Three different preparation methods have been used to synthesize CuO-CeO2 catalysts with 7 wt.% copper loading: coprecipitation (CP), sol-gel (SG) and urea nitrate combustion (UC). All the samples have been characterized by a series of techniques such as XRD, Raman, TPR, TPD and OSC, in order to understand their different performance in CO oxidation, as a function of redox properties and catalyst structure. Among the catalysts, clearly CuCe-CP shows the lower activity because it presents the structure of a solid solution. CuCe-SG and CuCe-UC catalysts show much better performance in CO oxidation, in accordance to their higher redox capacity. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.