title: Synthesis of Chainlike ZSM-5 Zeolites: Determination of Synthesis Parameters, Mechanism of Chainlike Morphology Formation, and Their Performance in Selective Adsorption of Xylene Isomers.
abstract: Chainlike zeolites are advantageous to various applications as a catalyst or an adsorbent with specific selectivity; however, it is often very difficult to get desired morphology due to the complexity of zeolite synthesis process. In this work, appropriate parameters for the synthesis of perfect chainlike ZSM-5 zeolites were well determined, which illustrates that the chain length can be controlled by the composition of synthesis mixture, the amount of residual alcohol in the synthesis system, and the crystallization time. Moreover, the mechanism of chainlike crystal growth was investigated by analyzing the surface species during the synthesis process, with the help of density functional theory (DFT) calculation. The results indicate that the formation of disk crystals with proper dimension and flat surface having abundant hydroxyl groups is crucial to the growth of chainlike ZSM-5 crystals; the condensation of Si-OH groups on the (010) facet is energetically more favorable than that on other facets, leading to the growth of MFI crystals along the b-orientation. Through finely tuning the multifarious synthesis parameters, chainlike ZSM-5 zeolites with controllable length in b-orientation are obtained without using any other extra organic additives except the necessary template agent such as tetrapropylammonium hydroxide (TPAOH). Owing to the increased tortuosity of pore channels in the chainlike ZSM-5, the difference between p-xylene and o/m-xylenes in their adsorption behavior and diffusivity is greatly enhanced. These results help to clarify the formation mechanism of zeolites with chainlike morphology and then bring forward an effective approach to get zeolite materials with specific properties in adsorption and catalysis.
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.|University of Chinese Academy of Sciences , Beijing 100049, PR China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Quan
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.|University of Chinese Academy of Sciences , Beijing 100049, PR China.
authors.forename: Shiying
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.|University of Chinese Academy of Sciences , Beijing 100049, PR China.
authors.forename: Sen
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.
authors.forename: Zhikai
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.
authors.forename: Mei
authors.initials: M
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.
authors.forename: Zhangfeng
authors.initials: Z
authors.lastname: Qin
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.
authors.forename: Weibin
authors.initials: W
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences , P.O. Box 165, Taiyuan, Shanxi 030001, PR China.
authors.forename: Jianguo
authors.identifier: http://orcid.org/0000-0002-5667-3170
authors.initials: J
authors.lastname: Wang
keywords: MFI zeolite; ZSM-5; chainlike morphology; crystal growth mechanism; zeolite synthesis