Abstract: The invention relates to a particle filter, which comprises a wall flow filter and SCR-active material, wherein the wall flow filter comprises ducts which extend in parallel between the first and the second end of the wall flow filter and which are alternately closed in a gas-tight manner either at the first or the second end and which are separated by porous walls, the pores of which have inner surfaces, and the SCR-active material is located in the form of a coating on the inner surfaces of the pores of the porous walls, characterized in that the coating has a gradient, such that the side of the coating facing the exhaust gas has a higher selectivity in the SCR reaction than the side of the coating that faces the inner surfaces of the pores. The SCR-active material is preferably a small-pore zeolite, which has a maximum ring size of eight tetrahedral atoms and is exchanged with copper and/or iron.

Abstract: The present invention relates to an SCR-active material, comprising a small-pore zeolite, aluminum oxide and copper, characterized in that it contains 5 to 25 wt-% of aluminum oxide in relation to the entire material and that the copper is present on the aluminum oxide in a first concentration and on the small-pore zeolite in a second concentration.

Abstract: The present invention relates to an SCR-active material, comprising a small-pore zeolite, aluminum oxide and copper, characterized in that it contains 5 to 25 wt-% of aluminum oxide in relation to the entire material and that the copper is present on the aluminum oxide in a first concentration and on the small-pore zeolite in a second concentration.

Abstract: The invention relates to a particle filter, which comprises a wall flow filter and SCR-active material, wherein the wall flow filter comprises ducts which extend in parallel between the first and the second end of the wall flow filter and which are alternately closed in a gas-tight manner either at the first or the second end and which are separated by porous walls, the pores of which have inner surfaces, and the SCR-active material is located in the form of a coating on the inner surfaces of the pores of the porous walls, characterized in that the coating has a gradient, such that the side of the coating facing the exhaust gas has a higher selectivity in the SCR reaction than the side of the coating that faces the inner surfaces of the pores. The SCR-active material is preferably a small-pore zeolite, which has a maximum ring size of eight tetrahedral atoms and is exchanged with copper and/or iron.

Abstract: The present invention relates to an SCR-active material, comprising a small-pore zeolite, aluminum oxide and copper, characterized in that it contains 5 to 25 wt-% of aluminum oxide in relation to the entire material and that the copper is present on the aluminum oxide in a first concentration and on the small-pore zeolite in a second concentration.

Abstract: The invention relates to an SCR-active material, comprising a small-pore zeolite of the structure type levyne (LEV), aluminum oxide, and copper, characterized in that, based on the total material, the material contains 4 to 25 wt % of aluminum oxide.

Abstract: The invention relates to a catalyst, which comprises a catalyst substrate of the length L and two SCR-catalytically active materials A and B, wherein the SCR-catalytically active material A contains a zeolite of the levyne structure type, which contains ion-exchanged iron and/or copper, and the SCR-catalytically active material B contains a zeolite of the chabazite structure type, which contains ion-exchanged iron and/or copper, wherein (i) the SCR-catalytically active materials A and B are in the form of two material zones A and B, wherein material zone A extends from the first end of the catalyst substrate at least over part of the length L and material zone B extends from the second end of the catalyst substrate at least over part of the length L, or wherein (ii) the catalyst substrate is formed by the SCR-catalytically active material A or B and a matrix component and the SCR-catalytically active material B or A extends at least over part of the length L of the catalyst substrate in the form of a material

Abstract: The invention relates to a particle filter, which comprises a wall flow filter and two SCR-catalytically active materials A and B which are different from each other, wherein the SCR-catalytically active material A contains a zeolite of the chabazite structure type, which contains ion-exchanged iron and/or copper, and the SCR-catalytically active material B contains a zeolite of the levyne structure type, which contains ion-exchanged iron and/or copper, wherein (i) the SCR-catalytically active materials A and B are in the form of two material zones A and B, wherein material zone A extends from the first end of the wall flow filter at least over part of the length L and material zone B extends from the second end of the wall flow filter at least over part of the length L, or wherein (ii) the wall flow filter is formed by the SCR-catalytically active material A or B and a matrix component and the SCR-catalytically active material B or A extends at least over part of the length L of the wall flow filter in the f

Abstract: The present invention relates to the use of different regeneration strategies for nitrogen oxide storage catalysts (NOx storage catalyst, LNT or NSC), depending on the exhaust gas temperatures, to reduce in the total exhaust gas the greenhouse gas N2O (nitrous oxide) that is produced as a secondary emission during the regeneration of the storage catalyst. If the exhaust gas temperature is below 275° C.-290° C., regeneration takes place using a strategy with short pulses of around 2 seconds and ? Lambda 0.95 rich.

Abstract: The invention relates to a method for reactivating a system composed of an oxidation catalytic converter (5) followed by a possibly catalytically coated particle filter (6), and to a correspondingly adapted exhaust-gas purification system for lean-burn engines (1) with low pressure EGR (14). The present invention relates in particular to the reactivation of such a system during overrun operation of the engine.

Abstract: The invention relates to a method for regenerating nitrogen oxide storage catalytic converters and to a correspondingly adapted exhaust-gas purification system for lean-burn engines. In particular, the present invention relates to the regeneration of nitrogen oxide storage catalytic converters during special driving situations of the vehicle.

Abstract: The present invention relates to the use of different regeneration strategies for nitrogen oxide storage catalysts (NOx storage catalyst, LNT or NSC), depending on the exhaust gas temperatures, to reduce in the total exhaust gas the greenhouse gas N2O (nitrous oxide) that is produced as a secondary emission during the regeneration of the storage catalyst. If the exhaust gas temperature is below 275° C.-290° C., regeneration takes place using a strategy with short pulses of around 2 seconds and ? Lambda 0.95 rich.

Abstract: The present invention relates to a regulating strategy for a special catalytic converter for exhaust-gas aftertreatment. The catalytic converter concept is distinguished in that at least two nitrogen oxide storage catalytic converters are used in the exhaust section of a vehicle. The first, possibly close-coupled unit is followed by one or more nitrogen oxide storage catalytic converters, which are possibly situated in the underbody of the vehicle. The nitrogen oxide storage catalytic converters are then regenerated as a function of the exceedance of nitrogen oxide threshold vales downstream thereof.

Abstract: The present invention relates to the use of a particular method for the targeted desulfurization of particular nitric oxide storage catalysts (NOx storage catalysts). In particular, this invention is directed to the use of an adapted method on specifically composed storage catalysts.

Abstract: The invention relates to a method for reactivating a system composed of an oxidation catalytic converter (5) followed by a possibly catalytically coated particle filter (6), and to a correspondingly adapted exhaust-gas purification system for lean-burn engines (1) with low pressure EGR (14). The present invention relates in particular to the reactivation of such a system during over run operation of the engine.

Abstract: The invention relates to a method for regenerating nitrogen oxide storage catalytic converters and to a correspondingly adapted exhaust-gas purification system for lean-burn engines. In particular, the present invention relates to the regeneration of nitrogen oxide storage catalytic converters during special driving situations of the vehicle.

Abstract: The present invention relates to a method for exhaust gas after-treatment for essentially lean-burn internal combustion engines and also a corresponding advantageous exhaust gas after-treatment system. In particular, the present invention relates to reducing the proportion of the greenhouse gas N20 in the total exhaust gas from a corresponding internal combustion system using at least one NOx storage catalyst as exhaust gas purification element. The objective of the invention is to operate the N20 depletion catalyst located downstream of the NOx storage catalyst under lambda=<1 conditions when the N20 formed by the NOx storage catalyst reaches the N20 depletion catalyst.

Abstract: The present invention relates to an exhaust-gas aftertreatment system which comprises a preferably catalytically active particle filter (wall-flow filter) which is followed in turn by a throughflow monolith (flow-through monolith) which is preferably provided with a catalytically active function. Both components have the same storage functions for gaseous substances present in the exhaust gas of internal combustion engines. The system is suitable in particular for the simultaneous removal of particles and pollutants from the exhaust gas of both predominantly lean-operated internal combustion engines and also of internal combustion engines operated predominantly with a stoichiometric air/fuel mixture. Likewise described is a process for the production and the use of such a system for exhaust-gas aftertreatment.

Abstract: A nitrogen oxide storage catalyst is provided, which has two catalytically active coatings on a support body. The lower coating applied directly to the support body has a nitrogen oxide storage function and includes platinum as a catalytically active component applied to a homogeneous magnesium-aluminum mixed oxide in combination with a nitrogen oxide storage material, in which a nitrogen oxide storage component is likewise present and applied to a homogeneous magnesium-aluminum mixed oxide. The second layer is notable for three-way catalytic activity, and includes palladium applied to aluminum oxide and barium oxide or strontium oxide, but no platinum.

Abstract: Nitrogen oxide storage catalysts are used to remove the nitrogen oxides present in the lean exhaust gas of lean-burn engines. As a result of the stress due to high temperatures in vehicle operation, they are subject to thermal aging processes which affect both the nitrogen oxide storage components and the noble metals present as catalytically active components. The present invention provides a process with which the catalytic activity of a nitrogen oxide storage catalyst which comprises, in addition to platinum as a catalytically active component, basic compounds of strontium and/or barium on a support material comprising cerium oxide, said catalytic activity being lost owing to the thermal aging process, can be at least partly restored. The two-stage process is based on the fact that strontium and/or barium compounds formed during the thermal aging with the support material, which also comprise platinum, are recycled to the catalytically active forms by controlled treatment with specific gas mixtures.