An exhaust system for the aftertreatment of exhaust gases of an internal combustion engine, having, in series as viewed in a flow direction of the exhaust gas, a catalyst for the oxidation of the exhaust gas and/or a catalyst for storing nitrogen oxides, having an introduction point for the feed of a reducing agent, having an SCR catalyst for the selective catalytic reduction of nitrogen oxides, and having a particle filter, wherein the particle filter is arranged downstream of the SCR catalyst in the flow direction, and a second SCR catalyst and/or an ammonia slippage catalyst is arranged downstream of the particle filter in the flow direction.

A honeycomb structure has partition walls defining a plurality of polygonal cells which become through channels for a fluid, a structure end face vertical to an axial direction has at least two cell regions possessing mutually different cell structures and surrounded by circumferential portions, and in the cell regions adjacent to each other, to first partition walls of a first cell structure of one first cell region, second partition walls of a second cell structure of the other or second cell region are tilted.

An exhaust gas purification system for an engine includes an exhaust passage extending from the combustion chambers of the engine, and an exhaust purifying unit disposed in the exhaust passage and configured to purify exhaust gas in the exhaust passage. The exhaust purifying unit includes a carrier disposed in the exhaust passage, a first purifier having at least a function of oxidizing components in the exhaust gas. The first purifier covers, as an underlayer, an outer surface of the carrier, and a second purifier having a function of purifying the exhaust gas by reducing, using occluded ammonia, the components in the exhaust gas that have been oxidized in the first purifier. The second purifier includes a superposed portion covering, as an upper layer, an outer surface of the first purifier.

A honeycomb body having intersecting porous walls which includes first through fourth cells, wherein the cells extend from inlet to outlet face and are plugged to define a repeating structural unit with three inlets and one outlet channel. Repeating structural unit includes a first channel including length L.sub.1, width W.sub.2, and area A.sub.1, a second channel including length L.sub.2, the width W.sub.2, and area A.sub.2, a third channel including the length L.sub.1, width W.sub.1, and area A.sub.3, and a fourth channel including the length L.sub.2, the width W.sub.1, and A.sub.4, wherein the first through third channels are inlets and the fourth channel is a rectangular outlet and at least one of W.sub.1>W.sub.2 and L.sub.1L.sub.2, i.e. W.sub.1>W.sub.2, or L.sub.1L.sub.2, or W.sub.1>W.sub.2 and L.sub.1L.sub.2. Repeating structural unit has a quadrilateral outer perimeter. Particulate filters including the honeycomb body, honeycomb extrusion dies, and methods of manufacturing the honeycomb body are provided.

An emissions control substrate. The emissions control substrate includes a first end in receipt of exhaust from an engine, and a second end from which exhaust exits the substrate. The second end is opposite to the first end. A plurality of channels are defined by sidewalls. The channels are arranged between the first end and the second end to direct exhaust from the engine through the emissions control substrate. The sidewalls at least one of filter and treat exhaust particulates as the exhaust passes through the sidewalls. The plurality of channels include at least one first channel defined by sidewalls that curve inward along lengths thereof from the first end to the second end.

An exhaust gas purification system, which includes an engine and an exhaust pipe that is connected to an exhaust manifold of the engine, includes: a catalyst converter disposed at a rear side the engine on the exhaust pipe; a selective catalytic reduction on diesel particulate filter (SDPF) disposed at a rear side of the catalyst converter on the exhaust pipe; a reducing agent injector disposed between the catalyst converter and the SDPF on the exhaust pipe and injecting a reducing agent; and a controller controlling an amount of the reducing agent injected from the reducing agent injector.

A honeycomb structure body has main cells having a tubular shape and main cell walls. Each main cell is surrounded by the main cell walls. A virtual base structure body has base cell walls and base cells. The honeycomb structure body has an improved structure obtained by modifying a structure of the virtual base structure body. Each base intersecting point, at which base cell walls intersect, is determined by a polar coordinate (r, ) using a radius vector r and a deflection angle . Each main intersecting point is formed on a polar coordinate (r, ) using the deflection angle and a main radius vector r which is obtained by multiplying the radius vector r and a constant magnification without changing the deflection angle . A cell density varying section varies its cell density and is formed in at least a part of the honeycomb structure body.

A honeycomb structure has partition walls defining a plurality of hexagonal cells the partition walls are constituted by combining standard partition walls having a partition wall thickness in a range smaller than 10% to an average partition wall thickness of the partition walls, wide partition walls having a partition wall thickness of +10% or more to the average partition wall thickness, and narrow partition walls having a partition wall thickness of 10% or less to the average partition wall thickness, and a non-standard partition wall ratio is in a range of 10% to 30% which is a ratio occupied by a subtotal number of non-standard partition walls obtained by adding the wide partition walls and the narrow partition walls in a total number of the partition walls which is obtained by adding the numbers of the standard partition walls, the wide partition walls and the narrow partition walls.

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: bismuth (Bi), antimony (Sb) or an oxide thereof; 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; wherein the platinum group metal (PGM) is supported on the support material; and wherein the bismuth (Bi), antimony (Sb) or an oxide thereof is supported on the support material and/or the refractory oxide comprises the bismuth, antimony or an oxide thereof.

A catalyst article for treating a flow of a combustion exhaust gas comprises: a catalytically active substrate comprising one or more channels extending along an axial length thereof through which, in use, a combustion exhaust gas flows, the one or more channels having a first surface for contacting a flow of combustion exhaust gas; wherein the substrate is formed of an extruded vanadium-containing SCR catalyst material, wherein a first layer is disposed on at least a portion of the first surface, wherein the first layer comprises a washcoat of an ammonia slip catalyst composition comprising one or more platinum group metals supported on a particulate metal oxide support material, and wherein a layer comprising a washcoat of SCR catalyst composition is disposed on a surface in the one or more channels, wherein at least the portion of the first surface on which the first layer is disposed comprises a compound of copper, iron, cerium or zirconium or a mixture of any two or more thereof.