A exhaust gas purification apparatus is provided with: a substrate having a wall-flow structure and including entry-side cells, exit-side cells, and a porous partition; a first catalyst region formed in small diameter pores having relatively small pore diameters among internal pores in the partition; and a second catalyst region formed in large diameter pores having relatively large pore diameters among the internal pores in the partition. The first catalyst region contains a support and any one or two species of precious metal selected from Pt, Pd, and Rh loaded on the support, while the second catalyst region contains a support and any one or two species of precious metal selected from Pt, Pd, and Rh loaded on the support and other than at least the precious metal present in the first catalyst region.

There is provided an exhaust system for the treatment of a humid exhaust gas comprising ammonia in an amount of up to 250 ppm, the system comprising: a dehumidifier system comprising a humid air inlet for providing a flow of humid exhaust gas; an exhaust gas inlet for providing a flow of dehumidified exhaust gas; an ammonia storage material arranged to receive the dehumidified exhaust gas from the exhaust gas inlet; an ammonia oxidation catalyst arranged downstream of a selected portion of the ammonia storage material; and a heating device for heating gas before it passes through the selected portion of the ammonia storage material to release ammonia stored therein for treatment on the ammonia oxidation catalyst; wherein the system is configured so that the selected portion of the ammonia storage material changes over time; and wherein the flow of dehumidified exhaust gas provided by the exhaust gas inlet is received from the dehumidifier system.

The present disclosure provides SCR catalyst compositions capable of reducing nitrogen oxide (NO.sub.x) emissions in engine exhaust. The catalyst compositions include a reducible metal oxide support containing ceria, one or more transition metal oxides as a redox promotor; and an oxide of niobium, tungsten, silicon, molybdenum, or a combination thereof as an acidic promotor. The redox promotor and the acid promotor are both supported on the reducible metal oxide support. Further provided are SCR catalyst articles coated with such compositions, processes for preparing such catalyst compositions and articles, an exhaust gas treatment system including such catalyst articles, and methods for reducing NO.sub.x in an exhaust gas stream using such catalyst articles and systems.

A selective catalytic reduction catalyst for the treatment of an exhaust gas stream of a passive ignition engine, the catalyst comprising a porous wall-flow filter substrate comprising an inlet end, an outlet end, a substrate axial length (w) extending between the inlet end and the outlet end, and a plurality of passages defined by porous internal walls of the porous wall flow filter substrate; wherein the catalyst further comprises a first coating, said first coating extending over x % of the substrate axial length from the inlet end toward the outlet end of the substrate, x being in the range of from 10 to 100, wherein the first coating comprises copper and an 8-membered ring pore zeolitic material; wherein the catalyst further comprises a second coating, the second coating extending over y % of the substrate axial length from the outlet end toward the inlet end of the substrate, y being in the range of from 20 to 90, wherein the second coating comprises copper, and optionally an 8-membered ring pore zeolitic material; wherein the catalyst optionally further comprises a third coating; wherein x+y is at least 90; wherein y % of w from the outlet end toward the inlet end of the substrate define the outlet zone of the coated substrate and (100−y) % of w from the inlet end toward the outlet end of the substrate define the inlet zone of the coated substrate; wherein the ratio of the loading of copper in the inlet zone, Cu(in), calculated as CuO, relative to the loading of copper in the outlet zone, Cu(out), calculated as CuO, Cu(in):Cu(out), is less than 1:1.

A catalytic composition for treating a NOx-containing exhaust gas, wherein the composition comprises a copper-substituted zeolite comprising: i) Ce in a total amount of about 0.1 to about 200 g/ft.sup.3; and ii) Mn in a total amount of about 0.1 to about 200 g/ft.sup.3.

The present disclosure is directed to an emission treatment system for NO.sub.x abatement in an exhaust stream of an ammonia-fueled engine, the emission treatment system including a selective catalytic reduction (SCR) catalyst disposed on a substrate in fluid communication with the exhaust stream, an oxidation catalyst disposed on a substrate positioned either upstream or downstream of the SCR catalyst and in fluid communication with the exhaust stream and the SCR catalyst, and optionally, one or more adsorption components disposed on a substrate positioned upstream and/or downstream of the SCR catalyst and in fluid communication with the exhaust stream and the SCR catalyst, the adsorption component chosen from low temperature NO.sub.x adsorbers (LT-NA), low temperature ammonia adsorbers (LT-AA), low temperature water vapor adsorbers (LT-WA), and combinations thereof. The disclosure further provides a related method of treatment of an exhaust gas.

Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NH.sub.3 that is stored in a SCR. The amount of NH.sub.3 that is stored in the SCR is a basis for generating additional NH.sub.3 or ceasing generation of NH.sub.3.

A method for preconditioning at least a part of an engine system of a vehicle. The engine system includes an engine and an exhaust aftertreatment system, EATS. The method providing predicted vehicle operational information comprising a vehicle operational initialization time and predicted engine operation, determining whether or not cold-start emissions of the predicted engine operation achieves a threshold criterium, in response to achieving the threshold criterium, preconditioning at least a part of the engine system such that at least said part of the engine system is preconditioned at a time of the vehicle operational initialization time.

An exhaust aftertreatment system, EATS, for converting NOx emissions in exhaust gases from an engine. The EATS includes a fluid channel for providing a fluid pathway for the exhaust gases; a selective catalytic reduction, SCR, catalyst arranged in the fluid channel, the SCR catalyst being configured to store ammonia; an injector configured to inject a reductant for providing ammonia to the SCR catalyst, the injector being arranged upstream of the SCR catalyst; a fluid flow inducer configured to cause an induced fluid flow in at least a part of the fluid channel when the engine is turned off; and a controlling apparatus configured to precondition the EATS prior to engine start by injecting the reductant into the fluid channel, and transport the reductant into the SCR catalyst by the induced fluid flow to store ammonia in the SCR catalyst.

The present invention relates to a catalyst for the selective catalytic reduction of nitrogen oxide, the catalyst comprising a first coating comprising a 12-membered ring pore zeolitic material comprising a first metal which is one or more of copper and iron, and a second coating comprising an 8-membered ring pore zeolitic material comprising a second metal which is one or more of copper and iron.