Affiliation:
1. School of Chemistry and Chemical Engineering/Institute of Clean Energy and Materials/Key Laboratory for Clean Energy and Materials/Key Laboratory for Water Quality and Conservation of the Pearl River Delta Ministry of Education Guangzhou Higher Education Mega Center Guangzhou University No. 230 Wai Huan Xi Road Guangzhou 510006 P. R. China
Abstract
AbstractThe introduction of noble metal into spinel structure is an effective strategy to develop efficient oxygen evolution/reduction reaction (OER/ORR) catalysts. Herein, surface Cooct is substituted by Ruoct in Rux‐Mn0.5Co2.5‐xO4/NCNTs by ion‐exchange, where presence of Ruoct─O─Cooct unit facilitates electron transfer. This strong electron coupling effect leads downward shift in d‐band center and a narrowing of d‐p bandgap. The increased charge density of Cooct bridged with Ruoct dioxygen optimizes adsorption of oxygen intermediates (*OH) and occupation of electrons in eg‐orbital octahedral. The measured ORR/OER voltage difference is only 0.71 V. The peak power density of assembled zinc–air battery reaches 148.8 mW h cm−2, and energy density at 100 mA cm−2 reaches 813.6 mA h gZn−1, approaching a theoretical value of 820 mA h gZn−1. The catalyst demonstrates stable operation for over 500 h at 10 mA cm−2 and over 200 h at 50 mA cm−2. This work provides new insights to guide fabrication of advanced oxygen electrocatalysts.
Funder
National Natural Science Foundation of China