CO_2加氢制备二甲醚CuO-ZnO-Al_2O_3/HZSM-5催化剂的研究  

Investigation on CuO-ZnO-Al_2O_3/HZSM-5 Catalysts for Synthesis of Dimethyl Ether from CO_2 Hydrogenation

作　　者：张雅静[1] 邓据磊[1] 张素娟[1] 王康军[1] 吴静[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3期235-241,共7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,草酸为沉淀剂,采用悬浮共沉淀法,一步合成CuO-ZnO-Al2O3/HZSM-5双功能催化剂.并研究了该催化剂在CO2加氢合成二甲醚反应中的催化性能,考察了CO2加氢合成甲醇组分(CuO-ZnO-Al2O3)与甲醇脱水组分(HZSM-5)配比对催化剂性能的影响以及催化剂的稳定性.结果表明,双功能催化剂加氢与脱水组分配比为8∶1时,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29.8%,二甲醚的选择性和收率分别达到53.8%和16%.XRD、BET、TPR和NH3-TPD对催化剂结构表征结果表明,不同组分配比影响双功能复合催化剂中脱水组分的酸性和加氢组分的结晶度、晶粒尺寸、CuO的还原性.Bifunctional catalysts of CuO-ZnO-Al2O3/HZSM-5 for dimethyl ether synthesis from hydrogenation of CO2 were directly prepared by parallel-flow-coprecipitation method,using anhydrous ethanol as solvent,and oxalic acid as precipitator.The catalytic performance of the catalyst was studied.The influence of mass ratio of the hydrogenation component（CuO-ZnO-Al2O3） to the methanol dehydration component（HZSM-5） and the stability of the catalyst were investigated.The experiments results demonstrated that there existed an optimal mass ratio between the two components of the CuO-ZnO-Al2O3/HZSM-5 bifunctional catalysts for dimethyl ether synthesis.At 270 ℃,3.0 MPa,space velocity 4 800 h-1,the one way conversion of CO2 was 29.8%,the selectivity and the yield of dimethyl ether could reach 53.8% and 16%,respectively.XRD,BET,TPR and NH3-TPD were employed to investigate the structure and surface performance of the catalysts.The results indicated the crystallization degree,grain size and the reducibility of the CuO of the hydrogenation component,as well as the acidic property of the dehydration component of HZSM-5,were highly determined by the mass ratio of the two components of the catalysts.

关 键 词：组分配比 二甲醚 双功能催化剂 二氧化碳加氢 CuO-ZnO-Al2O3 HZSM-5 

分 类 号：TQ426[化学工程] O643.32[理学—物理化学]