Effect of H2O/Al(i-OPr)3 Molar Ratio on the Structure and Performance of CuZnAl Catalyst for CO2 Hydrogenation to Methanol

The impact of the H2O/Al(i-OPr)3 molar ratio on the catalyst’s structural properties, surface nature, and performance in catalyzing CO2 hydrogenation to methanol was systematically evaluated. The role of H2O/Al(i-OPr)3 molar ratio in modulating the crystal phase composition, specific surface area, reducibility, surface acidity-basicity, and active site distribution of the catalysts was analyzed by XRD, N2 adsorption-desorption, H2-TPR, CO2-TPD, XPS, and In-situ DRIFTS.

The results show that H2O/Al(i-OPr)3 molar ratio significantly affects the dispersion and crystallite size of Cu species, thereby modulating the activity and selectivity of the catalysts. Among them, the CZA-103 catalyst achieved a CO2 conversion of approximately 12% and a methanol selectivity of around 40% at 250 ℃, 3.0 MPa, and GHSV of 4000 h−1, with no deactivation observed after more than 120 h on stream, exhibiting the optimal catalytic performance.