PROMOTION OF OXYGEN DESORPTION TO ENHANCE DIRECT NO DECOMPOSITION OVER TB-PT AL2O3 CATALYST/

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