Kinetic Modeling of Dynamic Aspectsof the Standard NH3-SCR Reaction OverV2O5-WO3/TiO2 and Fe-Zeolite CommercialCatalysts for the Aftertreatmentof Diesel Engines Exhausts

摘要

Dynamic kinetic data collected over commercial V2O5-WO3/TiO2 and Fe-zeolite catalysts analyzing the standard NH3-SCR of NO for the abatement of NO_x from vehicle exhausts showed transient effects at low temperatures related to the inhibiting action of excess ammonia.In order to describe such transient effects, a specific rate expression accounting for NH3 inhibition of the standard SCR reaction is needed in mathematical models of real SCR converters. We present herein a dual-site Mars-Ven Krevelen-type rate equation suitable to describe dynamic features associated with ammonia injection and shut-off over both V-based and Fe-zeolite catalysts.