An emissions control substrate for treating exhaust from an engine including a plurality of hexagonal cells extending between a first end and a second end of the substrate. Wash coats are at an interior of the hexagonal cells. At an inner region of the substrate through which a longitudinal axis of the emissions control substrate extends, for every group of three adjacent hexagonal cells of the plurality of hexagonal cells two are plugged at the first end and open at the second end, and one is open at the first end and plugged at the second end. At an outer region of the substrate surrounding the inner region, for every group of three adjacent hexagonal cells of the plurality of hexagonal cells, one is plugged at the first end and open at the second end, and two are open at the first end and plugged at the second end.

A method of making a ceramic honeycomb article which includes: applying at least one green membrane coating layer on a green substrate, the green substrate comprising a plurality of cells comprised of a plurality of interior channels and a plurality of porous interior walls between the channels; drying the at least one green membrane coating layer on the green substrate to produce a green coated substrate; and firing the green coated substrate into a porous substrate, wherein applying the at least one green membrane coating layer and the drying the at least one green membrane coating layer are repeated from 2 to 10 times prior to firing to form multiple green membrane coating layers on the green substrate and wherein the firing the green coated substrate forms a ceramic honeycomb article comprised of the porous substrate and multiple fired coating layers on the porous substrate.

An air filter article, including: a wall-flow honeycomb particulate filter; and at least one anti-microbial agent on at least a portion of the interior surfaces. The disclosure also provides a filtration system that incorporates or uses the air filter article, and methods for making the air filter article.

A honeycomb structure includes a pillar-shaped honeycomb structure body including porous partition walls defining and forming a plurality of cells which extend from an inflow end face to an outflow end face, and a porous outer wall surrounding the partition walls, a porous supporting bulge disposed to extend out from a circumference of the outer wall so that at least a part of the outer wall is exposed, and plugging portions arranged in open ends of the cells, and the supporting bulge has support portions and a side wall portion, and the partition walls and the outer wall of the honeycomb structure body and the support portions and the side wall portion of the supporting bulge are all formed monolithically by formation of a ceramic raw material.

A honeycomb filter includes a honeycomb structure body having porous partition walls arranged to surround cells, in a cross section of the honeycomb structure body which is perpendicular to an extending direction of the cells, a value of a porosity of the partition wall in a partitioning region between the inflow cell and the outflow cell is defined as a porosity A, among intersecting portions where partitioning regions of the partition walls between the cells intersect one another, a value of a porosity of the partition wall in an intersecting portion between the two inflow cells is defined as a porosity B, and a value of A/B obtained by dividing the porosity A by the porosity B is from 0.50 to 0.95.

A honeycomb structure includes a honeycomb body having a partition wall defining a plurality of cells that extend from an inflow-end face as one end face to an outflow-end face as the other end face, the honeycomb body having a circumferential shape at a cross section orthogonal to an extending direction of the cells that is a rectangular shape with four corners being chamfered and having a long diameter and a short diameter, wherein the plurality of cells are hexagon cells having a hexagonal shape at the cross section orthogonal to the extending direction of the cells, and the hexagon cells are configured so that a longest diagonal line of each hexagon cell and the long diameter L of the honeycomb body form an angle that is 0 to 6.

A honeycomb structure includes a honeycomb body having a partition wall defining a plurality of cells that extend from an inflow-end face as one end face to an outflow-end face as the other end face, the honeycomb body having a circumferential shape at a cross section orthogonal to an extending direction of the cells that is a rectangular shape with four corners being chamfered and having a long diameter and a short diameter, wherein the plurality of cells are hexagon cells having a hexagonal shape at the cross section orthogonal to the extending direction of the cells, and the hexagon cells are configured so that a longest diagonal line of each hexagon cell and the short diameter S of the honeycomb body form an angle that is 0 to 6.

A honeycomb structure having a hexagonal cross-sectional shape of cells and having specific open cells in which open changing portions are present only in a range of 30 mm or less from the first end face, and the open changing portion satisfies relations of 1|(1(D1/D2))100|70 and 1|(1(D3/D2))100|70. D1 indicates a diameter of an inscribed circle which comes in contact with a peripheral edge of the open end of the cell in the first end face. D2 indicates a diameter of the inscribed circle which comes in contact with the peripheral edge of the open end of the cell in the second end face. D3 indicates a diameter of an inscribed circle which comes in contact with a peripheral edge of the cell in a cross section perpendicular to a direction from the first end face toward the second end face.

A honeycomb structure includes a honeycomb substrate having a porous partition wall that defines a plurality of cells that extend from an inlet end face as an inlet side for a fluid to an outlet end face as an outlet side for the fluid, and a porous circumferential wall that is monolithically formed with the partition wall, and a coat layer that is disposed on at least a part of the outer surface of the circumferential wall. Here, a part of the coat layer penetrates into the pores of the circumferential wall, and a thickness of the part of the coat layer that penetrates into the pores of the circumferential wall is from 1 to 90% of the thickness of the circumferential wall.

In the plugged honeycomb structure, 30% or more of first intersection portions in which a first partition wall intersects a second partition wall are first specific intersection portions in which a diameter of a maximum inscribed circle drawn in the first intersection portion is a specific size for a shortest distance between an inflow cell and an outflow cell, and 30% or more of non-first intersection portions other than the first intersection portions are non-first specific intersection portions in which a diameter of a maximum inscribed circle drawn in a non-first intersection portion is a specific size for a shortest distance between the inflow cells or the outflow cells.