Copper-ceria solid solution with improved catalytic activity for hydrogenation of CO2 to CH3OH

Abstract A copper-ceria solid solution and ceria-supported copper catalysts were prepared and used for the catalytic hydrogenation of CO2 to CH3OH. According to site-specific classification and quantitative analyses (X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, and CO adsorption), the interfaces of the prepared catalysts were classified as Cu incorporated into ceria (Cu-Ov-Cex), dispersed CuO (D-CuO-CeO2), and bulk CuO (B-CuO-CeO2) over the CeO2 surface. These results, together with those of activity tests, showed that the Cu-Ov-Cex species was closely related to the CO2 hydrogenation activity and resulted in a much higher turnover frequency of CH3OH production than that observed with the D-CuO-CeO2 and B-CuO-CeO2 species. Thus, the copper-ceria solid solution exhibited improved activity due to the higher Cu-Ov-Cex fraction.