A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end and an outlet end with an axial length L; and a first catalytic region on the substrate; wherein the first catalytic region comprises a first PGM component and a first alumina, wherein the first alumina is doped with a first dopant of at least 5 wt. %, and wherein the first dopant is selected from the group consisting of Zr, Ta, Mo, W, Ti, Nb, and a combination thereof.

Methods and systems are provided for an exhaust aftertreatment arrangement. In one example, a system includes a LNT upstream of an SCR with an oxygen storage component arranged therebetween, and where a rich operation of an engine is limited based on an oxygen load of the oxygen storage component when an exhaust gas temperature is higher than a limit temperature.

Technical solutions are described for limiting exposure of components of an emissions control system to rich exhaust conditions. An example an emissions control system includes an oxygen storage component; and a controller that limits exposure of the oxygen storage component to rich exhaust conditions. The limiting includes determining an air-to-fuel equivalence ratio in exhaust gas in response to an engine receiving a request to generate torque, the request including a displacement of a pedal; determining an amount of oxygen in the exhaust gas based on the air-to-fuel equivalence ratio; determining an oxygen level stored by the oxygen storage component; and if the oxygen level is above a predetermined threshold, lowering a torque generation rate of the engine, which specifies amount of torque generated per unit displacement of the pedal.

An exhaust purification system includes an LAF sensor provided in an exhaust pipe and generates a signal corresponding to an air-fuel ratio of exhaust gas. An upstream catalytic converter is downstream of the LAF sensor and has a catalyst to purify the exhaust gas. An O2 sensor is downstream of the upstream catalytic converter, and generates a signal corresponding to the air-fuel ratio of the exhaust gas. A GPF is downstream of a the O2 sensor and purifies the exhaust gas. An ECU controls an air-fuel mixture in an engine using output signal KACT of the LAF sensor and an output signal VO2 of the O2 sensor such that the air-fuel ratio of exhaust gas flowing into the GPF converges to a target value near the stoichiometric ratio. The GPF has a filter substrate and a downstream TWC supported by a partition of the filter substrate.

An oxygen storage/release material includes: a ceria-zirconia composite oxide porous body that has at least one ordered phase of a pyrochlore phase and a phase, and that has a central pore diameter of 70 nm to 1 m as measured by a mercury penetration method, and in which a cumulative pore volume of pores that each have a pore diameter in the range of 0.5 times to 2 times the central pore diameter is 40% or more of the cumulative pore volume of pores that each have a pore diameter in the range of 10 nm to 10 m as measured by the mercury penetration method.

A NO.sub.x trap catalyst is disclosed. The NO.sub.x trap catalyst comprises a noble metal, a NO.sub.x storage component, a support, and a first ceria-containing material. The first ceria-containing material is pre-aged prior to incorporation into the NOx trap catalyst, and may have a surface area of less than 80 m.sup.2/g. The invention also includes exhaust systems comprising the NO.sub.x trap catalyst, and a method for treating exhaust gas utilizing the NO.sub.x trap catalyst.

A NO.sub.x absorber catalyst for treating an exhaust gas from a lean burn engine. The NO.sub.x absorber catalyst comprises a molecular sieve catalyst comprising a noble metal and a molecular sieve, wherein the molecular sieve contains the noble metal; an oxygen storage material for protecting the molecular sieve catalyst; and a substrate having an inlet end and an outlet end.

Technical solutions are described for limiting exposure of components of an emissions control system to rich exhaust conditions. An example an emissions control system includes an oxygen storage component; and a controller that limits exposure of the oxygen storage component to rich exhaust conditions. The limiting includes determining an air-to-fuel equivalence ratio in exhaust gas in response to an engine receiving a request to generate torque, the request including a displacement of a pedal; determining an amount of oxygen in the exhaust gas based on the air-to-fuel equivalence ratio; determining an oxygen level stored by the oxygen storage component; and if the oxygen level is above a predetermined threshold, lowering a torque generation rate of the engine, which specifies amount of torque generated per unit displacement of the pedal.

A particulate filter (1) is provided having a first wall flow region (2) and a second flow through region (3). The filter is provided with a catalytic washcoat, whereby the filter can be used to remove both particulate matter and harmful gaseous emissions from an exhaust gas stream.

A NO.sub.x trap catalyst is disclosed. The NO.sub.x trap catalyst comprises a noble metal, a NO.sub.x storage component, a support, and a first ceria-containing material. The first ceria-containing material is pre-aged prior to incorporation into the NOx trap catalyst, and may have a surface area of less than 80 m.sup.2/g. The invention also includes exhaust systems comprising the NO.sub.x trap catalyst, and a method for treating exhaust gas utilizing the NO.sub.x trap catalyst.