Design of Cu/ZnO/Al2O3 catalysts with a rich Cu–ZnO interface for enhanced CO2 hydrogenation to methanol using zinc-malachite as the precursor

Abstract

In Cu/ZnO/Al₂O₃ catalysts, the Cu–ZnO interface is crucial for the hydrogenation of CO₂ to methanol, which is beneficial to H₂ adsorption and CO₂ activation. In this research, a series of Cu/ZnO/Al₂O₃ catalysts (named CZA-X-Y, X is the sample number and Y is the sample state) with different Cu–ZnO interface contents were prepared by adjusting the components of zinc-malachite. The CZA-2-R catalyst, which was prepared from zinc-malachite with a zinc substitution amount of 27.13%, had small Cu particle sizes and uniform distribution of Cu and ZnO particles, creating a rich Cu–ZnO interface. As a result, the CZA-2-R catalyst had more catalytic active sites and displayed a good methanol yield of 11.2% as well as a long-term catalytic stability of 120 h. This study proposes a simple and feasible strategy to optimize the commercial Cu/ZnO/Al₂O₃ catalyst performance from the perspective of Cu–ZnO interface regulation.