Cobalt and nitrogen doped porous carbon nanofibers as an efficient electrocatalyst for high performance oxygen reduction reaction

Abstract

Efficient oxygen reduction reaction (ORR) electrocatalysts are critical for fuel cells. Herein, we report a facile synthetic method to prepare Co–N–C porous nanofibers (Co–N-CNFs) for high performance ORR electrocatalyst. Specifically, Polyacrylonitrile/Bimetallic (Cobalt and Zinc) ZIFs (PAN@BZIFs) hybrid is obtained by electrospinning and finally resulting in Co, N doped carbon nanofibers after pyrolysis. Electrochemical measurements demonstrate that it possesses remarkable ORR performance, superior stability and methanol tolerance under alkaline condition compared to commercial Pt/C catalyst. In this Co–N–C system, the ratio of Co/Zn in BZIFs and temperature of pyrolysis are confirmed as the important factors of specific surface area, graphitization and even ORR property. Thereby, through changing them, the best electrocatalytic activity was acquired with the ratio equals to 0.2 and pyrolyzing at 800 ℃. In addition, the excellent catalytic property can be attributed to the synergic coupling pores and hierarchical pore structure.