title: Seed-Assisted Synthesis of MWW-Type Zeolite with Organic Structure-Directing Agent-Free Na-Aluminosilicate Gel System.
abstract: The seed-assisted synthesis of zeolites without using organic structure-directing agents (OSDAs) has enabled alternative routes to the simple, environmentally friendly and low-cost production of industrially important zeolites. In this study, the successful seed-assisted synthesis of MCM-22 (MWW-type) zeolite with an OSDA-free gel is reported for the first time. MWW-type zeolites are obtained by the addition of as-synthesized MCM-22 seeds prepared with hexamethyleneimine (HMI) into OSDA-free Na-aluminosilicate gels. Based on the results of XRD, ICP-AES, NMR, N2physisorption and NH3-TPD, the product exhibited different features compared to those of the seeds. The H-form product can serve as a catalyst in Friedel-Crafts alkylation reaction of anisole with 1-phenylethanol, and its catalytic activity is comparable to the seeds. Furthermore, XRD, FE-SEM, TG-DTA, CHN, FT-IR and NMR analyses of products and intermediates provide insights into the role of seeds and occluded HMI, the crystallization process, and key factors for achieving seed-assisted synthesis of MWW-type zeolites with an OSDA-free gel system. The present results provide a new perspective for the economical and environmentally friendly production of MWW-type zeolites.
authors.affiliation: Department of Chemical Process, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
authors.forename: Yoshihiro
authors.identifier: http://orcid.org/0000-0002-0210-6488
authors.initials: Y
authors.lastname: Kamimura
authors.affiliation: Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.|UniZeo Co., Ltd., 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Itabashi
authors.affiliation: Department of Chemical Process, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kon
authors.affiliation: Department of Chemical Process, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Endo
authors.affiliation: Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Okubo
keywords: crystal growth; microporous materials; organic structure-directing agent (OSDA)-free system; seed-assisted synthesis; zeolites