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.

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.

In order to prevent injury from hot exhaust gas, water is condensed by a metal net in the exhaust pipe.

In order to prevent injury from hot exhaust gas, water is condensed by a metal net in the exhaust pipe.

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.

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.

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.

A filtration assembly for removing particulate matter from exhaust gas produced by an engine, including: a first filter; a second filter positioned downstream of the first filter; and a valve including: a first ring defining a plurality of first openings, and a second ring defining a plurality of second openings, the second ring abutting the first ring. The valve is moveable between a closed position in which the plurality of first openings are misaligned with the plurality of second openings to prevent a fluid from flowing through the plurality of first and second openings, and an open position in which the second ring is rotated relative to the first ring such that the plurality of first openings are aligned with the plurality of second openings allowing the fluid to flow therethrough. A first end of the valve is positioned at an outlet of the first filter, and a second end of the valve is positioned at an inlet of the second filter. In the closed position of the valve, substantially all of the exhaust gas flows through the second filter, and in the open position of the valve, at least a portion of the exhaust gas flows through the valve and bypasses the second filter.