WS Moiré Superlattices Supporting Au Nanoclusters and Isolated Ru to Boost Hydrogen Production.

Maximizing the catalytic activity of single-atom and nanocluster catalysts through the modulation of the interaction between these components and the corresponding supports is crucial but challenging. Herein, guided by theoretical calculations, a nanoporous bilayer WS Moiré superlattices (MSLs) supported Au nanoclusters (NCs) adjacent to Ru single atoms (SAs) (Ru/Au-2LWS) is developed for alkaline hydrogen evolution reaction (HER) for the first time. Theoretical analysis suggests that the induced robust electronic metal-support interaction effect in Ru/Au-2LWS is prone to promote the charge redistribution among Ru SAs, Au NCs, and WS MSLs support, which is beneficial to reduce the energy barrier for water adsorption and thus promoting the subsequent H formation. As feedback, the well-designed Ru/Au-2LWS electrocatalyst exhibits outstanding HER performance with high activity (η = 19 mV), low Tafel slope (35 mV dec), and excellent long-term stability. Further, in situ, experimental studies reveal that the reconstruction of Ru SAs/NCs with S vacancies in Ru/Au-2LWS structure acts as the main catalytically active center, while high-valence Au NCs are responsible for activating and stabilizing Ru sites to prevent the dissolution and deactivation of active sites. This work offers guidelines for the rational design of high-performance atomic-scale electrocatalysts.