▎ 摘　　要

Efficient catalysts are required to promote oxygen reduction reaction (ORR) in order to implant ORR-involved clean energy technologies such as fuel cells and metal-air batteries. In this study, (111) facet-exposed CoFe2O4 nano-octahedrons crystals (NOCs) were grown on graphene via facile hydrothermal method and investigated as catalyst for ORR. The as-made CoFe2O4 NOCs-graphene composite exhibits very high activity towards ORR, meanwhile, excellent durability and very good tolerance to methanol were observed, which verifies the importance of exposing active facets of non-precious metal-based catalysts and also demonstrates its high potentials of replacing precious Pt for practical applications.