title: Hierarchical mesoporous zeolites: direct self-assembly synthesis in a conventional surfactant solution by kinetic control over the zeolite seed formation.
abstract: By kinetic control over the zeolite seed formation, we report the direct fabrication of hierarchical mesoporous zeolites using hexadecyl trimethyl ammonium bromide (CTAB) as the soft template in a conventional solution route. Nanometer-sized, subnanocrystal-type zeolite seeds with a high degree of polymerization are essential to prevent the formation of a separate amorphous mesoporous phase and the phase separation between the mesophase and zeolite crystals in the presence of CTAB and a certain amount of ethanol. The mechanisms for the formation of hierarchically porous zeolites in the solution process, including the effect of mother liquid aging, formation of subnanocrystal zeolite seeds and their self-assembly effect with CTAB, and the role of ethanol are proposed and discussed in detail. The prepared mesoporous ZSM-5 zeolite showed much higher catalytic activity than conventional counterparts for aldol condensations involving large molecules, especially in the synthesis of vesidryl.
authors.affiliation: State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Science, No.1295 Ding-xi Road, Shanghai 200050, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhu
authors.forename: Zile
authors.initials: Z
authors.lastname: Hua
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.forename: Lijun
authors.initials: L
authors.lastname: Wang
authors.forename: Jinjin
authors.initials: J
authors.lastname: Zhao
authors.forename: Yun
authors.initials: Y
authors.lastname: Gong
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.forename: Meiling
authors.initials: M
authors.lastname: Ruan
authors.forename: Jianlin
authors.initials: J
authors.lastname: Shi