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Indexed by:期刊论文

Date of Publication:2000-09-15

Journal:MATERIALS CHEMISTRY AND PHYSICS

Included Journals:SCIE

Volume:66

Issue:1

Page Number:41-50

ISSN No.:0254-0584

Key Words:titanium silicalite-1; crystallization process; tetrapropylammonium bromide; solid state NMR; IR; UV-VIS

Abstract:Tetrapropylammonium bromide (TPABr) has been used as a template for the synthesis of titanium silicalite-l (TS-l), and the involved crystallization mechanism and the characteristics of the incorporated Ti in the zeolites were investigated by applying a variety of methods, e.g. solid-state NMR, IR, UV-VIS, XRD and SEM, as well as pH-meter techniques. It is revealed that the crystallization process performed with TPABr follows the well-known solution-mediated transformation mechanism, and that the Ti atoms were introduced into the frameworks synchronously with the formation of the zeolite structures. In addition, the formation of less amount of inactive TiO2 crystals with an anatase structure is not in the initial stage of the crystallization as reported by some authors, but through the whole process of the zeolite synthesis, which suggests that a careful control of the synthesis parameters throughout the whole crystallization process is quite important for obtaining the anatase-free titanium-silicalite zeolite. (C) 2000 Elsevier Science S.A. All rights reserved.