Applied Catalysis A: General, Vol.480, 34-41, 2014
Activated MnO2-Co3O4-CeO2 catalysts for the treatment of CO at room temperature
In the present work, different families of mixed MnO2-Co3O4-CeO2 catalysts prepared by a sol-gel synthesis were investigated for the treatment of CO at low temperature. It was found that some mixed MnO2-Co3O4-CeO2 catalysts exhibited superior activity compared to the single constituted oxides, temperature of 100% CO conversion decreased significantly to 60 degrees C in the mixed samples. These samples were characterized by XRD, SEM, BET, XPS, TPR-H-2,TPD-O-2 techniques to explain the improvement of catalytic activity. The results show that a reasonable replacement of Mn4+ and Ce4+ ions for Co3+ ions in Co3O4 crystals is supposed to be the reason for the enhancement of catalytic activity of the three component systems compared to single and two component oxide catalysts. Especially, when some mixed MnO2-Co3O4-CeO2 catalysts were activated under a certain non-harsh condition, they were able to convert 100% CO to CO2 at room temperature for at least 16 h on stream. The presences of up to 30 vol.% steam in the reactant flow did not result in any decrease of activity at room temperature. (C) 2014 Elsevier B.V. All rights reserved.