| abstract |
A device and a method for the detection of ammonia, in particular for the detection of an NH3 slip in a catalytic converter arrangement (1), is proposed, an SCR catalytic converter (12) using a first gas supply device, a gas, in particular an exhaust gas from a lean operated internal combustion engine, and ammonia are supplied via a second gas supply device. Furthermore, a first means, in particular an oxidation catalytic converter (10), is provided which, before the gas is supplied to the SCR catalytic converter (12), at least largely oxidizes the oxidizable gas components initially contained in the gas. In addition, a gas (5 ″) emerging from the SCR catalytic converter (12) is analyzed via a second means, in particular a gas sensor (15), with regard to the oxidizable components contained therein. The gas sensor (15) preferably detects non-selectively oxidizable gas components and is connected via a processing unit (16) and a control unit (17) to a metering system (13) which regulates the supply of ammonia. |