▎ 摘　　要

NOVELTY - Sintered body of a mixture comprises graphene oxide and a nitrogen-containing compound-based component. USE - The sintered body is used as electrolyte in a catalyst layer of a polymer electrolyte fuel cell, a catalyst carrier in the catalyst layer, and an electrolyte in a solid electrolyte membrane, polymer electrolyte fuel cell, and membrane electrode assembly (all claimed), and in fuel cells. ADVANTAGE - The sintered body suppresses agglomeration of solids in the catalyst ink used to prepare the catalyst layer of the fuel cell, improves the coating characteristics, improves power generation characteristics when used for the catalyst layer of the fuel cell. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: a composition comprising the sintered body and a metal catalyst; a polymer electrolyte fuel cell catalyst layer comprising the composition; and a membrane electrode assembly comprising a solid electrolyte membrane, a gas diffusion layer, and the polymer electrolyte fuel cell catalyst layer.