Promotion of oxygen desorption at low temperatures holds the key to the development of an effective NO decomposition catalyst. Addition of Tb oxide to Pt/Al2O3 allows oxygen from dissociated NO to desorb at 593 K, which is significantly lower than the reported oxygen desorption temperatures for Pt catalysts. Combined temperature-programmed desorption/reaction with in situ infrared study reveals that desorbed oxygen is produced from decomposition of chelating bidentate nitrate, which may result from the reaction of adsorbed oxygen on Pt and adsorbed NO on Tb oxide. The Tb-promoted Pt/Al2O3 catalyst which possesses oxygen desorption capability at low temperatures shows the activity for decomposition of NO to N-2, N2O, NO2, and O-2 under pulse and steady-state reaction conditions at 773-923 K.