Porównanie aktywności katalizatorów perowskitowego i palladowego w utlenianiu organicznych zanieczyszczeń powietrza

One of the advantageous methods for the control of VOC emission is their catalytic oxidation. In the study reported in this paper, hydrocarbons of choice and oxygen compounds were combusted alone or in mixtures over two monolithic catalysts - a perovskite catalyst (PER-Ag) and a palladium catalyst (M-2). It was only in the oxidation of toluene vapours that M-2 showed a noticeably higher activity than did PER-Ag. There was no difference in the activity between the two catalysts in the oxidation of ethanol and n-hexane, but PER-Ag performed much better in the oxidation of ethyl acetate and acetone. Although the presence of oxygen compounds practically did not affect the performance of M-2 in the combustion of toluene and n-hexane at temperatures higher than 380°C there was a distinct inhibiting effect when the hydrocarbons were combusted over PER-Ag. The presence of hydrocarbons did not very much influence the conversion of oxy-derivatives over M-2 or PER-Ag (over the latter only above 300°C). Toluene had an influence on the selectivity of the reaction to acetaldehyde when the oxy-derivatives were oxidized - over both catalysts the concen-trations were higher than when the oxy-derivative compounds were combusted alone. In the presence of n-hexane, no intermediate products of ethyl acetate and acetone oxidation were yielded over PER-Ag.