Exhaust gas aftertreatment device for exhaust gases of internal combustion engines, comprising a catalyst for selective catalytic reduction of nitrogen oxides.

摘要

The invention relates to a device for the after-treatment of engine exhaust gases, in particular diesel engines. BR/ The device comprises a catalyst 3 for the selective catalytic reduction of the nitrogen oxides contained in the exhaust gas, a metering device for the supra-stoichiometric addition of NH 3 or NH 3 forming materials, a first sensor 10 'determining the concentration of NH3 contained in the exhaust gas and interrupting the addition of NH3 when reaching a predetermined upper threshold, and a second sensor 12, determining the amount of NH3 adsorbed in the catalyst and by which the addition of NH3 is re-established when a predetermined lower threshold is reached.