Establishing an Optimal Metal–Support Interaction Regime in Cu/In2O3 Catalysts for Stable CO2 Hydrogenation to Methanol

Balancing metal-support interactions (MSI) is critical for achieving both activity and stability in Cu/In2O3 catalysts for CO2 hydrogenation. Herein, a metal-organic framework (MOF)-templated precursor strategy is employed to regulate the initial spatial distribution of Cu and In species, thereby generating Cu/In2O3 catalysts with distinct MSI regimes. Among the three MSI regimes constructed, the MIL-68(In)-derived catalyst exhibits a moderated MSI that provides a favorable balance between interfacial activation and structural stability. The MOF-derived catalyst suppresses Cu-In alloy formation while promoting oxygen-vacancy generation and maintaining a balanced Cu0/Cuδ+ equilibrium. The MIL-derived catalyst achieves a methanol space-time yield of 0.374 gMeOH·gcat-1·h-1 at 300 °C with stable performance. In situ DRIFTS measurements indicate that moderated MSI accelerates the conversion of formate intermediates into methoxy species, while DFT calculations provide atomistic insight into MSI-dependent interfacial charge transfer and H2/CO2 adsorption. In contrast, excessively strong MSI drives irreversible Cu-In alloy formation, whereas weak MSI leads to insufficient interfacial activation and particle sintering. These findings establish an optimal MSI regime for balancing interfacial reactivity and structural durability and highlight MOF-templated precursor engineering as an effective strategy for designing robust Cu/In2O3 catalysts for CO2 hydrogenation.