The role of Cu1-O3 species in single-atom Cu/ZrO2 catalyst for CO2 hydrogenation

Copper-based catalysts for the hydrogenation of CO2 to methanol have attracted much interest. The complex nature of these catalysts, however, renders the elucidation of their structure-activity properties difficult. Here we report a copper-based catalyst with isolated active copper sites for the hydrogenation of CO2 to methanol. It is revealed that the single-atom Cu-Zr catalyst with Cu-1-O-3 units contributes solely to methanol synthesis around 180 degrees C, while the presence of small copper clusters or nanoparticles with Cu-Cu structural patterns are responsible for forming the CO by-product. Furthermore, the gradual migration of Cu-1-O-3 units with a quasiplanar structure to the catalyst surface is observed during the catalytic process and accelerates CO2 hydrogenation. The highly active, isolated copper sites and the distinguishable structural pattern identified here extend the horizon of single-atom catalysts for applications in thermal catalytic CO2 hydrogenation and could guide the further design of high-performance copper-based catalysts to meet industrial demand.

Automated summary

This study reports a novel copper-based catalyst with isolated active copper sites for the hydrogenation of CO2 to methanol. The Cu-1-O-3 units in the Cu-Zr catalyst are found to contribute solely to methanol synthesis, while small copper clusters or nanoparticles with Cu-Cu structural patterns are responsible for the formation of CO by-product. Additionally, the migration of Cu-1-O-3 units to the catalyst surface during the catalytic process accelerates CO2 hydrogenation. These findings extend the application potential of single-atom catalysts for thermal catalytic CO2 hydrogenation and provide insights for the design of high-performance copper-based catalysts to meet industrial demand.