Metal‐Free B, N co‐Doped Hierarchical Porous Carbon Electrocatalyst with an Excellent O2 Reduction Performance

• Main Authors: Fangxiao Wang, Jianhai Ren, Zihao Zheng, Qiye Liu, Dr. Chun‐yang Zhang
• Format: Article
• Language: English
• Published: Wiley-VCH 2021-07-01
• Series: ChemistryOpen
• Subjects: fuel cells; heteroatoms doping; metal-free systems; oxygen reduction reactions; porous carbon
• Online Access: https://doi.org/10.1002/open.202100090

Abstract Fuel cells have attracted increasing attention due to their low cost, high energy density, low environmental pollution, and abundant raw materials. Oxygen reduction reaction (ORR) is a core technology of fuel cells, and the development of new electrocatalysts with high ORR performance is highly desirable. Herein, we synthesize a series of B, N co‐doped hierarchical porous carbons using a soft template method with the integration of self‐assembly, calcination and etching. The obtained materials exhibit hierarchical porous structures, controllable pore distribution, partial graphite structures, and B, N co‐doping. They can function as the cost‐effective and metal‐free electrocatalysts, facilitating the diffusion of electrolyte ions and the improvement of ORR performance. Especially, the B, N co‐doped porous carbon with the B‐to‐N molar ratio of 5 (BNC‐5) displays a high ORR activity with a half‐wave potential (E1/2) of 0.73 V, an onset potential (Eonset) of 0.94 V, and a high limiting current density (JL) of 5.98 mA cm−2, superior to the N‐doped C (NC) and BNC‐1 (the B‐to‐N molar ratio=1), BNC‐3 (the B‐to‐N molar ratio=3) and BNC‐7 (the B‐to‐N molar ratio=7) under the identical conditions. Moreover, the BNC‐5 exhibits good cycling stability after 5000 cyclic voltammetry (CV) cycles and excellent tolerance toward even 3 M methanol. This research provides a new approach for the facile synthesis of dual element‐doped carbon electrocatalysts with high ORR performance.