高硅沸石骨架结构及其稳定性的模拟计算(Ⅰ)  

Simulated Calculation of High-Silica Zeolites Structure and Stability（Ⅰ）

作　　者：李宝宗[1] 徐文国[2] 裘式纶[1] 庞文琴[1] 徐如人[1] 

机构地区：[1]吉林大学化学系,长春130023 [2]北京理工大学化工与材料学院,北京100081

出　　处：《物理化学学报》1998年第1期44-50,共7页Acta Physico-Chimica Sinica

基　　金：国家攀登计划;国家自然科学基金;国家教委博士点基金;吉林大学无机合成与制备化学研究研究实验室资助

摘　　要：采用品格能极小化技术模拟计算了一系列结构的高硅沸石全硅骨架品格。预测了它们的骨架结构和品格能．计算结果与二氧化硅致密相比较，发现这些高硅沸石彼此间的品格能相差很小（＜37kJ·mol-1）、与α-石英相差30～67kJ·mol-1．这意味着在高硅沸石的合成中，特定结构骨架的形成仅需要较少的能量，可以解释高硅沸石骨架结构的多样性及其相似性，同时讨论了计算品格能和骨架结构间的关系。The lattice energy of a series of high-silica zeolites was determined by using the lattice energy minimization method. Compared with the lattice energy of dense polymorphism of SiO_2, it is found that the difference in lattice energy among those high-silica zeolites is slight (<37 kJ/mol). All high-silica zeolite frameworks are only 30～67 kJ/mol less stable than αQuartz. The XRD data of the high-silica zeolites contain shorter SiO bond length (01431 nm), longer SiO bond length (0.1862 nm), and a large range of SiOO angles (77.51～13188°), an average OSiSi angle close to 153° and a larger range of OSiSi angle (120～180°). The results of PM3 molecular orbital calculation show that there is a small barrier (17.43 kJ/mol) to variation in the OSiSi angle between 114° and 180°, and there is the lowest energy for angle 135.4°.

关 键 词：高硅沸石 晶格能极小化 骨架密度 稳定性 沸石 

分 类 号：TQ424.25[化学工程]