Encapsulation of Co-based nanoparticle in N-doped graphitic carbon for efficient oxygen reduction reaction

Developing non-precious metal catalysts with high performance is highly desirable for oxygen reduction reaction (ORR). Here, we present the formation of graphene-supported Co-based nanoparticles (NPs) encapsulated in nitrogen-doped graphitic layers (Co@NC/rGO) for ORR application. Such composite electrocatalyst display activity with an onset potential of 0.98 V and a half-wave potential of 0.86 V in alkaline media, which is close to commercially used Pt/C electrocatalyst. Besides, the stability and methanol tolerant property is much better than that of Pt/C. A Zn-air battery made from Co@NC/rGO cathode catalyst show peak power density of 42.1 mW cm(-2) at 83.1 mA cm(-2), as well as superior longterm stability after 20 h at 10 mA cm(-2) and 20 mAcm(-2). Above experimental evidences promise such non-precious composite could be appropriate candidate to replace commercial Pt/C catalyst. (C) 2019 Elsevier Ltd. All rights reserved.