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ECNU‐36: A Quasi‐Pure Polymorph C H Beta Silicate Composed of Hierarchical Nanosheet Crystals for Effective VOCs Adsorption
Author(s) -
Jiao Meichen,
Huang Ju,
Xu Hao,
Jiang Jingang,
Guan Yejun,
Ma Yanhang,
Wu Peng
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202008327
Subject(s) - nanosheet , high resolution transmission electron microscopy , materials science , microporous material , crystallography , silicate , powder diffraction , fluoride , adsorption , crystal structure , hydroxide , chemical engineering , zeolite , phase (matter) , crystal (programming language) , inorganic chemistry , chemistry , transmission electron microscopy , catalysis , nanotechnology , organic chemistry , programming language , computer science , engineering , composite material
A quasi‐pure C H polymorph of microporous zeolite beta, named ECNU‐36, was obtained as a highly crystalline silicate using 1,5‐bis(tetramethylimidazolium) hydroxide as organic structure‐directing agent (OSDA) in fluoride media. An appropriate concentration of free fluoride in the synthetic mother liquor was crucial to purify the C H ‐phase. The framework structure of ECNU‐36 consists of polymorph C H (>95 %) and polymorph B, elucidated by a combination of PXRD data, DIFFaX simulation, EDT, and HRTEM techniques. For the first time, the framework structure of beta C H polymorph was directly confirmed and solved using electron diffraction data. The pure‐silica ECNU‐36 showed an unusual crystal morphology, composed of stacked nanosheets, with typical 17 nm thickness and exposed {100} facets, which exhibited attractive adsorption performance for hydrocarbons and aromatics.