完全液相法Cu-Zn-Si-Al催化剂一步合成二甲醚

采用完全液相法,以廉价的硅溶胶作为硅原料,制备了一系列的Cu-Zn-Si-Al双功能浆状催化剂,考察不同硅铝比对浆态床CO加氢合成二甲醚的影响。 两周的活性评价表明,硅的引入显著提高了催化剂的活性和稳定性。 当n(Si)/n(Al)=2时,CO转化率最高,为58.1%,且二甲醚的选择性为80.2%。 通过FTIR、XRD、TPR、TPD、BET、XPS和TEM等技术手段对催化剂进行了表征,结果表明,硅组分的添加可以促进活性组分Cu物种的分散,并能够改善完全液相法热处理而导致的积碳现象。 且Si组分的引入与催化剂中的Al相互作用,显著提高了催化剂的甲醇脱水性能,从而使催化剂具有较高的二甲醚选择性。

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

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 reaches 58.1% 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.