The influence of support on the activity of monolayer vanadia-titania catalysts for selective catalytic reduction of NO with ammonia
- Inst. of Catalysis, Novosibirsk (Russian Federation); and others
An investigation of the influence of support on the activity of monolayer vanadia-titania catalysts in selective catalytic reduction (SCR) of NO by ammonia has been carried out. The V{sub 2}O{sub 5}-TiO{sub 2} catalysts were prepared via VOCI{sub 3}, grafting on the TiO{sub 2} surface, V{sub 2}O{sub 5}-WO{sub 3}-TiO{sub 2} catalysts were prepared by inserting ammonium salts in TiO{sub 2}. The V{sub 2}O{sub 5}-TiO{sub 2} catalysts were prepared by inserting ammonium salts in TiO{sub 2}. The supports and catalysts were characterized by XPS, XRD, EPR, SIMS, electric conductivity, DRS UV-vis, BET, ICP, and X-ray fluorescence methods. The catalytic activity of samples was determined in a flow recycle reactor. On the basis of catalytic activity data it may be concluded that the specific activity, activation energy, and turnover frequency do not depend on the crystal structure of titania. The activation energy of the SCR process coincides with the vanadia reoxidation activation energy. Reoxidation of reduced vanadia species seems to be the rate-limiting step of the SCR process. NO SCR by ammonia with and without oxygen may have a common reaction mechanism. Conversion of one NO(NH{sub 3}) molecule proceeds on two surface vanadium atoms. Part of the supported vanadia penetrates into the sublayers of titania independent of the vanadia introduction method and titania crystal structure. 49 refs., 7 figs., 2 tabs.
- OSTI ID:
- 486291
- Journal Information:
- Journal of Catalysis, Vol. 155, Issue 2; Other Information: PBD: 1 Sep 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
Vanadia, vanadia-titania, and vanadia-titania-silica gels: Structural genesis and catalytic behavior in the reduction of nitric oxide with ammonia
{sup 15}N NMR study of the adsorption of NO and NH{sub 3} on titania-supported vanadia catalysts