The preferential oxidation of carbon monoxide in the presence of hydrogen (PROX reaction) was studied on Cu catalysts promoted with Fe, Nb, Ce, and Ni supported on TiO2 and on TiO2 nanotubes. The surface area of the untreated TiO2 anatase (150 m(2)/g) support was increase to 350 m(2)/g when transformed into TiO2 nanotubes (NT). XRD and SEM results confirm the formation of nanotubular structures responsible of the increase in BET surface area. The activity results indicate that a 10% Cu/5% Nb/TiO2-NT catalyst is highly active for this reaction compared to other transition metals and with a catalyst with the same composition supported on untreated TiO2. We found close to 80% CO conversion and 40% selectivity to CO2 formation at 170 A degrees C. The higher activity is ascribed to a higher dispersion of Cu on the TiO2 NT structures.