Asymmetric N, P‐Coordinated Single‐Atomic Fe Sites with Fe₂P Nanoclusters/Nanoparticles on Porous Carbon Nanosheets for Highly Efficient Oxygen Electroreduction

Abstract

Abstract Disrupting the symmetrical electron distribution of single‐atomic Fe sites is proposed as an effective strategy for improving the intrinsic activity in the oxygen reduction reaction (ORR). Herein asymmetric N, P‐coordinated single‐atomic Fe sites with Fe 2 P nanoclusters/nanoparticles on porous carbon nanosheets (FePNC) are constructed by a soft‐template self‐sacrificing pyrolysis. The synchrotron X‐ray absorption spectroscopy confirms the coexistence of FeN 3 P 1 moieties by the coordination of Fe atom with three nitrogen atoms and one phosphorus atom, and a small amount of Fe 2 P nanoclusters/nanoparticles. Benefiting from the unique asymmetric electronic and geometric configurations, the resultant FePNC catalyst exhibits excellent ORR activity with half‐wave potential of 0.76 V (0.5 m H 2 SO 4 ) and 0.90 V (0.1 m KOH), and good Zn–air battery performance. Theoretical analysis reveals that the synergistic effect of P coordination and Fe 2 P nanoclusters induces asymmetrical electron redistribution of single‐atomic Fe sites and thus optimize the absorption strength toward the ORR intermediates, which contribute to the improved ORR activity.