Kinetic study of the NO/NO2-NH3 SCR reactions over a V2O5–WO3/TiO2 commercial catalyst for the after treatment of Diesel engines exhausts

An extensive investigation of the chemistry, the mechanism and the kinetics of the NO-NO2/NH3 SCR reactions for mobile applications was performed over a commercial Vanadium-based catalyst. 2 3 On the basis of the collected results a Mars-Van Krevelen dynamic kinetic model was derived, which unifies Standard and Fast SCR into a single Redox-type approach. Intrinsic rate parameters were accordingly estimated and incorporated into a transient heterogeneous 1D mathematical model of SCR monolith reactors together with the relevant geometrical and morphological characteristics of the monolith commercial catalyst The model was validated by independent dynamic runs both over powdered catalyst at the microreactor scale and over monolith catalysts in engine test bench runs at the full scale.