N2O decomposition catalyzed by oxidized Fe clusters localized in the micropores of Fe/ZSM-5 has been
studied using the DFT approach and a binuclear cluster model of the active site. Three different reaction
routes were found, depending on temperature and water pressure. The results show that below 200 °C the
binuclear cluster is hydroxylated and is probably inactive. Above this temperature and up to 500 °C the
catalytic site has the [HO-Fe-O-Fe-OH]2+ structure, and above 500 °C
the site is predominantly [Fe-
O-Fe]2+. The reaction paths on the latter two forms of the site are similar. N2O dissociates on each of the
Fe ions with subsequent oxygen recombination and desorption. Some of the side reactions including NO
formation are also considered.