Enhanced Methanol Synthesis via CO2 Hydrogenation over ZnO/ZrO2 Catalysts by the Regulation of Precipitation Method.

A series of ZnO/ZrO₂ catalysts were synthesized by the precipitation method. The effect of different precipitation modes on the physicochemical properties of the ZnO/ZrO₂ catalysts for CO₂ hydrogenation to methanol was investigated. The catalysts were characterized by X-ray diffraction (XRD), N₂ adsorption–desorption, transmission electron microscopy (TEM), temperature programmed desorption of CO₂ (CO₂-TPD), temperature programmed reduction of H₂ (H₂-TPR), and X-ray photoelectron spectroscopy (XPS). The results showed that the catalyst of ZnO/ZrO₂ prepared by the concurrent precipitation method had more CO₂ adsorption sites, resulting in its higher CO₂ conversion. While the stepwise precipitation mode increased the surface oxygen content of ZnO/ZrO₂, which enhanced the methanol selectivity. Overall, the ZnO/ZrO₂ prepared by the concurrent precipitation mode exhibited a highly competitive efficacy for CO₂ hydrogenation, giving a methanol selectivity of 81.4% with a CO₂ conversion of 5.1% at 280 ℃ and 3 MPa, and the methanol yield reached 4.2%. The effect of different precipitation modes on the physicochemical properties of the ZnO/ZrO₂ catalysts for CO₂ hydrogenation to methanol was investigated, and the ZnO/ZrO₂ prepared by the concurrent precipitation mode exhibited a highly competitive efficacy for CO₂ hydrogenation. [ABSTRACT FROM AUTHOR]