WS 2 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 2 Moiré superlattices (MSLs) supported Au nanoclusters (NCs) adjacent to Ru single atoms (SAs) (Ru 1 /Au n -2LWS 2 ) 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 1 /Au n -2LWS 2 is prone to promote the charge redistribution among Ru SAs, Au NCs, and WS 2 MSLs support, which is beneficial to reduce the energy barrier for water adsorption and thus promoting the subsequent H 2 formation. As feedback, the well-designed Ru 1 /Au n -2LWS 2 electrocatalyst exhibits outstanding HER performance with high activity (η 10  = 19 mV), low Tafel slope (35 mV dec -1 ), and excellent long-term stability. Further, in situ, experimental studies reveal that the reconstruction of Ru SAs/NCs with S vacancies in Ru 1 /Au n -2LWS 2 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.