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Synthesis of Large‐Pore ECNU‐19 Material (12 × 8‐R) via Interlayer‐Expansion of HUS‐2 Lamellar Silicate
Author(s) -
Yang Boting,
Jiang JinGang,
Xu Hao,
Wu Haihong,
Wu Peng
Publication year - 2018
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201700607
Subject(s) - intercalation (chemistry) , lamellar structure , chemistry , silicate , silane , molecule , silicon , layer (electronics) , chemical engineering , crystallography , inorganic chemistry , organic chemistry , engineering
A large‐pore ECNU‐19 material with unique pore system consisting of 12‐ring (12R) pore channels intersected by 8R channels was post‐synthesized via interlayer‐expansion of HUS‐2 lamellar silicate with silylating agent of 1,3‐dimethyltetramethoxydisiloxane (DMTMDS). In consideration of the fact that the HUS‐2 precursor possessed a special structure with a malposition of the neighboring layers as well as silicon vacancies on layer surface, a “detemplating disassembly – intercalation reassembly – silylation” strategy was proposed to realize a successful interlayer‐expansion and structural amending. An acid treatment was firstly performed to remove a part of the structure‐directing agent molecules, which favored the following intercalation by bulk organic species. The intercalation not only rearranged the relative position of up‐down layers but also provided enough interlayer space for the insertion of dimeric silane molecules. Two –OH groups attached to one silicon atom of the silane molecule reacted with two close silanols on the up‐surface layer, while the other two –OH groups condensed with two silanols on the down‐surface layer, which then connected the two layers via ‐Si‐O‐Si‐ pillars and constructed new 12R pores along a axis and 8R pores along c axis, respectively.