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Kinetics of Oxygen Exchange over CeO2-ZrO2 Fluorite-Based Catalysts Full article

Journal The Journal of Physical Chemistry A
ISSN: 1089-5639 , E-ISSN: 1520-5215
Output data Year: 2007, Volume: 111, Number: 20, Pages: 4498-4505 Pages count : 8 DOI: 10.1021/jp0687706
Tags Adsorption; Catalysts; Desorption; Oxygen; Reaction kinetics; Zirconia
Authors Sadovskaya Ekaterina M. 1 , Ivanova Yulia A. 1 , Pinaeva Larisa G. 1 , Grasso Giacomo 2 , Kuznetsova Tatiana G. 1 , van Veen Andre 2 , Sadykov Vladislav A. 1 , Mirodatos Claude 2
Affiliations
1 Boreskov Institute of Catalysis SB RAS, Pr. Lavrientieva 5, 630090, Novosibirsk, Russia
2 Institut de Recherches sur la Catalyse et l'Environnement de Lyon−IRCELYON, UMR 5256 CNRS/ Université Lyon 1, 2 Avenue Albert Einstein, F-69626 Villeurbanne Cedex, France

Funding (1)

1 Russian Foundation for Basic Research 05-03-34761

Abstract: The kinetics of 18O/16O isotopic exchange over CeO2−ZrO2−La2O3 and Pt/CeO2−ZrO2 catalysts have been investigated under the conditions of dynamic adsorption−desorption equilibrium at atmospheric pressure and a temperature range of 650−850 °C. The rates of oxygen adsorption−desorption on Pt sites, support surface, oxygen transfer (spillover) from Pt to the support as well as the amount of oxygen accumulated in the oxide bulk, and oxygen diffusion coefficient were estimated. The nanocrystalline structure of lanthana-doped ceria-zirconia prepared via the Pechini route with a developed network of domain boundaries and specific defects guarantees a high oxygen mobility in the oxide bulk (D = (1.5 ÷ 2.0)·10-18 m2 s-1 at 650 °C) and allows accumulation of over-stoichiometric/excess oxygen. For Pt/CeO2−ZrO2, oxygen transfer from Pt to support (characteristic time < 10-2 s) was shown to be responsible for the fast exchange between the gas-phase oxygen and oxygen adsorbed on the mixed oxide surface. The rate of direct exchange between the phase and surface oxygen is increased as well due to the increased concentration (up to 2 monolayers) of surface/near subsurface oxygen species accumulated on the oxygen vacancies (originated from the incorporation of highly dispersed Pt atoms). The characteristic time of diffusion of the oxygen localized in the subsurface layers is about 1 s. The overall quantity of over-stoichiometric oxygen and/or hydroxyl groups accumulated in the bulk can reach the equivalent of 10 monolayers, and characteristic time of oxygen diffusion within the bulk is about 20 s. All these kinetic data are required for the further step of modeling partial oxidation of hydrocarbons under steady- and unsteady-state conditions.
Cite: Sadovskaya E.M. , Ivanova Y.A. , Pinaeva L.G. , Grasso G. , Kuznetsova T.G. , van Veen A. , Sadykov V.A. , Mirodatos C.
Kinetics of Oxygen Exchange over CeO2-ZrO2 Fluorite-Based Catalysts
The Journal of Physical Chemistry A. 2007. V.111. N20. P.4498-4505. DOI: 10.1021/jp0687706 WOS Scopus РИНЦ ANCAN PMID OpenAlex
Dates:
Submitted: Dec 20, 2006
Accepted: Mar 5, 2007
Published print: May 1, 2007
Published online: May 2, 2007
Identifiers:
Web of science: WOS:000246569300048
Scopus: 2-s2.0-34250180228
Elibrary: 13537894
Chemical Abstracts: 2007:477612
Chemical Abstracts (print): 147:80472
PMID: 17472353
OpenAlex: W2013823625
Citing:
DB Citing
Web of science 71
Scopus 78
Elibrary 72
OpenAlex 73
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