Computational Differentiation of Broensted Acidity Induced by Alkaline Earth or Rare Earth Cations in Zeolites Full article
Journal |
Inorganic Chemistry
ISSN: 0020-1669 , E-ISSN: 1520-510X |
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Output data | Year: 2012, Volume: 51, Number: 22, Pages: 12165-12175 Pages count : 11 DOI: 10.1021/ic301279v | ||||
Tags | SOLID-STATE NMR; GENERALIZED GRADIENT APPROXIMATION; ATOMIC BASIS-SETS; SELECTIVE OXIDATION; ELECTRIC-FIELD; HYDROXYL-GROUPS; CO ADSORPTION; ACTIVE-SITES; Y ZEOLITE; SPECTROSCOPY | ||||
Authors |
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Affiliations |
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Funding (2)
1 | Russian Foundation for Basic Research | 12-03-00749 |
2 | Fund for Scientific Research | 2.4.617.07.F |
Abstract:
For bi- and trivalent Me(q+) (Me = metal) cations of alkaline earth (AE) and rare earth (RE) metals, respectively, the formation of the nonacid MeOH((q-1)+) species and acid H-Ozeo group, where Ozeo is the framework atom, from water adsorbed at the multivalent Me(q+)(H2O) cation in cationic form zeolites was checked at both isolated cluster (8R or 6R + 4R) and periodic (the mordenite framework) levels. Both approaches demonstrate qualitative differences for the stability of the dissociated water between the two classes of industrial cationic forms if two Al atoms are closely located. The RE forms split water while the AE ones do not, that can be a basis of different proton transfer in the RE zeolites (thermodynamic control) than in the AE forms (kinetic control). The cluster models allow quantitatively explaining nearly equal intensities IHF ∼ ILF of the high frequency (HF) and low frequency (LF) OH vibrations in the RE forms and lowered IHF ≪ ILF in the AE forms, where HF bands are assigned to the Me-OH groups in the RE and AE forms, respectively, while LF bands are assigned to the Si-O(H)-Al groups. The role of electrostatic terms for water dissociation in the RE and AE forms is discussed.
Cite:
Rybakov A.A.
, Larin A.V.
, Zhidomirov G.M.
Computational Differentiation of Broensted Acidity Induced by Alkaline Earth or Rare Earth Cations in Zeolites
Inorganic Chemistry. 2012. V.51. N22. P.12165-12175. DOI: 10.1021/ic301279v WOS Scopus РИНЦ
Computational Differentiation of Broensted Acidity Induced by Alkaline Earth or Rare Earth Cations in Zeolites
Inorganic Chemistry. 2012. V.51. N22. P.12165-12175. DOI: 10.1021/ic301279v WOS Scopus РИНЦ
Dates:
Submitted: | Jun 17, 2012 |
Published online: | Nov 6, 2012 |
Published print: | Nov 19, 2012 |
Identifiers:
Web of science | WOS:000311173700013 |
Scopus | 2-s2.0-84869436000 |
Elibrary | 20493365 |
Chemical Abstracts | 2012:1634390 |
Chemical Abstracts (print) | 157:694231 |
OpenAlex | W2074798052 |