Enhanced performance of the CuO-ZnO-ZrO2 catalyst for CO2 hydrogenation to methanol by WO3 modification

A series of WO3 modified CuO-ZnO-ZrO2 mixed oxides with different WO3 contents (0-20 at.%) were prepared by co-precipitation method and used as catalyst for methanol synthesis from CO2 hydrogenation. The effects of WO3 content on the physicochemical and catalytic properties of the CuO-ZnO-ZrO2-WO3 catalysts were investigated by X-ray diffraction, X-ray photoelectron spectra, temperature-programed reduction of hydrogen, temperature-programed desorption of CO2, N-2 adsorption and desorption, reactive N2O adsorption, and activity testing. The results indicated that both CO2 conversion and methanol selectivity of the CuO-ZnO-ZrO2 catalyst was enhanced by the addition of small amounts (2 and 5 at.%) of WO3. However, the activity was significantly decreased by the addition of excessive WO 3 (20 at.%). The activity was closely related to the specific surface area of metallic Cu (S-cu), amount of weak basic sites, and reducibility of the catalyst.