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NOn the Porous Silicate HPM-5.
- Source :
- European Journal of Inorganic Chemistry; 5/18/2017, Vol. 2017 Issue 19, p2525-2531, 7p
- Publication Year :
- 2017
-
Abstract
- HPM-5, a porous aluminosilicate with an intricate and so far unsolved structure, has been synthesized by using 1,2,3-trimethylimidazolium in hydroxide medium in the absence of fluoride anions. It consistently displays an ill-defined XRD pattern with broad and overlapped reflections and contains a large concentration of defects, as evidenced by IR and <superscript>29</superscript>Si MAS NMR spectroscopy. <superscript>1</superscript>H MAS NMR spectroscopy confirmed the existence of highly deshielded protons (δ = -11.6 ppm) assigned to hydrogen atoms in relatively strong Si-O-H. . . .O-Si hydrogen bonds (O···O distance ≈ 2.64 Å) The calcined material shows limited microporosity (0.07-0.09 cm<superscript>3<M</superscript> g<superscript>-1</superscript>). The results of a high-resolution transmission electron microscopy study suggest HPM-5 may be far more complicated than "standard" layered zeolites and may consist of low-density layers profusely decorated by holes. The resulting lace-like layers may be too unstable to withstand reactions characteristic of more conventional layered materials (both delamination and expansion by silylation); although the derivatives show an increase in the specific surface area, the layers are apparently disassembled and, at most, only ribbons remain. [ABSTRACT FROM AUTHOR]
- Subjects :
- ALUMINUM silicates
MESOPOROUS materials
MESOPORES
MOLECULAR dynamics
ANIONS
Subjects
Details
- Language :
- English
- ISSN :
- 14341948
- Volume :
- 2017
- Issue :
- 19
- Database :
- Complementary Index
- Journal :
- European Journal of Inorganic Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 123164037
- Full Text :
- https://doi.org/10.1002/ejic.201700023