分级孔ZSM-5@ZIF-8催化剂的制备及其在串联催化中的应用

Preparation of hierarchical ZSM-5@ZIF-8 and its application in tandem catalysis

为解决串联反应中单一催化剂存在空间隔离引起的不同催化活性位点失活、副反应等问题,本文将ZSM-5与ZIF-8进行复合,得到一种多级孔酸碱催化剂,其中ZSM-5提供酸性位点,ZIF-8提供碱性位点。利用X射线衍射、比表面积测试仪和扫描电子显微镜等测试手段对催化剂的形貌以及结构进行表征。对其在苯甲醛二甲基缩醛的酸解缩合串联反应中的催化性能进行测试。结果表明:ZIF-8较好地复合在ZSM-5的孔道中,具有较高的结晶程度;在串联催化中表现出优异的转化率以及选择性,拥有很好的循环稳定性。

In order to solve the problems of deactivation of different catalytic active sites and side reactions caused by the spatial isolation of a single catalyst in a series reaction,hierarchical porous acid-base catalyst was prepared by combining ZSM-5 with ZIF-8,in which ZSM-5 provided acid site and ZIF-8 provided basic site.The morphology and structure of the catalyst were characterized by X-ray diffraction,BET and scanning electron microscope.At the same time,its catalytic performance in the tandem reaction of deacetalization knoevenagel condensation of benzaldehyde dimethyl acetal was also tested.The results showed that ZIF-8 was well combined in the channel of ZSM-5 with a crystallization degree.In addition,the catalyst showed excellent conversion and selectivity in tandem catalysis and good stability.