The honeycomb structure includes a honeycomb structure body made of a zeolite material containing at least a coarse particle zeolite having a large average particle diameter (coarse zeolite particles). A fine particle zeolite having an average particle diameter smaller than that of the coarse particle zeolite (fine zeolite particles), and an inorganic bonding material, the coarse particle zeolite (the coarse zeolite particles) is a chabazite type zeolite in which an average particle diameter of primary particles is 2 m or more and 6 m or less, and in the fine particle zeolite (the fine zeolite particles), an average particle diameter of primary particles is 0.02 m or more and smaller than 2 m, and in the zeolite material which is comprised the honeycomb structure body, a ratio of a volume of pores having pore diameters of 0.02 to 0.15 m to a volume of all pores is 42% or less.

An exhaust system for the treatment of an exhaust gas comprising a species to be treated, the system comprising: a first gas inlet for providing a flow of exhaust gas; a second gas inlet for providing a flow of heated gas; a plurality of sorbent beds for releasably storing the species; one or more catalysts for decomposing the species; first and second exhaust gas outlets; and a valve system configured to establish independently for each sorbent bed fluid communication in a first or second configuration, wherein: i) in the first configuration the flow of the exhaust gas from the first gas inlet contacts a sorbent bed for storing the species and then passes to the first gas outlet; and ii) in the second configuration the flow of heated gas from the second gas inlet contacts a sorbent bed for releasing the species, passes to one of the one or more catalysts and then passes to the second exhaust gas outlet; wherein the valve system is configured to ensure that at least one sorbent bed is in the first configuration and, preferably at least one other sorbent bed is in the second configuration.

An oxidation catalyst for treating an exhaust gas from a diesel engine, which oxidation catalyst comprises: a first washcoat region comprising platinum (Pt), manganese (Mn) and a first support material; a second washcoat region comprising a platinum group metal (PGM) 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.

A porous ceramic honeycomb body including a substrate of intersecting porous walls forming axial channels extending from a first end face to a second end face. An active portion of the walls include a zeolite catalyst disposed inside pores thereof and/or is comprised of an extruded zeolite and a three way catalyst (TWC) is disposed on wall surfaces of at least a portion of the active portion.

An exhaust system for a compression ignition engine comprising an oxidation catalyst for treating carbon monoxide (CO) and hydrocarbons (HCs) in exhaust gas from the compression ignition engine, wherein the oxidation catalyst comprises: a platinum group metal (PGM) component selected from the group consisting of a platinum (Pt) component, a palladium (Pd) component and a combination thereof; an alkaline earth metal component; a support material comprising a modified alumina incorporating a heteroatom component; and a substrate, wherein the platinum group metal (PGM) component, the alkaline earth metal component and the support material are disposed on the substrate.

The invention provides an automotive catalyst composite that includes a catalytic material on a carrier, the catalytic material including a plurality of core-shell support particles including a core and a shell surrounding the core, wherein the core includes a plurality of particles having a primary particle size distribution d.sub.90 of up to about 5 ?m, wherein the core particles include particles of one or more molecular sieves and optionally particles of one or more refractory metal oxides; and wherein the shell comprises nanoparticles of one or more refractory metal oxides, wherein the nanoparticles have a primary particle size distribution d.sub.90 in the range of about 5 nm to about 1000 nm (1 ?m); and optionally, one or more platinum group metals (PGMs) on the core-shell support. The invention also provides an exhaust gas treatment system and related method of treating exhaust gas utilizing the catalyst composite.

An exhaust gas purifying composition of the present invention contains zeolite that is BEA zeolite having an SiO.sub.2/Al.sub.2O.sub.3 molar ratio of greater than 25 and 600 or less and containing phosphorus. Furthermore, the exhaust gas purifying composition preferably contains zirconium in addition to phosphorus. Furthermore, the zeolite has an SiO.sub.2/Al.sub.2O.sub.3 molar ratio of from 30 to 150. The present invention provides an exhaust gas purifying composition having excellent HC adsorbability for exhaust gas purification in internal combustion engines such as gasoline engines.

Provided is a hydrocarbon reduction catalyst including a carrier including a cerium-zirconium composite oxide, and palladium supported on the carrier, wherein the palladium is included in an amount of about 1 wt % to about 10 wt % based on a total weight of the catalyst.

A porous ceramic honeycomb body including a substrate of intersecting porous walls forming axial channels extending from a first end face to a second end face. An active portion of the walls include a zeolite catalyst disposed inside pores thereof and/or is comprised of an extruded zeolite and a three way catalyst (TWC) is disposed on wall surfaces of at least a portion of the active portion.

The manufacturing method includes a step of mixing a coarse particle zeolite, a fine particle zeolite, and a raw material of an inorganic bonding material to prepare a zeolite raw material; a step of forming the prepared zeolite raw material into a honeycomb shape to prepare a honeycomb formed body; and a step of firing the prepared honeycomb formed body to prepare the honeycomb structure. In the step of preparing the zeolite raw material, as the coarse particle zeolite, a chabazite type zeolite having a specific average particle diameter, the fine particle zeolite having a specific average particle diameter, the raw material of the inorganic bonding material which includes at least basic aluminum lactate is used.