Selective catalytic reduction of N2O by C3H6 over Fe-ZSM-5

The direct decomposition and the selective reduction of nitrous oxide (N2O) over Fe-ZSM-5 has been investigated in the presence of water and oxygen, using propene (C3H6) as reductant. The results are compared with those obtained over Cu-ZSM-5, which is known to possess very high activity for the direct decomposition. When propene was added as reductant, Fe-ZSM-5 showed very high activity even in the low-temperature region and at low propene concentrations, whereas Cu-ZSM-5 was strongly deactivated. In the case of Fe-ZSM-5, no significant deactivation in the presence of water vapor or oxygen has been detected in the transient responses compared with the values of Cu-ZSM-5. Furthermore, in the case of Fe-ZSM-5, the oxidation of C3H6 is directly correlated to the conversion of N2O, indicating that the selective catalytic reduction is the preferred reaction. The reaction mechanism we can assume is as follows: first, C3H6 is adsorbed over a catalyst, and then N2O and O-2 react with it. With regard to Fe-ZSM-5, N2O in the feed tends to react with absorbed C3H6. (C) 1998 Elsevier Science B.V. All rights reserved.