Ti－Al pentasil型分子筛的表征及其热稳定性能

用气固相同晶取代法合成了Ｔｉ－ＡｌＺＳＭ－５和Ｔｉ－ＡｌＺＳＭ－１１型分子筛，并测定了它们的ＩＲ光谱、ＵＶ－Ｖｉｓ光谱以及晶胞参数，证实Ｔｉ进入了分子筛的骨架．热稳定性能的研究表明，Ｔｉ进入骨架后，分子筛热稳定性基本不变．另外，当高温处理时，Ｎａ型含钛分子筛的结晶度下降，直至转化为方石英，９６０ｃｍ－１处钛的特征峰不会消失．

STUDIES OF THERMOSTABILITY OF Ti-Al PENTASIL TYPE MOLECULAR SIEVES AND THEIR CHARACTERIZATION

The Ti-AlZSM-5 and Ti-AlZSM-11 type molecular sieves havebeen synthesized by gas-solid isomorphous replacement. IR spectra ofTi-containing zeolites showed a characteristic absorption band at 960cm-1, which is not observed in the spectra of their precursors; UV-Visspectra of Ti-containing zeolites exhibited a strong transition around 212nm; crystalline cell parameters of zeolites containing Ti expanded.These facts have proved that the Ti entered into the molecular sieveframework. The studies of thermostability showed that the thermostability of the molecular sieves keeps constant after the Ti enters intoframework. In addition, the crystallinity of Na type Ti-containingmolecular sieves decreases when treated at high temperature; even ifZSM-5 type molecular sieves(Na type) are converted to a-cristobalite,the characteristic peak of Ti at 960 cm-1 doesn't disappear.