Using Zn-MOFs as partial Zn source to prepare Cu/ZnO/Al2O3 catalysts for methanol synthesis via CO2 hydrogenation

ZIF-8 was employed as partial Zn source to prepare high-performance Cu/ZnO/Al 2 O 3 catalysts for methanol synthesis via carbon dioxide (CO 2 ) hydrogenation. Among the CuZnAl-x catalysts (x = 1, 0.75, 0.5, 0.25 and 0, denoting molar ratio of ZIF-8/(ZIF-8 + Zn(NO 3 ) 2 ·6H 2 O), the CuZnAl-0.5 catalyst possessed the highest space time yield of methanol ( STY MeOH ), which recorded 416.4 g MeOH kg cat −1 h −1 at 250 °C and 3.0 MPa. Using ZIF-8 as partial Zn source was found to increase the specific surface area, induce oxygen vacancies, intensify metal-oxide interactions and enrich medium basic sites, which may rationalize the excellent methanol synthesis activity of the CuZnAl-0.5 catalyst. Besides, the CuZnAl-0.5 catalyst showed good stability for 30 h of reaction. This work offers a unique route to fabricate catalysts with the aid of MOFs precursors and highlights the significance of oxygen vacancies in methanol synthesis catalysts.