【摘要】 以ZSM-5分子筛为基体,采用分级晶化方式合成ZSM-5/KL复合分子筛。通过调控晶化时间、晶化温度和晶化级数等合成因素控制复合分子筛的合成过程及形貌,并利用X射线衍射(XRD)、N2吸附脱附、扫描电镜(SEM)等技术对样品进行表征,采用正戊烷芳构化反应考察复合分子筛的催化性能。结果表明,不同的晶化方式对复合分子筛的形貌具有明显影响。与单级晶化方式相比,多级晶化方式可有效调控壳相L纳米晶体在ZSM-5晶粒表面的生长和形貌,并促进核壳型复合分子筛的生成。反应实验结果表明,与混晶型复合分子筛相比,核壳型复合分子筛具有更好的芳构化性能。更多还原

【Abstract】 The ZSM-5/KL composite zeolite,using ZSM-5as base material,was synthesized by two-step crystallization.The morphology of shell was controlled by regulating the series,temperature and time of crystallization.These samples were characterized by XRD,Nitrogen adsorption-desorption and SEM,respectively,and evaluated by the n-pentane aromatization.The results show that different ways of crystallization has great effect on composite zeolite morphology.Compared with singlestep crystallization method,the two-step crystallization can effectively control the grain growth of shell phase L nanocrystals on the ZSM-5surface,and promote the formation of core-shell structure composite zeolite.Reaction experiment shows that the core-shell composite zeolite has better performance of aromatization than epitaxial crystal type composite zeolite.更多还原