CO2 hydrogenation with shape-controlled Pd nanoparticles embedded in mesoporous silica: elucidating stability and selectivity issues

Martins, J. [IFP Energies Nouvelles, Lyon, France] Batail, N. [IFP Energies Nouvelles, Lyon, France] Silva, S. [IFP Energies Nouvelles, Lyon, France] Rafik-Clement, S. [IFP Energies Nouvelles, Lyon, France] Karelovic Burotto, Alejandro [UCL] Debecker, Damien P. [UCL] Chaumonnot, A. [IFP Energies Nouvelles, Lyon, France] Uzio, D. [IFP Energies Nouvelles, Lyon, France] et al.[show all]

Shape-controlled Pd nanocubes and nanopolyedra particles were embedded in mesoporous silica shells and their catalytic properties for the CO2 hydrogenation were compared to a reference Pd/SiO2 catalyst 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. CH4 selectivity is shown to be correlated to the mean coordination number of surface atoms which controls the adsorption strength of CO as intermediate species.