Abstract:

Fully crystalline ZSM-5 zeolite catalyst with 100% active components was efficiently synthesized by the microwave radiation method, and the samples were characterized by X-ray diffraction (XRD), scanning/transmission electron microscopy (SEM and TEM), solid-state nuclear magnetic resonance (NMR), specific surface area and pore size analysis, and mechanical strength measurement. The results showed that the relative crystallinity of the obtained catalyst reached 100% after 8h crystallization under the optimized synthesis condition and heated by microwave irradiation. And the crystal morphology of the obtained ZSM-5 zeolite catalyst was regular and 97% of the aluminum atoms were in tetrahedral coordination. The mechanical strength of the catalyst was as high as 110N/cm, which fully meets the industrial application requirements. Under the process conditions close to the industrial ones, the fully crystalline ZSM-5 catalyst exhibited excellent catalytic performance and long-term stability in the gas-phase alkylation reaction of benzene and ethylene to ethylbenzene. The ethylene conversion rate was about 100% and the ethide selectivity was higher than 99.6%, while the key impurity xylene content was about 450μL/L.

Key words: microwave radiation method, fully crystalline, molecular sieves, catalyst, benzene, ethylbenzene

摘要：

采用微波法高效合成含有100%活性组分的全结晶ZSM-5分子筛催化剂，并采用X射线衍射、扫描/透射电子显微镜、固体核磁共振、比表面积及孔径分析以及机械强度测试等手段对样品进行综合表征分析。结果表明：采用微波辐射的加热方式，在优化的合成配方条件下，经过8h晶化，ZSM-5分子筛催化剂的相对结晶度已达到100%，其晶体形貌规整、97%铝原子为四配位状态，机械强度高达110N/cm，完全满足工业应用需求。此全结晶ZSM-5分子筛催化剂在接近工业装置的工艺条件下，在苯和乙烯气相烷基化反应中表现出优异的催化性能，其中乙烯转化率接近100%，乙基选择性大于99.6%，关键杂质二甲苯含量仅为450μL/L左右，且长周期稳定性能良好。

关键词: 微波法, 全结晶, 分子筛, 催化剂, 苯, 乙苯