Provided is an exhaust gas purifying device of an internal-combustion engine, and a method of manufacturing the same, with which it is possible for a honeycomb carrier to be held securely within a case member using a low-cost, simple structure. The exhaust gas purifying device is provided with: a columnar honeycomb carrier 11 in which a plurality of cells which extend from an exhaust gas inflow side to an outflow side, and which serve as exhaust gas flow paths, are demarcated and famed by means of porous separating walls; a three-way catalyst supported in the honeycomb carrier 11; and a cylindrical case member 12 in which the honeycomb carrier 11 is housed, with the interposition of a retaining member 13. The honeycomb carrier 11 is provided with outer circumferential plugging portions 111a and 111b formed in such a way as to plug, to a prescribed depth, openings Ca and Cb of cells in an outer circumferential portion P of at least one end surface of the two end surfaces, in the central axis X-direction, of the honeycomb carrier 11; and inclined portions 112a and 112b formed in a direction whereby the length, in the central axis X-direction, of the outer circumferential plugging portions 111a and 111b decreases toward the outer circumferential edge. Further, the inclined portions 112a and 112b catch on the inner walls of the case member 12, with the interposition of the retaining member 13, thereby retaining the honeycomb carrier 11 in the case member 12.

The present disclosure generally relates to emission control catalyst articles comprising a platinum group metal (PGM) enriched zone, methods of making such emission control catalyst articles, and methods of using such emission control catalyst articles.

The presently invention provides an emission control catalyst article comprising a substrate, a bottom washcoat layer comprising a platinum group metal coated on the 60 to 100% length of the substrate, and a top washcoat layer comprising a platinum group metal coated on the 60 to 100% length of the substrate such that the top coat covers at least 60% of the length of the bottom washcoat layer, wherein at least a portion of the top washcoat layer, the bottom washcoat layer or both washcoat layers comprises a platinum group metal deposited within the said washcoat layer(s) with a platinum group metal gradient such that the PGM concentration in a top-most portion of the said washcoat layer is at least two time higher compared to the PGM concentration in a bottom-most portion of the said washcoat layer.

An exhaust gas purification device of the present invention is provided with: a substrate of wall flow structure having an inlet cell, an outlet cell and a porous partition wall; an upstream catalyst layer, provided inside the partition wall and disposed in an upstream portion of the substrate including an exhaust gas inflow end section; and a downstream catalyst layer, provided inside the partition wall and disposed in a downstream portion of the substrate including an exhaust gas outflow end section. The upstream catalyst layer and the downstream catalyst layer each contain a carrier and at least one noble metal from among Pt, Pd and Rh, supported on the carrier. The noble metal in the upstream catalyst layer and the noble metal in the downstream catalyst layer are different from each other.

A catalytic aftertreatment system for a diesel engine exhaust gas is described. The system comprises a diesel oxidation catalyst (DOC) and an aftertreatment device located downstream of the diesel oxidation catalyst (DOC), which aftertreatment device requires periodic heat treatment, and means to generate a temperature increase within the aftertreatment device, said diesel oxidation catalyst (DOC) comprising an upstream zone of length from 0.5 to 2 inches (12.7-50.81 mm) of higher oxidation activity for hydrocarbons (HC) than the remainder of the diesel oxidation catalyst (DOC).

An oxidation catalyst may include hydrocarbon storage material. One implementation relates to a diesel oxidation catalyst that includes a catalyst having a front zone and a rear zone and a gradient of hydrocarbon storage material on the catalyst extending from the front zone to the rear zone. The gradient of hydrocarbon storage material, may comprise a linear gradient, a step gradient, a parabolic gradient, a logarithmic gradient, or other forms thereof.

An exhaust-gas purification apparatus includes: a honeycomb base material including a plurality of exhaust-gas flow paths partitioned by a porous wall; and one or more catalyst noble metals carried by the honeycomb base material. The catalyst noble metals are selected from the group consisting of platinum, palladium, and rhodium. The honeycomb base material has a noble metal concentrated surface section in which a 50%-by-mass noble metal carry depth for a specific noble metal that is one type among one or two catalyst noble metals is less than 50% of the distance from the surface to the center of the inside of the porous wall. The 50%-by-mass noble metal carry depth is the depth at which, when the amount of the specific noble metal carried between the surface and the center of the inside of porous wall is used as a reference, 50% by mass of specific noble metal is carried.

Certain selective catalytic reduction (SCR) articles, systems and methods provide for high NOx conversion while at the same time low N.sub.2O formation. The articles, systems and methods are suitable for instance for the treatment of exhaust gas of diesel engines. Certain articles have zoned coatings containing copper-containing molecular sieves disposed thereon, where for example a concentration of catalytic copper in an upstream zone is lower than the concentration of catalytic copper in a downstream zone.

An exhaust gas purification catalyst device having a substrate and one or more catalytic noble metals supported on the substrate. The substrate has a plurality of cells partitioned by a porous wall 1 and includes ceria-zirconia compound oxide particles. A specific noble metal that is one of the one or more catalytic noble metals satisfies both the following requirements (1) and (2): (1) the noble metal 50% support depth for the specific noble metal is 30% or less of the distance from the surface of the porous wall 1 to the center of the interior of the porous wall 1, and (2) the noble metal 90% support depth for the specific noble metal is 35% or more of the distance from the surface of the porous wall 1 to the center of the interior of the porous wall 1.

The present invention relates to a honeycomb catalytic converter including: a honeycomb structured body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween; and a noble metal supported on the honeycomb structured body, wherein the honeycomb structured body contains a ceria-zirconia complex oxide and alumina, each partition wall includes a first carrier layer defining a surface layer of the partition wall and carrying Pd, and a second carrier layer located more inwardly of the partition wall than the first carrier layer and carrying Rh.