A 10%Co/ZrO₂ catalyst prepared by impregnation was tested for its activity for the oxidation of CO to CO₂ in excess oxygen. Activity tests showed that conversion could be obtained at temperatures as low as 20 °C. Time-on-stream studies showed no loss of activity in these experiments, indicating that this catalyst is stable in the experimental oxidizing conditions. The activation energy for the CO to CO₂ oxidation reaction was calculated as E_a = 54 kJ/mol over this catalyst. Characterization of the material by thermogravimetric analysis, temperature-programmed techniques, X-ray photoelectron spectroscopy, and laser Raman spectroscopy indicate that Co₃O₄ is present on monoclinic ZrO₂ after the calcination of the catalyst.