The present disclosure is directed to an emission treatment system for NO.sub.x abatement in an exhaust stream of a lean burn engine. The emission treatment system includes a lean NO.sub.x trap (LNT) in fluid communication with and downstream from the lean burn engine and a low-temperature NO.sub.x adsorber (LT-NA) in fluid communication with and downstream of the LNT. Further provided is a method for abating NO.sub.x in an exhaust stream from a lean burn engine utilizing the disclosed system.

An exhaust-gas purification system and method are provided for an internal combustion engine having an NOx storage catalytic converter and a downstream SCR catalytic converter. The NOx storage catalytic converter can be supplied in a first operating mode with an oxidizing exhaust gas and in a second operating mode with a reducing exhaust gas. A third operating mode is provided between the first operating mode and the second operating mode, in which an exhaust gas which has a lower content of oxidizing constituents than the first operating mode and a lower content of reducing constituents than the second operating mode can be supplied to the NOx storage catalytic converter to improve NH.sub.3 production at the start of converter regeneration.

The present disclosure relates to a method of compacting an ash deposited in a particulate filter for a vehicle exhaust gas system, the method includes the steps of: a) providing a low-temperature melting salt to the particulate filter, thereby forming a mixture of the ash and the low-temperature melting salt: and b) heating the particulate filter to a compaction temperature, thereby compacting the mixture of the ash and the low-temperature melting salt. The disclosure further relates to engine oils, dosage products, engine systems and vehicles for implementing such a method.

A catalyst article including a substrate with an inlet side and an outlet side, a first zone and a second zone, where the first zone includes a passive NOx adsorber (PNA), and an ammonia slip catalyst (ASC) comprising a platinum group metal on a support and a first SCR catalyst; where the second zone includes a catalyst selected from the group consisting of a diesel oxidation catalyst (DOC) and a diesel exotherm catalyst (DEC); and where the first zone is located upstream of the second zone. The first zone may include a bottom layer with a blend of: (1) the platinum group metal on a support and (2) the first SCR catalyst; and a top layer with a second SCR catalyst, the top layer located over the bottom layer.

A catalyst article including a substrate with an inlet side and an outlet side, a first zone and a second zone, where the first zone includes a passive NOx adsorber (PNA), and an ammonia slip catalyst (ASC) comprising a platinum group metal on a support and a first SCR catalyst; where the second zone includes a catalyst selected from the group consisting of a diesel oxidation catalyst (DOC) and a diesel exotherm catalyst (DEC); and where the first zone is located upstream of the second zone. The first zone may include a bottom layer with a blend of: (1) the platinum group metal on a support and (2) the first SCR catalyst; and a top layer with a second SCR catalyst, the top layer located over the bottom layer.

Methods and systems are provided for a low temperature NOx adsorber (LTNA). In one example, a method includes initiating a desulfation of an LTNA responsive to an estimated sulfur exposure exceeding a threshold, the desulfation including heating the LTNA to a first threshold temperature while maintaining an exhaust oxygen level above a threshold level throughout the entire desulfation.

A catalyst article including a substrate with an inlet side and an outlet side, a first zone and a second zone, where the first zone includes a passive NOx adsorber (PNA), and an ammonia slip catalyst (ASC) comprising a platinum group metal on a support and a first SCR catalyst; where the second zone includes a catalyst selected from the group consisting of a diesel oxidation catalyst (DOC) and a diesel exotherm catalyst (DEC); and where the first zone is located upstream of the second zone. The first zone may include a bottom layer with a blend of: (1) the platinum group metal on a support and (2) the first SCR catalyst; and a top layer with a second SCR catalyst, the top layer located over the bottom layer.

A system includes an exhaust gas source that provides exhaust gas pollutants and an adsorbent-filled canister downstream of the exhaust gas source and configured to adsorb exhaust gas pollutants. The systems may further include a heat exchanger. A process includes introducing exhaust gas comprising exhaust gas pollutants into a system that includes an adsorbent-filled canister, such that the exhaust gas may flow through the adsorbent-filled canister and the exhaust gas pollutants may be adsorbed into an adsorption media in the adsorbent-filled canister as adsorbed exhaust gas pollutants. A depleted exhaust gas may pass from the adsorbent-filled canister.

Vehicle exhaust system uses delta pressure based estimation of accumulated soot within a diesel particulate filter. The exhaust system has a diesel oxidation catalyst and a diesel particulate filter. A fuel injector is connected upstream from the diesel oxidation catalyst and the diesel particulate filter. A delta pressure sensor measures difference in pressure at inlet and outlet of the diesel particulate filter. A controller determines when to regenerate the diesel particulate filter based on an estimated amount of soot. The controller, in a first regeneration mode, causes the fuel injector to inject fuel at a first rate into the exhaust stream, and to re-evaluate amount of soot accumulated within the diesel particulate filter under increased volumetric flow. The controller, in a second regeneration mode, causes the fuel injector to inject fuel at a second rate into the exhaust stream in order to combust soot trapped in the diesel particulate filter.

An exhaust system for an internal combustion engine, and methods of using, the system comprising a hydrocarbon trap; and a gasoline particulate filter, located downstream from the hydrocarbon trap.