▎ 摘　　要

NOVELTY - A double-carbon-limited iridium nano-cluster catalyst is a composite material formed by dispersing iridium nano-dots on a carbon substrate, which is graphene oxide and sulfur-doped mesoporous carbon. USE - A double-carbon-limited iridium nano-cluster catalyst for water electrolysis reaction used in regenerative fuel cell, sensor, and water electrolysis device (all claimed). ADVANTAGE - The ultra-small nano-sized iridium nano-clusters are prepared by dual confinement of two carbon groups, which effectively prevents the agglomeration of iridium nanoparticles. The resulting catalyst has a large specific surface area, where increased active site of the catalyst greatly reduces the overpotential of the electrolyzed water reaction and the Tafel slope; effectively improves the performance of the catalyst; and has a long service life and good stability. The preparation method of the catalyst is simple and easy to operate; and the raw material is cheap and easy to obtain, and the reserves are abundant. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of double-carbon-limited iridium nano-cluster catalyst which involves (1) mixing sulfur- and carbon-containing surfactant and iridium(IV)-containing salt to obtain solution, slowly adding solution dropwise to hydrotalcite precursor solution containing magnesium and aluminum salts of graphene, adjusting pH of mixture to 8-12 with an alkali solution, and crystallizing at a high temperature to obtain a surfactant and iridium(IV) salt intercalated hydrotalcite precursor; and (2) calcining mixed solution at a high temperature and acid etching to obtain double-carbon-limited iridium nano-cluster catalyst.