ROLE OF THE REDOX PROPERTIES IN THE SCR OF NO BY NH3 OVER V2O5-WO3 TIO2 CATALYSTS/

The reactivity of ternary V2O5-WO3/TiO2 De-NOx catalysts is investigat ed by transient and steady-state techniques, and results have been com pared with those obtained over binary V2O5/TiO2 samples having the sam e V2O5 loading. The results indicate that the reactivity of the ternar y catalysts in the SCR reaction is higher than that of the vanadia-tit ania samples, and that at low temperatures the SCR reaction occurs via a redox mechanism that involves at first the participation of the cat alyst lattice oxygen and then the reoxidation of the reduced sites by gas-phase oxygen. Accordingly, the higher reactivity of the ternary ca talysts has been related to their superior redox properties.