title: Synthesis of ZSM-5 with intracrystal or intercrystal mesopores by polyvinyl butyral templating method.
abstract: Three facile routes were utilized to synthesize ZSM-5 materials with intracrystal or intercrystal mesopores, where the polyvinyl butyral gel served as mesopore directing template. The three routes were divided into two synthesis strategies: the hydrothermal treatment of silica/PVB composite and re-crystallization of preformed zeolite precursor with the assistance of PVB gel. The fabrication of silica/PVB composite was accomplished by two routes including sol-gel process and impregnation method. The resulting composite was undergone hydrothermal treatment. During the crystallization PVB was occluded in the ZSM-5 crystal, creating intracrystal mesopores in the zeolite. The last route for the synthesis of mesoporous ZSM-5 was realized by re-crystallization of preformed ZSM-5 zeolite in the presence of PVB. This route involved the pre-crystallization of the amorphous aluminosilicate to produce the pre-formed ZSM-5 precursor. Upon further crystallization of the mixture of PVB gel and pre-formed ZSM-5, the ZSM-5 precursor was transformed into ZSM-5 aggregate of nanocrystals, while the PVB gel was occluded in the ZSM-5 particles. Removal of the template generated the typical microporosity associated with ZSM-5 structure along with intercrystal mesoporosity produced from the PVB. The mesoporous ZSM-5 exhibited enhanced catalytic activity in the toluene disproportionation and transalkylation with C(9) and C(10) aromatics.
authors.affiliation: School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Zhu
authors.forename: Zhicheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Dejin
authors.initials: D
authors.lastname: Kong
authors.forename: Yangdong
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yuan
authors.forename: Zaiku
authors.initials: Z
authors.lastname: Xie