NH3 oxidation to nitrogen and water at low temperatures using supported transition metal catalysts

The ability of several alumina-supported metal catalysts and transition-met al ion-exchanged zeolite Y catalysts to oxidize ammonia to nitrogen and wat er at low temperatures (between 200 and 350 degrees C) was tested both at h igh and low ammonia concentrations. Copper-containing zeolite Y catalysts w ere comparable in activity and were more selective than noble-metal contain ing zeolite catalysts of similar metal loading. Cu/zeolite-Y catalysts were superior to copper/molybdenum and vanadium/alumina catalysts. Postsynthesi s treatment of Cu/zeolite-Y with NaOH increased the activity for ammonia ox idation; dispersion and size of the supported copper-oxide particles were v ery important parameters. Go-fed steam dramatically increased the deactivat ion on all catalysts, especially at lower temperatures. (C) 2000 Published by Elsevier Science B.V.