Temperature-Scanning Method for the kinetic studies of CO oxidation over ceria-zirconia supported gold catalysts
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2015-12-15
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ELSEVIER SCIENCE SA
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The experimental data of CO oxidation over the series of 2 wt.% Au/Ce1-xZrxO2 (x=0, 0.25, 0.5, 0.75, 1) catalyst were analyzed using a variation of the Temperature Scanning Method with the aim of catalyst's composition optimization. The catalysts were prepared by the Direct Anionic Exchange technique. The kinetic of CO oxidation was quantified by conversion-rate-temperature (X, r, T) triplets, calculated from raw data obtained using a plug flow reactor, working at oxygen stoichiometric, rich, and lean conditions. The data were fitted to the Mars-van Krevelen adsorption-reaction model (MvK). The results showed that the MvK model is able to predict the superficial reaction and the re-oxidation of the catalyst surface. Additionally, the data at oxygen lean conditions revealed the distinctive characteristic of Ce-containing catalysts, which act as oxygen buffer by releasing-uptalcing oxygen. The obtained values of the fitted parameters allowed re-mapping raw data onto the conversion-temperature-catalyst composition surface plot and their application as a tool for the optimization of catalyst composition. (C) 2015 Elsevier B.V. All rights reserved.
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Kinetic studies, Temperature-Scanning Method, Gold catalyst, Ceria-zirconia mixed oxide, CO oxidation, Catalyst composition optimization