Provided is a system for treating an exhaust gas comprising a first SCR catalyst zone comprising an iron loaded medium- or large-pore molecular sieve having a first ammonia storage capacity; and a second SCR catalyst zone comprising a copper loaded small-pore molecular sieve having a second ammonia storage capacity, wherein the first SCR catalyst zone is disposed upstream of the second SCR catalyst zone with respect to normal exhaust gas flow through the system and wherein the second ammonia storage capacity is greater than the first ammonia storage capacity. Also provided is a method for using the system to treat exhaust gas.

A control method for improving nitrogen oxide purification performance (NO.sub.x) includes starting NO.sub.x regeneration, comparing first and second lambda values measured at first and second lambda sensors in a control unit, checking the lean NO.sub.x trap (LNT) temperature, and measuring a second time that has elapsed after the first and second lambda values are found to be the same, and checking whether the second time is greater than or equal to a predetermined time when it is observed that the temperature of the LNT is greater than or equal to the predetermined temperature value.

An exhaust gas aftertreatment component includes a ceramic carrier body with a plurality of axial flow channels, wherein the carrier body has an inner region and an outer region, which radially surrounds the inner region. A cell density of the carrier body is smaller in the inner region than a cell density in the outer region. At least the outer region of the carrier body has a coaling, wherein the coating of the outer region has an HC adsorber function for a reversible adsorption of unburnt hydrocarbons. An exhaust gas system, which is equipped with such an exhaust gas aftertreatment component, and a vehicle, which has such an exhaust gas system are also provided.

Systems, apparatus and methods are provided for reducing reductant consumption in an exhaust aftertreatment system that includes a first SCR device and a downstream second SCR device, a first reductant injector upstream of the first SCR device, and a second reductant injector between the first and second SCR devices. NOx conversion occurs with reductant injection by the first reductant injector to the first SCR device in a first temperature range and with reductant injection by the second reductant injector to the second SCR device when the temperature of the first SCR device is above a reductant oxidation conversion threshold.

The catalytic converter of the vehicle includes: an LNT converter including an LNT catalyst to reduce nitrogen oxides; an SDPF converter including an SDPF catalyst to capture particulate matters and reduce the nitrogen oxides; a connection housing connecting the LNT converter and the SDPF converter to each other; an injection module provided in the connection housing to inject the reducing agent from the LNT converter toward the SDPF converter; an impactor atomizing and vaporizing the reducing agent injected from the injection module; a first guide mixer provided inside the connection housing to form a swirl-direction flow of the exhaust gas mixed with the reducing agent atomized through the impactor; and a second guide mixer provided downstream of the first guide mixer inside the connection housing to form an additional swirl-direction flow of the exhaust gas mixed with the reducing agent.

An aftertreatment system of an internal combustion engine is disclosed. The aftertreatment system includes in a sequence along the exhaust pipe, a lean NOx trap and a particulate filter. An air/fuel ratio sensor is located upstream of the lean NOx trap and downstream of the turbine outlet to determine the air/fuel ratio during a regeneration process (DeNOx) in the lean NOx trap. A NOx sensor is located downstream of the lean NOx trap or downstream of the particulate filter, to determine NOx in the exhaust pipe. A turbine temperature is determined in accordance with a first means, and a temperature during a desulphation process (DeSOx) in the lean NOx trap is determined in accordance with a second means. At least one of the first and second means for determining a temperature may be a temperature sensor.

An exhaust gas filter for purifying exhaust gases including particulate matter discharged from an internal combustion engine includes a honeycomb structure whose axial direction matches an exhaust gas flow, a plug portion which selectively plugs upstream end faces of the honeycomb structure which faces the exhaust gas flow, and catalyst carried on the honeycomb structure.

The honeycomb structure has a plurality of partition walls and cells surrounded by the partition walls, and pores formed inside partition walls between adjacent cells communicating with each other. The plurality of the cells have open cells which are penetrated in the axial direction and plugged cells having one upstream end which face the exhaust gas flow plugged by the plug portion. The honeycomb structure has a first region which does not carry the catalyst on the partition walls and a second region which carries the catalyst on the partition walls.

A method for operating an exhaust-gas aftertreatment system arrangement is provided. The method includes in a first operating state, flowing a substantial majority of an exhaust-gas stream from the internal combustion engine through a first NO.sub.x storage catalytic converter positioned in a main exhaust branch of an exhaust aftertreatment system arrangement and in a second operating state, flowing a substantial majority of the exhaust-gas stream through a first bypass branch branching off from the main exhaust branch upstream of the first NO.sub.x storage catalytic converter and which opens into the main exhaust branch downstream of the first NO.sub.x storage catalytic converter and regenerating the first NO.sub.x storage catalytic converter.

A system includes a controller for an exhaust aftertreatment system including a SCR catalyst in exhaust gas-receiving communication with an engine and at least one reductant dosing system structured to provide reductant to the exhaust gas. The controller is structured to determine a ratio of NO to NO.sub.2 at or proximate an inlet of the SCR catalyst. The controller is further structured to command the at least one reductant dosing system to increase, decrease, or maintain an amount of reductant provided to the exhaust gas based on comparing the ratio of NO to NO.sub.2 to a previous NO to NO.sub.2 ratio.

A system includes a controller for an exhaust aftertreatment system including a catalyst. The controller is structured to: receive information indicative of a first characteristic of the exhaust gas at a first time; receive information indicative of a second characteristic of the exhaust gas at a second time after the first time; determine one or more of a concentration of one or more of nitric oxide (NO), nitrogen dioxide (NO2), or a ratio of NO to NO2 at or proximate an inlet of the catalyst; and command at least one reductant dosing system to increase, decrease, or maintain an amount of reductant provided to the exhaust gas based on each of the first characteristic, the second characteristic, and the determination.