Synthesis of ZSM-5 hierarchical microsphere-like particle by two stage varying temperature crystallization without secondary template
Synthesis of ZSM-5 hierarchical microsphere-like particle by two stage varying temperature crystallization without secondary template
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DOI：
10.1016/j.cej.2010.11.071
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发表时间：
2011-02
影响因子：
15.1
通讯作者：
Jianhua Yang;Suxia Yu;Huiye Hu;Yan Zhang;Jinming Lu;Jinqu Wang;Dehong Yin
中科院分区：
文献类型：
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作者：
Jianhua Yang;Suxia Yu;Huiye Hu;Yan Zhang;Jinming Lu;Jinqu Wang;Dehong Yin
本文采用分离水解结合两段变温结晶（SHTSVTC）的方法，成功合成了分级ZSM-5微球样颗粒（ZSM-5- hm）。XRD、SEM和TEM分析表明，ZSM-5- hm颗粒尺寸为300-600nm，由30-50nm的ZSM-5原生纳米晶构成。基于n2吸附等温线和脱附等温线的BJH孔径分别为9.7nm和9.4nm。为了比较，在共水解条件下分别采用恒温结晶法（CTC）和两段变温结晶法（TSVTC）进行了合成。为了深入了解分级ZSM-5-HM的生长情况，我们进行了一项计时生长研究。结果表明，ZSM-5-HM的生长过程涉及聚集和组装相结合的结晶过程。当第二阶段结晶时间延长24h以上时，TSVTC法合成的ZSM-5颗粒具有相似的层次结构。结果表明，TSVTC对ZSM-5-HM产物的形成起主要作用，但单独水解可以缩短结晶时间。这种简便高效的合成介孔分子筛的方法可以推广到其他具有独特层次结构的分子筛的合成中。
In the present paper, Hierarchical ZSM-5 microsphere-like particles (ZSM-5-HM) were successfully synthesized by separate hydrolysis combined two stage varying temperature crystallization (SHTSVTC) without any secondary template. XRD, SEM and TEM analysis revealed that the ZSM-5-HM particles were 300–600nm in size and constructed by primary ZSM-5 nanocrystals of 30–50nm. The BJH pore size based on the N2adsorption isotherm and desorption isotherm was 9.7nm and 9.4nm, respectively. For comparison the synthesis was carried out by the constant temperature crystallization (CTC) and two stage varying temperature crystallization methods (TSVTC) under cohydrolysis, respectively. A time trial growth study was conducted for insight into the growth of the hierarchical ZSM-5-HM. It is suggested that the growth of ZSM-5-HM products involves aggregation and assembly combined crystallization process. The synthesis by the TSVTC method gave rise to similar hierarchical ZSM-5 particles when the second stage crystallization time was extended for more 24h. It indicates that the TSVTC is mainly responsible for the formation of the ZSM-5-HM products but the separate hydrolysis can reduce the crystallization time. The demonstrated facile and highly effective approach to mesoporous zeolites can be extended to the synthesis of other zeolites with unique hierarchical structure.