Abstract

Shape-controlled Pd nanocubes and nanopolyedra particles were embedded in mesoporous silica shells and their catalytic properties for the CO2hydrogenation were compared to a reference Pd/SiO2catalyst prepared by wetness impregnation. Whereas the Pd impregnated silica exhibits a strong deactivation, the activity of both embedded solids is remarkably stable. This difference is due to a significant Pd particles sintering in the reference catalyst while no increase of particle size is observed for the core@shell solids. CH4selectivity is shown to be correlated to the mean coordination number of surface atoms which controls the adsorption strength of CO as intermediate species.