Effect of surface basicity over the supported Cu-ZnO catalysts on hydrogenation of CO2 to methanol

MgO in Cu-ZnO catalyst strengthened the catalysts surface basicity, which promoted CO2 adsorption and then promoted CO2 conversion. Meanwhile, the surface basicity strengthened CO adsorption and weakened methanol adsorption, which greatly increased methanol selectivity. Methanol adsorption on catalyst surface seriously inhibited CO2 adsorption, while the strong surface basicity greatly weakened the inhibition due to the stronger adsorption of CO2 and the weaker adsorption of methanol on basic surface. Besides, the strong surface basicity inhibited methanol dissociation into CO species. Finally, the Cu-ZnO catalyst with strong surface basicity showed the excellent activity and selectivity in CO2 hydrogenation to methanol.