Copper-based catalysts supported on niobium-doped ceria have been prepared and tested in the preferential oxidation of CO in excess of H-2 (PROX) and in total oxidation of toluene. Supports and catalysts have been characterized by several techniques: N-2 adsorption, ICP-OES, XRF, XRD, Raman Spectroscopy, SEM, TEM, H-2-TPR and XPS, and their catalytic performance has been measured in PROX, with an ideal gas mixture (CO, O-2 and H-2) with or without CO2 and H2O, and in total oxidation of toluene. The effects of the copper loading and the amount of niobium in the supports have been evaluated. Remarkably, the addition of niobia to the catalysts may improve the catalytic performance in total oxidation of toluene. It allows us to prepare cheaper catalysts (niobia it is far cheaper than ceria) with improved catalytic performance. (C) 2015 Elsevier B.V. All rights reserved.