A method of manufacturing a catalyst article, the method comprising: providing a complex of a polyphenol and a PGM, the PGM comprising rhodium and/or platinum, the polyphenol comprising an ester functional group; providing a support material; applying the complex to the support material to form a loaded support material; disposing the loaded support material on a substrate; and heating the loaded support material to form nanoparticles of the PGM on the support material.

An oxidation catalyst is described for treating hydrocarbons in an exhaust gas produced by an internal combustion engine, wherein the oxidation catalyst comprises a region disposed on a substrate, wherein the region comprises ruthenium (Ru) supported on a support material comprising a refractory oxide.

Systems and methods for an aftertreatment system configured for use with a dual-fuel engine system are described. The method comprises determining an operating mode of the dual-fuel engine. Upon determining that the dual-fuel engine is operating in a dual-fuel mode or a natural gas mode, the dual-fuel engine operates in a stoichiometric operating condition, and the exhaust is received into a three-way catalyst communicatively connected to a selective catalytic reduction catalyst. Upon determining that the dual-fuel engine is not operating in the dual-fuel mode or the natural gas mode, the engine operates in a lean operating condition.

A layered emission control device for an engine system is provided, including a plurality of catalytic layers, the catalytic layers optionally or additionally comprising sublayers, each sublayer having a distinct composition. Advantages of such a device include providing increased treatment rates of one or more engine exhaust gas species over a wide range of engine exhaust operating conditions, while reducing exhaust emissions, and reducing a size of the emissions control system.

An exhaust emission control system of an engine is provided including a NO.sub.x catalyst for oxidizing HC and storing NO.sub.x within exhaust gas when an air-fuel ratio of the exhaust gas is lean, and reducing the NO.sub.x when the air-fuel ratio is approximately stoichiometric or rich. The system includes a SCR catalyst for purifying NO.sub.x by causing a reaction with NH.sub.3, a urea injector, a fuel injection controlling module, and a processor configured to execute a NO.sub.x reduction controlling module for performing a NO.sub.x reduction control to enrich the air-fuel ratio to reach a target ratio. When the urea injection is determined to be abnormal, the NO.sub.x reduction controlling module performs a NH.sub.3-supplied NO.sub.x reduction control in a state where a larger amount of unburned fuel than the amount of unburned fuel in the exhaust passage in the NO.sub.x reduction control is supplied to the exhaust passage.

Methods and systems are provided for an aftertreatment system arranged in a vehicle underbody downstream of close-coupled aftertreatment devices, the aftertreatment system including a first aftertreatment device and a second aftertreatment device adjacent one another. In one example, the first aftertreatment device is a hydrocarbon trap and the second aftertreatment device is a three-way catalyst.

An exhaust gas purification catalyst, excellent in the NOx purification capacity and the HC purification capacity, includes a substrate and a catalyst coating layer formed on the surface of the substrate, wherein the catalyst coating layer comprises the upper and lower layer including a lower layer being closer to the surface of the substrate and an upper layer being relatively remote from the surface of the substrate. The upper layer of the catalyst coating layer includes Rh, Pd, and a carrier. The lower layer of the catalyst coating layer includes at least one noble metal selected from Pd and Pt and a carrier. 65% by mass or more of Pd in the upper layer exists in a layer up to 50% of the upper layer in a thickness direction from the surface of the upper layer being relatively remote from the surface of the substrate. The ratio of Pd to Rh by mass (Pd/Rh) is 0.5 to 7.0 in the upper layer.

An exhaust gas purification catalyst provides excellent removal performance of methane, which is chemically stable. Exhaust gas purification catalyst includes a substrate that divides cells through which an exhaust gas flows and a catalyst layer that is provided on a surface of the substrate. The catalyst layer includes a palladium layer containing palladium that extends from a first end part which is an end part on the side into which an exhaust gas in the cells flows to a second end part which is an end part on the side from which an exhaust gas flows out, a platinum layer containing platinum that extends from the second end part to the first end part, and a rhodium layer containing rhodium that is laminated with both the palladium layer and the platinum layer.

A heat exchanger system for treatment of a flow of exhaust gases in an exhaust gas aftertreatment system of a vehicle. The heat exchanger system includes a nitrogen monoxide (NO) oxidation site for oxidizing nitrogen monoxide to nitrogen dioxide (NO2). The NO oxidation site is positioned such that the flow of exhaust gases at a downstream end (40) of the NO oxidation site in use of the heat exchanger system is arranged to proceed at a temperature within a predetermined temperature interval corresponding to a desired NO to NO2 (NO:NO2) ratio interval in the flow of exhaust gases. An exhaust gas aftertreatment system and a vehicle including such a heat exchanger system, and a method for using such a heat exchanger system, are also provided.

The present invention relates to catalysts for lean burn and provides a catalyst for lean burn that is capable of purifying NO.sub.x sufficiently and that has a high ability to purify CO and HC over a wide temperature range from low to high temperatures. The present invention provides a catalyst for a lean-burn engine to purify exhaust gas, the catalyst including: an integrally structured support; and a catalyst layer containing a precious metal element, provided on the integrally structured support and having at least two layers that include an upper layer and a lower layer; wherein the upper layer of the catalyst layer contains at least a proton-substituted -type zeolite and a ceria-based oxide supporting rhodium, and the lower layer of the catalyst layer contains at least a NO.sub.x storage component and platinum supported on an inorganic oxide.