Synergistically enhanced oxygen reduction electrocatalysis by atomically dispersed and nanoscaled Co species in three-dimensional mesoporous Co, N-codoped carbon nanosheets network

• Published in: Applied catalysis. B, Environmental Environmental, 2020-01, Vol.260, p.118207, Article 118207
• Main Authors: Zhao, Shulin, Yang, Jing, Han, Min, Wang, Xiaoming, Lin, Yue, Yang, Rui, Xu, Dongdong, Shi, Naien, Wang, Qi, Yang, Minjun, Dai, Zhihui, Bao, Jianchun
• Format: Article
• Language: English
• Subjects: Carbon; Catalysts; Chemical etching; Chemical reduction; Co nanoparticles; Co-N-C nanosheets; Electrocatalysis; Electrocatalysts; Etching; Folic acid; Fuel cells; Fuel technology; Nanohybrids; Nanoparticles; Nanosheets; Nanostructure; Nitrogen; Optimization; Organic chemistry; Oxygen; Oxygen reduction reaction; Oxygen reduction reactions; Pyrolysis; Synergistic effect
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2019.118207

[Display omitted] •3D mesoporous Co-N-C nanosheets network enwrapping Co nanohybrids were prepared.•The nanohybrids possess high content of Co-N4-type single-atom sites (>5 wt%).•The synergy of the two Co species lets the nanohybrids show superior ORR activity.•Such nanohybrids manifest better electrocatalytic stability than Pt/C catalyst.•The contributions of atomic and nanoscaled Co species were determined. Metal-nitrogen-codoped carbon (M-N-C) nanostructures are promising electrocatalysts for oxygen reduction reaction (ORR). Despite the great progress that has been achieved, synthesizing three-dimensional porous nanoarchitectures derived from Co-N-C nanosheets or related nanohybrids with high content (> 5 wt%) of exposed single-atom sites remains a challenge. Herein, novel three-dimensional mesoporous Co-N-C nanosheets network enwrapping small amount of Co nanoparticles nanohybrids are fabricated by molten-salt template-assisted pyrolysis of Co-folic acid precursors and chemical etching. In the obtained nanohybrids, the content of single-atom-like Co (SA-Co%) is 7.4 wt% < SA-Co%