▎ 摘　　要

NOVELTY - An electrochemical device has a catalyst promoter including an amorphous metal oxide and a substrate supporting the catalyst promoter and including graphene. The content of amorphous metal oxide is more than 50 wt.% with respect to content of catalyst promoter. USE - Electrochemical device e.g. fuel cell is used for vehicles. ADVANTAGE - The economical electrochemical device is potential low emission energy sources to power vehicles. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for manufacture of electrochemical device, which involves forming catalyst promoter including amorphous metal oxide on substrate, and depositing noble metal catalyst on the substrate.