The invention relates to a wall-flow filter as a particle filter with catalytically active coatings in the channels which are closed in a gas-tight manner at the opposing closed ends of the channels A at the first end, wherein the inlet region of the filter is additionally supplied with a dry powder-gas aerosol which contains metal compounds with a high melting point (such as the metal oxides Al2O3, SiO2, FeO2, TiO2, ZnO2, etc. for example) and which is to simultaneously improve the catalytic activity and the degree of filtration efficiency with respect to the exhaust gas back-pressure.

The invention relates to a wall-flow filter as a particle filter with catalytically active coatings in the channels which are closed in a gas-tight manner at the opposing closed ends of the channels A at the first end, wherein the inlet region of the filter is additionally supplied with a dry powder-gas aerosol which contains metal compounds with a high melting point (such as the metal oxides Al203, Si02, Fe02, Ti02, Zn02, etc. for example) and which is to simultaneously improve the catalytic activity and the degree of filtration efficiency with respect to the exhaust gas back-pressure.

A honeycomb structure includes: a honeycomb structure body; and a convex part that protrudes outward from a part of circumference of the honeycomb structure body. The convex part surrounds the circumference of the honeycomb structure body like a ring. The convex part is of a tapered shape at least at one end having a tapered face. The convex part has a circumference coating layer making up the tapered face. The convex part has a maximum thickness of 1 to 20 mm, and a rough-face region on the tapered face, the rough-face region having surface roughness of 5 to 70 μm. The rough-face region has a total of a rough-face region angle of 108° or more. An inclination angle formed between the tapered face and the extending direction of the cells is 10 to 80 degrees.

A plugged honeycomb structure in which in a cross section of a honeycomb structure body which is perpendicular to an extending direction of cells, inflow cells are disposed to surround an outflow cell, and the number of the inflow cells is larger than the number of the outflow cells, and the cross section has a plurality of intersecting portions of partition walls each defining the inflow cells which are adjacent to each other, and in 60% or more of a total number of the intersecting portions, a relation between a diameter (D.sub.1) of a circle inscribed in the intersecting portion and a diameter (D.sub.0) of a circle inscribed in the partition wall defining the inflow cell and the outflow cell which are adjacent to each other satisfies D.sub.1/(√2×D.sub.0)=1.20 to 1.80

The invention relates to a wall-flow filter as a particle filter with catalytically active coatings in the channels which are closed in a gastight manner at the opposing closed ends of the channels A at the first end, wherein the inlet region of the filter is additionally supplied with a dry powder-gas aerosol which contains metal compounds with a high melting point (such as the metal oxides Al2O3, SiO2, FeO2, TiO2, ZnO2, etc. for example) and which is to simultaneously improve the catalytic activity and the degree of filtration efficiency with respect to the exhaust gas back-pressure.

In a porous composite, a base material has a honeycomb structure whose inside is partitioned into a plurality of cells. In the plurality of cells, a plurality of first cells whose one ends in the longitudinal direction are sealed, and a plurality of second cells whose other ends in the longitudinal direction are sealed are arranged alternately. A collection layer covers inner surfaces of the plurality of first cells. An overall Sa that is an arithmetical mean height Sa indicating a surface roughness of a surface of the collection layer in the plurality of first cells is greater than or equal to 0.1 μm and less than or equal to 12 μm. An overall mean thickness that is a mean thickness of the collection layer in the plurality of first cells is greater than or equal to 10 μm and less than or equal to 40 μm.

A honeycomb body for exhaust gas aftertreatment, having a multiplicity of stacked layers. Flow channels are formed between the layers, which extend along the axial extent of the honeycomb body and are flowed through in the axial direction. The honeycomb body has first structured layers formed by successive wave peaks and wave valleys. Protuberances in the direction of the wave peaks belonging to a respective layer are formed from adjacently arranged wave valleys of a first structured layer. The adjacently arranged protuberances of a first structured layer form a channel-like structure extending in the circumferential direction in the first structured layer into which a second layer is inserted to be is fixed in the axial direction with respect to the first structured layer.

A separator element comprising a porous rigid single-piece substrate (2) presenting firstly, at its periphery, a perimeter wall (2.sub.1) that is continuous between an inlet (4) for the fluid medium for treatment at one end of the porous substrate and an outlet (5) for the retentate at the other end of the porous substrate, and secondly, internally, a surface covered by a separator layer (6) and defining an open structure made up of empty spaces (3) for passing a flow of the fluid medium for treatment. The empty spaces (3) are arranged in the porous substrate so as to create within the porous substrate a first flow network (R1) for the fluid medium for treatment, having at least two interconnected flow circuits (R1.sub.1, R1.sub.2) for the fluid medium between the inlet (4) and the outlet (5) of the porous substrate.

A honeycomb body for exhaust gas aftertreatment, having a multiplicity of stacked layers. Flow channels are formed between the layers, which extend along the axial extent of the honeycomb body and are flowed through in the axial direction. The honeycomb body has first structured layers formed by successive wave peaks and wave valleys. Protuberances in the direction of the wave peaks belonging to a respective layer are formed from adjacently arranged wave valleys of a first structured layer. The adjacently arranged protuberances of a first structured layer form a channel-like structure extending in the circumferential direction in the first structured layer into which a second layer is inserted to be is fixed in the axial direction with respect to the first structured layer.

A substrate for an exhaust gas treatment unit, particularly for an exhaust system of an internal combustion engine, includes a substrate body (18) elongated in the substrate longitudinal direction (S). The substrate body (18) is flattened in a flattening direction (A) essentially at right angles to the substrate longitudinal direction (S). A plurality of cells (24), which extend essentially in the substrate longitudinal direction (S) and provide flow ducts, are formed in the substrate body (18). The cells (24) are defined by cell walls (20, 22), which extend essentially in the substrate longitudinal direction (S). The cell walls (20, 22) are disposed at an angle in relation to the flattening direction (A).