The role of the metal core in the performance of WO_x 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 WO_x 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 WO_x dispersion and modulate the Brønsted acidity of submonolayer WO_x on metal surfaces by tuning the deprotonation energy (DPE) and oxidation state of WO_x. The metal core affects the water splitting and hydroxylation of WO_x. Water splitting on Ru-WO_x is more thermodynamically favorable and has a higher dehydration rate than that on Ni-WO_x, leading to an activity enhancement as a result of an increased H₂ pulsing frequency. This study provides insights into optimizing inverse catalysts.