不同骨架硅铝比Y分子筛热改性过程的固体NMR表征  

SOLID STATE NMR CHARACTERIZATION OF THERMAL MODIFICATIONS OF ZEOLITE Y WITH DIFFERENT FRAMEWORK Si/Al RATIONS

作　　者：要旸[1] 肖强[1] 李丽颖[1] 陈铁红[1] 孙平川[1] 丁大同[2] 

机构地区：[1]南开大学化学学院,天津300071 [2]南开大学物理系,天津300071

出　　处：《南开大学学报（自然科学版）》2004年第2期102-106,共5页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：国家自然科学基金资助项目(29803004)

摘　　要：不同次邻近铝含量可导致改性后Y分子筛酸中心性质的较大差别,较高Si／Al比Y分子筛焙烧脱羟时可能出现三配位铝.随骨架Si／Al比不同,Y型分子筛脱铝形成的非骨架铝性质也有所不同.以化学环境敏感的四极核Na+为探针,证实了改性产生的非骨架Al对骨架阳离子位的环境有较大影响,这可能是B,L酸协同作用后出现增强酸性的证据.Two zeolite Y samples with different framework Si/Al ratio were studied by solid state NMR method. It was shown that due to the different Si/Al ratio, the results of thermal modifications are quite different. In the sample with the Si/Al ratio is 4. 2, there may appear framework tri-coordinated Al during the calcination. By 23Na MAS NMR of the sodium cations exchanged into zeolite, it was proved that the extra-framework Al formed has some effect on the cation's chemical environment, and it may be the evidence of the enhanced acid sites due to the cooperation of B and L acid sites.

关 键 词：Y分子筛 热改性 固体核磁共振 

分 类 号：O643.32[理学—物理化学]