▎ 摘　　要

The chemical state of Pd supported on reduced graphene oxide (rGO) changed dynamically and sensitively between Pd-0 and Pd2+ by switching atmosphere between H-2 and O-2. In contrast, Pd supported on graphene oxide (GO) did not show such dynamic redox properties. The catalytic activity in dehydrogenation and hydrogenation reactions also depended on the oxygen content of GO.