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, et al.. In situ XAS study on the Cu and Ce local structural changes in a CuO-CeO/AlO catalyst under propane reduction and re-oxidation. Journal of Physics and Chemistry of Solids, Elsevier, 2009, 70 (9) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.A c c e p t e d m a n u s c r i p t

The CO oxidation with on an active catalyst has been studied using a TAP (temporal analysis O 2 Au/Ti(OH) 4 * of products) transient technique to gain insights into the CO oxidation mechanism. Taking advantage of the TAP system, we have tried to elucidate the controversial mechanism proposed for the CO oxidation on supported gold catalysts. PumpÈprobe experiments have been performed to determine the lifetime of surface reactive intermediates involved in the oxidation reaction. In a typical pumpÈprobe experiment the catalyst is Ðrst charged with a reactant pulse from the pump valve and then interrogated with a di †erent pulse from the probe valve. Varying the time between the pump and probe pulses gives information related to the lifetime of surface intermediates. The pumpÈprobe experiments together with single-pulse experiments revealed that molecularly and irreversibly adsorbed oxygen contributed to the catalytic CO oxidation. When CO was a pump molecule, the yield was not inÑuenced by the pumpÈprobe time interval. This means that CO CO 2 reversibly adsorbs on the surface with a lifetime long enough to react with oxygen. Moreover, the nature and role of oxygen species in the reaction have been examined in the TAP reactor using transient 18O 2 experiments. The results revealed that oxygen passed over the catalyst without isotope scrambling and that the lattice oxygen atoms exchanged only with formed by the CO oxidation reaction. CO 2