Kinetics of selective catalytic reduction of nitric oxide by ammonia over vanadia/titania
- Univ. of Wisconsin, Madison, WI (United States)
- Haldor Topsoe Research Labs., Lyngby (Denmark)
A kinetic model based on a previously proposed reaction scheme was used to describe reaction kinetics measurements for the selective catalytic reduction of nitric oxide by ammonia over a 6 wt% vanadia/titania catalyst in the presence of oxygen (2 mol%) at nitric oxide and ammonia concentrations from 100 to 500 ppm and at temperatures of 523 and 573 K. This reaction scheme involves adsorption of ammonia on Bronsted acid sites (V{sup 5+} -OH), followed by activation of ammonia via reaction with redox sites (V=O). This activated form of ammonia reacts with gaseous or weakly adsorbed NO, producing N{sub 2} and H{sub 2}O, and leading to partial reduction of the catalyst. The V{sup 4+}-OH species formed by the selective catalytic reduction (SCR) reaction combine to form water, and the catalytic cycle is completed by reaction of the reduced sites with O{sub 2}. Water adsorbs competitively with ammonia on acid sites. This reaction scheme can be used to describe the kinetics of the SCR reaction under laboratory as well as under industrially relevant reaction conditions. 28 refs., 4 figs., 4 tabs.
- OSTI ID:
- 501851
- Journal Information:
- Journal of Catalysis, Vol. 163, Issue 2; Other Information: PBD: Oct 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Vanadia/titania catalysts for selective catalytic reduction of nitric oxide by ammonia. II. Studies of active sites and formulation of catalytic cycles
Study of the NO[sub 2]-NH[sub 3] interaction on a titania (ANATASE) supported vanadia catalyst