The role of the metal core in the performance of WOx inverse catalysts

Metal-metal oxide inverse catalysts are valuable in diverse applications, but selecting pairs is challenging. Here, we investigate the role of metal cores (Pt, Ru, Rh, Pd, and Ni) in the formation and dynamics of Brønsted acid sites on the WOx overlayer on carbon. By in situ and ex situ characterizations, probe chemistry kinetics, and density functional theory (DFT) calculations, we demonstrate that metals with varying work functions promote WOx dispersion and modulate the Brønsted acidity of submonolayer WOx on metal surfaces by tuning the deprotonation energy (DPE) and oxidation state of WOx. The metal core affects the water splitting and hydroxylation of WOx. Water splitting on Ru-WOx is more thermodynamically favorable and has a higher dehydration rate than that on Ni-WOx, leading to an activity enhancement as a result of an increased H2 pulsing frequency. This study provides insights into optimizing inverse catalysts.