A dual-layer catalyst includes a substrate, a first layer disposed on the substrate, and a second layer disposed on the first layer. The first layer includes a first catalyst for storing NO.sub.x when the first catalyst has a temperature below an active temperature of a second catalyst. The first catalyst is to release the stored NO.sub.x when the first catalyst is heated to the active temperature of the second catalyst. The second layer includes the second catalyst for ammonia Selective Catalytic Reduction of the released NO.sub.x. The dual-layer catalyst is to be included in a catalytic converter and a catalyst system for reducing NO.sub.x emissions from a diesel engine, the NO.sub.x emissions including NO.sub.x emitted during a predetermined cold-start time period.

A dual-layer catalyst includes a substrate, a first layer disposed on the substrate, and a second layer disposed on the first layer. The first layer includes a first catalyst for storing NO.sub.x when the first catalyst has a temperature below an active temperature of a second catalyst. The first catalyst is to release the stored NO.sub.x when the first catalyst is heated to the active temperature of the second catalyst. The second layer includes the second catalyst for ammonia Selective Catalytic Reduction of the released NO.sub.x. The dual-layer catalyst is to be included in a catalytic converter and a catalyst system for reducing NO.sub.x emissions from a diesel engine, the NO.sub.x emissions including NO.sub.x emitted during a predetermined cold-start time period.

The present invention relates to the processing of hydrocarbon-containing feedstreams in the presence of an interstitial metal hydride comprised of at least one chemical element selected from Groups 3-11 (including the lanthanides, atomic numbers 58 to 71), and at least one chemical element selected from Groups 13-15 from the IUPAC Periodic Table of Elements. These interstitial metal hydrides, their catalysts and processes using these interstitial metal hydrides and catalysts of the present invention improve overall hydrogenation, product conversion, as well as sulfur reduction in hydrocarbon feedstreams.

To be able to produce an SCR catalyst (2), in particular one having a zeolite fraction (Z) as catalytically active fraction, in a reliable process and at the same time achieve good catalytic activity of the catalyst (2), an inorganic binder fraction (B) which is catalytically inactive in the starting state and has been treated to develop catalytic activity is mixed into a catalyst composition (4). The inorganic binder component for the binder fraction (B) is, in the starting state, preferably porous particles (10), in particular diatomaceous earth, which display mesoporosity. To effect catalytic activation, the individual particles (10) are either coated with a catalytically active layer (12) or transformed into a catalytically active zeolite (14) with maintenance of the mesoporosity.

There are provided a catalyst composition for producing hydrocarbons and a method for producing hydrocarbons which exhibit a high CO conversion rate, generates minimal amount of gaseous components, and is also capable of efficiently obtaining, from a syngas, a gasoline fraction which is selective for and rich in the components having a high octane number, such as aromatic, naphthenic, olefinic and branched paraffinic hydrocarbons, by using a Fischer-Tropsch synthesis catalyst that contains at least one type of metal exhibiting activity in Fischer-Tropsch reaction and manganese carbonate and a zeolite serving as a solid acid.

There are provided a catalyst composition for producing hydrocarbons and a method for producing hydrocarbons which exhibit a high CO conversion rate, generates minimal amount of gaseous components, and is also capable of efficiently obtaining, from a syngas, a gasoline fraction which is selective for and rich in the components having a high octane number, such as aromatic, naphthenic, olefinic and branched paraffinic hydrocarbons, by using a Fischer-Tropsch synthesis catalyst that contains at least one type of metal exhibiting activity in Fischer-Tropsch reaction and manganese carbonate and a zeolite serving as a solid acid.

A cold start catalyst is disclosed. The cold start catalyst comprises a zeolite catalyst and a supported platinum group metal catalyst. The zeolite catalyst comprises a base metal, a noble metal, and a zeolite. The supported platinum group metal catalyst comprises one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the cold start catalyst. The cold start catalyst and the process result in improved NO.sub.x storage and NO.sub.x conversion, improved hydrocarbon storage and conversion, and improved CO oxidation through the cold start period.

Unique SCR catalyst including multiple washcoat formulations with differing performance characteristics are disclosed. One exemplary embodiment is an apparatus including a catalyst substrate defining a plurality of flow channels leading from an inlet to an outlet, a first washcoat composition distributed over a first portion of the flow channels, and a second washcoat composition distributed over a second portion of the flow channels. The first washcoat composition has a lower ammonia storage density than the second washcoat composition.

Unique SCR catalyst including multiple washcoat formulations with differing performance characteristics are disclosed. One exemplary embodiment is an apparatus including a catalyst substrate defining a plurality of flow channels leading from an inlet to an outlet, a first washcoat composition distributed over a first portion of the flow channels, and a second washcoat composition distributed over a second portion of the flow channels. The first washcoat composition has a lower ammonia storage density than the second washcoat composition.

Accordingly, the present invention provides a catalyst composition suitable for converting light naphtha comprising one or more of C5 to C8 carbon atoms to aromatic compounds ranging from C6 to C10 carbon atoms, said catalyst composition comprising: (a) a medium pore size zeolite; (b) 0.1 to 5.0 wt % of zinc; and (c) 0.1 to 5 wt % of gallium. Also, the present invention provides a process for converting light naphtha comprising one or more of C5 to C8 carbon atoms to aromatic compounds ranging from C6 to C10 carbon atoms, said process comprising the step of contacting a feedstock comprising the light naphtha with a catalyst composition comprising (a) a medium pore size zeolite; (b) 0.1 to 5.0 wt % of zinc; and (c) 0.1 to 5 wt % of gallium in presence of carrier gas at temperatures ranging from 400 to 600 C.