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 between 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 electrolytes. Moreover, the alkaline and neutral Zn-air batteries driven by Fe,Zn/N-C show satisfactory performance with peak power densities 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.