Hydrogen Aggregation Enhances CO ₂ Hydrogenation to Methanol Over In ₂ O ₃ ‐Based Catalysts

The hydrogen (H) spillover on the catalyst surface is crucial in the CO₂ hydrogenation reaction, but its effects on product selectivity have been rarely investigated. Herein, we reveal the H-spillover mediated regulatory role of oxide supports, which changed the CO₂ hydrogenation selectivity on In₂O₃-based catalysts. By replacing the supports from TiO₂ to ZrO₂, the primary product of CO₂ hydrogenation experiences a significant shift from carbon monoxide (95.6%) to methanol (84.2%). In situ characterization and theoretical modeling evidence that the degree of H-spillover influences the distribution of surface hydrogen species on In₂O₃-based catalysts, affecting the hydrogenation behavior of formate intermediates and the product distribution. The results illustrate the intrinsic relationship between surface hydrogen atom concentration and methanol synthesis rate in catalytic CO₂ hydrogenation over In₂O₃-based catalysts. This provides the potential to design selective catalysts for CO₂ hydrogenation by modulating the degree of H-spillover.