▎ 摘　　要

An oxygen reduction reaction (ORR) electrocatalyst with high performance, low cost and good durability is extremely desirable for promoting the commercial application of fuel cells. Much efforts have been made to explore efficient and nonprecious catalysts to replace the platinum-based catalyst. Particularly, cobalt oxide (Co3O4 or CoO) decorated carbon materials has been demonstrated as promising ORR electrocatalysts. In this paper, we report a kind of tiny hollow nano-Co3O4 anchored 3D graphene aerogels (3DG) in the first time, which derived from direct oxidation carbon wrapped Co/3DG through Kirkendall effect. Due to its unique structure, the hollow Co3O4/3DG shows excellent ORR catalytic activity with almost four-electron reduction pathway, high methanol tolerance and long-term durability in alkaline media.