The catalytic activity of a mixed phase of copper-cobalt and copper-manganese oxides supported on magnesium fluorine or alumina has been studied in low temperature CO oxidation at 30 degrees C. During calcination, the oxides studied partially react to form different type spinels depending on the calcination temperature. These spinels have different effect on the catalytic activity. In low temperature CO oxidation the copper-manganese catalysts are more active than the copper-cobalt ones. C (c) 2006 Elsevier B.V. All rights reserved.