Dual‐Type Ru Atomic Sites for Efficient Alkaline Overall Water Splitting

Abstract Monotypic catalytic site for bifunctional hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at low overpotential is a grand challenge in alkaline water splitting. Herein, a new strategy of dual‐type atomic site‐support interaction is reported, in which ruthenium heteroatoms are in situ implanted into both the N‐C nanosheet matrix (Ru¹‐N‐C) and supported Co₂P nanoparticle lattice (Ru²‐P‐Co) for boosting alkaline water splitting. It is found that the Ru¹‐N‐C and Ru²‐P‐Co can give rise to a synergistic effect for boosting HER and OER catalysis. Density functional theory calculations disclose that for HER, the Ru‐functionalized Co sites in Co₂P assume the task of expediting H₂O adsorption‐dissociation, and the adjacent coordination unsaturated Ru¹‐N‐C sites can facilitate the following H₂ desorption kinetic. The study found that the hydrogen spillover mechanism contributes to an ultralow HER polarization of 69 mV at 10 mA cm⁻². While for OER, due to electronegativity discrepancies, the doped Ru within Co₂P triggers electronic coupling, thereby efficiently tuning Ru d‐band center. This grants its electronic characteristic preferred for modulating rate‐determining step of OER to reduce the corresponding energy barrier, leading to superior OER catalytic activity . This work offers new understandings into catalyzing different reactions with multiple intermediate adsorptions by different atomic site‐support interplays.