THE NO AND N2O SELECTIVE CATALYTIC REDUCTION ON COPPER AND IRON CONTAINING ZSM-5 CATALYSTS: A COMPARATIVE STUDY

In this work a comparison among the activities of H-ZSM-S, H-[Fe]-ZSM-5, Cu-[Fe]-ZSM-5, Cu-ZSM-S and Fe-ZSM-S catalysts for the selective catalytic reduction (SCR) of NO and N2O by C3H8 in presence of excess oxygen is reported. The results show that the activity for the NO reduction increases as iron and copper are loaded in the parent materials, i.e. H-ZSM-S - H-[Fe]-ZSM-S < Fe-ZSM-S < Cu- ZSM-' * Cu-[Fel-ZSM-5. In the case of the N2O reduction the order of activity changed as follows: H-ZSM-S < Cu-ZSM-S * Cu-[Fe]-ZSM-5 < Fe-ZSM-S < H-[Fe]- ZSM-5. In order to provide a more comprehensive picture of the catalytic behaviour, some catalytic results concerning the N2O decomposition are also presented.