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

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.