Nitrous oxide deposits its oxygens on Fe-ferrierites at 200-250degreesC in contrast with nitric oxide and nitrogen dioxide. This oxygen is readily exchangeable for O-18(2) at room temperature and the reaction proceeds via a single-step exchange mechanism. All three nitrogen oxides in a mixture with O-18 labeled dioxygen undergo isotopic exchange (IE) at 200-250degreesC, N2O via the same single-step mechanism, while NO and NO2 react via a multiple-step mechanism. Zeolitic oxygens participate in IE above 250degreesC during temperature-programmed desorption of surface species formed in the reaction of nitrogen oxides with O-18(2).