Influence of calcination temperature (400-800 degrees C) on the structure and catalytic activity of CuOx-CoOy-CeO2 ternary mixed oxide (atomic Cu:Co:Ce ratio of 1:5:5) prepared by co-precipitation method is investigated by N-2 physisorption, XRD, TPR, TEM, TG-DTA, XPS, and CO oxidation reaction. The assynthesized CuOx-CoOy-CeO2 undergoes successive structural changes with the calcination temperature, involving the hydroxide dehydration below 400 degrees C, enhanced interaction between Co3O4 and CeO2 at ca. 600 degrees C, and CO3O4 decomposition to CoO at 700 degrees C. The catalyst calcined at 600 degrees C shows a relative enrichment of Cu+ on the surface of CuOx-CoO5-CeO2 and an enhanced interaction between Co3O4 and CeO2 along with the appearance of oxygen vacancies in CeO2, which seems to be responsible for its highest catalytic activity for CO oxidation among all the tested catalysts. The complete conversion of CO is obtained at 70 degrees C and about 50% of CO conversion is reached at 55 degrees C. (C) 2012 Elsevier B.V. All rights reserved.