Gallium Cluster-Promoted In₂O₃ Catalyst for CO₂ Hydrogenation to Methanol

In this work, highly dispersed gallium clusters are constructed on In2O3 (denoted as Ga/In2O3) to promote hydrogenation of CO2 to methanol. Compared to pristine In2O3, the Ga/In2O3 catalysts show markedly improved CO2 conversion and methanol space-time yield (STY), as well as enhanced stability over 60 h on stream. A strong electronic interaction between the loaded gallium and In2O3 support, as confirmed by multiple techniques, results in well-dispersed, stable gallium clusters on In2O3, which is beneficial to long-term performance. The interface between gallium clusters and the defective In2O3 support serves as active sites to facilitate the activation of H2 and CO2. This interfacial synergy not only enhances the adsorption and dissociation of H2 but also effectively inhibits the strong adsorption of CO2 as carbonate. The activated CO2 at the interface sites can be dissociated readily into adsorbed CO for further hydrogenation into methanol.