Molecular level combination of coordination and interfacial regulations via functional ligands for industrial AEM water electrolysis

Coordination engineering is often used to tune the electronic structures of active sites, while their catalytic performances are determined not only by electronic structures but also by microenvironments. Herein, we introduce interfacial functional ligands that not only optimize the electronic structures of active sites but also regulate the interfacial microenvironment for oxygen evolution reaction (OER). Specifically, the pore edge-hosted FeF₃O₂ sites enable a favorable electronic structure to generate ^*OOH intermediates and simultaneously promote the interfacial transport of hydroxide for enhanced OER kinetics. The F ligands in FeF₃O₂ sites interact with interfacial water strongly via H-bonding to promote H-bond network connectivity, thus encouraging the temporally concerted proton transfer during hydroxide diffusion. Consequently, FeF₃O₂ sites realize the 331.5-fold enhancement in turnover frequency for alkaline OER over the NiOOH and efficient water electrolyzers (1.663 voltage at 1.0 amperes per square centimeter at 60°C, durably operating at 1.0 amperes per square centimeter > 1200 hours).