CATALYST PARTICLES, CATALYST INK, ELECTRODE CATALYST LAYER FOR FUEL CELLS, MEMBRANE ELECTRODE ASSEMBLY, POLYMER ELECTROLYTE FUEL CELL, METHOD FOR PRODUCING CATALYST PARTICLES AND METHOD FOR PRODUCING CATALYST INK

摘要

Catalyst particles includes a catalyst material and carbon particles supporting the catalyst material. The catalyst particles has a water content of 4.8 mass % or more and 20 mass % or less. A manufacturing method of catalyst particles includes exposing catalyst particles, which are carbon particles supporting a catalyst material, to a humidified atmosphere, prior to dispersing the carbon particles and a polymer electrolyte in a solvent for a catalyst ink.