화학공학소재연구정보센터
Applied Catalysis B: Environmental, Vol.16, No.2, 177-186, 1998
Selective catalytic reduction of nitrous oxide over Fe-MFI in the presence of propene as reductant
The direct decomposition and the selective reduction of nitrous oxide (N2O) over Fe-MFI have been investigated in the presence of water and oxygen, using propene (C3H6) as reductant. Comparative studies have been performed over H-MFI, Cu-MFI and Na-MFI zeolite catalyst. Although Fe-MFI showed the highest catalytic activity among all materials under investigation in the presence of C3H6, no significant deactivation in the presence of water vapor and oxygen has been detected. Furthermore, in the case of Fe-MFI, the oxidation of C3H6 is directly correlated to the conversion of N2O, indicating the selective catalytic reduction being the preferred reaction. The conversion of N2O over Fe-MFI as well as the number of hydroxyl groups detected by FTIR spectroscopy increases with increasing Fe loading, and even Fe-MFI samples with rather low exchange levels exhibit remarkably high N2O conversions. FTIR experiments applying C3H6 and pyridine as probe molecules have been carried out in order to elucidate the adsorption behavior, as well as the nature of the active sites and the acidity of the different ion-exchange zeolite catalysts. The studies indicate the surface properties of the Fe-MFI catalysts, with regard to acidity and adsorption behavior, as being strongly depending on the ion-exchange level.