Exhaust gas catalysts are disclosed. One exhaust gas catalyst comprises a noble metal and a molecular sieve, and has an infrared spectrum having a characteristic absorption peak from 750 cm.sup.1 to 1050 cm.sup.1 in addition to the absorption peaks for the molecular sieve itself. The exhaust gas catalyst also comprises a noble metal and a molecular sieve, having greater than 5 percent of the noble metal amount located inside pores of the molecular sieve. The exhaust gas catalyst also comprises a first and second molecular sieve catalyst. The first molecular sieve catalyst comprises a first noble metal and a first molecular sieve, and the second molecular sieve catalyst comprises a second noble metal and a second molecular sieve. The first and second molecular sieves are different. The invention also includes exhaust systems comprising the exhaust gas catalysts, and a method for treating exhaust gas utilizing the exhaust gas catalysts.

An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine comprising a catalytic region and a substrate, wherein the catalytic region comprises a catalytic material comprising: a copper (Cu) component; a platinum group metal (PGM) selected from the group consisting of (i) platinum (Pt), (ii) palladium (Pd) and (iii) platinum (Pt) and palladium (Pd); and a support material, which is a refractory oxide comprising alumina; wherein the platinum group metal (PGM) and the copper (Cu) component is each supported on the support material.

The present invention provides a method for treating a used particulate filter, comprising: removing particulates from the particulate filter; and introducing simulated ash into inlet channels of the particulate filter after removing the particulates.

A hydrocarbon adsorbent having high hydrocarbon adsorbing properties even after exposed to a high temperature/high humidity reducing atmosphere, includes a FAU type zeolite having in ESR measurement a spin concentration of a least 1.010{circumflex over ()}19 (spins/g) and a ratio of a peak intensity at a magnetic field of at least 260 mT and at most 270 mT to a peak intensity at a magnetic field of at least 300 mT and at most 320 mT of at least 0.25 and at most 0.50 and containing bivalent copper. The hydrocarbon adsorbent may be used for a method for adsorbing hydrocarbons to be exposed to a high temperature/high humidity environment, and may be used particularly for a method for adsorbing hydrocarbons in an exhaust gas of an internal combustion engine, such as an automobile exhaust gas.

The invention provides an exhaust gas cleaning oxidation catalyst and in particular to an oxidation catalyst for cleaning the exhaust gas discharged from internal combustion engines of compression ignition type (particularly diesel engines). The invention further relates to a catalysed substrate monolith comprising an oxidising catalyst on a substrate monolith for use in treating exhaust gas emitted from a lean-burn internal combustion engine. In particular, the invention relates to a catalysed substrate monolith comprising a first washcoat coating and a second washcoat coating, wherein the second washcoat coating is disposed in a layer above the first washcoat coating.

The present invention relates to a catalyst comprising a carrier substrate of the length L extending between substrate ends a and b and two washcoat zones A and B, wherein washcoat zone A comprises a zeolite having a smallest lower channel width of at least 0.4 nm and extends starting from substrate end a over a part of the length L, and washcoat zone B comprises the same components as washcoat A and palladium and extends from substrate end b over a part of the length L, wherein L=L.sub.A+L.sub.B, wherein L.sub.A is the length of washcoat zone A and L.sub.B is the length of substrate length B.

An exhaust treatment apparatus and method for providing a controlled and well-timed feeding of supplemental oxygen to offset low oxygen content in exhaust flow passing over a desorbing hydrocarbon trap that previously accumulated hydrocarbons during a cold start cycle. Included is an ambient air injection system and associated control unit to offset the lacking oxygen level upstream of a reaction area for a downstream uf-HCT (preferably catalyzed with TWC material) with the exhaust placed in a lean state upon contact with the uf-HCT. An air injection embodiment makes use of preexisting vehicle components as to provide for a minimization of added components to a vehicle, while still addressing the need to clean-up exhaust emissions in an effort to satisfy stringent emission control requirements, such as those set forth in LEVIII.

Methods and systems are featured for reducing harmful exhaust gas components of combustion devices such as gasoline-powered combustion engines (e.g., predominately stoichiometric running engines). The methods and systems include an underbody combination of a hydrocarbon trap (HCT), suited for cold start hydrocarbon adsorption, as well as an associated NOx trap. The system is inclusive of a control unit for extending a lean exhaust condition reaching the desorbing HCT as to avoid a deficiency in oxygen during the time period of HCT desorption. The system is also inclusive of one or more TWCs as in one associated with the underbody HCT-NOx-trap combination and/or one positioned in a close coupled position. Platinum group metals as in Pd, Rh and Pt are also featured on one, two or all three of the HCT, NOx-trap, and TWC when present.

The present invention relates to a catalyst comprising a carrier substrate of the length L extending between substrate ends a and b and a first washcoat zone, which comprises a) a zeolite, b) a redox active base metal compound and c) palladium in oxidic or metallic state which is fixed to the surface of a support oxide.

A nitrogen oxides (NO.sub.x) and hydrocarbon (HC) storage catalyst for treating an exhaust gas flow is provided. The NO.sub.x and HC storage catalyst includes (a) a zeolite, (b) noble metal atoms, and (c) a metal oxide, a non-metal oxide, or a combination thereof. One or more of the noble metal atoms is present in a complex with the metal oxide, the non-metal oxide or a combination thereof. The complex is dispersed within a cage of the zeolite. Methods of preparing the NO.sub.x and HC storage catalyst and methods of using the NO.sub.x and HC storage catalyst for treating an exhaust gas stream flowing from a vehicle internal combustion engine during a period following a cold-start of the engine are also provided.