Copper oxide and niobium pentoxide were supported on silica-alumina with 2, 5, 10, 15 and 25 mass% loadings and 1:1 mass ratio of CuO:Nb2O5. XRD and BET measurements confirmed that monolayer coverage is reached with loadings between 5-10 mass% (similar to 308 m(2) g(-1)). The DRIFTS spectra of pyridine adsorbed catalysts showed bands associated with Bronsted, Lewis and a combination of both acidic sites. Thermal analysis and liquid phase microcalorimetry provided the parameters for the best catalyst (10 mass%), which has the highest number of acidic sites (0.38 mmol g(-1)) and enthalpies of interaction with pyridine for Bronsted and Lewis sites (Delta H-1 = -107.5 and Delta H-2 = -64.4 kJ mol(-1), respectively).