▎ 摘　　要

NOVELTY - Catalyst is claimed. The catalyst is platinum group metal ion- hexamethylenediamine/graphene oxide, and composed of graphene oxide, hexamethylenediamine and platinum group metal, where the platinum group metal is ruthenium, rhodium, or palladium. USE - The catalyst is useful for preparing carboxylated hydrogenated nitrile butadiene rubber (claimed). ADVANTAGE - The method has simple operation method, and atomic utilization rate of 100%; and is environmentally friendly. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing the catalyst comprising fully stirring graphene oxide and hexamethylenediamine, and then adding chloride of the platinum group metal to carrying out reduction reaction, oxidizing graphene oxide and hexamethylene diamine at room temperature for 10-24 hours, and/or adding chloride of the platinum group metal, stirring at normal temperature for 10-24 hours, and/or carrying out reduction reaction with sodium borohydride, where the amount of sodium borohydride of 1-2 mol/l is 5-10%; and (2) preparing carboxylated hydrogenated nitrile butadiene rubber (HNBR) using rubber as a raw material, comprising taking catalyst and then dissolving rubber in an organic solvent with a mass fraction of 5-30%, where the rubber is styrene butadiene rubber or nitrile rubber.