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CO oxidation over nonstoichiometric nickel manganite spinels

Laberty-Robert, Christel and Marquez-Alvarez, C. and Drouet, Christophe and Alphonse, Pierre and Mirodatos, Claudine CO oxidation over nonstoichiometric nickel manganite spinels. (2001) Journal of Catalysis, pp. 198 (2). 266-276. ISSN 0021-9517

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Official URL: http://dx.doi.org/10.1006/jcat.2000.3110

Abstract

Nonstoichiometric nickel–manganese spinel oxides, NixMn3−x ▭3δ/4O4+δ (1≥x≥0), have been synthesized by calcination in air of mixed oxalates at 623 K. These materials are shown to be highly reactive for CO oxidation, some conversion being observed at room temperature for the most active solid (x=1.0). The interaction of CO and O2 with these oxides has been studied by in situ IR spectroscopy under steady-state and transient reaction conditions. A detailed mechanism is proposed wherein CO reacts with coordinatively unsaturated cations to give carbonyl complexes which in turn react with surface oxygen activated on anionic vacancies. Adsorbed and gaseous CO2 also undergo much slower side reactions with lattice oxygen or surface hydroxide groups to give more stable hydrogen carbonate and carbonates species, which lead to catalyst deactivation. Marked effects of pretreatment are explained on the basis of the observed kinetics and the proposed mechanism

Item Type:Article
Additional Information:Thanks to Elsevier editor. The definitive version is available at http://www.sciencedirect.com/science/article/pii/S0021951700931105#
HAL Id:hal-00998519
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UPS (FRANCE)
Other partners > Université Claude Bernard-Lyon I - UCBL (FRANCE)
Laboratory name:
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Deposited By: Christophe DROUET
Deposited On:02 Jun 2014 10:11

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