Dimethyl ether synthesis via CO2 hydrogenation over CuO–TiO2–ZrO2/HZSM-5 bifunctional catalysts

A series of CuO–TiO2–ZrO2 catalysts with various Ti and Zr molar ratios were prepared by co-precipitation method and characterized by N2 physisorption, X-ray diffraction (XRD) and temperature-programmed reduction of hydrogen (H2-TPR). The prepared CuO–TiO2–ZrO2 samples were mixed physically with HZSM-5 zeolite to synthesize dimethyl ether (DME) via CO2 hydrogenation. The results indicated that CuO–TiO2–ZrO2/HZSM-5 had higher CO2 conversion and DME yield compared to CuO–TiO2/HZSM-5 and CuO–ZrO2/HZSM-5 catalyst, in which the catalyst with equimole of Ti and Zr got the best performance. The activities of CuO–TiO2–ZrO2/HZSM-5 catalysts were well correlated to the reduction properties of CuO–TiO2–ZrO2 samples.