Insight into the Role of Cu-ZrO2 Interaction in Methanol Synthesis from CO2 Hydrogenation

The metal-oxide interaction in heterogeneous catalysis is of significance to fundamental studies and practical applications. This study examines the catalytic role of the Cu-ZrO2 interaction and mechanistic pathways in the CO2 hydrogenation to methanol. A series of Cu-ZrO2 catalysts with different extents of interaction are achieved via tuning the component (Cu and ZrO2) particle sizes over Cu/ZrO2 and inverse ZrO2/Cu catalysts. The methanol synthesis from CO2 hydrogenation does not exclusively depend on the metallic Cu sites or the surface oxides but rather on the extent of the interaction between the metal and oxide. A highly dispersed Cu-ZrO2 interface with appropriate compositions can provide efficient active sites and promote the selective conversion to methanol. The mechanistic analysis demonstrates that surface formate and methoxy species are the major intermediates under the condition where methanol is the dominant product. The methanol formation principally follows the formate-methoxy intermediate pathway.