Modulating the electronic spin state of atomically dispersed iron sites by adjacent zinc atoms for enhanced spin-dependent oxygen electrocatalysis

Spin-state regulation is currently judged to be a very efficient approach to improving oxygen electrocatalytic capacity. Herein, we propose a bimetallic iron-zinc atomic catalyst and elucidate its main spintronic catalysis mechanism through a combination of in situ spectroelectrochemistry and molecular orbital theory. The electron/charge interaction between bimetals can elicit the transition of the electronic spin state and a change in charge density at active centers. As demonstrated by mechanistic study, these alterations can optimize the bond-order values of the orbital interactions be-tween intermediates and active centers. This renders its oxygen reduction reaction (ORR) activity and stability comparable to or even exceeding that of the benchmark Pt/C in pH-universal electro-lytes. Moreover, the alkaline and neutral Zn-air batteries driven by Fe,Zn/N-C show satisfactory performance with peak power den-sities of 211.7 and 95.0 mW cm -2, respectively. This work offers an approach to designing more efficient electrocatalysts and further understanding spintronic oxygen electrocatalysis.