The hydrogenation of carbon dioxide over Cu-Mo/HZSM-5 composite catalysts prepared by an impregnation method has been studied. The reduction property and adsorption ability of the catalyst towards hydrogen and carbon dioxide have been investigated by TPR and TPD-MS techniques. The results indicated that the addition of Mo increased the activity and dimethyl ether selectivity of Cu/HZSM-5 catalyst, the most active and selective for dimethyl ether was the catalyst with n (Cu)/n (Mo) = 5:1. The addition of Mo caused the TPR peaks of Cu/HZSM-5 to move to higher temperatures. CO2-TPD results revealed the raise of the adsorbability of the catalyst toward CO2.
