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 CO 2 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 CO 2 hydrogenation selectivity on In 2 O 3 ‐based catalysts. By replacing the supports from TiO 2 to ZrO 2 , the primary product of CO 2 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 In 2 O 3 ‐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 CO 2 hydrogenation over In 2 O 3 ‐based catalysts. This provides the potential to design selective catalysts for CO 2 hydrogenation by modulating the degree of H‐spillover.