Performance of Cu-Zn-Si-Al Catalyst Prepared by a Complete Liquid-phase Techonology for Dimethyl Ether Synthesis

Abstract

A series of Cu-Zn-Si-Al bifunctional catalysts for the synthesis of dimethyl ether( DME) was prepared by a liquid-phase technology. The catalysts were prepared with low-cost silica sol as the silica source. The addition of silica exhibits a strong promoting effect on the CO conversion and DME selectivity.When n( Si) / n( Al) is 2,the catalyst shows the best catalytic performance. The conversion of CO reaches58. 1% and the selectivity of DME is improved to 80. 2%. The catalysts were characterized by FTIR,XRD,TPR,TPD,BET,XPS and TEM. The results show that the addition of silicon components can promote the dispersion of active components on the catalysts and decrease the carbon deposition caused by heat treatment in the liquid phase. In addition, the Si components interact with Al, which significantly improves the performance of the catalyst for methanol dehydration and the selectivity of DME.