▎ 摘　　要

Developing low cost oxygen reduction catalysts that perform with high efficiency is highly desirable for the commercial success of environmentally friendly energy conversion devices such as fuel cells and metal-air batteries. In this work a three-dimensional, 3D, self-assembled Mn3O4 hierarchical network has been grown on nitrogen doped reduced graphene oxide (NrGO), by a facile and controllable electrodeposition process and its electrocatalytic performance for oxygen reduction reaction (ORR) has been assessed. The directly electrodeposited MnOx on a glassy carbon electrode (GCE) exhibits little electrocatalytic activity, whereas the integrated Mn3O4/NrGO catalyst is more ORR active than the NrGO. The resulting electrode architecture exhibits an "apparent" four-electron oxygen reduction pathway involving a dual site reduction mechanism due to the synergetic effect between Mn3O4 and NrGO. The 3D Mn3O4/NrGO hierarchical architecture exhibits improved durability and methanol tolerance, far exceeding the commercial Pt/C. The enhanced ORR performance of the room temperature electrodeposited Mn3O4 nanoflake network integrated with NrGO reported here offers a new pathway for designing advanced catalysts for energy conversion and storage.