Abstract: A catalyst having both durability and high activity, a method for manufacturing the catalyst, and an intermediate product suitable for manufacturing the catalyst are provided. A catalyst includes a nickel substrate, a nickel oxide layer containing NiOOH, and a layer containing NiFe.

Abstract: Provided is a catalyst layer for gas diffusion electrode that can be used without using carbon supports, a method for manufacturing the same, a membrane electrode assembly, and a fuel cell. The catalyst layer for gas diffusion electrode according to the present invention includes a network-like metallic catalyst formed of a sintered body, the network-like metallic catalyst including nanoparticles linked with each other to have electron conductivity; and an ion conductor, at least a part of the ion conductor contacting the network-like metallic catalyst. Further, the membrane electrode assembly according to the present invention includes a polymer electrolyte membrane provided between an anode catalyst layer and a cathode catalyst layer, and the catalyst layer for gas diffusion electrode stated above is used in at least one of the anode catalyst layer and the cathode catalyst layer.

Abstract: Provided is a catalyst layer for gas diffusion electrode that can be used without using carbon supports, a method for manufacturing the same, a membrane electrode assembly, and a fuel cell. The catalyst layer for gas diffusion electrode according to the present invention include a network-like metallic catalyst formed of a sintered body, the network-like metallic catalyst including nanoparticles linked with each other to have electron conductivity; and an ion conductor, at least a part of the ion conductor contacting the network-like metallic catalyst. Further, the membrane electrode assembly according to the present invention includes a polymer electrolyte membrane provided between an anode catalyst layer and cathode catalyst layer, and the catalyst layer for gas diffusion electrode stated above is used in at least one of the anode catalyst layer and the cathode catalyst layer.

Abstract: The disclosed methods enable zirconium sulfophenyl phosphonate, zirconium sulfate, or zirconia sulfate, which has high performance as a proton conducting material and high catalytic activity, to be produced at low temperature by reaction by adding sulfophenyl phosphonic acid or sulfuric acid to zirconium nanoparticles, the zirconium nanoparticles being a precursor of strongly acidic zirconium particles obtained by reacting zirconium alkoxide with zirconium butoxide as a chelating agent and nitric acid as a catalyst in isopropyl alcohol as a solvent.