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 N-2 physisorption, X-ray diffraction (XRD) and temperature-programmed reduction of hydrogen (H-2-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. (C) 2009 Published by Elsevier B.V.