CO₂ hydrogenation to methanol on tungsten-doped Cu/CeO₂ catalysts

The catalytic hydrogenation of CO₂ to methanol depends significantly on the structures of metal-oxide interfaces. We show that doping a high-valency metal, viz. tungsten, to CeO₂ could render improved catalytic activity for the hydrogenation of CO₂ on a Cu/CeW_0.25O_x catalyst, whilst making it more selective towards methanol than the undoped Cu/CeO₂. We experimentally investigated and elucidated the structural-functional relationship of the Cu/CeO₂ interface for CO₂ hydrogenation. The promotional effects are attributed to the irreversible reduction of Ce⁴⁺ to Ce³⁺ by W-doping, the suppression of the formation of redox-active oxygen vacancies on CeO₂, and the activation of the formate pathway for CO₂ hydrogenation. This catalyst design strategy differs fundamentally from those commonly used for CeO₂-supported catalysts, in which oxygen vacancies with high redox activity are considered desirable.