The NOx selective catalytic reduction (SCR) is extensively studied as an effective process for air pollutants abatement from lean burn and Diesel vehicles. In the implemented Urea-SCR technology, the NO2/NOx ratio is a key parameter that limits the deNO(x) efficiency at low temperature (175-250 degrees C). We demonstrate that co-feeding of ammonia and ethanol on a Ag/Al2O3 catalyst enables a drastic enhancement of the NOx conversion at temperatures below 200 degrees C using only NO as NOx (standard SCR condition). Even if NO2 is provided at low temperature by the NO oxidation over Ag/Al2O3 in presence of EtOH, the NO. conversion improvement is not only due to a direct reaction between NH3 and NOx, but mainly attributed to the availability of hydrogen H* species resulting from EtOH oxidation (similar to a H-2 assisted NH3-SCR process). Due to the presence of remaining NH3 and NO2 (formed over Ag/Al2O3 catalyst), further deNO(x) efficiency improvement was obtained at low temperature by addition of a NH3-SCR catalyst (WO3/CeZr). The critical dependence of the SCR process on the Diesel Oxidation Catalyst (DOC) efficiency at low temperature is thus avoided. (C) 2017 Elsevier B.V. All rights reserved.