Cluster Quantum-Chemical Study of the Chemisorption of Methane on a Lithium-Promoted Magnesium Oxide Doped by Zinc Oxide Full article
Journal |
Journal of Molecular Catalysis A: Chemical
ISSN: 1381-1169 |
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Output data | Year: 1995, Volume: 99, Number: 3, Pages: 139-142 Pages count : 4 DOI: 10.1016/1381-1169(95)00030-5 | ||||
Tags | Chemisorption, Lithium-promoted magnesium oxide, Magnesium oxide, Methane, Quantum-chemical study, Zinc oxide | ||||
Authors |
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Affiliations |
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Funding (2)
1 | German Research Foundation | |
2 | German Research Foundation |
Abstract:
The reaction of a methane molecule with a lithium-doped magnesium oxide catalyst (LiMgO) containing small amounts of Zn2+ cations (Zn/Li/MgO) was theoretically studied using a modified MINDO/3 method and applying a supermolecular approach. The surface of magnesium oxide (MgO) was modelled by a Mg32O32 four-layer molecular cluster containing all types of structural defects i.e., low-coordinated magnesium and oxygen ions (Mg2+LC and O2−LC) of various faces, edges, corners etc. Molecular clusters of lithium-promoted magnesia (LiMgO) were simulated by isomorphic substitution of Mg2+LC by Li+LC; the excess negative charge of the cluster was compensated by a proton connected to an O2−3C site. For Zn-doped LiMgO or MgO an isomorphic substitution of Mg2+LC by Zn2+LC was assumed. The calculations indicate that for Zn/Li/MgO or ZnMgO the substitution of a threefold coordinated magnesium cation by zinc is more favourable by energetics than for four- and five-fold coordinated Mg cations. The computational results are used to interpret the experimentally observed increase of C2+ hydrocarbons selectivity in the oxidative coupling of methane when doping a NaOH-promoted CaO catalyst with minor amounts of Zn2+ cations.
Cite:
Zhanpeisov N.U.
, Baerns M.
Cluster Quantum-Chemical Study of the Chemisorption of Methane on a Lithium-Promoted Magnesium Oxide Doped by Zinc Oxide
Journal of Molecular Catalysis A: Chemical. 1995. V.99. N3. P.139-142. DOI: 10.1016/1381-1169(95)00030-5 WOS Scopus РИНЦ
Cluster Quantum-Chemical Study of the Chemisorption of Methane on a Lithium-Promoted Magnesium Oxide Doped by Zinc Oxide
Journal of Molecular Catalysis A: Chemical. 1995. V.99. N3. P.139-142. DOI: 10.1016/1381-1169(95)00030-5 WOS Scopus РИНЦ
Dates:
Submitted: | Feb 9, 1994 |
Accepted: | Feb 7, 1995 |
Published print: | Jul 3, 1995 |
Published online: | Jul 24, 2001 |
Identifiers:
Web of science | WOS:A1995RG91700002 |
Scopus | 2-s2.0-1542574615 |
Elibrary | 31124149 |
Chemical Abstracts | 1995:727109 |
Chemical Abstracts (print) | 123:198128 |
OpenAlex | W1988491788 |