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-CoO (Mn-CoO@CN), we unravel that the hydrogen-bond interaction between CN units and HO molecule not only drags the free water to enrich the surface of Mn-CoO 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-CoO@CN surpasses RuO at high current density (100 mA cm @ ~538 mV).