Uniform Nitrogen and Sulfur Co-doped Carbon Bowls for the Electrocatalyzation of Oxygen Reduction

• Published in: ACS sustainable chemistry & engineering Vol. 7; no. 7; pp. 7148 - 7154
• Main Authors: Li, Xiaobao, Gao, Xiaohong, Xu, Peiyan, You, Chenghang, Sun, Wei, Wang, Xianghui, Lin, Qiang, Liao, Shijun
• Format: Journal Article
• Language: English
• Published: American Chemical Society 01.04.2019
• Subjects: uniform carbon bowls; oxygen reduction reaction; nitrogen and sulfur co-doped; polyacrylonitrile
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.9b00126

Developing highly efficient and low-cost catalyst to replace platinum (Pt) is a key task for the commercialization of advanced energy systems, e.g., proton exchange membrane fuel cells, direct methanol fuel cells, and metal–air batteries, etc. In this work, we fabricated hollow carbon bowls doped with nitrogen and sulfur by using polyacrylonitrile and sulfur as the precursors through a pyrolysis procedure. The obtained catalyst exhibited high oxygen reduction reaction performance, with a half-wave potential comparable to that of Pt/C catalyst in an alkaline medium. Our catalyst also demonstrated outstanding methanol tolerance and stability, as well as high selectivity toward a four-electron path. In combination with the characterization results, the following factors are suggested as the proper origins for our catalyst’s outstanding performance: (1) the high contents of active species, including graphitic/pyridinic N species and sulfide S (-C–S-C-), which are believed to modify the surface charge distribution and create defects and active sites; (2) the high surface area (1146 m2 g–1), which can supply more exposed active sites; (3) bowl-like morphologies, which make the inner surface of the carbon shell more accessible to electrolyte and O2.