▎ 摘　　要

NOVELTY - Preparing monoatomic catalyst comprises (i) obtaining silica-graphene oxide composite material; (ii) adding silica-graphene oxide composite material into a solution containing trishydroxymethylaminomethane (Tris) to obtain a dispersion, adding dopamine hydrochloride into the dispersion, stirring and reacting for at least 3 hours, polymerizing dopamine hydrochloride to form polydopamine and encapsulating on silica-graphene oxide nanospheres to obtain silica-graphene oxide-polydopamine composite material; (iii) obtaining reduced graphene oxide-nitrogen-doped carbon composite material; and (iv) dispersing reduced graphene oxide-nitrogen-doped carbon composite material in deionized water to prepare an reduced graphene oxide-nitrogen-doped carbon aqueous dispersion with a concentration of 0.5-5 mg/ml, adding metal salt precursor into the solution at 0-10 degrees C, stirring and reacting for more than 1 hour to obtain reduced graphene oxide-nitrogen-doped/palladium monoatomic catalyst. USE - The catalyst is useful in catalyzing reduction reaction of arylnitro compound (claimed). ADVANTAGE - The method improves the overall process flow setting, and the reaction conditions and parameters of each key process step, improves dispersibility of single metal atoms, catalyst activity and cycle stability. DETAILED DESCRIPTION - Preparing monoatomic catalyst comprises (i) dispersing aminated silica nanospheres in deionized water, adding graphene oxide aqueous solution under stirring conditions, continuously stirring and reacting, so that graphene oxide wraps on the surface of the aminated silica ball by electrostatic action to obtain silica-graphene oxide composite material; (ii) adding silica-graphene oxide composite material into a solution containing trishydroxymethylaminomethane (Tris) to obtain a dispersion, adding dopamine hydrochloride into the dispersion, stirring and reacting for at least 3 hours, polymerizing dopamine hydrochloride to form polydopamine and encapsulating on silica-graphene oxide nanospheres to obtain silica-graphene oxide-polydopamine composite material; (iii) annealing silica-graphene oxide-polydopamine composite material under an atmosphere of an inert gas at 600-1000 degrees C for 0.5-5 hours, annealing polydopamine component to form nitrogen-doped carbon component, reducing graphene oxide components to reduced graphene oxide to obtain silica-reduced graphene oxide-nitrogen-doped carbon composite material, treating silica-reduced graphene oxide-nitrogen-doped carbon composite material with hydrofluoric acid solution and removing silica nanosphere template to obtain reduced graphene oxide-nitrogen-doped carbon composite material; and (iv) dispersing reduced graphene oxide-nitrogen-doped carbon composite material in deionized water to prepare an reduced graphene oxide-nitrogen-doped carbon aqueous dispersion with a concentration of 0.5-5 mg/ml, adding metal salt precursor into the solution at 0-10 degrees C, stirring and reacting for more than 1 hour to obtain reduced graphene oxide-nitrogen-doped/palladium monoatomic catalyst. An INDEPENDENT CLAIM is also included for monoatomic catalyst prepared by the above method.