Ce-Cu and Ce-Zr-Cu oxide systems with a flower-like morphology were prepared by slow co-precipitation in the absence of any structure directing agent. For the sake of comparison, Ce-Cu and Ce-Zr-Cu oxide samples were also prepared by a classic co-precipitation method. All the samples were calcined in air flow at 650 degrees C. The materials were characterized by SEM and TEM microscopy, quantitative X-ray diffraction, N-2 physisorption, H-2-TPR, O-2-TPD and XPS. The catalytic activity of the prepared samples was evaluated in the preferential oxidation of CO in excess of H-2 (CO-PROX), in the 40-190 degrees C temperature range. (C) 2012 Elsevier B.V. All rights reserved.