硅铝比对MWW层状结构分子筛的物相、结构及酸性的影响  

Influence of Si to Al Ratio on the Structure and Acidity of MWW Structure Molecular Sieves

作　　者：赵飞[1] 柳静[2] 耿树东[3] 陈连发[3] 张钰[3] 

机构地区：[1]吉林化工学院研究生处,吉林吉林132022 [2]东北师范大学化学学院,吉林长春130022 [3]吉林化工学院化工与材料工程学院,吉林吉林132022

出　　处：《吉林化工学院学报》2013年第5期5-8,共4页Journal of Jilin Institute of Chemical Technology

基　　金：吉林省教育厅"十二五"科学技术研究项目(吉教科合字[2013]第714号)

摘　　要：采用动态水热合成方法合成了具有不同硅铝比的MWW层状结构分子筛,分别制得MCM-22和MCM-49分子筛,采用XRD、N2吸附-脱附、NH3-TPD和FTIR等技术研究了硅铝比对MWW层状结构分子筛的物相、结构及酸性的影响.结果表明,采用动态水热合成方法制得了高结晶度的MWW结构分子筛,当原料硅铝比(Si/Al)在17.5～30之间,所得晶化产物为MCM-22分子筛;当原料硅铝比为12.5～15时,所得晶化产物为MCM-49分子筛.样品表面强酸中心和弱酸中心的酸量随着硅铝比的增加而降低,B酸量在总酸量中所占比例逐渐减小.在硅铝比为12.5～25范围内,酸强度基本保持不变;当硅铝比升至30,酸强度减弱.MWW structure molecular sieves with different Si/A1 were prepared by dynamic hydrothermally method. The resulting solids were characterized by different techniques ,such as XRD ,N2adsorption-desorption, NH3-TPD and FTIR. The effects of Si/AI on the structure and acidity of MWW structure molecular sieve were studied. XRD results indicate that MCM-22 zeolite would be prepared when the silicon to alumina ratio ranges from 17.5 to 30 ,and MCM-49 zeolite would be obtained when the silicon to alumina ratio ranges from 12.5 to 15. NH3-TPD and FTIR results reveal that both the total acid amounts and the B acid amounts decrease with the increment of Si/Al in zeolite. When the Si/Al of zeolite is range from 12.5 to 25, acid strength of zeolite keeps consistent. When the Si/Al of zeolite is above 30, acid strength becomes weaker.

关 键 词：MWW层状结构分子筛 MCM-49 MCM-22 酸性 

分 类 号：O643.1[理学—物理化学]