Synthesis and characterization of Ga-substituted MER-type zeolites

Citation
Sh. Kim et al., Synthesis and characterization of Ga-substituted MER-type zeolites, MICROP M M, 42(1), 2001, pp. 121-129
Citations number
21
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
MICROPOROUS AND MESOPOROUS MATERIALS
ISSN journal
1387-1811 → ACNP
Volume
42
Issue
1
Year of publication
2001
Pages
121 - 129
Database
ISI
SICI code
1387-1811(200101)42:1<121:SACOGM>2.0.ZU;2-F
Abstract
Ga-substituted merlinoite (MER)-type zeolites are hydrothermally synthesize d using aluminosilicate MER crystals as seeds under wholly inorganic condit ions. The presence of Ga in tetrahedral positions is evidenced by powder X- ray diffraction, Si-29 and Ga-71 MAS NMR, and IR spectroscopies. The bulk S i/(Ga + Al) ratio in the framework determined by elemental analysis is in t he range 1.9-3.0, depending on the initial Si/Ga ratio of the synthesis mix ture. An attempt to fully substitute framework Al by Ga was not successful: a gallosilicate with GIS topology, denoted TNU-2, is produced when alumino silicate MER seed crystals are not added to the synthesis mixture. This cle arly shows that the structure-directing ability of Ga is different from tha t of Al in the synthesis conditions used here. (C) 2001 Elsevier Science B. V. All rights reserved.