An oxidation catalyst includes cerium dioxide particles and a metal oxide. The cerium dioxide particles contain an ancillary component that is at least one of lanthanum, aluminum, and iron. The metal oxide contains iron and manganese and is held by the cerium dioxide particles.

An after treatment system is disclosed. The after treatment system may include an exhaust pipe through which an exhaust gas flows; a three-way catalyst (TWC) mounted on the exhaust pipe and purifying HC, CO, and NOx contained in the exhaust gas, an ammonia production catalyst (APC) mounted on the exhaust pipe at a downstream of the TWC, storing NOx at a lean air/fuel ratio, and generating H.sub.2, releasing the stored NOx, and generating NH.sub.3 using the released NOx and the generated H.sub.2 at a rich air/fuel ratio, and a selective catalytic reduction (SCR) catalyst mounted on the exhaust pipe at a downstream of the APC, storing the NH.sub.3 generated in the TWC and the APC, and reducing the NOx contained in the exhaust gas using the stored NH.sub.3.

A reductant generator includes a housing defining a chamber, an inlet to direct engine exhaust gas into the chamber, a moveable member that receives driving input from an engine and which is configured to compress engine exhaust gases within the chamber, and a supply to provide a fluid into the chamber to be transformed into reductant. The generator also includes an outlet from which the reductant is directed into an exhaust system.

An exhaust aftertreatment system for use with an automotive diesel engine, the system includes a selective catalytic reduction unit a reagent storage tank, and a reagent distribution system. A reagent fluid is stored in the reagent storage tank. The reagent is delivered to exhaust gases produced by the engine using the reagent distributor. The selective catalytic reduction unit is positioned downstream of the reagent distributor and is configured to remove effluents from the exhaust gases.

A computer-implemented method for detecting and reducing the amount of urea crystals in an exhaust aftertreatment system including at least one NOx sensor upstream of a urea injector is provided, The method includes: acquiring measurement values from the NOx-sensor; determining lambda values associated with the measurement values, wherein a lambda value being indicative of a ratio between an amount of air and an amount of fuel in a combustion chamber of an engine connected to the exhaust aftertreatment system; determining at least one ratio between the measurement values and the inverse of the determined lambda values, when the ratio between the measurement values and an inverse of the determined lambda values is equal to or exceeds a threshold, using a NOx engine emissions model for urea dosing control in the exhaust aftertreatment system.

An exhaust aftertreatment system for use with an automotive diesel engine, the system includes a selective catalytic reduction unit a reagent storage tank, and a reagent distribution system. A reagent fluid is stored in the reagent storage tank. The reagent is delivered to exhaust gases produced by the engine using the reagent distributor. The selective catalytic reduction unit is positioned downstream of the reagent distributor and is configured to remove effluents from the exhaust gases.

An exhaust component assembly includes a first exhaust component extending along a first axis, a second exhaust component extending along a second axis, and a mixer having a mixer inlet portion connected to an outlet from the first exhaust component and a mixer outlet portion connected to an inlet to the second exhaust component. A flexible connection couples the mixer inlet portion to the mixer outlet portion.

An over-the-road vehicle including an engine unit and an engine-integrated exhaust treatment system is disclosed. The engine-integrated exhaust treatment system can selectively reduce nitrous oxides (NOx) in exhaust gases from the engine unit. The engine-integrated exhaust treatment system includes a reagent doser integrated into the engine unit and a catalyst in fluid communication with the engine unit. The reagent doser injects aqueous urea solution into at least one cylinder of the engine unit without fuel while fuel is injected into at least one other cylinder of the engine unit for combustion. The aqueous urea solution is converted in the cylinder to ammonia gas that is mixed with exhaust gases from the other cylinders. This mixture is then exposed to the catalyst to encourage reduction of NOx in the exhaust gases before they are discharged to atmosphere.

An over-the-road vehicle including an engine unit and an engine-integrated exhaust treatment system is disclosed. The engine-integrated exhaust treatment system can selectively reduce nitrous oxides (NOx) in exhaust gases from the engine unit. The engine-integrated exhaust treatment system includes a reagent doser integrated into the engine unit and a catalyst in fluid communication with the engine unit. The reagent doser injects aqueous urea solution into at least one cylinder of the engine unit without fuel while fuel is injected into at least one other cylinder of the engine unit for combustion. The aqueous urea solution is converted in the cylinder to ammonia gas that is mixed with exhaust gases from the other cylinders. This mixture is then exposed to the catalyst to encourage reduction of NOx in the exhaust gases before they are discharged to atmosphere.

An NH.sub.3 supply amount controller reduces and adjusts a supply amount of NH.sub.3 to an SCR catalyst by an NH.sub.3 supplier, when an exhaust gas flowing into an NO.sub.X catalyst has a rich air-fuel ratio and NO.sub.X occluded by the NO.sub.X catalyst is reduced to N.sub.2. A reduction amount of the supply amount of the NH.sub.3 controlled by the NH.sub.3 supply amount controller is set smaller when a temperature of the NO.sub.X catalyst detected or estimated by an NO.sub.X catalyst temperature detector is higher.