An object of the present invention is to provide an exhaust gas purification system including a first exhaust gas treatment section provided upstream in an exhaust pathway of an internal-combustion engine, a second exhaust gas treatment section provided upstream in the exhaust pathway of the internal-combustion engine, wherein the exhaust gas purification system allows rhodium element contained in a catalyst layer of the second exhaust gas treatment section to efficiently exhibit the catalytic activity, and the present invention provides an exhaust gas purification system (1) configured to purify exhaust gas emitted from an internal-combustion engine, the exhaust gas purification system (1) including an exhaust gas path (2) through which exhaust gas flows, a first exhaust gas treatment section (3) provided upstream in the exhaust gas path (2), and a second exhaust gas treatment section (4) provided downstream in the exhaust gas path (2); wherein first catalyst layers of the first exhaust gas treatment section (3) each contain cerium element; wherein a percentage of the mass of the cerium element contained in the first catalyst layers in terms of cerium oxide, to the mass of the first catalyst layers, is 5.0% by mass or more and 13.0% by mass or less; and wherein second catalyst layers of the second exhaust gas treatment section (4) each contain rhodium element.

A porous composite includes a porous base material, and a porous collection layer. The collection layer is provided on the base material. The collection layer contains praseodymium oxide.

A plugged honeycomb structure includes intersecting porous walls extending in an axial direction between an inlet end and an outlet end of the honeycomb structure, the intersecting porous walls forming a matrix of repeating unit cells arranged in a repeating pattern. The repeating unit cells comprise: three or four channels, each channel formed by four walls, wherein the three or four channels comprise more inlet channels than outlet channels, at least one wall of an inlet channel or an outlet channel is intersected midwall by a wall, an area of an outlet channel is equal to or less than an area of any of the inlet channels, and continuous line segments extending along walls of at least three repeating unit cells. Other plugged honeycomb structures, plugged honeycomb bodies, honeycomb extrusion dies, and methods are disclosed.

Batch compositions containing pre-reacted inorganic spheroidal particles, small amount of fine inorganic particles (“fines”), and an extremely large amount of liquid vehicle. The batch compositions contain pre-reacted inorganic particles having a particle size distribution with 20 μm≤D50≤100 μm, D90≤100 μm, and D5≥10 μm; less than 20 wt % of fine inorganic particles (fines) whose particle distribution(s) have a median diameter of less than 5 μm; and a liquid vehicle in a weight percent (LV %≥28%) by super-addition to all inorganic particles in the batch composition. Fast extruding batch compositions having extremely high Tau Y/Beta ratios are provided. Green bodies, such as green honeycomb bodies and methods of manufacturing green honeycomb bodies are provided, as are other aspects.

A exhaust gas purification apparatus is provided with: a substrate having a wall-flow structure and including entry-side cells, exit-side cells, and a porous partition; a first catalyst region formed in small diameter pores having relatively small pore diameters among internal pores in the partition; and a second catalyst region formed in large diameter pores having relatively large pore diameters among the internal pores in the partition. The first catalyst region contains a support and any one or two species of precious metal selected from Pt, Pd, and Rh loaded on the support, while the second catalyst region contains a support and any one or two species of precious metal selected from Pt, Pd, and Rh loaded on the support and other than at least the precious metal present in the first catalyst region.

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.

Ceramic candle filter and use of the filter in the removal of particulate matter in form of soot, ash, metals and metal compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, the filter comprises a combined SCR and oxidation catalyst arranged at least on the dispersion side and/or within wall of the filter, the combined SCR and oxidation catalyst comprises palladium, a vanadium oxide and titania.

The present disclosure is directed to an emission treatment system for NO.sub.x abatement in an exhaust stream of a lean burn engine. The emission treatment system includes a lean NO.sub.x trap (LNT) in fluid communication with and downstream from the lean burn engine and a low-temperature NO.sub.x adsorber (LT-NA) in fluid communication with and downstream of the LNT. Further provided is a method for abating NO.sub.x in an exhaust stream from a lean burn engine utilizing the disclosed system.

The invention relates to a wall-flow filter as a particle filter with catalytically active coatings in the channels which are closed in a gas-tight manner at the opposing closed ends of the channels A at the first end, wherein the inlet region of the filter is additionally supplied with a dry powder-gas aerosol which contains metal compounds with a high melting point (such as the metal oxides Al2O3, SiO2, FeO2, TiO2, ZnO2, etc. for example) and which is to simultaneously improve the catalytic activity and the degree of filtration efficiency with respect to the exhaust gas back-pressure.

An object of the present invention is to provide an exhaust gas purification catalyst including a wall-flow substrate and a catalyst layer, and having an improved exhaust gas purification performance, and, in order to achieve such an object, the present invention provides an exhaust gas purification catalyst including: a wall-flow substrate, first catalyst layers; and second catalyst layers; wherein the first catalyst layers and the second catalyst layers satisfy the following expressions (1) to (3):

L1<L2  (1)

T1<T2  (2)

WC1>WC2  (3)

wherein L1 represents the length of the first catalyst layers, L2 represents the length of the second catalyst layers, T1 represents the thickness of the rising portions of the first catalyst layers, T2 represents the thickness of the rising portions of the second catalyst layers, WC1 represents the mass of the first catalyst layers per unit volume of the portion of the substrate provided with the first catalyst layers, and WC2 represents the mass of the second catalyst layers per unit volume of the portion of the substrate provided with the second catalyst layers.