稀土改性SAPO-34分子筛的制备及其在CO_2加氢合成低碳烯烃中的催化性能  

Preparation of Rare Earths Modified SAPO-34 and its Catalysis Performance in Synthesis of Light Olefins from CO_2 Hydrogenation

作　　者：刘蓉[1] 王鹏飞[1] 查飞[1] 田海锋[1] 常玥[1] 

机构地区：[1]西北师范大学化学化工学院,甘肃兰州730070

出　　处：《精细化工》2016年第4期413-418,424,共7页Fine Chemicals

基　　金：国家自然科学基金(21161017)~~

摘　　要：采用水热合成法分别制备了氧化钇、氧化镧和氧化铈改性SAPO-34分子筛(M-SAPO-34,M=Y、La、Ce),用XRD、SEM、FTIR、BET、NH3-TPD和TG进行了表征,结果表明,稀土金属成功地引入到了分子筛骨架中,改性后的催化剂比表面积增大,粒径减小,孔径和酸性强度均有所改变。将CuO-ZnO-ZrO_2与稀土改性的SAPO-34分子筛按质量比1∶1机械混合制备了复合催化剂CuO-ZnO-ZrO_2/M-SAPO-34,用于催化二氧化碳加氢合成低碳烯烃,在反应温度为400℃、压强为3.0 MPa、碳氢摩尔比为1∶3、空速(SV)为1 800 m L/(gcat·h)、复合催化剂用量为1.0 g时,CuO-ZnO-ZrO_2/La-SAPO-34显示了良好的催化活性,二氧化碳的单程转化率为49.7%,低碳烯烃的选择性和产率分别为54.5%和27.1%。Yttrium oxide,lanthanum oxide and cerium oxide modified SAPO-34（M-SAPO-34,M = Y,La,Ce） were prepared by hydrothermal method,respectively.The samples were characterized by the methods of XRD,SEM,FTIR,BET,NH3-TPD and TG.The results showed that rare earths were added into SAPO-34 framework.They have higher specific surface area and smaller particles size,as well as the changes in the pore diameter and acidity.Bifunctional catalysts of CuO-ZnO-ZrO_2/ M-SAPO-34 were prepared by mechanically mixing M-SAPO-34 with CuO-ZnO-ZrO_2 in the weight ratio of 1 ∶1.Its catalytic activity for carbon dioxide hydrogenation to light olefins was investigated.Under the conditions of reaction temperature at 400 ℃,pressure at 3.0 MPa,space velocity（SV） of 1 800 m L /（gcat·h）,CO_2/ H2（molar ratio） of 1 ∶ 3,bifunctional catalyst mass of 1.0 g,CuO-ZnO-ZrO_2/ La-SAPO-34 exhibited better catalytic activity,the conversion of CO_2 could reach to 49.7% with a light olefins selectivity and yield of 54.5% and 27.1%,respectively.

关 键 词：稀土改性SAPO-34 CuO-ZnO-ZrO_2 低碳烯烃 二氧化碳加氢 催化技术 

分 类 号：Q013[生物学] TQ032[化学工程]