A honeycomb filter comprising a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells which serve as fluid through channels extending from a first end face to a second end face and a plugging portion provided at an open end on the first end face side or the second end face side of each of the cells, wherein the partition wall has an average number of branches of pores existing at the outermost surface of the partition wall of greater than 7.5 and less than 9.0.

A honeycomb filter comprising a pillar-shaped honeycomb structure body having a porous partition wall and a plugging portion, wherein a thickness of the partition wall is 0.217 mm or less, a porosity of the partition wall is 57 to 63%, an average pore diameter of the partition wall is 6 to 14 μm, a number per unit area of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 μm is 800 to 1500 /mm.sup.2, an average equivalent circle opening diameter of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 μm is 6.7 to 12.5 μm, and in a pore diameter distribution of the partition wall, D10 is 3.0 to 7.0 μm, D90 is 13.0 to 27.0 μm, and (Log (D90)-Log (D10))/Log (D50) is 0.75 or less.

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 coated ceramic honeycomb body comprising a honeycomb structure comprising a matrix of intersecting porous walls forming a plurality of axially-extending channels, at least some of the plurality of axially-extending channels being plugged to form inlet channels and outlet channels, wherein a total surface area of the outlet channels is greater than a total surface area of the inlet channels, and wherein a catalyst is preferentially located within the outlet channels, and preferentially disposed on non-filtration walls of the outlet channels. Methods and apparatus configured to preferentially apply a catalyst-containing slurry to the outlet channels and non-filtration walls are provided, as are other aspects.

A method of manufacturing a ceramic honeycomb structure by mixing a ceramic precursor batch composition having a median particle diameter less than or equal to about 10 μm and at least one starch-based pore former having a median particle diameter greater than or equal to about 10 μm. The method also includes forming a mixture of ceramic precursor batch composition and a starch-based pore former into a green ceramic structure having a web structure, and firing the green ceramic structure to yield a ceramic honeycomb structure.

A coated ceramic honeycomb body comprising a honeycomb structure comprising a matrix of intersecting porous walls forming a plurality of axially-extending channels, at least some of the plurality of axially-extending channels being plugged to form inlet channels and outlet channels, wherein a total surface area of the outlet channels is greater than a total surface area of the inlet channels, and wherein a catalyst is preferentially located within the outlet channels. and preferentially disposed on non-filtration walls of the outlet channels. Methods and apparatus configured to preferentially apply a catalyst-containing slurry to the outlet channels and non-filtration walls are provided, as are other aspects.

A honeycomb filter includes: a honeycomb substrate having porous partition walls disposed so as to surround cells extending from an inflow end face to an outflow end face, an outer peripheral coating layer disposed so as to surround an outer periphery of the honeycomb substrate, and plugging portions that are disposed at any one of ends on the inflow end face and ends on the outflow end face, of the cells, wherein, the outer peripheral coating layer has an inflection point at which thermal expansion in thermal expansion behavior of the outer peripheral coating layer turns to contraction and a temperature T1 of which is 1000 to 1500° C., and the outer peripheral coating layer has a porosity P1 of 36 to 48%, and a thermal expansion coefficient C1 between 40 to 800° C. of 2.5 to 3.5×10.sup.-6 /°C.

A honeycomb filter comprising a pillar-shaped honeycomb structure body having a porous partition wall and a plugging portion, wherein a thickness of the partition wall is 0.257 mm or less, a porosity of the partition wall is 52 to 57%, an average pore diameter of the partition wall is 6 to 13 .Math.m, a number per unit area of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 .Math.m is 800 to 1500 /mm.sup.2, an average equivalent circle opening diameter of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 .Math.m is 8.0 to 12.0 .Math.m, and in a pore diameter distribution of the partition wall, D10 is 2.0 to 5.5 .Math.m, D90 is 13.0 to 25.5 .Math.m, and (Log(D90)-Log(D10))/Log(D50) is 0.84 or less.

A honeycomb filter comprising a pillar-shaped honeycomb structure body having a porous partition wall and a plugging portion, wherein, in a pore diameter distribution of the partition wall, in the case where the pore diameter (.Math.m) whose cumulative pore volume is 10% of the total pore volume is denoted by D10, the pore diameter (.Math.m) whose cumulative pore volume is 50% of the total pore volume is denoted by D50, and the pore diameter (.Math.m) whose cumulative pore volume is 90% of the total pore volume is denoted by D90, all of the following equations (1) to (6) are satisfied.

[00001]$\begin{array}{cc}3.9\mu \text{}\text{m<D10}& \text{­­­(1)}\end{array}$

[00002]$\begin{array}{cc}10.5\mu \text{}\text{m<D50<16}\text{.6}\mu \text{}\text{m}& \text{­­­(2)}\end{array}$

[00003]$\begin{array}{cc}\text{D90<38}\text{.7}\mu \text{}\text{m}& \text{­­­(3)}\end{array}$

[00004]$\begin{array}{cc}\left(\log \text{}\text{D90-logD10}\right)/\log \text{}\text{D50<0}\text{.80}& \text{­­­(4)}\end{array}$

[00005]$\begin{array}{cc}\log \text{}\text{D90}/\text{logD50<1}\text{.36}& \text{­­­(5)}\end{array}$

[00006]$\begin{array}{cc}\log \text{}\text{D50}/\text{logD10<1}\text{.56}& \text{­­­(6)}\end{array}$

A honeycomb filter includes a honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion disposed at one end of the cells, wherein the plurality of cells are arranged in a square grid pattern along a first direction and a second direction in a section orthogonal to an extending direction of the cells, the shape in the section is a deformed square having a specific corner, the specific corner includes a first curved portion, a second curved portion, and a connecting portion, a radius of curvature R1 of the first curved portion and a radius of curvature R2 of the second curved portion are 40 to 80 μm, respectively, and a center distance between a center of curvature O1 of the first curved portion and a center of curvature O2 of the second curved portion is 80 to 200 μm.