两步晶化法制备MCM-48/ZSM-5复合分子筛

利用两步晶化法制备了高水热稳定性的MCM48/ZSM-5介微孔复合分子筛.通过SEM、TEM、XRD、IR和N₂吸附脱附进行表征，结果显示，该材料的结构不同于简单的机械混合，而是具有微孔孔壁和三维立方介孔孔道的复合材料，其孔道尺寸为2.6nm左右.该复合分子筛在沸水中处理6h后，介孔结构仍保留完好.通过考察晶化时间对复合分子筛的影响，证明了介孔和微孔的组装是一个竞争的过程，复合分子筛中介孔与微孔结构的比例随晶化时间的变化而变化，且具有介孔孔道和微孔孔壁的复合分子筛150℃的最优晶化时间为8h.

Synthesis of MCM-48/ZSM-5 Composite Molecular Sieve by Two-step Crystallization

Composite micro/mesoporous MCM-48/ZSM-5 materials were successfully prepared by using a two step synthesis route. The different structures of composite materials compared with the mechanical mixture were characterized by powder XRD，IR spectroscope，SEM，TEM，N₂ adsorption and the influence of the crystallization time was investigated. The results show that the composite MCM-48/ZSM-5 materials possess mesoporous wall constructed by secondary building units characteristic of ZSM-5 and three dimensional pore structure with pore size of about 2.6nm. The mesoporous framework of MCM-48/ZSM-5 is still found to be somewhat preserved after treatment in boiling water for 6h. It is proved that the self assemble is a competitive process and the ratio of mesopore to micropore has a close relationship with crystallization time. The optimum crystallization time under 150℃ is 8h.