(EtOH+NH3) synergism in lean-NOx reduction over Ag/Al2O3 catalyst

Abstract

International audienceThe implemented Urea-SCR technology is an effective process for NOx reduction from Diesel vehicles but is strongly dependent at low temperature (175-250°C) to the NO2/NOx ratio. By means of co-feeding of ammonia and ethanol over Ag/Al2O3 catalyst, a drastic enhancement of the NOx conversion is evidenced using only NO as NOx. The ammonia activation is mainly attributed to the availability of hydrogen H* species resulting from EtOH oxidation. A remarkable DeNOx efficiency is additionally achieved with a dual-bed configuration (Ag/Al2O3+NH3-SCR catalyst) leading to impressive performances of this EtOH-assisted process without critical dependence to the NO2 yield