Study of the NO2-NH3 Interaction on a Titania (ANATASE) Supported Vanadia Catalyst

摘要: Abstract The adsorption and coadsorption of nitrogen dioxide ammonia on an anatase-supported vanadia catalyst prepared by ion exchange from acidic aqueous solution ammonium vanadate are investigated IR spectroscopy ESR. sequence formation adsorbed species the thermal stability surface complexes studied. It is established that active sites for selective catalytic reduction (SCR) NO2 NH3 vanadiatitania catalysts (i) V5+O groups, which interact with NO2, and, as a result, vanadium reduced to V4+, while oxidized nitrate coordinated (IV); (ii) V5+-OH react thus giving rise strong Bronsted acidity. Ammonia participation induced acid NH+4, whereas coordinatively bound Lewis displaced NO2. presence delocalized protons sample registered. found these play essential role in occurrence SCR process. Some conclusions drawn concerning mechanism NOx NH3. A scheme proposed according reaction takes place between NO−3 ion, having more pronounced symmetry, NH+4 both coadsorbed phase, NO−2 appearing intermediate.