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.