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Indexed by:期刊论文

Date of Publication:2013-04-15

Journal:SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY

Included Journals:SCIE、EI、PubMed

Volume:107

Page Number:218-226

ISSN No.:1386-1425

Key Words:MCM-41; Zeolite Y building units; Zeolite precursor; UV Raman spectroscopy

Abstract:The formation process of MCM-41 containing zeolite Y building units has been investigated by UV Raman spectroscopy, Si-29 and Al-27 MAS NMR spectroscopy, X-ray diffraction (XRD), N-2 adsorption and electron microscopy (SEM and TEM). It is found that the precursor containing zeolite Y secondary building units promotes the formation of a metastable mesopore structure just after mixing the zeolite precursors with CTAB. In contrast, the low-polymerized aluminosilicates and well-crystallized zeolite crystals cannot be assembled with CTAB at this stage. The result supports that the zeolite secondary building units should promote to the formation of the mesopore wall. This has been ascribed to its high anionic charge density as well as the appropriate multidentate coordination. Lowering down the pH value to 9.3 facilitates the further polymerization of the aluminosilicate species to build up a stable mesoporous phase. (C) 2013 Elsevier B.V. All rights reserved.