Zn, Fe Dual-Atom Sites Catalyst Constructed by Metal Vacancy Strategy for Oxygen Reduction Reaction and Zn-Air Battery

Developing highly efficient electrocatalysts toward oxygen reduction reaction is significant for Zn-air battery (ZAB), which is still arduous. In this work, based on a metal vacancy strategy, we synthesized an atomically dispersed Zn, Fe dual-atom catalyst on N-doped carbon (Zn, Fe/NC) by pyrolyzing the ZIF-8, postadsorbing Fe3+, and second pyrolysis steps. Due to the introduction of Fe atoms, the obtained Zn, Fe/NC-800 catalyst displays outstanding performance in an alkaline electrolyte (half-wave potential: 0.881 V), which approaches closely that of commercial Pt/C (0.903 V). Theoretical calculations indicate that the excellent activity of Zn and Fe/NC-800 can be attributed to the integration of Fe atoms that effectively optimizes the rate-limiting step. Zn, Fe/NC-800 also presents robust durability and strong methanol tolerance. Moreover, the ZAB assembled with Zn, Fe/NC-800 delivers charge-discharge cycling life (550 h) at 10 mA cm(-2) without noticeable decay. Furthermore, Zn, Fe/NC-800 even show a glorious flexible adaptability when employed as the cathode in a flexible ZAB.