A NO.sub.x adsorber catalyst composition, a NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst composition a support material and one or more platinum group metals disposed on the support material, wherein the support material comprises a NO.sub.x storage enhancer.

The present disclosure relates to a substrate containing passive NO.sub.x adsorption (PNA) materials for treatment of gases, and washcoats for use in preparing such a substrate. Also provided are methods of preparation of the PNA materials, as well as methods of preparation of the substrate containing the PNA materials. More specifically, the present disclosure relates to a coated substrate containing PNA materials for PNA systems, useful in the treatment of exhaust gases. Also disclosed are exhaust treatment systems, and vehicles, such as diesel or gasoline vehicles, particularly light-duty diesel or gasoline vehicles, using catalytic converters and exhaust treatment systems using the coated substrates.

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 exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway that receives exhaust gas from the engine, a temperature sensor configured to generate a temperature signal associated with a temperature of the exhaust gas at a position along the exhaust gas pathway, and a reductant source. The system also includes first and second injectors in fluid communication with the reductant source. The first and second injectors are configured to inject reductant into the exhaust gas pathway at first and second rates. The system also includes a first treatment element positioned downstream of the first injector and within the exhaust gas pathway, and a controller in communication with the temperature sensor. The controller is configured to receive the temperature signal from the temperature sensor and adjust at least one of the first rate or the second rate based at least in part on the temperature signal.

The present disclosure provides an exhaust gas purification catalyst having improved performance for purifying an exhaust gas, in particular, an exhaust gas containing NOx. The exhaust gas purification catalyst of the present disclosure includes Rh-supporting composite oxide support particles containing Al, Zr, and Ti and Rh-supporting aluminum phosphate-based support particles. Furthermore, in the exhaust gas purification catalyst of the present disclosure, the ratio of the moles of metals constituting the aluminum phosphate-based support particles, relative to the total moles of metals constituting the composite oxide support particles and the aluminum phosphate-based support particles is 7.5% or more and 15.0% or less.

The present invention relates to a catalyst for decomposition of nitrous oxide and also to its method of preparation and use.

An oxidation catalyst is described for treating an exhaust gas produced by a diesel engine. The oxidation catalyst comprises a washcoat region disposed on a substrate, wherein the washcoat region comprises a mixture of: platinum (Pt) supported on a first support material; and ruthenium (Ru).

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.

An ammonia slip catalyst (ASC) comprising a first SCR catalyst, an oxidation catalyst comprising ruthenium or a Ru mixture, such as a Pt and Ru mixture, on a support comprising a rutile phase and a substrate is described. In some configurations, the ASC comprises a second oxidation catalyst. In other configurations, the ASC comprises a second oxidation catalyst and a third oxidation catalyst. The ASC's are useful for selective catalytic reduction (SCR) of NOx in exhaust gases and in reducing the amount of ammonia slip. Methods for producing such articles are described. Methods of using the ammonia slip catalyst in an SCR process, where the amount of ammonia slip is reduced, are also described.

Phosphorus tolerant or resistant three-way catalysts (TWC) are disclosed. The TWC may include a substrate defining a plurality of channels. It may include front and rear washcoat portions overlying the substrate and having respective first and second washcoat loadings, the first washcoat loading being at most 2.0 g/in.sup.3 and less than the second washcoat loading. The front washcoat portion may include a catalyst material supported on a support material comprising a cerium oxide, such as ceria or CZO, or a pre-phosphated material, such as AlPO.sub.4, or CePO.sub.4. In one embodiment, the support material may comprise at least 85 wt. % of a cerium oxide or at least 85 wt. % of a phosphate-containing material. The front portion and the underlying substrate may comprise from 3 to 25 vol. % of the three-way catalyst or the front portion may overly up to an initial 15% of an axial length of the substrate.