An electric heating type support includes: a pillar shaped honeycomb structure being configured to a ceramic, including: an outer peripheral wall; and a partition wall disposed on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells, each of the cells extending from one end face to other end face to form a flow path; an electrode layer disposed on a surface of the outer peripheral wall of the pillar shaped honeycomb structure; two or more underlayers having conductivity, the underlayers being provided on the electrode layer so as to be spaced apart from each other; and a metal electrode provided on the underlayers.

A surface of each of the underlayers has a concave portion forming a space between each of the underlayers and the metal electrode.

A silicon carbide ceramic honeycomb structure having large numbers of axially penetrating flow paths partitioned by porous silicon carbide cell walls, the cell walls comprising silicon carbide particles as aggregate and binder layers for binding the silicon carbide particles, the binder layers having at least a cordierite phase and a spinel phase, and the molar ratio M1 of the cordierite phase [=cordierite phase/(cordierite phase+spinel phase)] being 0.4-0.9.

A substrate (11) includes an inflow-side cell (21), an outflow-side cell (22), and a porous, gas-permeable partition wall (23) that separates the inflow-side cell (21) and the outflow-side cell (22) from each other, and also includes a first catalyst portion (14) that is provided on a side of the partition wall (23) that faces the inflow-side cell (21) at least at a portion in upstream side in an exhaust gas flow direction, and a second catalyst portion (15) that is provided on a side of the partition wall that faces the outflow-side cell at least at a portion in downstream side. With respect to a pore volume of pores with a pore size of 10 to 18 m, when a measured value of the pore volume in the first catalyst portion (14) and the partition wall (23) within a region where the first catalyst portion (14) is provided is defined as a first pore volume, and a measured value of the pore volume in the second catalyst portion (15) and the partition wall (23) within a region where the second catalyst portion (15) is provided is defined as a second pore volume, the first pore volume is greater than the second pore volume. A catalytically active component contained in the first catalyst portion (14) and a catalytically active component contained in the second catalyst portion (15) are of different types.

An electrically heated catalyst includes a honeycomb structure and is designed to be mounted in an exhaust pipe in which exhaust gas flows. The honeycomb structure exhibits catalytic activities and produce heat upon electrical energization. The honeycomb structure includes a grid portion defining a plurality of cells and an outer peripheral portion which covers an outer periphery of the grid portion. A surface of the grid portion and a surface of the outer peripheral portion are designed to ensure electrical insulation from the exhaust pipe.

A catalyst for gasoline engine exhaust gas after-treatment, comprising Pt and optionally at least one other platinum group metal on a hydrothermal stable support material which is coated onto a gasoline particulate filter. The catalyst oxidizes particulate matter trapped in the gasoline particulate filter under low temperature and abates NO.sub.x, CO and HC. Also a process for preparing the catalyst is disclosed, and a method for after-treatment of gasoline engine exhaust gas using the catalyst is disclosed.

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 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.

A device for the aftertreatment of exhaust gases of an internal combustion engine, having at least one catalytic converter, through which exhaust gas can flow, and at least one muffler formed by a closed volume and through which exhaust gas can flow along an inflow section to an outflow section. The catalytic converter is formed by a honeycomb body that has a plurality of flow channels through which exhaust gas can flow. The honeycomb body is accommodated in a casing tube, which surrounds the honeycomb body, and is connected to the casing tube in a materially bonded manner. The catalytic converter is arranged in the interior of the muffler.

A honeycomb structure body is constituted of a circumferential region including the outermost circumference in a cross section of the honeycomb structure body which is perpendicular to an extending direction of cells, and a central region excluding the circumferential region. The circumferential region includes a specific circumferential region in which pressure loss with soot when an amount of the deposited soot is 4 g/L is higher than the pressure loss with soot of the central region as much as 15% or more and in which an open frontal area of the circumferential region is the same as or larger than an open frontal area of the central region. In the cross section of the honeycomb structure body, a ratio of an area of the specific circumferential region is 5% or more to a total area of the circumferential region and the central region.

The plugged honeycomb structure includes a plurality of honeycomb segments, a bonding layer, and plugging portions which plug open ends of cells of each honeycomb segment, and in the honeycomb segment, at least two types of cells having different sectional shapes are formed to constitute predetermined repeated arrangement patterns, and in rim circumferential wall cells including rims of the cells surrounded with partition walls and segment circumferential walls, an inflow open area of each corner rim circumferential wall cell disposed in each corner portion of the honeycomb segment is 1.1 times or more as large as an average inflow open area of non-corner rim circumferential wall cells arranged in portions other than the corner portions, or an outflow open area of the corner rim circumferential wall cell is 1.1 times or more as large as an average outflow open area of the non-corner rim circumferential wall cells.

A plugged honeycomb structure includes a plurality of honeycomb segments, a bonding layer, and plugging portions plugging open ends of cells of the honeycomb segments. The honeycomb segments include circumferential segments and central segments. The circumferential segments include at least one specific circumferential segment in which pressure loss with soot when an amount of the deposited soot is 4 g/L is higher than the pressure loss with soot of the central segment as much as 15% or more and in which an open frontal area of the circumferential segment is the same as or larger than an open frontal area of the central segment. In a cross section of a honeycomb structure body which is perpendicular to an extending direction of the cells, a ratio of an area of the specific circumferential segment is 4% or more to a total area of the circumferential segments and the central segments.