CO2 hydrogenation to methanol over Ce-doped Cu-ZrO2 catalysts: The critical role of oxygen vacancy concentration

CO 2 hydrogenation to methanol emerges as a promising strategy, offering a dual advantage of carbon dioxide fixation and the production of a valuable liquid fuel and chemical feedstocks. However, its industrial application is limited by the high stability of the CO 2 molecule, resulting in low CO 2 conversion and methanol selectivity. In this work, a series of Ce-doped Cu-ZrO 2 catalysts were synthesized by an oxalic acid gel co-precipitation method, and the effect of Ce/Zr molar ratios on catalyst structure and catalytic performance were investigated. Comprehensive characterization techniques, including XRD, N 2 physical adsorption–desorption, HRTEM, H 2 -TPR, XPS, CO 2 /H 2 -TPD and DFT calculation were employed to analyze the influence of Ce doping on oxygen vacancy concentration, surface basicity distribution, electron transfer, and catalytic performance. The results demonstrate that the CC 0.4 Z catalyst (n(Ce)/n(Zr) = 0.4) forms a Ce 0.4 ZrO solid solution structure, significantly enhancing CuO dispersion and generating abundant Cu δ+ -Ce 0.4 ZrO interfacial sites and oxygen vacancies. These features synergistically promote CO 2 /H 2 adsorption and activation while stabilizing Cu + species. Under optimized reaction conditions (260 ℃, 3.0 MPa, 9000 h −1 ), the CC 0.4 Z catalyst exhibits outstanding performance: CO 2 conversion of 14.6 %, methanol selectivity of 74.1 %, and a methanol yield of 10.8 %. Compared to the unmodified catalyst, this represents an increase of 5.8 percentage points in CO 2 conversion and 6.3 percentage points in methanol yield, providing a novel catalyst design strategy for efficient CO 2 conversion.