Methanol Synthesis from CO2 Hydrogenation on CuO–ZnO–ZrO2 Prepared by Solvothermal Method: The Influence of Solvent on Catalyst Properties and Catalytic Behavior.

A series of CuO-ZnO–ZrO₂ (CZZ) catalysts were synthesized via a solvothermal method. The effects of four saturated monohydric alcohols (methanol, ethanol, n-propanol, and n-butanol) as solvents on the physicochemical properties and catalytic performance for the direct synthesis of methanol from CO₂ hydrogenation of the prepared catalysts were investigated. N₂ physical adsorption, X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy mapping, reactive N₂O adsorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction by H₂ (H₂-TPR), and temperature programmed desorption (H₂-TPD, CO₂-TPD) techniques were used to characterize the catalysts. The results indicate that the catalyst prepared with methanol as solvent (CZZ-M) has the smallest Cu crystallites and the largest metallic Cu surface area, thus exhibiting the highest methanol yield of 7.4% at 240 °C, 3.0 MPa, H₂:CO₂ of 3 (v/v), and GHSV of 2400 mL/(g_cat·h). [ABSTRACT FROM AUTHOR]