Synergistic ZrO2 effects in Co/In2O3 catalysts: Enhancing activity and selectivity for CO2 hydrogenation to methanol

The In 2 O 3 -ZrO 2 solid solution catalyst has emerged as a versatile catalytic support for CO 2 hydrogenation to methanol, enabling noble metal-based systems (e.g., Pt, Ir) to achieve improved methanol selectivity. Building on this foundation, we introduce cobalt into the In 2 O 3 -ZrO 2 matrix, creating a novel Co/In 2 O 3 -ZrO 2 composite catalyst that synergistically integrates transition metal functionality with oxide engineering. The optimized catalyst achieves a methanol space-time yield of 0.80 g MeOH ·gcat −1 ·h −1 at a 5.0 MPa, H 2 /CO 2 = 3:1, 320 °C, GHSV = 48,000 cm 3 · g cat − 1 · h −1 , surpassing reported In 2 O 3 -ZrO 2 and Co/In 2 O 3 benchmarks. Mechanistic studies reveal that methanol synthesis follows the formate pathway, where ZrO 2 amplifies oxygen vacancy density to improve CO 2 adsorption and weakens CO adsorption through electronic modulation.