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

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. Here, a new "dual atomic site-support interactions" strategy is reported for high-efficiency alkaline water splitting, during which ruthenium heteroatoms are simultaneously in situ implanted into both the N-C matrix and the supported Co2P nanoparticle lattice. The strongly coupled Ru1-N-C and Ru2-P-Co sites facilitate H2O dissociation, H2 desorption, and O2 release, respectively, which synergistically guarantee enhanced HER and OER catalytic kinetics. image