The honeycomb filter of the present invention includes a honeycomb fired body that includes multiple cells serving as channels of exhaust gas; and porous cell partition walls defining the cells, the cells including exhaust gas introduction cells whose ends on an exhaust gas inlet side are open and whose ends on an exhaust gas outlet side are plugged, and exhaust gas emission cells whose ends on the exhaust gas outlet side are open and whose ends on the exhaust gas inlet side are plugged, wherein the honeycomb fired body contains ceria-zirconia composite oxide particles and alumina particles, when the pore size of the cell partition walls of the honeycomb fired body is measured by mercury porosimetry, and the measurement results are presented as a pore size distribution curve with pore size (μm) on the horizontal axis and log differential pore volume (mL/g) on the vertical axis, the volume of micropores having a pore size of 1 to 100 μm accounts for 80 vol % or more of the total pore volume, and a value obtained by dividing the half width (μm) of the maximum peak in the pore size range of 1 to 100 μm by the mode size (μm) is 0.5 or less.

A porous honeycomb structure including cordierite, having a plurality of cell channels which pass through an interior of the porous honeycomb structure and are partitioned by porous partition walls, wherein the porous partition walls have a porosity of 45 to 60% as measured by a mercury intrusion method, wherein in a volume-based cumulative pore diameter distribution measured by the mercury intrusion method, the porous partition walls have a cumulative 10% pore diameter (D10) and a cumulative 50% pore diameter (D50) calculated from a small pore side, and satisfy a relationship of 0.45≤(D50−D10)/D50, and 3 μm≤D50≤10 μm.

Disclosed herein are filtration articles comprising a porous ceramic structure comprising a plurality of channels separated by a plurality of porous interior walls, and a nanomembrane disposed on at least a portion of a surface of the porous ceramic structure, wherein the nanomembrane comprises nanoparticles of at least one inorganic oxide, and wherein the nanoparticles are present in a concentration ranging from about 0.001 g/L to about 1 g/L based on the total volume of the porous ceramic structure. Methods for making such filtration articles and methods for filtering a particulate from a fluid using such filtration articles are also disclosed herein.

A porous ceramic structure intended to form the reinforcement of a ceramic matrix composite component, the structure having a connected porosity delimited by an internal surface which includes a plurality of first points, each first point being associated with a second point aligned with this first point along a normal to the internal surface taken at the first point, the structure being divisible into a plurality of unit volumes of a size less than or equal to 5 mm3 in each of which: a characteristic pore length, corresponding to the maximum of the distance separating each first point from its associated second point, is less than or equal to 0.5 mm; and a porosity ratio is greater than or equal to 50%.

A porous honeycomb structure including cell channels passing through an interior of the porous honeycomb structure and partitioned by porous partition walls, wherein the porous partition walls include skeleton portions containing an aggregate and a bonding material, and pore portions formed among the skeleton portions and through which a fluid can flow; and the porous partition walls have a porosity of 40 to 48% as measured by a mercury intrusion method, and a cumulative 50% pore diameter (D50) from a large pore side of 6 to 10 μm in a volume-based cumulative distribution of pore diameters measured by the mercury intrusion method, and a maximum pore diameter observed with a scanning electron microscope of 40 μm or less, and a ratio of a contact area between the aggregate and the bonding material to a surface area of the bonding material observed with the scanning electron microscope of 61 to 80%.

A substrate (11) of an exhaust gas purification catalyst (10) includes inflow-side cells (21), outflow-side cells (22), and porous partition walls (23) each separating the inflow-side cell and the outflow-side cell. Catalyst portions (14, 15) are provided on surfaces of the partition walls that each face the inflow-side cell and/or surfaces of the partition walls that each face the outflow-side cell. In a cross section vertical to an exhaust gas flow direction, the percentage of the total area of voids, each void satisfying the expression L/{2(πS).sup.1/2}≤1.1, wherein L is the perimeter of the void in the cross section and S is the area of the void in the cross section, is from 3 to 10% based on the apparent area of the catalyst portion present on the partition wall.

A honeycomb filter includes a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion provided at an open end on a first end face side or a second end face side of the cells, wherein the partition wall is composed of a material containing cordierite as a main component, a porosity of the partition wall is 60 to 70%, an average pore diameter of the partition wall is 20 to 30 μm, an open porosity of pores existing at the partition wall surface and having equivalent circle diameters exceeding 1.5 μm is 31% or more, and, in a pore diameter distribution which indicates a cumulative pore volume of the partition wall, a half-value width of a first peak including a maximum value of a log differential pore volume is 0.20 or less.

Provided is an exhaust purification filter that is able to reduce pressure loss and that has high exhaust purification performance and particulate matter trapping performance. This exhaust purification filter comprises a filter substrate having a wall flow structure, and an exhaust purification catalyst supported on a partition wall of the filter substrate. The volume-based median pore diameter (D50) of the filter substrate is 18 μm or greater, the full width at half maximum of the pore distribution of the filter substrate is 7 μm to 15 μm, and the exhaust purification catalyst is supported in an unevenly distributed manner in a high-density layer in which the density of the exhaust purification catalyst is relatively high and a low-density layer in which the density of the exhaust purification catalyst is relatively low.

The present invention relates to a catalytically coated wall-flow filter, to a method for the production thereof and to the use thereof in order to reduce harmful exhaust gases of an internal combustion engine.

A porous composite includes a porous base material and a porous collection layer formed on the base material. The collection layer has a thickness greater than or equal to 6 μm. The collection layer has a plurality of large pores, each exposing the surface of the base material. A sum of areas of exposed regions of the base material that are each exposed from each large pore of the plurality of large pores is greater than or equal to 1% of the total area of the collection layer and less than or equal to 30% thereof. This allows the porous composite to achieve a favorable efficiency of collecting particulate matter and to increase the accessible area between the particulate matter and the collection layer and thereby accelerate oxidation of the particulate matter collected by the porous composite.