▎ 摘　　要

NOVELTY - A catalyst comprises 55-99 %mass graphene aerogel and 1-45 %mass nickel. USE - Catalyst used for methanation of carbon dioxide, hydrogenation of acetylene for producing ethylene and decomposition of ammonia to hydrogen (all claimed). ADVANTAGE - The catalyst has large specific surface area, surface defects, surface oxygen-containing functional group and high filling density, increased steric effect, and catalytic activity. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the catalyst, which involves oxidizing graphite prepared by Hummers method, washing obtained graphene, freeze-drying, processing with crosslinking agent, hydrothermally reacting, freezing and drying to obtain graphene aerogel, adding nickel ion aqueous solution, drying and calcining under inert gas protection to obtain catalyst precursor, and reducing precursor.