Characterisation by vibrational and electronic spectroscopies

The EUROCAT SCR catalyst has been characterised by IR spectroscopic methods (transmission/absorption and diffuse reflectance techniques) by investigat ing its spectrum after different outgassing treatments, and the spectra of the surface species arising from adsorption of water (surface hydroxyl, gro ups), carbon monoxide, ammonia, pyridine, nitrogen monoxide, trimethyl bera te and NO + NH3 coadsorptions. Additionally, Raman spectra and DR UV-Vis sp ectra have been reported after different outgassing treatments. The presenc e of Lewis and Bronsted acid sites has been discussed, as well as the evide nce of different electronic states. A picture for the surface structure of the catalyst has been obtained. This picture is not significantly modified after extensive use of the catalyst in an SCR reactor for denitrifaction of flue gases from an incineration plant. (C) 2000 Elsevier Science B.V. All rights reserved.