文献类型：期刊文献

英文题名：Highly stable hierarchical ZSM-5 zeolite with intra- and inter-crystalline porous structures

作者：Tao, Haixiang[1];Yang, Hong[1];Liu, Xiaohui[1];Ren, Jiawen[1];Wang, Yanqin[1];Lu, Guanzhong[1]

机构：[1]E China Univ Sci & Technol, Shanghai Key Lab Funct Mat Chem, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China

年份：2013

卷号：225

起止页码：686

外文期刊名：CHEMICAL ENGINEERING JOURNAL

收录：;EI(收录号：20132016332740);WOS:【SCI-EXPANDED(收录号:WOS:000321313800080)】；

基金：This project was supported financially by the National Basic Research Program of China (No. 2010CB732306), the National Natural Science Foundation of China (Nos. 20973058, 21101063, and 21273071), and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Hierarchical zeolite; Polyethylene glycol; Steam-assisted conversion; Separation

摘要：Highly stable hierarchical ZSM-5 zeolites with intra-crystalline mesopores and inter-crystalline macropores have been synthesized via a steam-assisted conversion in the presence of polyethylene glycol. XRD, SEM, TEM, N-2 sorption and mercury intrusion measurement revealed that the irregular intra-crystal mesopores (2-10 nm) in each zeolite nanocrystal were generated by the removal of encapsulated PEG, and the inter-crystalline macropores (50-90 nm) were formed by the aggregation of the well crystallized ZSM-5 nanocrystals with a small size (50-200 nm). The ZSM-5 zeolite nanocrystals were achieved by a dense-gel with high TPA(+)/SiO2, highly concentrated TPA(+) can induce a burst in nucleation rate during the first step of steam-assisted conversion, which makes the dry gel easy to convert into zeolite nanocrystals, PEG arrested in the gel can be easily encapsulated by zeolite crystals during the steam-assisted conversion. Finally, these nanocrystals containing intra-crystalline mesopores aggregate into the bulky materials with an inter-crystalline macroporous network. In addition, the mesopore volume and external surface areas of Hier-ZSM-5 can be easily adjusted by changing the amount of PEG. Catalytic tests showed that Hier-ZSM-5 had a similar activity to Nano-ZSM-5, which must be collected by high-speed centrifugation; while had a higher activity than Con-ZSM-5, especially for the reactions involving large molecules. The high catalytic activity and easy separation from liquid mixture of Hier-ZSM-5 would facilitate its practical applications in chemical industry. Crown Copyright (c) 2013 Published by Elsevier B.V. All rights reserved.