Binary copper manganese oxides were prepared by a novel redox method and their catalytic activity for CO oxidation at ambient temperature evaluated. The catalytic activity was found to be high, and compared favorably with a commercial Hopcalite catalyst. The most active catalyst was able to completely oxidize CO at ambient temperature. Catalytic activity decay, most likely due to carbon dioxide retention was observed. The catalysts were deactivated by moisture but expelling water at moderate temperatures easily restored their catalytic activity. The catalysts were characterized by means of BET, FE-SEM, TEM, EDAX, XPS, TPD and X-ray powder diffraction. The optimum copper loading was determined to be similar to 9% of the manganese content. (C) 2010 Elsevier B.V. All rights reserved.