介孔交联蒙脱土固体酸催化剂的结构与性能  

Structure and Catalytic Properties of Mesoporous Ti-Pillared Montmorillonite Solid Acid Catalysts

作　　者：郭锡坤[1] 张俊豪[1] 韩宝诚[1] 鲍仁周[1] 

机构地区：[1]汕头大学化学系,汕头515063

出　　处：《无机化学学报》2005年第10期1483-1489,共7页Chinese Journal of Inorganic Chemistry

基　　金：广东省科技计划项目(No.2003C33004);汕头大学研究与发展项目(NO.130-512042)

摘　　要：采用溶胶凝胶法制备介孔钛交联蒙脱土,再采用SO42-和CeO2进行两次改性,然后以之为载体,制备铜基交联蒙脱土介孔固体酸催化剂。催化剂的结构通过BET、XRD、TPR、Py-IR、FTIR、XPS和SEM等手段进行表征,并研究了它们在富氧条件下对丙烯选择还原NO的催化性能。结果表明,钛交联剂能很好地撑开蒙脱土的土层,形成良好的介孔结构,其孔径分布集中在3￣7nm,并且使制得的交联蒙脱土载体的比表面积明显增大;SO42-与钛形成了螯合双配位结构,增加了催化剂表面的酸量,促使了Br,nsted(B)酸中心的形成;铜和铈的相互作用阻止了铜晶粒的团聚,促进了铜的还原作用,有效地提高了催化剂的性能。Mesoporous Ti-pillared montmorillonite was prepared by employing a Sol-Gel method, and then was modified by SO4^2- and CeO2 respectively. With this material as carrier, Cu-based Ti-pillared montmorillonite mesoporous solid acid catalysts was therelore prepared. Structure of the prepareu catalyst was characterized by means of BET, XRD, TPR, Py-IR, FTIR, XPS and SEM. The catalytic properties of the material for the selective reduction of NO by propylene in excess of oxygen were further studied. The results indicate that the pillaring agent can effectively insert into the layer of montmorillonite, creating a good mesoporous structure with the distribution of pores diameters centered at 3 to 7 nm,and furthermore, obviously increasing its specific surface area. In addition, it was revealed that the chelating ligand structure formed by SO4^2- with Ti caused an increase in the acid amount and facilitated the formation of Bronsted acid sites. Moreover, the presence of CeO2 promoter greatly prevented the aggregation of copper crystallites. Consequently, the reduction efficacy of copper was enhanced and the performance of the prepared catalysts was significantly improved.

关 键 词：钛交联蒙脱土 氧化铈 SO4^2-改性 丙烯选择还原NO 

分 类 号：O643[理学—物理化学] X7[理学—化学]