▎ 摘　　要

NOVELTY - Preparation of graphene composite catalyst comprises taking 1-butyl-3-methylimidazolium hexafluorophosphate and 1-butyl-3-methylimidazolium tetrafluoroborate, stirring for 24 hours to obtain mixed ionic liquid, stirring 50 mg graphene oxide and aqueous methanol for 20-40 minutes, adding 2 ml mixed ionic liquid dropwise, stirring for 40-80 minutes, adding 2 ml 0.038 M chloroplatinic acid dropwise, stirring, adding 0.5 M potassium hydroxide to adjust pH value to 9-12, adding 200 mg sodium borohydride, stirring for 20-24 hours, collecting precipitate, washing and drying at 50 degrees C for 20-24 hours. USE - Method for preparing graphene composite catalyst (claimed). ADVANTAGE - The catalyst has high catalytic activity and stability.