硅氧化合物化学蒸气沉积法精细调变沸石分子筛

本文报告了用化学蒸气沉积法精细调变沸石孔径的结果，着重考察了正硅酸乙酯和六甲基硅醚沉积条件的关系。间二甲苯和均三甲苯的吸附动力学实验表明，用Ｓｉ－（ＯＥｔ）４制得的ＳｉＨβ和ＳｉＨＺＳＭ－５上的吸附速率及吸附量明显下降，证实沸石的孔口得到了调变。正己烷的吸附等温线和异丙醇探针反应，沸石孔容和孔道内酸性未受孔口调变的影响。结果还表明Ｓｉ（ＯＥｔ）４未进入沸石孔道，而六甲基硅醚分子则进入Ｈβ沸石孔道，

STUDY ON THE-FINE CONTROL OF ZEOLITES BY CHEMICAL VAPOUR DEPOSITION WITH SILICON-OXYGEN COMPOUNDS

he method for the fine control of zeolite pore size by vapour deposition with St(OEt)4 and (CH3)3 SiOSi(CH3)3 is reported. After deposition of St(OEt)4 and calcination with oxygen, the silica-coated zeolite isproduced with the pore size reduced but the pore structure and propertyunchanged. Adsorption study indicates that the adsorption rate and adsorbed amount of SiHS and St HZSM-5 for m-xylene and mesitylene arestrikingly depressed, and this gives an evidence of the pore size beingcontrolled. The study on adsorption isotherm of n-he-cane and isopropanol probe reaction shows that St(OEt)4 did not enter the channelof the zeolites, thqpore volume and the acidity of the channels still keepunaffected, hut (CH3)3 SiOSi (CH3)3 entered the channels of Hg after deposition and calcination, both the internal and external surfaces are silica-coated. Furthermore, the relationship between deposition amountand deppsition condition is investigated, and the change of surface hydroxyl groups after deposition is also discussed.