Catalytic oxidation of CO gas over nanocrystallite CuxMn 1-xFe2O4

Abstract

The catalytic oxidation of CO over nanocrystallite CuxMn (1-x)Fe2O4 powders was studied using advanced quadruple mass gas analyzer system. The oxidation of CO to CO2 was investigated as a function of reactants ratio and firing temperature of ferrite powders. The maximum CO conversion was observed for ferrite powders which have equal amount of Cu2+ and Mn2+ (Cu0.5Mn 0.5Fe2O4). The high catalytic activity of Cu0.5Mn0.5Fe2O4 can be attributed to the changes of the valence state of catalytically active components of the ferrite powders. The firing temperature plays insignificant role in the catalytic activity of CO over nanocrystallite copper manganese ferrites. The mechanism of catalytic oxidation reactions was studied. It was found that the CO catalytic oxidation reactions on the surface of the Cux Mn 1-xFe2O4 was done by the reduction of the ferrite by CO to the oxygen deficient lower oxide then re-oxidation of this phase to the saturated oxygen metal ferrite again. © Springer Science+Business Media, LLC 2008.