Oscillatory Behaviour during C2-C4 Hydrocarbon Oxidation over Palladium Catalysts

Oscillatory behaviour during ethane, propane and butane oxidation over a palladium foil had been studied using on-line mass-spectrometry and a catalyst temperature monitoring. The striking similarity of oscillations properties in all these reactions had been observed. In reactant mixtures with the constant carbon atoms content no significant differences in the parameter space, oscillation shape, or period of temperature oscillations in all three reactions studied had been detected. It was shown that the temperature range of the oscillation phenomena on Pd coincides not only for C-2-C-4 hydrocarbon oxidation, but also for methane oxidation. However, by contrast to the oscillations during methane oxidation, the sustained oscillations with the large amplitude during C-2-C-4 hydrocarbon oxidation could be obtained only for the diluted reactant mixtures. It was demonstrated that the oscillatory phenomena during all light hydrocarbons oxidation reactions have the common origin and are related to oxidation-reduction processes of a Pd catalyst.