摘要
以程序升温分解(TPDE)为主要研究手段,分析了β沸石中四乙基胺模板剂的热分解机理。结果表明,四乙基胺模板剂的热分解分四个阶段进行:第一阶段发生的是包藏于沸石孔道中的四乙基氢氧化胺(TEAOH)的第一级Hofmann降解反应;第二阶段是平衡骨架负电荷的四乙基胺离子(TEA+)的第一级Hofmann降解反应以及第一阶段降解产物Et3N再吸附后发生的连续不同级乙基取代胺的Hofmann降解反应;第三阶段是前两阶段的降解产物再吸附后,再吸附产物的连续不同级乙基取代胺的Hofmann降解反应;第四阶段是残留有机物的分解反应。
The mechanism of the thermal decomposition of tetraethylammonium ion in zeolite β has been investigated mainly by using TPDE techniques. The results show that the complete decomposition of the template needed four steps: the TEAOH species occluded in zeolite β decomposed in the first step; the TEA cations balancing the framework negative charges decomposed in the second step; the amines readsorbed on the acidic sites of zeolite β decomposed into lighter amines by sequential Hofmann elimination reactions in the third step; the organic species produced on the acid sites decomposed in the fourth step.
出处
《北京化工大学学报(自然科学版)》
CAS
CSCD
1999年第1期53-57,共5页
Journal of Beijing University of Chemical Technology(Natural Science Edition)
关键词
Β沸石
程序升温
四乙基胺
沸石
热分解
模板剂
zeolite β
temperature programmed techniques
tetraethylammonium
mechanism of decomposition
kinetics