Molecular Mechanism of Oxygen Exchange over Supported Vanadium Oxide Catalyst VOx/TiO2 Full article
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The Journal of Physical Chemistry C
ISSN: 1932-7447 , E-ISSN: 1932-7455 |
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| Output data | Year: 2013, Volume: 117, Number: 6, Pages: 2879-2887 Pages count : 9 DOI: 10.1021/jp311322b | ||
| Tags | Activation energy; Catalysts; Catalytic oxidation; Electronic structure; Isotopes; Paramagnetism; Three dimensional; Titanium dioxide | ||
| Authors |
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| Affiliations |
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Funding (2)
| 1 | Federal Agency for Scientific Organizations | V.45.3.2. |
| 2 | Russian Foundation for Basic Research | 12-03-00905 |
Abstract:
Detailed molecular mechanisms of oxygen isotopic exchange over VOx/TiO2 catalyst following the R0, R1, and R2 mechanisms were studied using periodic DFT analysis of possible pathways by the CI-NEB method. The electronic structures of surface VOx species formed on the VOx/TiO2 model surface after interaction of molecular oxygen with fully oxidized O═V5+–O–V5+═O sites and reduced V3+–O–V3+ sites were analyzed. We found a number of metastable surface structures that are potential intermediates in the exchange reaction pathways. We present evidence that adsorption of two gas-phase oxygen molecules on a reduced V3+–O-V3+ site leads to the formation of a superoxide complex, followed by its transformation into a peroxide complex with low activation energy about E* = 0.04 eV (0.92 kcal/mol). Subsequent transformation of this surface superoxide-peroxide species follows the Langmuir–Hinshelwood mechanism without participation of lattice oxygen along the R0 reaction pathway. We demonstrate that adsorption of molecular oxygen on fully oxidized O═V5+–O–V5+═O sites results in the formation of either monodentate V<(O3) or bidentate V<(O3)>V surface ozonide species. Their subsequent transformations result in oxygen isotopic exchange following the R1 or R2 mechanisms with the activation energies in the range of 1.44 to 1.64 eV for the R1 mechanism and 1.81 eV for the R2 one. These processes follow the Eley–Rideal mechanism with participation of one or two lattice oxygen atoms, correspondingly.
Cite:
Avdeev V.I.
, Bedilo A.F.
Molecular Mechanism of Oxygen Exchange over Supported Vanadium Oxide Catalyst VOx/TiO2
The Journal of Physical Chemistry C. 2013. V.117. N6. P.2879-2887. DOI: 10.1021/jp311322b WOS Scopus РИНЦ ANCAN OpenAlex
Molecular Mechanism of Oxygen Exchange over Supported Vanadium Oxide Catalyst VOx/TiO2
The Journal of Physical Chemistry C. 2013. V.117. N6. P.2879-2887. DOI: 10.1021/jp311322b WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Nov 16, 2012 |
| Accepted: | Jan 15, 2013 |
| Published online: | Jan 30, 2013 |
| Published print: | Feb 14, 2013 |
Identifiers:
| Web of science: | WOS:000315181800058 |
| Scopus: | 2-s2.0-84873953626 |
| Elibrary: | 20434352 |
| Chemical Abstracts: | 2013:111796 |
| Chemical Abstracts (print): | 158:227190 |
| OpenAlex: | W2317467103 |