▎ 摘　　要

NOVELTY - Preparation of catalyst (I) supported by carbon nanotubes and graphene involves (i) preparing transition metal/carbon nanotubes (CNT) particles by thermal reduction of a salt of a transition metal in the presence of carbon nanotubes, (ii) preparing transition metal/graphene particles by thermal reduction of a salt of a transition metal in the presence of graphene, and (iii) mixing transition metal/carbon nanotubes particles and transition metal/graphene particles. USE - Preparation of catalyst is used for preparing electrode ink for cathode used in proton exchange membrane fuel cell and proton exchange membrane electrolyzer (all claimed). ADVANTAGE - The method enables preparation of catalyst with excellent electrocatalytic performance, electroactive surface area, uniform distribution of metal particles, diffusion of gases, and stability. The fuel cell comprising the catalyst produced by the method has excellent corrosion resistance. DETAILED DESCRIPTION - Preparation of catalyst of formula: M1(CNT/Gr) (I) supported by carbon nanotubes and graphene involves (i) preparing M1/CNT particles of a transition metal (M1) and supported by carbon nanotubes (CNT) by thermal reduction of a salt of a transition metal in the presence of carbon nanotubes, (ii) preparing M1/Gr particles of a transition metal (M1) and supported graphene (Gr) by thermal reduction of a salt of a transition metal M1 in the presence of graphene, and (iii) mixing M1/CNT particles with M1/Gr particles. An INDEPENDENT CLAIM is included for preparation of electrode ink, which involves mixing catalyst (I) supported by carbon nanotubes and graphene with an ionomer and a solvent.