Facile pyrolysis synthesis of abundant FeCo dual-single atoms anchored on N-doped carbon nanocages for synergistically boosting oxygen reduction reaction

Single-atom transition metal-based nitrogen-doped carbon (M−N x −C) is regarded as high-efficiency and cost-effectiveness alternatives to replace noble metal catalysts for oxygen reduction reaction (ORR) in renewable energy storage and conversion devices. In this work, rich FeCo dual-single atoms were efficiently entrapped into N -doped carbon nanocages (FeCo DSAs-NCCs) by simple pyrolysis of the bimetallic precursors doped zeolitic imidazolate framework-8 (ZIF-8), as affirmed by a series of characterizations. The graphitization degree of the N -doping carbon substrate was regulated by modulating the pyrolysis temperature and the types of the metal salts. The typical catalyst substantially improved the alkaline ORR performance, with the onset potential ( E onset ) of 0.99 V ( vs . RHE) and half-wave potential ( E 1/2 ) of 0.88 V ( vs . RHE). Ultimately, the catalyst-assembled Zn-air battery possessed a higher open-circuit voltage of 1.501 V, larger power density of 123.7 mW cm −2 , and outstanding durability for 150 h. This study provides a guide on developing ORR catalysts for electrochemical energy conversion and storage technology.