Combined DFT theoretical calculation and solid-state NMR studies of Al substitution and acid sites in zeolite MCM-22
Article Abstract:
The distribution of Bronsted acidic protons distribution, and their acid strengths in H-MCM-22 zeolite is studied using density functional theory (DFT) calculation combined with magic angle spinning NMR methods. Theoretical results indicate that the Al substitution takes place in the order of Al1-OH-Si2 > A18-OH-Si8> A15-Oh-Si7 and the DFT theoretical and NMR experimental results show that the acidic strength of the three Bronsted acid sites in H-MCM-22 zeolite is slightly lower than that of H-ZSZ-5 zeolite and Al1-OH-Si(sub 2) have the strongest acid strength.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2005
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Characterization of microporosity in ordered mesoporous material MAS-7 by (super 129)Xe NMR spectroscopy
Article Abstract:
An investigation is conducted by (super 129)Xe NMR spectroscopy on an ordered mesoporous aluminosilicate material MAS-7, which contains micropores inside its pore walls. (super 129)Xe results reveal that two different independent micropore systems were present in the mesoporous walls of MAS-7.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2004
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