Cu/ZnO/Al2O3 Catalyst Promoted with Amorphous MgO for Enhanced CO2 Hydrogenation to Methanol

Abstract CO 2 hydrogenation to methanol not only reduces CO 2 emissions but also produces a high‐quality energy source that is easy to store and transport. We found that the Cu/ZnO/Al 2 O 3 /MgO catalyst prepared by the deposition‐precipitation method, exhibits a higher methanol space‐time yield compared to the Cu/ZnO/Al 2 O 3 catalyst below 2 MPa. However, no activity difference was observed beyond 2 MPa. Characterization techniques revealed that for the Cu/ZnO/Al 2 O 3 /MgO catalyst, MgO is amorphous attributed to the influence of Al during calcination. The presence of amorphous MgO not only reduces the size of Cu 0 particles but also enhances CO 2 adsorption on the catalyst surface. We also demonstrate that improvement of CO 2 adsorption capacity is the key factor for the higher activity of the Cu/ZnO/Al 2 O 3 /MgO catalyst below 2 MPa.