沉淀剂对悬浮共沉淀法制备二甲醚催化剂的影响  

Influence of Precipitators on Catalysts for Synthesis of Dimethyl Ether Prepared by Suspended Coprecipitation Method

作　　者：张雅静[1] 邓据磊[1] 吴静[1] 王康军[1] 张素娟[1] 张宽[1] 

机构地区：[1]沈阳化工大学化学工程学院,辽宁沈阳110142

出　　处：《分子催化》2013年第1期43-48,共6页Journal of Molecular Catalysis(China)

基　　金：辽宁省科技厅工业攻关项目(No.2007223016)

摘　　要：以无水乙醇为溶剂,将Cu、Zn和Al的硝酸盐并流共沉淀在HZSM-5分子筛的悬浮溶液中,一步合成CuO-ZnO-Al2O3/HZSM-5双功能催化剂.研究了沉淀剂的种类、加入顺序和加入量对催化剂活性的影响.结果表明,以适量的草酸作沉淀剂,采用悬浮液并流共沉淀法制备的双功能催化剂,对CO2加氢直接合成二甲醚有较高的催化性能:在固定床反应器中,温度为270℃,压力为3.0 MPa,空速为4 800 h-1的反应条件下,CO2的单程转化率达到28.7%,二甲醚的选择性达到53.2%.BET、XRD、TPR、TPD和N2O滴定等对催化剂结构表征结果表明,双功能复合催化剂CuO-ZnO-Al2O3/HZSM-5的结构影响CO2加氢合成二甲醚的催化性能.Bifunctional catalysts of CuO-ZnO-A1203/HZSM-5 for dimethyl ether synthesis from hydrogenation of CO2 were directly prepared by parallel-flow-coprecipitation method, using anhydrous ethanol as solvent. The influ- ence of the kinds of precipitators, additive sequence and the amount of precipitators on the activity of the catalysts were investigated. The experiments results demonstrated that the as-prepared bifunctional catalysts showed higher catalytic activity for dimethyl ether synthesis. At 270 ℃, 3.0 MPa, space velocity 4 800 h^-1 , the one way conver- sion of CO2 was 28.7%, the yield of dimethyl ether could reach 53.2%. BET, XRD, TPR, TPD and N2O decomposition were employed to investigate the structure and surface performance of the catalysts. The results indica- ted the catalytic performance was determined by the structure of the catalysts, an interaction existed between the metal oxides, which exhibits with the composite effect of HZSM-5.

关 键 词：并流共沉淀 草酸 二甲醚 双功能催化剂 二氧化碳加氢 

分 类 号：TQ426[化学工程] O643.3[理学—物理化学]