Crystal structure modulation of ZrO2 support for enhanced CO2 hydrogenation to methanol over In–Pd/ZrO2 catalysts

Mix-ZrO 2 supports have tunable monoclinic and tetragonal crystalline phases. • InPd/Mix-ZrO 2 –400 achieves 11.5% CO 2 conversion and 52% methanol selectivity. • The specific composition improves H 2 dissociation and CO 2 adsorption. • Methanol synthesis over InPd/Mix-ZrO 2 proceeds via the formate pathway. Upgrading CO 2 to methanol represents a pivotal strategy for achieving carbon neutrality, yet the development of highly efficient indium-based catalysts remains constrained by the urgent need for precise modulation of the support structure. Herein, we rationally design an In Pd catalyst supported on mixed crystal phase ZrO 2 (Mix-ZrO 2 ) with tunable monoclinic and tetragonal fractions. The optimized InPd/Mix-ZrO 2 –400 catalyst exhibits a CO 2 conversion of 11.5% and methanol selectivity of 52% at 270 °C, significantly outperforming other comparative catalysts, and retains stability over 50 h. Crucially, the enhanced performance is intrinsically attributed to the synergistic effect derived from the specific monoclinic-tetragonal phase ratio, which significantly boosts the dissociation of H 2 and CO 2 adsorption capacity. In-situ DRIFTS analysis confirms the reaction proceeds via the formate (HCOO*) pathway, where the optimized support facilitates the rapid hydrogenation of intermediates. This work elucidates the synergistic effect of crystal phase engineering in oxide supports, offering a robust pathway for designing advanced CO 2 hydrogenation catalysts.