15N nuclear magnetic resonance studies of the NO–O2–NH3 reaction over ZSM-5 zeolites

Abstract

¹⁵ N nuclear magnetic resonance spectra produced by adsorption on ZSM-5 zeolites of NO alone or together with O₂ and NH₃ have been examined. N₂ and N₂O as products of NO disproportionation were identified by their ¹⁵N NMR spectra. Cationic and acidic centres were suggested to be responsible for the catalytic activity of zeolites in this reaction. The ¹⁴N–¹⁵N isotopic exchange between reaction components indicates the formation of the intermediate complexes between NH₃ and N_xO_y· M⁺ species in the adsorbed state.