Synthesis and characterization of IM-10: a new microporous silicogermanate with a novel topology

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• 作者：Mathieu ; Yannick ; Paillaud ; Jean-Louis ; Caullet ; Philippe ; Bats ; Nicolas
• 关键词：Hydrothermal synthesis ; Hexamethonium ; Germanium oxide ; IM-10 ; Clathrate ; Structure determination from powder
• 刊名：Microporous and Mesoporous Materials
• 出版年：2004
• 出版时间：October 12, 2004
• 年：2004
• 卷：75
• 期：1-2
• 页码：13-22
• 全文大小：575 K

文摘

A novel GeO₂ or (Si,Ge)O₂ zeolite phase called IM-10 was obtained in the presence of the well-known hexamethonium ion as template and in fluoride media, from gels with Ge/Si molar ratios aaa1. With decrease of the Ge/Si molar ratio, BEC-type zeolite and ITH-type zeolite were successively obtained. The recovered IM-10 samples were characterized by X-ray diffraction, SEM, elemental and thermal analysis, ¹⁹F MAS and ¹H liquid (after dissolution of the samples in HF) spectroscopies. Due to the small crystal sizes (1aaa4 aam), the structure was determined from powder X-ray diffraction (of the GeO₂ as-made sample) and refined by the Rietveld method. IM-10 is a new member of the clathrate family. It crystallizes in the tetragonal symmetry, the space group being P Formula Not Shown . The framework is made of F^aaa-containing D4R units, bridged by GeO₄ tetrahedra. The arrangement of the D4R units creates [6²⁰4²] supercages, each of them occluding one hexamethonium cation. Structural similarities exist between ASU-9 (AST), ASU-7 (ASV) and the new IM-10 zeolite with a novel topology (UOZ).