Method and device for determining the storage state of an ammonia-storing SCR catalytic converter

摘要

A method for determining the storage state of an ammonia-storing SCR catalyst, the change in at least one physical property of the SCR catalyst material, changing with the NH3 storing process, being sensed, the measurement taking place on the SCR catalyst material itself by applying a measuring pickup to the SCR catalyst or bringing it into direct contact with the latter and determining the storage state on the basis of these results. In an alternative embodiment, a material identical or similar to the SCR catalyst material with regard to its physical properties is arranged in the exhaust-gas stream in addition to the SCR catalyst material, and the change in at least one physical property of this substitute material changing with the NH3 storing process, is sensed, the measurement taking place on the substitute material itself by applying the substitute material to the measuring pickup or bringing it into direct contact with the latter and determining the storage state of the SCR catalyst on the basis of these results.