▎ 摘　　要

Electrochemical oxygen reduction reaction (ORR), using nonprecious metal catalysts, has attracted great attention due to the importance in renewable energy technologies, such as fuel cells and metal-air batteries. A simple and scalable synthetic route is demonstrated for the preparation of a novel 3D hybrid nanocatalyst consisting of Co9S8 nanoparticles which are incorporated in N, S-doped carbon (N, S-C) with rational structure design. In particular, the hybrid catalyst is prepared by direct pyrolysis and calcination of a gel mixture of Mg, Co nitrate-thiourea-glycine under Ar atmosphere, with subsequent HCl washing. The properties of obtained hybrid catalyst are quite dependent on calcination temperature and added glycine amount. Under a molar ratio of Co5-Mg15-tu10-gl45 and a calcination temperature of 900 degrees C, Co9S8 nanoparticles are embedded in a well-developed carbon matrix which shows a porous 3D few-layer graphene-like N, S-C with open and hierarchical micro-meso-macro pore structure. Because of the synergistic effect between Co9S8 nanoparticles and well-developed carbon support, the composite exhibits high ORR activity close to that of commercial Pt/C catalyst. More importantly, the composite displays superior long-term stability and good tolerance against methanol. The strategy developed here provides a novel and efficient approach to prepare a cost-effective and highly active ORR electrocatalyst.