硅钨杂多酸在中孔全硅分子筛HMS上的固载及其催化性能

用十二烷基胺代替传统的季铵盐合成了中孔全硅分子筛ＨＭＳ，并将硅钨杂多酸浸渍固载在ＨＭＳ上，用ＸＲＤ，ＦＴ－ＩＲ以及ＮＨ３－ＴＰＤ等手段对ＨＭＳ及不同负载量的焙烧温度的负载论剂进行了表征，即使在固载量为５０％的ＳｉＷ１２／ＨＭＳ中，ＳｉＷ１２仍保持其Ｋｅｇｇｉｎ结构产均匀分布在载体表面上，没有ＳｉＷ１２晶相生成，同时，在气－固相反应体系中研究了固载在ＨＭＳ上的ＳｉＷ１２在合成乙酸丁酯中的催化性能，实

CATALYSTS COMPRISING 12 SILICOTUNGSTIC ACID IMMOBILIZED ON A HEXAGONAL MESOPOROUS SILICAS (HMS) AND THEIR CATALYTIC PROPERTIES

Hexagonal mesoporous silicas (HMS) is a novel mesoporous molecular sieve which is synthesized by dodecylamine as a template replacing conventional quaternary ammonium ion surfactant. The supported catalysts with different loadings and calcined at different temperatures, consisting of 12 silicotungstic acid (SiW 12 ) immobilized on HMS have been prepared and characterized by X ray diffraction, FT IR and NH 3 temperature programmed desorption. It shows that SiW 12 retains the Keggin structure on the HMS surface and forms finely dispersed HPA species. No HPA crystal phase is developed even with SiW 12 loading as high as 50%. And in the esterification of n butanol by acetic acid, it can be found that the loaded amount of SiW 12 and calcination temperature have a significant effect on catalytic activity. Especially, SiW 12 /HMS catalysts show a higher activity and stability at lower temperature and hold some promise of practical application.