A Cobalt(III) Corrole with a Tethered Imidazole for Boosted Electrocatalytic Oxygen Reduction Reaction

Abstract

Comprehensive SummaryDeveloping electrocatalysts with high activity and selectivity for the oxygen reduction reaction (ORR) is vital to promote the performance of the next‐generation energy technologies, which depend on the efficiency of the catalytic reduction of dioxygen. In the structure of cytochrome c oxidases (CcOs), a histidine imidazole residue binding to the axial position of Fe plays a crucial role in facilitating the selective reduction of O2 to water. Inspired by nature, we herein report on the synthesis of CoIII corrole 1 tethered with an imidazole ligand as well as its electrocatalytic ORR and O2 binding features. As compared to the imidazolium‐free analogue, complex 1 displayed remarkably boosted activity for the selective four‐electron/four‐proton (4e‐/4H+) ORR with a half‐wave potential of E1/2 = 0.82 V versus reversible hydrogen electrode (RHE) in 0.1 mol/L KOH solutions. Importantly, we demonstrate that the tethered axial imidazole ligand improves the O2 binding ability of 1 thermodynamically and dynamically, which is crucial to boost electrocatalytic ORR performance. This work presents an example to improve electrocatalytic ORR activity and selectivity of Co corroles by introducing an axial imidazole ligand to enhance the O2 binding and activation.