The activity of the CuO-CeO2 couple supported on a MSU silica doped with zirconium (Si/Zr = 7), was evaluated in the preferential oxidation of CO (CO-PROX) in hydrogen-rich gas stream (1.2% CO, 1.2% O-2, 50% H-2, 0-15% CO2, 0-10% H2O He balance) and the catalytic performance was compared with that of CuO-CeO2 supported on a pure MSU silica. The samples were characterized by X-ray powder diffraction (XRPD), N-2 physisorption at 77 K, temperature-programmed reduction (H-2-TPR) and X-ray photoelectron spectroscopy (XPS). Correlations between catalytic performances and physico-chemical properties of the materials have been made.