A lean NO.sub.x trap catalyst and its use in an emission treatment system for internal combustion engines is disclosed. The lean NO.sub.x trap catalyst comprises a first layer and a second layer.

A hydrocarbon trap catalyst and method of forming the same are disclosed. The method may include introducing copper into a zeolite at 10% to 75% of an ion-exchange level of the zeolite, introducing at least one of nickel and manganese into a zeolite at 50% to 100% total of an ion-exchange level of the zeolite, and applying a three-way catalyst layer. The copper and nickel and/or manganese may be introduced into a single zeolite or the copper may be introduced into a first zeolite layer and the nickel and/or manganese may be introduced into a second zeolite layer. If copper and another metal are introduced into the same zeolite, copper may be introduced first. The disclosed trap catalyst may increase the release temperature of hydrocarbons such as ethanol, propylene and toluene, and thus reduce vehicle cold start tailpipe emissions.

A three-way catalyst is disclosed. The three-way catalyst comprises a silver-containing extruded zeolite substrate and a catalyst layer disposed on the silver-containing extruded zeolite substrate. The catalyst layer comprises a supported platinum group metal catalyst comprising one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the three-way catalyst. The three-way catalyst results in improved hydrocarbon storage and conversion, in particular during the cold start period.

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.

It is an object of the present disclosure to provide a YFl-type zeolite with a small difference in desorption starting temperature due to hydrothermal durability treatment, a method for producing the YFl-type zeolite, a hydrocarbon adsorbent containing the YFl-type zeolite and a hydrocarbon adsorption method using the YFl-type zeolite The YFl-type zeolite is characterized in that the ratio of the mass of extra-framework aluminum to the mass of contained aluminum is 0% by mass or more and 28% by mass or less.

An exhaust gas purification catalyst including: a substrate; and an adsorbent portion provided to the substrate and containing a Si-containing adsorbent material. The adsorbent portion includes a plurality of voids, and in a cross section orthogonal to an exhaust gas flow direction, the percentage of a total area of the voids that are present in the adsorbent portion and that each satisfy the expression below is greater than 5% to 30% or less with respect to an apparent area of the adsorbent portion present on the substrate. Expression: L/{2(S)}1.1. (L is a perimeter of the void in the cross section, and S is an area of the void in the cross section.)

An oxidation catalyst composite, methods, and systems for the treatment of exhaust gas emissions from a diesel engine are described. More particularly, an oxidation catalyst composite including a first washcoat layer comprising a Pt component and a Pd component, and a second washcoat layer including a refractory metal oxide support containing manganese, a zeolite, and a platinum component is described.

An emissions treatment system for an exhaust stream of an internal combustion engine including hydrocarbons, carbon monoxide, and nitrogen oxides is provided. The disclosed system can include an exhaust conduit in fluid communication with the internal combustion engine via an exhaust manifold; a first three-way conversion catalyst (TWC-1) located downstream of the internal combustion engine in the exhaust conduit; an SCR-HCT catalyst comprising a selective catalytic reduction catalyst and a hydrocarbon trap downstream of the TWC-1 in the exhaust conduit; and a third catalyst downstream of the SCR-HCT combination in the exhaust conduit, the third catalyst comprising a platinum group metal (PGM) e.g., in an amount effective to oxidize hydrocarbons. Methods of making and using such systems and components thereof are also provided.

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.

An oxidation catalyst for treating an exhaust gas from a diesel engine and an exhaust system comprising the oxidation catalyst are described. The oxidation catalyst comprises: a first washcoat region for oxidising carbon monoxide (CO) and hydrocarbons (HCs), wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material; a second washcoat region for oxidising nitric oxide (NO), wherein the second washcoat region comprises platinum (Pt), manganese (Mn) and a second support material; and a substrate having an inlet end and an outlet end; wherein the second washcoat region is arranged to contact the exhaust gas at the outlet end of the substrate and after contact of the exhaust gas with the first washcoat region.