Method and device for the operation of NO¶x¶ storage catalytic converters in compliance with the exhaust gas standard and for the diagnosis of aging thereof

摘要

The present invention relates to a method for operating a NO¶x¶ storage catalytic converter (1) which conforms to the exhaust gas standard and which is arranged in the exhaust gas path of an internal combustion engine (2). During a storage phase of the catalytic converter (1), NO¶x¶ from the exhaust gas of the internal combustion engine (2) is stored. During a regeneration phase, the NO¶x¶ stored during the storage phase is catalyzed. During a lean phase in which a sub-stoichiometric air-fuel mixture is burned, the resulting route-related average NO¶x¶ concentration is determined. If the route-related average NO¶x¶ concentration reaches a predetermined limit value, which corresponds to a legally prescribed exhaust gas limit value, the lean phase is terminated and the regeneration phase of the NO¶x¶ storage catalytic converter (1) is initiated. DOLLAR A If you compare the number of terminations determined within a comparison period with an empirically pre-determined value for the maximum number of terminations still permissible in this comparison period due to aging, you get a termination criterion for separating out an aged storage catalytic converter.