The effect of zirconia modification on gamma-Al2O3 Support to the Cu based catalyst was studied. It is found that the catalytic activity and methanol selectivity of the catalyst after Zr addition are both improved. The influences of reaction temperature, space velocity and the molar ratio of H-2:CO2 on Cu/y-Al2O3 and 12CulOZr/gamma-Al2O3 catalyst were also studied. The results indicate that low temperature, high space velocity and proper molar ratio of H-2/CO2 are advantageous to methanol synthesis. The XRD and TPR characterization show that the addition of Zr enhances the dispersion of CuO species, which is responsible for the enhanced catalytic performance of Cu based catalyst supported on zirconia modified 7-Al2O3 catalyst. (c) 2006 Elsevier Ltd. All rights reserved.