TY - JOUR
T1 - OSDA-free synthesis of MTW-type zeolite from sodium aluminosilicate gels with zeolite beta seeds
AU - Kamimura, Yoshihiro
AU - Iyoki, Kenta
AU - Elangovan, Shanmugam Palani
AU - Itabashi, Keiji
AU - Shimojima, Atsushi
AU - Okubo, Tatsuya
N1 - Funding Information:
This work was financially supported in parts by Nippon Chemical Industrial Co. Ltd. , a Grant-in-Aid for Scientific Research (B) from the Japan Society for the Promotion of Science (JSPS), and a Grant-in-Aid for Young Scientists from the JSPS. Yoshihiro Kamimura gratefully thanks the JSPS for a post-doctorial fellow and a Grant-in-Aid for Scientific Research. Kenta Iyoki gratefully thanks the JSPS for a Grant-in-Aid for Scientific Research.
PY - 2012/11/15
Y1 - 2012/11/15
N2 - Seed-assisted methods have provided a new route for the organic structure-directing agent (OSDA)-free synthesis of industrially valuable zeolites. In the present study, we have reported the discovery of the OSDA-free synthesis of ZSM-12 (MTW-type zeolite) by adding calcined zeolite beta seed crystals to the OSDA-free Na-aluminosilicate gel. Various parameters in this synthesis have been comprehensively investigated. Characterization by XRD, FE-SEM, ICP-AES, and 27Al MAS NMR showed that the obtained MTW products without impurity (SiO 2/Al 2O 3 = 31.8-46.4) possessed high crystallinity and a well-defined rod-like morphology. Adsorption-desorption isotherm of water and NH 3-TPD profiles of MTW product showed enough adsorption capacity for water and ammonia molecules, respectively. Moreover, considering the crystallization behavior of seeded and non-seeded Na-aluminosilicate gels, the following key factors were found for inducing the crystallization of MTW by zeolite beta seeds under the hydrothermal condition: the structural similarity between seeds and target zeolite, and the initial gel compositions that provide specific aluminosilicate precursors for the crystallization of MTW prior to the spontaneous nucleation of other zeolite. This methodology provides a promising approach toward designed syntheses of valuable zeolites under environmentally benign conditions.
AB - Seed-assisted methods have provided a new route for the organic structure-directing agent (OSDA)-free synthesis of industrially valuable zeolites. In the present study, we have reported the discovery of the OSDA-free synthesis of ZSM-12 (MTW-type zeolite) by adding calcined zeolite beta seed crystals to the OSDA-free Na-aluminosilicate gel. Various parameters in this synthesis have been comprehensively investigated. Characterization by XRD, FE-SEM, ICP-AES, and 27Al MAS NMR showed that the obtained MTW products without impurity (SiO 2/Al 2O 3 = 31.8-46.4) possessed high crystallinity and a well-defined rod-like morphology. Adsorption-desorption isotherm of water and NH 3-TPD profiles of MTW product showed enough adsorption capacity for water and ammonia molecules, respectively. Moreover, considering the crystallization behavior of seeded and non-seeded Na-aluminosilicate gels, the following key factors were found for inducing the crystallization of MTW by zeolite beta seeds under the hydrothermal condition: the structural similarity between seeds and target zeolite, and the initial gel compositions that provide specific aluminosilicate precursors for the crystallization of MTW prior to the spontaneous nucleation of other zeolite. This methodology provides a promising approach toward designed syntheses of valuable zeolites under environmentally benign conditions.
KW - Crystallization
KW - MTW-type zeolite
KW - Organic structure-directing agent (OSDA)-free
KW - Seed-assisted synthesis
KW - Zeolite beta
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U2 - 10.1016/j.micromeso.2012.07.014
DO - 10.1016/j.micromeso.2012.07.014
M3 - Article
AN - SCOPUS:84864800595
SN - 1387-1811
VL - 163
SP - 282
EP - 290
JO - Microporous Materials
JF - Microporous Materials
ER -