Reconstructing Hydrogen‐Bond Network for Efficient Acidic Oxygen Evolution

Developing highly active oxygen evolution reaction (OER) catalysts in acidic conditions is a pressing demand for proton-exchange membrane water electrolysis. Manipulating proton character at the electrified interface, as the crux of all proton-coupled electrochemical reactions, is highly desirable but elusive. Herein we present a promising protocol, which reconstructs a connected hydrogen-bond network between the catalyst-electrolyte interface by coupling hydrophilic units to boost acidic OER activity. Modelling on N-doped-carbon-layer clothed Mn-doped-Co₃O₄ (Mn-Co₃O₄@CN), we unravel that the hydrogen-bond interaction between CN units and H₂O molecule not only drags the free water to enrich the surface of Mn-Co₃O₄ but also serves as a channel to promote the dehydrogenation process. Meanwhile, the modulated local charge of the Co sites from CN units/Mn dopant lowers the OER barrier. Therefore, Mn-Co₃O₄@CN surpasses RuO₂ at high current density (100 mA cm^-2 @ ~538 mV).