wherein the method comprises applying a potential cycle, wherein the lowest cell potential when a load is applied and OCV are alternately repeated between the fuel electrode and the oxidant electrode, and in the potential cycle, fuel gas is supplied to the fuel electrode, and oxidant gas and carbon monoxide gas are supplied to the oxidant electrode.

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: First, a reaction gas is supplied to a fuel cell stack including a laminate of solid polymer electrolyte fuel cells and power generation is performed so that a temperature of the fuel cell stack reaches 65° C. or higher (heating power generation step). Next, the reaction gas is supplied to the fuel cell stack and the power generation is performed under a condition in which relative humidity is 100% or more (cleaning power generation step). Cooling water of room temperature may be supplied to the fuel cell stack from the outside before the cleaning power generation step is performed after the heating power generation step is completed, or after the cleaning power generation step is completed (quenching step).

Abstract: A membrane electrode assembly according to the invention includes a solid polymer electrolyte membrane and an electrode joined to each of two sides of the solid polymer electrolyte membrane. The solid polymer electrolyte membrane is such that some or all of the protons included in the entire solid polymer electrolyte membrane, a band region, or a non-power generating region are ion exchanged with one or more cations selected from among complex cations, class four alkylammonium cations, and high valence cations. In addition or alternatively, the solid polymer electrolyte membrane includes an organo-metalloxane polymer obtained by impregnating the entire solid polymer electrolyte membrane, the non-power generating region, or the band region with an organo-metalloxane monomer that includes an ammonium cation or a class four ammonium cation at its terminus and then hydrolyzing and polycondensing the organo-metalloxane monomer.

Abstract: A membrane electrode assembly according to the invention includes a solid polymer electrolyte membrane and an electrode joined to each of two sides of the solid polymer electrolyte membrane. The solid polymer electrolyte membrane is such that some or all of the protons included in the entire solid polymer electrolyte membrane, a band region, or a non-power generating region are ion exchanged with one or more cations selected from among complex cations, class four alkylammonium cations, and high valence cations. In addition or alternatively, the solid polymer electrolyte membrane includes an organo-metalloxane polymer obtained by impregnating the entire solid polymer electrolyte membrane, the non-power generating region, or the band region with an organo-metalloxane monomer that includes an ammonium cation or a class four ammonium cation at its terminus and then hydrolyzing and polycondensing the organo-metalloxane monomer.