Chemical shift anisotropy : a promising parameter to distinguish the 29Si NMR peaks in Zeolites
Chemical shift anisotropy : a promising parameter to distinguish the 29Si NMR peaks in Zeolites
Using a combination of (i) symmetry-based recoupling in 29Si NMR, (ii) spin dynamics-based simulations, and (iii) DFT-based theoretical calculations, we show how the 29Si NMR peaks of (≡Si−O−Si≡) (Q4(0Al)), Brønsted acid sites (≡ Si−OH−Al) (Q4(1Al)≡), and silanols (≡Si−OH) (Q3) can be characterized in nanosized ZSM-5 zeolites. Significant differences in the chemical shift anisotropy are calculated theoretically and observed experimentally for silicon nuclei close to aluminum (Q4(1Al)) compared to those which are not, i.e., Q4(0Al) and Q3, allowing one to clearly assign the 29Si NMR peaks. The isotropic chemical shift alone cannot resolve such differences.
10792-10796
Dib, Eddy
e076d8a9-4c7a-442e-9e26-79690eb92731
Mintova, Svetlana
a4b811f0-b3ba-453c-b0a3-fb200ab57c53
Vayssilov, Georgi N.
cccd8a32-a6ee-46b4-a46a-51f548c88e85
Aleksandrov, Hristiyan A.
a3257772-ee4a-4a2a-9038-942002b02e83
Carravetta, Marina
1b12fa96-4a6a-4689-ab3b-ccc68f1d7691
30 May 2023
Dib, Eddy
e076d8a9-4c7a-442e-9e26-79690eb92731
Mintova, Svetlana
a4b811f0-b3ba-453c-b0a3-fb200ab57c53
Vayssilov, Georgi N.
cccd8a32-a6ee-46b4-a46a-51f548c88e85
Aleksandrov, Hristiyan A.
a3257772-ee4a-4a2a-9038-942002b02e83
Carravetta, Marina
1b12fa96-4a6a-4689-ab3b-ccc68f1d7691
Dib, Eddy, Mintova, Svetlana, Vayssilov, Georgi N., Aleksandrov, Hristiyan A. and Carravetta, Marina
(2023)
Chemical shift anisotropy : a promising parameter to distinguish the 29Si NMR peaks in Zeolites.
The Journal of Physical Chemistry C, 127 (22), .
(doi:10.1021/acs.jpcc.3c01533).
Abstract
Using a combination of (i) symmetry-based recoupling in 29Si NMR, (ii) spin dynamics-based simulations, and (iii) DFT-based theoretical calculations, we show how the 29Si NMR peaks of (≡Si−O−Si≡) (Q4(0Al)), Brønsted acid sites (≡ Si−OH−Al) (Q4(1Al)≡), and silanols (≡Si−OH) (Q3) can be characterized in nanosized ZSM-5 zeolites. Significant differences in the chemical shift anisotropy are calculated theoretically and observed experimentally for silicon nuclei close to aluminum (Q4(1Al)) compared to those which are not, i.e., Q4(0Al) and Q3, allowing one to clearly assign the 29Si NMR peaks. The isotropic chemical shift alone cannot resolve such differences.
Text
230514_29Si_CSA_recoupling_main_text_revised
- Accepted Manuscript
More information
Accepted/In Press date: 22 May 2023
Published date: 30 May 2023
Additional Information:
Funding Information:
The authors acknowledge the support of the Label of Excellence for the Centre for zeolites and nanoporous materials by the Region of Normandy (CLEAR) and the International Exchange program of the Royal Society of Chemistry, grant number IES\R3\213078. The authors also acknowledge the use of the IRIDIS High Performance Computing Facility and associated support services at the University of Southampton, in the completion of this work. Prof. Malcolm H. Levitt and Prof. Ilya Kuprov are acknowledged for stimulating discussions.
Publisher Copyright:
© 2023 American Chemical Society.
Identifiers
Local EPrints ID: 480583
URI: http://eprints.soton.ac.uk/id/eprint/480583
ISSN: 1932-7447
PURE UUID: 2933f798-84f5-4407-aa40-a2f8cb3e71a1
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Date deposited: 07 Aug 2023 16:33
Last modified: 28 Aug 2024 04:01
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Author:
Eddy Dib
Author:
Svetlana Mintova
Author:
Georgi N. Vayssilov
Author:
Hristiyan A. Aleksandrov
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