Pristine Ru generally shows unsatisfying activity for the electrocatalytic hydrogen evolution reaction (HER). How to activate its HER activity through facile methodologies is very challenging. Recently, metal-supported electrocatalysts integrating metals with efficient hydrogen adsorption and supports with facile hydrogen desorption delivered a high HER performance through a metal-to-support hydrogen spillover process, where the small metal–support work function difference (ΔΦ) was identified as the criterion for the successful interfacial hydrogen spillover. Herein, we demonstrate that a hydrogen spillover strategy significantly boosts the HER activity of Ru by depositing a Ru1Fe1 alloy on CoP (Ru1Fe1/CoP) with a small ΔΦ of 0.05 eV. Experimentally, Ru1Fe1/CoP (0.7 wt % Ru loading) delivered a high Ru utilization activity of 139.8 A/mgRu and a long-term durability in acid. Mechanism investigations authenticated that the small ΔΦ guaranteed the interfacial hydrogen spillover from Ru1Fe1 with efficient hydrogen adsorption to CoP with facile hydrogen desorption and thereafter boosted the HER activity of Ru.

Most oxide semiconductor photoanode materials for water splitting are synthesized in ambient environment. Oxygen vacancy exists in these samples making them intrinsically n-type at the as-synthesized state. Oxygen vacancy has been widely reported for enhancing the performance of a photoanode by improving the electron conductivity. Besides the effect on the bulk materials properties, oxygen vacancy also plays an important role in the interfacial charge transfer to electrolyte, on which much less attention has been paid in the past. Herein, we found that although air-annealed W-doped BiVO4 has a higher electron density, lower surface charge transfer resistance, and a slightly better light absorption than the O2-annealed sample, the latter displays a higher photocurrent density. Experimentally we found that the enhanced performance comes from a better charge separation efficiency, despite that the presence of oxygen vacancy does lead to a better charge transfer efficiency. Theoretical calculation finds that there is a localized state formed inside the bandgap in W-doped BiVO4 with oxygen vacancy, which serves as recombination center to reduce its charge separation efficiency. Oxygen vacancy on the V site activates two different kinds of V into reactive sites for improved surface catalysis. Oxygen vacancy also facilitates the adsorption of the OHads, Oads, and OOHads involved in a water splitting process, which benefits the surface catalytic process. It is predicted from this study that better performance can be achieved by introducing oxygen vacancy on the surface of a doped BiVO4 and simultaneously avoiding oxygen vacancy in the bulk. The current study provides an important understanding of the roles played by oxygen vacancy in doped photoanode materials.

Carbon neutrality initiative has stimulated the development of the sustainable methodologies for hydrogen generation and safe storage. Aqueous-phase reforming methanol and H2O (APRM) has attracted the particular interests for their high gravimetric density and easy availability. Thus, to efficiently release hydrogen and significantly suppress CO generation at low temperatures without any additives is the sustainable pursuit of APRM. Herein, we demonstrate that the dual-active sites of Pt single-atoms and frustrated Lewis pairs (FLPs) on porous nanorods of CeO2 enable the efficient additive-free H2 generation with a low CO (0.027%) through APRM at 120 °C. Mechanism investigations illustrate that the Pt single-atoms and Lewis acidic sites cooperatively promote the activation of methanol. With the help of a spontaneous water dissociation on FLPs, Pt single-atoms exhibit a significantly improved reforming of *CO to promote H2 production and suppress CO generation. This finding provides a promising path towards the flexible hydrogen utilizations.

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