Synthesis of a Cu@ZnO1−x/Al2O3 catalyst with high-density ZnO1−x–Cu interfacial sites for enhanced CO2 hydrogenation to methanol

Abstract

The development of catalysts with high-density interfacial sites is crucial for enhancing catalytic performance. However, the efficient construction of interfacial sites remains a significant challenge. In this study, we introduced a ligand-regulated co-precipitation synthesis strategy to fabricate a Cu@ZnO_1−x/Al₂O₃ catalyst. The catalyst possesses high-density partially-reduced ZnO_1−x–Cu interfacial sites and exhibits enhanced activity for CO₂ hydrogenation to methanol. The methanol space-time yield (STY) of the Cu@ZnO_1−x/Al₂O₃ was 3.8 times higher than that of the commercial Cu/ZnO/Al₂O₃ after 14 h of continuous reaction. Molecular dynamics (MD) simulations and in situ Raman spectroscopy indicated that Cu–X–Zn linkage ligands formed in the precursor solution during hydrothermal treatment facilitated zinc-malachite formation during co-precipitation, which promoted Cu–ZnO interface formation during H₂ reduction. Moreover, density functional theory (DFT) calculations confirmed partially-reduced ZnO_1−x–Cu interfaces were more active via the formate pathway. This work reveals a novel and robust route for designing catalysts with high-density interfacial sites, shedding light on catalyst development.