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 hydrocarbon adsorbent having high hydrocarbon adsorbing properties even after exposed to a high temperature/high humidity reducing atmosphere, includes a FAU type zeolite having in ESR measurement a spin concentration of a least 1.0 × 10^19 (spins/g) and a ratio of a peak intensity at a magnetic field of at least 260 mT and at most 270 mT to a peak intensity at a magnetic field of at least 300 mT and at most 320 mT of at least 0.25 and at most 0.50 Å and containing bivalent copper. The hydrocarbon adsorbent may be used for a method for adsorbing hydrocarbons to be exposed to a high temperature/high humidity environment, and may be used particularly for a method for adsorbing hydrocarbons in an exhaust gas of an internal combustion engine, such as an automobile exhaust gas.

A honeycomb structure includes a pillar-shaped honeycomb structure body which has porous partition walls disposed to surround a plurality of cells Among the partition walls surrounding one of the cells, each of the partition walls constituting two opposite sides of the cell sandwiched therebetween is provided with a projection which project to extend into the cell and which is continuously provided in a direction in which the cell extends, and the area S1 of one region of the cell divided by a virtual line that virtually connects distal ends of the two projections in a section of the honeycomb structure body, and the area S2 of the other region (S1≤S2) of the cell satisfy 70%≤S1/S2×100%.

A honeycomb structure includes a central area and a reinforced outer peripheral area. For a boundary cell having cell walls with different wall thicknesses on two sides parallel with an imaginary parallel line, a thin wall thickness t1<a thick wall thickness t3, an inner wall thickness t2<an outer wall thickness t4, t1=t2, and t3=t4. The honeycomb structure includes a cross-shaped unit having a thin wall, an inner wall, a cell wall, and a cell wall and a cross-shaped unit having a thick wall, an outer wall, a cell wall, and a cell wall. The honeycomb structure also includes cross-shaped units extending vertically and horizontally from alternate cell vertexes arranged from a cell vertex as a starting point. In the central area and the reinforced outer peripheral area, the cell walls of each cross-shaped unit have a substantially equal wall thickness.

To provide a hydrocarbon adsorbent having high hydrocarbon adsorbing properties even after exposed to a high temperature/high humidity reducing atmosphere. A hydrocarbon adsorbent, which includes a FAU type zeolite having a lattice constant of at least 24.29 Å and containing copper. Such a hydrocarbon adsorbent may be used for a method for adsorbing hydrocarbons to be exposed to a high temperature/high humidity environment, and may be used particularly for a method for adsorbing hydrocarbons in an exhaust gas of an internal combustion engine, such as an automobile exhaust gas.

Proposed inventions are a recipe of denitrification-oxidation complex catalyst containing an SCR catalyst and an oxidation catalyst to simultaneously remove nitrogen oxides, carbon monoxide, hydrocarbons, and ammonia, a manufacturing method thereof, an exhaust gas treatment method using the denitrification-oxidation complex catalyst, and an SCR denitrification system including the denitrification-oxidation complex catalyst. The denitrification-oxidation complex catalyst simultaneously removes nitrogen oxides, carbon monoxide, hydrocarbons, and ammonia and exhibits an increased catalytic effect compared to the cases where the denitrification catalyst used alone and the denitrification and the oxidation catalyst ratios are and not properly balanced. When the denitrification-oxidation complex catalyst is applied to an SCR denitrification system, the structure is simplified, space is saved, cost is reduced, and catalyst maintenance is easy.

An exhaust gas purification filter comprises a base material part, a catalyst layer, and sealing parts. The base material part comprises porous partition walls. The catalyst layer is supported on pore walls of the partition walls. The partition walls supporting the catalyst layer comprise 10% or less of pores having a pore diameter of 50 μm or more. In the pore diameter distribution in the partition walls supporting the catalyst layer, the pore diameter D50 at which the cumulative pore volume becomes 50% is 10 μm or more. The pore diameter D50, and the pore diameter D10 at which the cumulative pore volume becomes 10%, satisfy the relationship of the following Expression 1.

(D50−D10)/D50≤0.9  Expression 1

An exhaust gas purification filter is configured to he disposed in an exhaust passage in a gasoline engine. The exhaust gas purification filter includes partition walls including a plurality of pores, a plurality of cells partitioned by the partition walls, and sealing portions alternately sealing ends of a plurality of the cells in the exhaust gas purification filter. The partition walls each have an average pore diameter of more than 16 μm and less than 21 μm, and have a ratio of an average surface opening diameter of the pores in a partition wall surface to the average pore diameter of the partition wall of 0.66 or more and 0.94 or less.

A honeycomb structure includes a central area and a reinforced outer peripheral area. A reference boundary cell with an inner wall orthogonal to an imaginary straight line, adjacent to the honeycomb center, and thinner than an outer wall adjacent to the honeycomb periphery has a reference wall different in wall thickness from the other three cell walls among the remaining four cell walls excluding the inner wall and the outer wall. The honeycomb structure includes a reference Y-shaped unit having the reference wall, the outer wall, and a cell wall. The honeycomb structure includes a plurality of Y-shaped units extending in the same directions as the reference Y-shaped unit. For every Y-shaped unit in the central area and the reinforced outer peripheral area of the honeycomb structure, the cell walls of each Y-shaped unit has an equal wall thickness.

A honeycomb body includes wound and/or stacked layers having a geometric center axis, a cavity rotationally symmetrically around the center axis and an outer lateral surface. Each layer extends approximately concentrically around the axis. At least one of the layers is at least partially structured forming channels through which a fluid can flow. The channels extend from the cavity outward to the outer lateral surface at a non-right cone angle to the axis. The channels have a cross-section changing along the channels from inside to outside. At least one structured layer and at least one intermediate layer are alternatingly disposed and helically layered. The structure height of the structured sheet-metal layer forming the channels is substantially constant and channel cross-sectional areas increase from inside to outside. The intermediate layer can be made of simple wires or of specially cut or folded smooth sheet-metal layers.