Room temperature oxidation of carbon monoxide over copper oxide catalyst

Carbon monoxide oxidation has been studied over different oxides of copper as well as a copper oxide sample obtained from precipitation. Room temperature oxidation of carbon monoxide to carbon dioxide has been achieved for the first time over unsupported copper oxide catalyst prepared by a controlled heating of precipitated copper hydroxide after activation of the catalyst in a redox environment. It is found that drying and calcination of the precipitated hydroxide are crucial parameters that affect the catalyst performance dramatically. Experimental results indicate that the active phase is a metastable non-stoichiometric form of copper oxide formed during the treatment of the oxide in a redox environment. This species loses its activity upon exposure to the outside atmosphere due to absorption of moisture. Nevertheless, the activity can be regained by an activation step. (c) 2005 Elsevier B.V. All rights reserved.