An efficient Cu-based catalyst derived from the Cu–Al spinel for CO2 hydrogenation to methanol

Abstract

Development of highly active and stable catalysts is critical for the hydrogenation of CO₂ to methanol. Herein, a Cu-based catalyst was demonstrated by impregnating 20%ZnO onto the Cu–Al spinel followed by reduction. The catalyst delivers a methanol yield of 0.218 g g⁻¹ h⁻¹ with a CO₂ conversion of 9.2% at 220 °C, 3 MPa, 6000 mL g⁻¹ h⁻¹, and is stable over a 300 h test. Various characterization techniques reveal that ZnO inhibits the growth of Cu nanoparticles during exsolution. Furthermore, there is strong electronic interaction between the components, i.e., the electron migrates from ZnO to the Cu–Al spinel, which leads to more oxygen vacancies and an electron-rich support and thus beneficial for CO₂ hydrogenation to methanol.