Diatomite-Templated Fabrication of Porous N, S-Co-Doped Carbon as High-Performance Catalyst for Oxygen Reduction

Abstract

Oxygen reduction reaction (ORR) catalysts free of noble metals serve an essential function in boosting the practical deployment of fuel cells and metal–air batteries. Herein, an N, S-co-doped porous carbon electrocatalyst was fabricated using polyacrylonitrile (PAN), thiourea and diatomite as the precursors, sulfur source and hard template, respectively. The optimal catalyst (S-PAC-D) exhibits a high ORR performance, with a half-wave potential of 0.84 V (vs. RHE), as well as a predominant four-electron pathway, short-term stability and methanol resistance. After being constructed as a zinc–air battery (ZAB), it can deliver a peak power density of 126.6 mW·cm−2 and a capacity of 804.1 mAh g−1Zn. This work offers a scalable, low-cost versatile methodology to fabricate high-performance non-noble metal ORR catalysts, which holds great promise for clean energy conversion devices.