An exhaust gas purification filter includes a plurality of cells extending in a filter axial direction, a porous partition separating and defining the plurality of cells, and a sealing section sealing the plurality of cells alternately at both filter ends. The partition has a void volume of a reduced dale, Vvv, and a material volume of a reduced peak, Vmp, as volume parameters determined in noncontact surface roughness measurement on a surface of the partition, with their total value being more than 1.3 μm.sup.3/μm.sup.2 and 1.7 μm.sup.3/μm.sup.2 or less. The partition has a mean pore size of 12 μm or more and 20 μm or less. The partition also has a porosity of 50% or more and 75% or less.

An electric heating type carrier including a conductive honeycomb structure portion and a pair of electrode layers, wherein in a cross-section orthogonal to the direction in which the cells extend, the honeycomb structure portion is classified into following three regions: a first resistance region having a contact portion with a first electrode layer, a second resistance region having a contact portion with a second electrode layer, and a third resistance region that does not come into contact with either the first electrode layer or the second electrode layer, and traverses the cross-section so as to be sandwiched between the first resistance region and the second resistance region, and has a higher electrical resistance per unit volume (1 cm.sup.3) than an electrical resistance per unit volume (1 cm.sup.3) of the first resistance region and the second resistance region.

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 honeycomb structure prevents catalyst slurry from leaching out when applying a wash coat for making a catalyst supported, ensuring air permeability of the outer portion and in which there is no occurrence of cracking when used as a gasoline particulate filter. The honeycomb structure having: a honeycomb substrate composed of porous partition walls forming a plurality of cells and a porous outer portion; and a resin composition on the outer portion of the honeycomb substrate, wherein the outer portion and the partition walls of the honeycomb substrate are formed of the same material; a porosity of the honeycomb structure is 50% or more; and the resin composition is impregnated into pores of the whole outer portion; and the impregnation depth is equal to the outer portion thickness or a part of the resin composition is impregnated deeper than the outer portion and reaches the cell partition walls.

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.

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.1≠L.sub.2, i.e. W.sub.1≥W.sub.2, or L.sub.1≠L.sub.2, or W.sub.1≥W.sub.2 and L.sub.1≠L.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.

A honeycomb structure 20 according to the present invention includes: a ceramic honeycomb structure portion 10 including: an outer peripheral wall 12; a partition wall 13, the partition wall 13 defining a plurality of cells 16; and a pair of electrode layers 14a, 14b each arranged so as to extend in a form of a band on an outer surface of the outer peripheral wall 12, across a central axis of the honeycomb structure portion 10, wherein the honeycomb structure portion 10 is provided in an end portion region(s) extending in a direction from the one end face and/or the other end face to a center in a flow path length direction of the honeycomb structure portion 10, and the honeycomb structure portion 10 comprises at least one low porosity portion 4 having a lower porosity than an average porosity of the whole honeycomb structure portion 10.

A honeycomb body (300) including a plurality of radially-extending walls (322) intersecting with a plurality of circumferentially-extending walls (324), the plurality of radially-extending walls (322) and the plurality of circumferentially-extending walls (324) form a plurality of circumferential zones (334A, 334B, 334C) of cells (308). The plurality of circumferential zones (334A, 334B, 334C) of cells (308) includes a first zone of cells (334A) including two or more first rings of cells (330) and having a first cell density, and a second zone of cells (334B) including two or more rings of cells (330) having varying cell densities across the two or more rings of cells. Other structures and extrusion dies are disclosed.

To provide an exhaust gas purification filter having a high capability of collecting particulate matter. The exhaust gas purification filter includes a filter base material having a wall flow structure and an exhaust gas purification catalyst. A wash coating amount of the exhaust gas purification catalyst ranges from 60 to 110 g/L or less. When the exhaust gas purification filter is divided into an upstream part, a middle part, and a downstream part, and average values of catalyst area ratios of the exhaust gas purification catalyst supported by surfaces of the partition walls are acquired at predetermined locations in cells on an inflow side and cells on an outflow side, a minimum value, among the average values, is 28% or greater. A maximum value, among sizes of pores in the partition walls after the exhaust gas purification catalyst is supported, is 14.6 μm or less.

An exhaust gas purification catalyst having a substrate having a wall flow structure, and a catalyst layer. The catalyst layer has: an A section provided in the interior of the partition wall, along an extension direction X of the partition wall, from an exhaust gas inflow end section; a C section provided in the interior of the partition wall, along the extension direction X of the partition wall, from an exhaust gas outflow end section; and a B section disposed between the A section and the C section in the extension direction X of the partition wall, and provided over the surface of the partition wall on the side in contact with the inlet cell, the interior of the partition wall, and the surface of the partition wall on the side in contact with the outlet cell.