TS-1分子筛骨架钛原子引入过程的研究

STUDIES ON THE PROCESS OF Ti INCORPORATION INTO THE FRAMEWORK DURING THE CRYSTALLIZATION OF TS 1 ZEOLITE

采用廉价的四丙基溴化铵（ＴＰＡＢｒ）为模板剂合成了ＴＳ１分子筛．在晶化过程中，运用ＸＲＤ，ＩＣＰ，ＩＲ，２９ＳｉＭＡＳＮＭＲ和ＵＶＶｉｓ光谱等表征手段，系统地研究了钛原子引入分子筛骨架的机制，观察到钛原子随分子筛的形成同步进入骨架的规律．另外，尽管在晶化初期固相中没有ＴｉＯ２结晶出现，但存在分散态的ＴｉＯｘ物种．随晶化时间的延长，液相中钛物种之间聚合的几率增加，使固相中ＴｉＯ２晶体不断形成．

TS 1 zeolite was synthesized by using inexpensive tetrapropylammonium bromide (TPABr) as a template, and the process of crystallization was studied by XRD, IR, 29 Si MAS NMR, UV Vis and ICP methods. The IR and 29 Si MAS NMR spectra of the calcined samples showed that the process of Ti incorporation into the framework proceeded simultaneously with the formation of the zeolite. The UV Vis spectra indicated that TiO 2 crystals appeared during the process of crystallization, which implies that the probability of the condensation between soluble Ti species is increased with the proceeding of the crystallization. The constant Ti content in solid phase reflects that TiO x species in solid is gradually dissolved in order to compensate for the consumption of soluble Ti species due to the formation of the zeolite and the TiO 2 crystals.