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

Copper-based catalysts for the hydrogenation of CO 2 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 CO 2 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 °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 CO 2 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 CO 2 hydrogenation and could guide the further design of high-performance copper-based catalysts to meet industrial demand. Copper-based catalysts are traditionally very effective for the hydrogenation of CO 2 to methanol, although control over the active site has remained elusive. Here, the authors design a Cu 1 /ZrO 2 single-atom catalyst featuring a Cu 1 –O 3 site responsible for a remarkable performance at 180 °C.