An investigation was conducted of the decomposition of N2O over Fe-ZSM-5. The zeolite used in this study was prepared with Fe and Al in the framework and is designated as Fe/Al-MFI (Si/Al = 84 and Fe/Al = 0.38). The as-prepared material was then calcined to remove the templating agent and pretreated at temperatures up to 1123 K. EXAFS characterization of the pretreated catalyst indicates that Fe is present as isolated Fe cations at cation-exhchange sites associated with framework Al. Above 548 K, N2O decomposes stoichiometrically to N-2 and O-2, but below 548 K, N2O decomposes to adsorbed oxygen and gas-phase N-2. Surface oxygen loadings are in the range of O/Fe-total = 0.10-0.14. For the stoichiometric decomposition of N2O to N-2 and O-2, the calculated values of the apparent activation energy and the preexponential factor are 44.2 kcal/mol and 9.9 x 108 mol N2O/(s mol Fe-total Pa N2O), respectively. The first step in the overall decomposition sequence is the dissociative adsorption of N20 to produce N-2 and an adsorbed O atom. The activation energy for this step is 16.8 kcal/mol and the preexponential factor is 1.4 x 10(1) mol N2O/(s mol Fe-total Pa N2O). The desorption of O-2 from iron sites occurs with an apparent activation energy of 45.7 kcal/mol and a preexponential factor of 8.9 x 10(12) mol O-2/(s mol Fe-total) (C) 2004 Elsevier Inc. All rights reserved.