Preferential oxidation of CO on copper-containing manganese oxides

Copper-containing manganese oxides (Cu/Mn (molar ratio) = 0-1/1) prepared by the sol-gel method were characterized by temperature-programmed desorption of CO (CO-TPD) and of H-2 (H-2-TPD), temperature-programmed reduction with H-2 (H-2-TPD), and competitive adsorption of CO and H-2. Copper-containing manganese oxides (amorphous structure, mesopores of about 6 nm, and high surface areas of 170-230 m(2) g(-1)) were used for preferential oxidation (PROX) of CO in a large excess of H-2. It was observed that copper-containing manganese oxides could preferentially and totally oxidize 1 vol% CO at temperature lower than 100 degrees C. The reason for high O-2 selectivity to CO oxidation was discussed. Preferential adsorption of CO to H-2 on the highly active sites and low activity of the manganese oxide-based catalysts to oxidize H-2 were the reasons for the favorable performance. (C) 2009 Elsevier B.V. All rights reserved.