Photocatalytic reduction of CO 2 offers a promising approach to storing energy from intermittent sunlight in carbon-containing fuels and chemicals, thereby enabling carbon recycling. Single-atom Cu catalysts have attracted attention because they enhance CO 2 photoreduction. However, the roles of single-atom active sites and adjacent atoms in these catalysts have not been well understood.
Now, a new study published in Chem Catalysis has revealed how dynamic Cu and Ti active sites in single-atom Cu-TiO 2 catalysts cooperate under light to reduce CO 2 to CO.
The researchers, led by Prof. BI Yingpu and WANG Kangkang from the Lanzhou Institute of Chemical Physics (LICP) of the Chinese Academy of Sciences (CAS), conducted an experimental study of the dynamic interactions of CO 2 and H 2 O molecules at the surface active sites of single-atom Cu-TiO 2 catalysts by integrating in-situ X-ray photoelectron spectroscopy with infrared spectroscopy.
They found that single-atom Cu and adjacent Ti sites play distinct roles during CO 2 photoreduction. Specifically, H 2 O adsorption and electron injection at single-atom Cu sites promote CO 2 adsorption and activation at adjacent Ti sites, and their cooperative catalysis significantly improves CO 2 -to-CO conversion efficiency.
They further found that single-atom Cu-TiO 2 exhibits substantially enhanced activity for CO 2 -to-CO conversion (161.1 μmol g -1 h -1 ) relative to pristine TiO 2 (31.8 μmol g -1 h -1 ).
“These experimental findings challenge the conventional speculations on single-atom Cu catalysts and provide new insights for the re-evaluation of static structure–activity models,” said BI.
Chem Catalysis
Unexpected active sites in single-atom Cu-TiO2 catalysts for CO2 photoreduction
22-Jul-2026