【摘要】 利用差热分析、原位ＸＲＤ技术、高温条件下的焙烧和水蒸气处理并关联其催化性能变化，研究了ＳＡＰＯ－３４分子筛的热及水热稳定性．差热分析结果表明，ＳＡＰＯ－３４的骨架破坏温度高于１３００Ｋ．原位ＸＲＤ跟踪研究证实，ＳＡＰＯ－３４分子筛原粉在高温焙烧以除掉有机胺及随后的降温过程中无明显的骨架破坏；而焙烧型ＳＡＰＯ－３４在空气中放置一定时间后，水分子吸附于微孔中明显降低样品的ＸＲＤ峰强度，且降低幅度随放置时间的延长而增大．样品在１０７３Ｋ焙烧的前５０ｈ内有显著的结晶度下降，但下降幅度不超过２０％；更长时间的焙烧不再使其下降，显示其优异的热稳定性．经不同时间焙烧过的样品在甲醇转化制取低碳烯烃反应中的催化性能无明显变化．在１０７３Ｋ用水蒸气处理时，样品的结晶度不断下降，但在６５ｈ的处理时间内，其催化性能只有较小幅度的下降，表明ＳＡＰＯ－３４具有较好的水热稳定性．更多还原

【Abstract】 The thermal and hydrothermal stability of molecular sieve SAPO 34 have been investigated with DTA, XRD, severe treatment at high temperature and methanol conversion tests. DTA determination of as synthesized and calcined samples revealed that the framework destruction temperature is over 1300 K. According to in situ XRD studies, no framework collapse happens during the organic template removing process at ￣973 K and the following cooling period. The crystallinity of SAPO 34 sample remains over 80% and its catalytic performance in methanol conversion changes little after the continuous calcination at 1073 K for 300 h. The successive steaming treatment at 1073 K for over 45 h only lowered the sample′s crystallinity by less than 20% and damaged a little of the catalytic performance, showing the high hydrothermal stability. The surface composition analysis results disclose that the calcination, especially steaming at 1073 K, gives rise to the deprivation of aluminum and phosphorus from the framework.更多还原