Steering Local Electronic Configuration of Fe–N–C‐Based Coupling Catalysts via Ligand Engineering for Efficient Oxygen Electroreduction

Abstract

AbstractFe–N–C materials are prospective candidates to displace platinum‐group‐based oxygen reduction reaction (ORR) catalysts, but their application is still impeded by the conundrums of unsatisfactory activity and stability. Herein, a feasible strategy of ligand engineering of the metal‐organic framework is proposed to steer the local electronic configuration of Fe–N–C‐based coupling catalysts by incorporating engineered sulfur functionalities. The obtained catalysts with rich Fe‐N4 sites and FeS nanoparticles are embedded on N/S‐doped carbon (denoted as FeS/FeNSC). In this unique structure, the engineered FeS nanoparticles and oxidized sulfur synergistically induce electron redistribution and modulate electronic configuration of Fe‐N4 sites, contributing to substantially accelerated kinetics and improved activity. Consequently, the optimized FeS/FeNSC catalyst displays outstanding ORR performance with a half‐wave potential of 0.91 V, better four electron pathway selectivity, lower H2O2 yield, and superior long‐term stability. As a proof‐of‐concept, zinc‐air batteries based on FeS/FeNSC deliver high capacity of 807.54 mA h g−1, a remarkable peak power density of 256.06 mW cm−2, and outstanding cycling stability over 600 h at 20 mA cm−2. This study delivers an efficacious approach to manipulate the electronic configuration of Fe–N–C catalysts toward elevated catalytic activity and stability for various energy conversion/storage devices.