Catalytically active particulate filter body and method of making

Abstract

To provide a catalyzed particulate filter with high clean filtration efficiency and low pressure drop, and a method of making the catalyzed particulate filter.SOLUTION: A method is disclosed for making a catalyzed particulate filter with high clean filtration efficiency which may include a step of applying a catalyst material to a filter body having porous filter walls. Therein a filtration material comprising filtration particles are disposed on or in or both on and in the porous filter walls, and the filtration material is hydrophobic while the catalyst material is applied. The catalyzed particulate filter with high clean filtration efficiency is also disclosed. Therein the filter includes: the porous filter walls with the filtration particles disposed on or in or both on and in the porous filter walls; and the catalyst material disposed on or in or both on and in the porous filter walls. Therein the catalyst material substantially does not touch the filtration particles.SELECTED DRAWING: Figure 2

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Patent Application No. 63 / 139,185, filed January 19, 2021, the contents of which are relied upon and incorporated herein by reference in their entirety. This application is also a divisional application of Japanese Patent Application No. 2023-543161, filed January 19, 2022. [Technical Field]

[0002] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to catalytically active particulate filters, and more particularly to catalytically active particulate filter bodies having high filtration efficiency, and methods of making the same. [Background technology]

[0003] For example, particulate filters such as diesel particulate filters and gasoline particulate filters (GPFs) filter particulates from exhaust streams from engines such as automobiles that burn diesel fuel and gasoline fuel, respectively. In various engine exhaust configurations, catalytically active particulate filters can reduce the space required and / or improve catalytic performance for the exhaust stream. Summary of the Invention

[0004] In a first aspect, disclosed herein is a method for manufacturing a catalyzed particulate filter having high clean filtration efficiency and low pressure drop. In some embodiments, the method includes applying a catalytic material to a filter body including a porous filter wall and a filtration material comprising filtration particles disposed on or within, or both on and within, the porous filter wall, wherein the filtration material is hydrophobic while the catalytic material is applied to the filter body. In some embodiments, the methods disclosed herein are advantageous for manufacturing a filter body that is loaded with catalyst primarily or predominantly within the wall, preferably with little, and more preferably no, penetration of the catalytic material, especially among the filtration particles.

[0005] In a second aspect, disclosed herein is a catalyzed particulate filter having high clean filtration efficiency, the filter comprising a porous filter wall including filtration particles disposed on or within or both on and within the porous filter wall, and a catalytic material disposed on or within or both on and within the porous filter wall, the catalytic material being substantially absent between the filtration particles. In some embodiments, the filter body advantageously provides a catalytic loading primarily or predominantly within the wall, preferably with little or no penetration of the catalytic material among the filtration particles.

[0006] Further embodiments of the present disclosure are disclosed herein.

[0007] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure, briefly summarized above, can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the present disclosure is also susceptible to other equally effective embodiments, and therefore, the accompanying drawings illustrate only typical embodiments of the disclosure, and therefore, should not be considered as limiting the scope of the present disclosure. [Brief explanation of the drawings]

[0008] [Figure 1] Schematic diagram of an apparatus and method for applying filtration material to a filter body, including applying filtration material (including filtration particles) by a filtration method. [Figure 2] Schematic diagram of an apparatus and method for depositing catalytic material on the filter walls of a filter body. [Figure 3]1 is a schematic diagram of the method steps disclosed herein, including starting with a bare filter body comprising a plugged honeycomb structure having an inlet end and an outlet end, then applying a filtration material comprising filtration particles to the inlet end of the filter body to deposit it on the inlet surface of the filter wall of the honeycomb structure, then performing a pretreatment on the filter body, such as a heat treatment on the filter body, then loading a catalytic material onto the filter body, wherein the catalytic material is introduced at the outlet end of the filter body, then the filter body is subjected to drying conditions, then optionally, one or more additional loads of catalytic material may be introduced at the outlet end of the filter body, and optionally calcining the catalytic material after the last or final load of catalytic material is applied. [Figure 4] Schematic of an SEM cross section of the filter wall of a filter body containing a porous ceramic honeycomb structure that has been wash-coated with catalytic material (the porous ceramic portion of the filter wall is shown in medium grey, the catalytic material is shown in dark grey, and the distribution of filter particles deposited on the cell walls of the wash-coated filter body, represented by small solid (usually circular) dots). [Figure 5] Schematic SEM cross-section of the filter wall of a filter body containing a porous ceramic honeycomb structure that has not been washcoated with catalytic material (filter particles are represented by small solid (usually circular) dots). [Figure 6] 6 is a schematic SEM cross-section of a filter wall of a filter body including the porous ceramic honeycomb structure of FIG. 5 having a catalytic material applied thereto, after deposition of the filtration material including the filtration particles, but after exposure to a heat treatment (above 500° C.) that reduces the hydrophobicity of the filtration material prior to washcoating with the catalytic material, such that the filtration material does not have hydrophobicity during washcoating. As can be seen in FIG. 6, at least some of the catalytic material is coextensive with the filtration particles, in addition to the catalytic material present "in-wall" within the monolithic honeycomb wall formed, for example, by extrusion. [Figure 7]6 is a schematic SEM cross-section of a filter wall of a filter body comprising the porous ceramic honeycomb structure of FIG. 5 , to which a catalytic material has been applied after deposition of the filtration material comprising the filtration particles, but before the filtration material is exposed to a heat treatment that reduces its hydrophobicity (e.g., exposure to one or more temperatures below 500° C., in some embodiments between 300 and 500° C.), i.e., washcoated with a catalytic material while the filtration material is hydrophobic during the washcoating. [Figure 8] Graph showing pressure drop in kPa versus particle loading (soot loading) in grams / liter (grams of loading per liter of filter body, or g / l) for: (A) a bare high porosity porous ceramic filter body without washcoated catalytic material and no filtration particles present in or on the filter body; (B) a filter body with washcoated catalytic material present in or on the filter body and no filtration particles present; and (C) a filter body with washcoated catalytic material present in or on the outlet surface of the filter body and filtration particles present in or on the inlet surface of the filter body (where the filtration particles have been applied by deposition onto a filter body that has already been washcoated (or "catalyzed") with catalytic material (such as that shown in FIG. 4), and the filtration particles have been heat treated (to remove hydrophobicity) after the washcoating process). [Figure 9] Graph of filtration efficiency in % versus particle loading (soot loading) in grams per liter (g / l) for filter bodies (A), (B), and (C) of FIG. 8. [Figure 10]Graph showing pressure drop in kPa versus particle loading (soot loading) in grams / liter (grams of loading per liter of filter body, or g / l) for: (A) a bare high porosity porous ceramic filter body with no washcoated catalyst material and no filter particles in or on the filter body; (B) a filter body with washcoated catalyst material in or on the filter body at a catalyst loading of 92 grams per liter of filter body and no filter particles; and (D) a filter body with washcoated catalyst material in or on the filter body at a catalyst loading of 6.4 grams per liter of filter body and no filter particles. and (E) a filter body having a washcoated catalyst material in or on the outlet surface of the filter body at a catalyst loading of 95 grams per liter of filter body and filtration particles in or on the inlet surface of the filter body at an amount of 6.4 grams of filtration particles per liter of filter body (where the washcoat was applied to a filter body already comprising filtration material made of filtration particles that had been heat treated at a temperature of up to 600° C. (i.e., a hydrophobicity-reducing heat treatment or a hydrophobicity-removing heat treatment), where the filtration material (in this case the filtration particles) was not hydrophobic when the washcoat was applied (such as that shown in FIG. 6), and the TWC material was calcined). [Figure 11] 11 is a graph showing filtration efficiency in % versus particle loading (soot loading) in grams per liter (g / l) for filter bodies (A), (B), (D), and (E) of FIG. 10. [Figure 12]Graph showing pressure drop in kPa versus particle loading (soot loading) in grams / liter (grams of loading per liter of filter body, or g / l) for: (A) a bare high porosity porous ceramic filter body without washcoated catalytic material and no filtration particles present in or on the filter body; (B) a filter body with washcoated catalytic material present in or on the filter body and no filtration particles present; and (F) a filter body with no washcoated catalytic material present in or on the filter body and filtration particles present; and (G) a filter body with washcoated catalytic material present in or on the outlet surface of the filter body and filtration particles present in or on the inlet surface of the filter body (wherein a catalytic washcoat is applied to a filter body already comprising filtration material (including filtration particles) that has been heat treated in a manner sufficiently reducing its hydrophobicity such that the filtration material becomes hydrophobic when the catalytic washcoat is applied, illustrating a preferred embodiment disclosed herein). [Figure 13] Filtration efficiency in % versus particle load (soot load) in grams per liter (g / l) for filter bodies (A), (B), (F), and (G). [Figure 14] Graphs schematically illustrating the % increase in clean filtration efficiency (first bar set), clean pressure drop (second bar set), and particulate / soot loaded pressure drop (third bar set). [Figure 15A] Schematic diagram of an FE measurement system suitable for measuring clean FE and soot-loaded FE. [Figure 15B] Schematic of a pressure drop (dP) measurement rig suitable for measuring the pressure drop across a particulate filter [Figure 15C] Schematic diagram of an apparatus for loading soot onto one or more particulate filters [Figure 16] 1 is a schematic diagram of an exemplary honeycomb body according to embodiments disclosed and described herein; [Figure 17] 1 is a schematic diagram of a wall-flow particulate filter according to embodiments disclosed and described herein; [Figure 18] Schematic of the relative position of a filter material including filter particles supported by honeycomb body walls that also support catalytic material, most of which is disposed within the walls and spaced apart from the filter particles, such that at least a portion of the solid particulate matter carried by the exhaust stream is captured by the filter particles. DETAILED DESCRIPTION OF THE INVENTION

[0009] Before describing some exemplary embodiments of the present disclosure, it should be understood that the present disclosure is not limited to the details of the configuration or process steps set forth in the following description. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways. As used herein, "filter body volume" or "liters of filter body" refers to the total volume calculated by multiplying the overall axial length of the filter body by the area of ​​an end (e.g., inlet end) of the filter body (pi / outer diameter squared). As used herein, "filter matrix volume" is equal to the closed frontal area of ​​the honeycomb matrix structure multiplied by the axial length of the honeycomb structure for an unplugged honeycomb structure; thus, the closed frontal area is the area occupied by the various honeycomb matrix walls at the inlet end of the honeycomb structure. Also, as used herein, a "predominantly intra-wall" or "predominantly intra-wall" catalyst loading of a porous wall, such as a porous wall of a honeycomb structure, refers to a catalyst material disposed within the porous wall, with a thickness of 0 to 25 micrometers on the wall at any location on the surface of the wall; thus, a honeycomb structure or matrix comprised of porous walls, such as porous ceramic walls, containing a "predominantly intra-wall" or "predominantly intra-wall" catalyst loading may have one or more wall surfaces with a thickness of 25 micrometers or less of catalyst material disposed on the surface, or "on the wall," of the honeycomb matrix wall. Preferably, in embodiments disclosed herein, no on-wall component of catalyst material is disposed on the gas inlet surface of the matrix wall; in some embodiments, no on-wall component of catalyst material is disposed on some, more preferably all, gas outlet surfaces of the matrix wall, such as the second wall surface defining the outlet channel (thickness of on-wall catalyst material is 0 micrometers).

[0010] In one set of embodiments, methods of manufacturing a porous ceramic honeycomb filter body are disclosed herein, the methods comprising depositing a filtration material comprising filtration particles onto porous filter walls of a filter structure, the filter structure comprising a matrix of filter walls configured as a cellular honeycomb structure of cells, surfaces of the filter walls defining channels extending from an inlet end to an outlet end of the filter structure, the channels including inlet channels and outlet channels, the filter structure comprising a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end, and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end, the porous filter walls comprising opposing first plugs and a second wall surface, wherein filtration particles are carried by the filter wall on, within, or both on and within the first wall surface; then heat treating the filter structure to provide heat treatment of the filtration material by heating the filter structure to one or more filtration heat treatment temperatures of 500°C or less for a time sufficient to reduce the hydrophobicity of the filtration material, wherein the filtration material is hydrophobic prior to deposition and / or is rendered hydrophobic after deposition and prior to heat treatment; and depositing a catalytic material on a second surface of the porous filter wall such that the catalytic material is disposed within the filter wall and / or on the second surface of the filter wall, the second surface defining the outlet channel.

[0011] In some embodiments, the filtration material exhibits hydrophobicity prior to deposition.

[0012] In some embodiments, the filtration material exhibits hydrophobicity prior to heat treatment.

[0013] In some embodiments, a mixture of filter particles and a carrier gas is transported through a duct toward a filter body at a downstream end of the duct and enters the inlet end of the filter body. In some of these embodiments, the filter material includes filter particles and one or more hydrophobic organic materials. In some of these embodiments, the at least one hydrophobic organic material is mixed with the filter particles before mixing with the carrier gas. In some of these embodiments, the organic material and the filter particles are injected into the carrier gas through a nozzle.

[0014] In some embodiments, at least some of the hydrophobicity of the filtration material remains after heat treatment of the filtration material.

[0015] In some embodiments, the filter structure is heat treated to provide heat treatment of the filtration material for more than 0.5 hours and less than 10 hours.

[0016] In some embodiments, the method further comprises reducing the hydrophobicity of the filtration material after the catalytic material is deposited.

[0017] In some embodiments, the method further comprises eliminating the hydrophobicity of the filtration material after the catalytic material is deposited.

[0018] In some embodiments, the method further comprises heat treating the filter structure after deposition of the catalytic material.

[0019] In some embodiments, the method further comprises, after depositing the catalytic material, heat treating the filter structure for a time and at one or more temperatures sufficient to calcine the catalytic material.

[0020] In some embodiments, depositing the catalytic material includes depositing the catalytic material in successive loads, and in some of these embodiments, the filter structure is heated between loads of the catalytic material without removing the hydrophobic properties of the filtration material.

[0021] In some embodiments, depositing the catalytic material comprises depositing the catalytic material in successive loads, wherein the catalytic material is dried between loads of the catalytic material.

[0022] In some embodiments, the method further comprises heat treating the filter structure after the selected amount of catalytic material has been deposited by heating the filter structure to a heat treatment temperature of greater than 500° C. for more than one hour.

[0023] In some embodiments, a selected amount of catalytic material is deposited, resulting in a catalytic loading of between 1 and 500 grams of catalytic material per liter of filter structure volume.

[0024] In some embodiments, depositing the catalytic material comprises applying a catalytic material slurry to the second surface of the filter wall.

[0025] In some embodiments, the filtration material comprises inorganic filtration particles and a binder material. In some of these embodiments, the binder material is hydrophobic; in some embodiments, the binder material comprises a silicon-containing material; in some embodiments, the binder material comprises a silicone material; in some embodiments, the binder material comprises a silicone resin; in some embodiments, the binder material comprises a siloxane or polysiloxane; in some embodiments, the binder material comprises an alkali siloxane; in some embodiments, the binder material comprises an alkoxy siloxane.

[0026] In some embodiments, the filtration particles comprise inorganic nanoparticles; in some embodiments, the inorganic nanoparticles comprise refractory nanoparticles; in some of these embodiments, the refractory nanoparticles comprise alumina, aluminum titanate, cordierite, silicon carbide, mullite, spinel, silica, zeolite, zirconia, silicon nitride, zirconium phosphate, or combinations thereof.

[0027] In some embodiments, the filtration material comprises an aggregate of inorganic nanoparticles and a binder material that exhibits hydrophobic properties.

[0028] In some embodiments, the filtration particles are not hydrophobic and hydrophobicity is imparted to the filtration material prior to depositing the catalytic material.

[0029] In some embodiments, the filtration particles are not hydrophobic and hydrophobicity is imparted to the filtration material by mixing the filtration particles with a hydrophobic material prior to depositing the catalytic material, hi some of these embodiments, the hydrophobic material comprises a hydrophobic organic material.

[0030] In another set of embodiments, disclosed herein is a method of manufacturing a porous ceramic honeycomb filter body, comprising: depositing a filtration material comprising filtration particles onto porous filter walls of a filter structure, wherein the filtration material is disposed on or within the filter walls, and the filtration material is hydrophobic; the filter structure comprises a matrix of filter walls configured as a cellular honeycomb structure of cells, wherein surfaces of the filter walls define channels extending from an inlet end to an outlet end of the filter structure, the channels including inlet channels and outlet channels; and wherein the filter structure comprises a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end; and a second group of plugs disposed within the inlet end and sealing the inlet channels at or near the inlet end. and a second group of plugs sealing the outlet channels near the first wall surface, wherein the porous filter walls include opposing first and second wall surfaces, and the filtration material is carried by the filter walls on, within, or both on and within the first wall surface; followed by heat treating the filter structure to one or more filtration heat treatment temperatures to provide heat treatment of the filtration material by maintaining at least some hydrophobicity of the filtration particles; followed by depositing a catalyst material on the second surface of the porous filter walls such that the catalyst material is disposed within and / or on the second surface of the filter walls while the filtration material is hydrophobic, the second surface defining the outlet channels.

[0031] In another set of embodiments, disclosed herein is a filter body including a porous honeycomb structure comprising porous filter walls, filtration particles carried by the porous filter walls, and a catalyst material, wherein the structure includes a matrix of filter walls configured as a cellular honeycomb structure with cells having an average wall thickness WT (in mils) and a cell density CD (cells per square inch (approximately 645.16 square millimeters)), wherein the surfaces of the filter walls define channels extending from an inlet end to an outlet end of the filter structure, the channels including an inlet channel and an outlet channel, and wherein the filter body has an effective diameter D (in mils). and a length L (in inches) extending axially from the inlet end to the outlet end, the filter structure including a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end, the porous filter wall including opposing first and second wall surfaces, filtration particles disposed within and / or on the filter wall at or near the first wall surface, a catalytic material disposed within and / or on a second surface of the porous filter wall, the catalytic material having a bulk density (BD) (g / m 3 The filter body has a filter matrix volume unit, a catalyst loading disposed primarily within the filter wall, a second surface defining an outlet channel, and a clean filtration efficiency of greater than 80% at a particle loading of 0.0 normalized to a reference filter body having a reference cell density of 300 cells per square inch (approximately 645.16 square millimeters) and a reference average wall thickness of 8 mils (approximately 203 micrometers).

[0032] In some embodiments, the filter body has a normalized clean filtration efficiency of greater than 85% at a particle loading of 0.0.

[0033] In some embodiments, the filter body has a normalized clean filtration efficiency of greater than 90% at a particle loading of 0.0.

[0034] In some embodiments, the filter body has a catalyst loading of 150 to 200 g of catalyst material per liter of filter matrix volume, the filter body exhibits a normalized clean filtration efficiency of greater than 92% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized clean pressure drop of less than 2.81 kPa at 0.0 g / L.

[0035] In some embodiments, the filter body has a catalyst loading of 200 to 350 g of catalyst material per liter of filter matrix volume, the filter body exhibits a normalized clean filtration efficiency of greater than 88% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized clean pressure drop of less than 3.24 kPa at 0.0 g / L.

[0036] In some embodiments, the filter body has a catalyst loading of 350 to 580 g of catalyst material per liter of filter matrix volume, the filter body exhibits a normalized clean filtration efficiency of greater than 85% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized clean pressure drop of less than 3.60 kPa at 0.0 g / L.

[0037] In some embodiments, the walls of the matrix are configured to define 300 cells per square inch (approximately 645.16 square millimeters) in an axial cross-section of the honeycomb structure; the filter walls have an average thickness of 8 mils (203 micrometers); the filter body has a catalyst loading of greater than 350 g of catalyst material per liter of filter matrix volume, the filter body exhibits a normalized clean filtration efficiency of greater than 85% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized clean pressure drop of less than 3.24 kPa at 0.0 g / L.

[0038] In some embodiments, the filter body has a catalyst loading of 150 to 200 g of catalyst material per liter of filter matrix volume, the filter body exhibits a normalized clean filtration efficiency of greater than 94% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized clean pressure drop of less than 2.6 kPa at 0.0 g / L.

[0039] In some embodiments, the filter body has a catalyst loading of 200 to 350 g of catalyst material per liter of filter matrix volume, the filter body exhibits a normalized clean filtration efficiency of greater than 90% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized clean pressure drop of less than 3.02 kPa at 0.0 g / L.

[0040] In some embodiments, the filter body has a catalyst loading of 350 to 580 g of catalyst material per liter of filter matrix volume, the filter body exhibits a normalized clean filtration efficiency of greater than 88% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized clean pressure drop of less than 3.40 kPa at 0.0 g / L.

[0041] In some embodiments, the walls of the matrix are configured to define 300 cells per square inch (approximately 645.16 square millimeters) in an axial cross section of the honeycomb structure; the filter walls have an average thickness of 8 mils (203 micrometers); the filter body has a catalyst loading of greater than 350 g of catalyst material per liter of filter matrix volume, the filter body exhibits a clean filtration efficiency of greater than 88% at a particulate loading of 0.0 g / L, and the filter body exhibits a clean pressure drop of less than 3.0 kPa at 0.0 g / L.

[0042] In some embodiments, the catalytic material is present at a catalyst loading of 40 to 50 g per liter of filter body, and the filter body exhibits a normalized clean filtration efficiency of greater than 92% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized pressure drop at a particulate loading of 0.5 g / L that is less than 115% of its normalized pressure drop at a particulate loading of 0.0 g / L.

[0043] In some embodiments, the catalytic material is present at a catalyst loading of 150 to 200 g per liter of filter matrix volume, and the filter body exhibits a normalized clean filtration efficiency of greater than 92% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized pressure drop at a particulate loading of 0.5 g / L that is less than 115% of its normalized pressure drop at a particulate loading of 0.0 g / L.

[0044] In some embodiments, the catalytic material is present at a catalyst loading of 200 to 350 g per liter of filter matrix volume, and the filter body exhibits a normalized clean filtration efficiency of greater than 88% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized pressure drop at a particulate loading of 0.5 g / L that is less than 120% of the normalized pressure drop at a particulate loading of 0.0 g / L.

[0045] In some embodiments, the catalytic material is present at a catalyst loading of 350 to 580 g per liter of filter matrix volume, and the filter body exhibits a normalized clean filtration efficiency of greater than 85% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized pressure drop at a particulate loading of 0.5 g / L that is less than 125% of the normalized pressure drop at a particulate loading of 0.0 g / L.

[0046] In some embodiments, the catalytic material is present at a catalyst loading of greater than 350 g per liter of filter matrix volume, the filter body exhibits a clean filtration efficiency of greater than 85% at a particulate loading of 0.0 g / L, and the filter body exhibits a pressure drop at a particulate loading of 0.5 g / L that is less than 125% of its pressure drop at a particulate loading of 0.0 g / L.

[0047] In some embodiments, the catalytic material is present at a catalyst loading of 150 to 200 g per liter of filter matrix volume, and the filter body exhibits a clean filtration efficiency of greater than 94% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized pressure drop at a particulate loading of 0.5 g / L that is less than 110% of its normalized pressure drop at a particulate loading of 0.0 g / L.

[0048] In some embodiments, the catalytic material is present at a catalyst loading of 200 to 350 g per liter of filter matrix volume, and the filter body exhibits a normalized clean filtration efficiency of greater than 90% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized pressure drop at a particulate loading of 0.5 g / L that is less than 115% of its normalized pressure drop at a particulate loading of 0.0 g / L.

[0049] In some embodiments, the catalytic material is present at a catalyst loading of 350 to 580 g per liter of filter matrix volume, and the filter body exhibits a normalized clean filtration efficiency of greater than 88% at a particulate loading of 0.0 g / L, and the filter body exhibits a normalized pressure drop at a particulate loading of 0.5 g / L that is less than 120% of its normalized pressure drop at a particulate loading of 0.0 g / L.

[0050] In another set of embodiments, disclosed herein are methods of making a filter body, such as a porous ceramic honeycomb filter body, the method comprising depositing a filtration material onto porous filter walls of a filter structure, the filtration material being hydrophobic, the filter structure comprising a matrix of filter walls configured as a cellular structure, such as a cellular honeycomb structure, the surfaces of the filter walls defining channels including inlet and outlet channels, such that the inlet and outlet channels are configured to receive a fluid flow, such as an exhaust gas stream, that carries particulates into some of the channels and fluid out of some of the channels, the channels extending from an inlet end to an outlet end of the filter structure, the filter structure comprising a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end, and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end, the porous filter walls comprising opposing first and second wall surfaces, and wherein filtration particles are deposited within and / or on the filter walls, e.g., at or near the filter wall or near the first wall surface carried by the filter wall; then heat treating the filter structure by heating the filter structure to one or more filtration heat treatment temperatures below 500°C, in some embodiments between 200°C and 500°C, in some embodiments between 300°C and 500°C, and in some embodiments between 350 and 400°C, for example, for 0.1 to 3.0 hours, or 0.1 to 2.0 hours, or 0.5 to 1.5 hours to provide heat treatment of the filtration material; in some embodiments, the temperature is between 450 and 500°C for 0.1 to 2.0 hours, and in some embodiments, the temperature can be between 475 and 495°C for 0.1 to 0.3 hours, preferably in a manner that tends to retain or maintain at least some hydrophobicity of the filtration material; then depositing a catalytic material on a second surface of the porous filter wall such that the catalytic material is disposed within the filter wall and / or on the second surface of the filter wall, the second surface defining the outlet channel.

[0051] In some embodiments, the hydrophobicity, or at least a portion of the hydrophobicity, of the filtration material remains after heat treatment of the filtration material.

[0052] In some embodiments, the filter structure is heat treated for less than 10 hours, in some embodiments, 0.1 to 5 hours, in some embodiments, 0.1 to 4 hours, in some embodiments, 0.1 to 3 hours, in some embodiments, 0.1 to 2 hours, in some embodiments, 0.1 to 1.5 hours, in some embodiments, 0.5 to 1.5 hours, for example, about 1 hour, to provide heat treatment of the filtration material.

[0053] The method preferably further includes reducing the hydrophobicity of the filtration material after the catalytic material is deposited. In some embodiments, the method includes reducing, removing, or substantially eliminating the hydrophobicity of the filtration material after the catalytic material is deposited. In some embodiments, reducing the hydrophobicity includes heat treating the filter structure after depositing the catalytic material; in some embodiments, the method includes heat treating the filter structure after depositing the catalytic material until the hydrophobicity of the filtration material is reduced; in some embodiments, the method includes heat treating the filter structure after depositing the catalytic material until the hydrophobicity of the filtration material is reduced or preferably removed.

[0054] In some embodiments, the method further comprises, after depositing the catalytic material, heat treating the filter structure for a time and at one or more temperatures sufficient to calcine the catalytic material.

[0055] In some embodiments, depositing the catalytic material includes depositing the catalytic material on the filter body in successive loads. In some embodiments, depositing the catalytic material includes depositing the catalytic material in successive loads, with the filter structure being heated between loads of catalytic material. In some embodiments, depositing the catalytic material includes depositing the catalytic material in successive loads, with the filter structure being heated between loads of catalytic material without removing or substantially reducing the hydrophobicity of the filtration material; in some of these embodiments, heating the filter structure reduces the hydrophobicity of the walls themselves without substantially affecting the hydrophobicity of the filtration material. In some embodiments, depositing the catalytic material includes depositing the catalytic material in successive loads, with the catalytic material being dried between loads of catalytic material. In some embodiments, depositing the catalytic material includes depositing the catalytic material in successive loads, with the catalytic material being dried between loads of catalytic material without removing or substantially reducing the hydrophobicity of the filtration material.

[0056] In some embodiments, depositing the catalytic material includes depositing the catalytic material in successive loads, and in some of these embodiments, the filter structure is heat treated between loads of catalytic material.

[0057] In some embodiments, where the method includes multiple loadings of catalytic material, the method further includes, between loadings of catalytic material, heating the filter structure to a drying temperature not exceeding 200° C., in some embodiments not exceeding 150° C., in some embodiments not exceeding 120° C., in some embodiments not exceeding 110° C., and in some embodiments not exceeding 100° C. In some embodiments, the filter structure is exposed to a heated environment having a drying temperature not exceeding 200° C., in some embodiments not exceeding 150° C., in some embodiments not exceeding 120° C., in some embodiments not exceeding 110° C., and in some embodiments not exceeding 100° C.

[0058] In some embodiments, the method further comprises heat treating the filter structure after the selected amount of catalytic material has been deposited.

[0059] In some embodiments, the method further includes heat treating the filter structure after the selected amount of catalytic material has been deposited by heating the filter structure to a heat treatment temperature of greater than 300°C, in some embodiments greater than 400°C, in some embodiments greater than 500°C, in some embodiments between 500°C and 800°C, in some embodiments between 500°C and 700°C, and in some embodiments between 500°C and 600°C.

[0060] In some embodiments, the heat treatment reduces the hydrophobicity of the filter particles compared to the hydrophobicity of the filter particles before the catalytic material is dried; in some embodiments, the heat treatment reduces the hydrophobicity of the filter particles compared to the hydrophobicity of the filter particles before the drying step; in some embodiments, the heat treatment reduces the hydrophobicity of the filter particles compared to the hydrophobicity of the filter particles during deposition of the catalytic material.

[0061] In some embodiments, the method further includes heat treating the filter structure after the selected amount of catalytic material has been deposited by heating the filter structure to a heat treatment temperature of greater than 500°C, in some embodiments greater than 600°C, and in some embodiments greater than 700°C, for a period of greater than 1 hour, in some embodiments greater than 2 hours, in some embodiments greater than 3 hours, in some embodiments greater than 4 hours, in some embodiments between 1 and 4 hours, and in some embodiments between 1 and 3 hours.

[0062] Preferably, a selected amount of catalytic material is deposited, hi some embodiments, the selected amount of catalytic material is between 1 and 500 grams of catalytic material per liter of filter structure volume.

[0063] In some embodiments, depositing the catalytic material comprises applying a slurry including the catalyst particles to the filter structure. In some embodiments, depositing the catalytic material comprises applying the slurry to the filter wall. In some embodiments, depositing the catalytic material comprises applying the slurry to a second surface of the filter wall.

[0064] In some embodiments, the filtration particles are comprised of inorganic particles and a binder material, which in some embodiments is preferably a hydrophobic binder material. In some embodiments, the inorganic particles and / or the binder material can be rendered hydrophobic, such as after deposition on the filter component.

[0065] In some embodiments, the binder material is hydrophobic. In some embodiments, the binder material comprises a silicon-containing material. In some embodiments, the binder material comprises a silicone material. In some embodiments, the binder material comprises a silicone resin. In some embodiments, the binder material comprises a siloxane or polysiloxane. In some embodiments, the binder material comprises an alkali siloxane. In some embodiments, the binder material comprises an alkoxy siloxane.

[0066] In some embodiments, the filtration particles comprise inorganic nanoparticles. In some embodiments, the inorganic nanoparticles comprise refractory nanoparticles. In some embodiments, the refractory nanoparticles comprise alumina, aluminum titanate, cordierite, silicon carbide, mullite, spinel, silica, zeolite, zirconia, silicon nitride, zirconium phosphate, and combinations thereof. In some embodiments, the filtration material comprises aggregates of inorganic nanoparticles, such as aggregates of inorganic nanoparticles and a hydrophobic binder material. In some embodiments, the filter structure is a honeycomb structure. In some embodiments, the matrix of the filter wall is configured as a honeycomb structure. In some embodiments, the filter body is a porous ceramic honeycomb filter body.

[0067] FIG. 1 schematically illustrates an apparatus and method for applying filtration material to a filter body, including applying the filtration material by a filtration method in which a mixture of fluid and filtration particles is sprayed from a nozzle and transported with a carrier gas through a duct toward the filter body at the downstream end of the duct and into the inlet end of the filter body, where the filtration material is deposited on, within, or both the surface of the wall of the filter body defining the inlet channel, and the carrier gas can pass through the porous wall of the filter body and exit through an outlet duct, possibly assisted by an outlet fan. The particles exiting the nozzle may agglomerate before reaching the filter body, resulting in the filtration material comprising agglomerates of filtration particles, which may further comprise a binder material. The fluid and particle streams may be heated before entering the filter body.

[0068] 2 illustrates a schematic diagram of an apparatus and method for depositing catalytic material onto a filter wall of a filter body, such as by drawing a vacuum on the inlet end of the filter body while the filter body is at least partially immersed in a slurry of catalytic material, such as a TWC slurry. The slurry may be drawn into the outlet end of the filter body by a vacuum created by a vacuum pump.

[0069] 3 schematically illustrates various process steps disclosed herein, including starting with a bare filter body consisting of a plugged honeycomb structure having an inlet end and an outlet end, then applying a filtration material to the inlet end of the filter body and depositing it on the inlet surface of the honeycomb structure's filter wall, then subjecting the filter body to a heat treatment, then introducing a load of catalytic material into the outlet end of the filter body, then subjecting the filter body to drying conditions such as exposure to an environment at a temperature of 110° C. for 12 to 24 hours, then optionally introducing one or more additional loads of catalytic material into the outlet end of the filter body, and after the last or final load of catalytic material is applied, calcining the catalytic material by subjecting it to calcination conditions such as exposure to an environment at a temperature of 550° C. for 2 to 4 hours. The resulting filter body includes filtration particles disposed on, within, or both the cell walls defining the inlet channels and catalytic material disposed on, within, or both the cell walls defining the outlet channels.

[0070] Figure 4 shows a schematic SEM cross-section of a filter wall of a filter body containing a porous ceramic honeycomb structure that has been wash-coated with a catalytic material. The porous ceramic portion of the filter wall is shown in medium gray, and the catalytic material is shown in dark gray. The catalytic material is applied via a slurry. During the slurry-coating process, the coating material is forced into the cell walls by capillary forces, with the catalytic material (or washcoat) occupying the smaller pores and leaving the larger pores open. This allows subsequent deposition of filtration particles to more freely penetrate and occupy the larger pores. Figure 4 shows the distribution of filtration particles deposited on the cell walls of the wash-coated filter body, where the filtration particles are represented by small, solid (usually circular) dots (they are shown positioned on and below (intra-) the cell walls of the inlet channels). Thus, in addition to being present on the inlet surface of the filter wall, the filtration particles also occupy the relatively large pores in the cell walls and penetrate relatively deeply into the cell walls. Such a distribution of filtered particles contributes to very high clean and soot loaded pressure drops (depth effect).

[0071] Figure 5 shows a schematic SEM cross-section of a filter wall of a filter body containing a porous ceramic honeycomb structure that has not been washcoated with a catalytic material. The porous ceramic portion of the filter wall is shown in medium gray. The distribution of filtration particles deposited on the cell walls of the unwashcoated (bare) filter body is shown in Figure 5, where the filtration particles are represented by small, solid (usually round) dots (they are shown positioned on and below the cell walls of the inlet channels). Therefore, the deposition of filtration material, including filtration particles, on the bare filter body tends to be more locally deposited to a uniform penetration depth, occupying less of the larger pores compared to Figure 4. Therefore, the filtration particles penetrate into the cell walls, to a lesser extent, in addition to being present on the inlet surface of the filter wall.

[0072] FIG. 6 shows a schematic SEM cross-section of a filter wall of a filter body including the porous ceramic honeycomb structure of FIG. 5 coated with a catalytic material after deposition of the filtration material and after the filtration material has been exposed to a heat treatment exceeding 500°C before washcoating with the catalytic material to prevent the filtration particles from becoming hydrophobic during washcoating. The porous ceramic portion of the filter wall is shown in medium gray, and the catalytic material is shown in dark gray. The distribution of filtration particles deposited on the cell walls of a bare filter body without washcoating is shown in FIG. 6, where the filtration particles are represented by small solid (usually round) dots (they are shown positioned on and below (intra-wall) the cell walls of the inlet channels). Therefore, deposition of filtration material, including filtration particles, on a bare filter body tends to result in more locally uniform penetration depth, so that in addition to being present on the inlet surface of the filter wall, the filtration particles occupy less of the larger pores compared to FIG. 4 but penetrate into the cell walls. Additionally, the filtration stack preferably has a high porosity that provides high capillary forces that can draw the catalytic washcoat or slurry material into the pores of the filtration stack, which tends to increase the pressure drop of the flow through the filter wall and can lead to very high pressure drops through the wall; therefore, the dark gray shading generally surrounding the filtration particles on the inlet side of the cell wall represents the catalytic washcoat material that has filled the filtration stack.

[0073] FIG. 7 shows a schematic SEM cross-section of a filter wall of a filter body including the porous ceramic honeycomb structure of FIG. 5 , in which a catalytic material is applied after deposition of a filtration material containing filtration particles, and after the filtration material (and particles) have been exposed to a heat treatment below 500°C, more specifically, one or more temperatures between 300 and 500°C, i.e., after the filtration material is washcoated with a catalytic material while it remains hydrophobic during the washcoating. In some embodiments, the application of the catalytic washcoat occurs after the filtration particles have been exposed to some degree of heating, so long as at least some, preferably most, of the hydrophobicity is maintained or preserved after heating. The porous ceramic portion of the filter wall is shown in medium gray, and the catalytic material is shown in dark gray. The distribution of filtration particles deposited on the cell walls of an unwashcoated (bare) filter body is shown in FIG. 7 , where the filtration particles are represented by small, solid (usually circular) dots (they are shown disposed on and below (intra-) the cell walls of the inlet channels). Therefore, the deposition of the filtration particles on the bare filter body tends to be more uniform, so that in addition to being present on the surface of the inlet side of the filter wall, the filtration particles penetrate into the cell walls, occupying fewer of the larger pores compared to Figure 4. Even though the filtration deposit has a high porosity due to the hydrophobicity of the filtration material containing the filtration particles, providing a high capillary force that may draw the catalytic washcoat or slurry material into the pores of the filtration deposit, the dark gray shading generally surrounding the filtration particles on the inlet side of the cell walls in Figure 6 is not present because the catalytic washcoat material does not fill the filtration deposit. Therefore, the high porosity of the filtration deposit can be maintained even after subsequent treatments, such as heat treatment of the filtration material and / or calcination of the catalytic material.

[0074] FIG. 8 graphically illustrates pressure drop in kPa versus particle loading (soot loading) in grams / liter (grams of loading per liter of filter body, or g / l) for: (A) a bare high porosity (approximately 65% ​​porosity by mercury porosimetry) porous ceramic filter body with no washcoated catalytic material and no filtering particles present in or on the filter body; (B) a TWC washcoated catalytic material present in or on the filter body in an amount of 90 grams per liter of filter body and filtering particles present in or on the filter body; (C) a filter body with no particles present, and (D) a filter body with TWC washcoated catalytic material present in or on the outlet surface of the filter body in an amount of 90 grams per liter of filter body and filtration particles present in or on the inlet surface of the filter body (wherein the filtration particles were applied by deposition onto a filter body previously washcoated (or "catalyzed") with TWC catalytic material, with approximately 2 grams of filtration particles present on the filter body per liter of filter body, and the filtration particles were heat treated (to remove hydrophobicity). The filter body was 4.66 inches in diameter, 4.72 inches long (axially), and had a matrix wall with 300 cells per square inch (cpsi) and an 8 mil thickness.

[0075] FIG. 9 graphically illustrates the filtration efficiency in % versus particle loading (soot loading) in grams per liter (g / l) for the filter bodies (A), (B), and (C) of FIG.

[0076] As seen in Figures 8-9, a very high FE (approximately 98%) was obtained with a particulate loading of only approximately 2 g / L, resulting in a very high pressure drop penalty: the clean (nearly 0.0 soot (particulate) loading) dP increased by approximately 81.8% compared to the bare filter body and 69% compared to the TWC-coated filter body. The dP increase for the TWC-coated filter body compared to the bare filter body is only approximately 7.6%. Furthermore, the presence of a pronounced knee in the soot-loading pressure drop curve (the "SLdP knee") suggests a deep filtration mechanism, corresponding to the higher pressure drop with increasing soot loading.

[0077] FIG. 10 graphically illustrates pressure drop in kPa versus particle loading (soot loading) in grams / liter (grams of loading per liter of filter body, or g / l) for: (A) a bare high porosity porous ceramic filter body with no washcoated catalyst material and no filter particles in or on the filter body; (B) a filter body with TWC washcoated catalyst material in or on the filter body in an amount of 92 grams per liter of filter body and no filter particles; and (D) a filter body with filtration particles in an amount of 6.4 grams per liter of filter body and no filter particles in or on the filter body. (E) a filter body having no washcoated catalytic material on the filter body, and (F) a filter body having TWC washcoated catalytic material in or on the outlet surface of the filter body in an amount of 95 grams per liter of filter body and filtration particles in or on the inlet surface of the filter body in an amount of 6.4 grams per liter of filter body (wherein the TWC washcoat was applied to a filter body already having filtration particles that had been heat-treated (i.e., hydrophobicity-reducing or hydrophobicity-removing) at a temperature of up to 600°C, where the filtration particles were not hydrophobic when the TWC washcoat was applied, and the TWC material was calcined). The filter body was 4.66 inches in diameter, 6 inches (axially) long, and had a matrix wall with 300 cells per square inch (cpsi) and an 8 mil (0.203 mm) thickness.

[0078] FIG. 10 shows that the filter body (E) has a higher clean (at a soot particle loading of 0.0) pressure drop that is 51.8% higher than the clean pressure drop for the bare filter body (A), and that the filter body (E) has a higher clean (at a soot particle loading of 0.0) pressure drop that is 40.8% higher than the clean pressure drop for the wash-coated filter body (B).

[0079] 10 shows that filter body (E) has a higher clean (at 0.0 soot particle loading) pressure drop that is 51.8% higher than the clean pressure drop for the bare filter body (A), and that filter body (E) has a higher clean (at 0.0 soot particle loading) pressure drop that is 40.8% higher than the clean pressure drop for the wash-coated filter body (B). Furthermore, the presence of a pronounced knee ("SLdP knee") in the soot loading pressure drop curve suggests a depth filtration mechanism, corresponding to higher pressure drops with increasing soot loading.

[0080] FIG. 11 graphically illustrates the filtration efficiency in % versus particle loading (soot loading) in grams per liter (g / l) for filter bodies (A), (B), (D), and (E) of FIG. 10.

[0081] FIG. 11 shows that filter bodies having filtration particles after undergoing high temperature heat treatment and not having hydrophobic properties when a catalytic material is applied to the filter body provide significantly lower clean filtration efficiency (“FE”), for example, compared to filter body (D) having a clean filtration efficiency of 96% and filter body (E) having a clean filtration efficiency of about 70%.

[0082] FIG. 12 graphically illustrates pressure drop in kPa versus particle loading (soot loading) in grams / liter (grams of loading per liter of filter body, or g / l) for: (A) a bare high porosity porous ceramic filter body with no washcoated catalyst material and no filter particles in or on the filter body, (B) a filter body with TWC washcoated catalyst material in or on the filter body at a catalyst loading of 92 grams per liter of filter body and no filter particles, and (C) a filter body with no washcoated catalyst material in or on the filter body and filter particles in an amount of 6.4 grams per liter of filter body, and (D) a filter body with no washcoated catalyst material in or on the filter body and filter particles in an amount of 6.4 grams per liter of filter body. G) A filter body having TWC washcoated catalyst material present in or on the outlet surface of the filter body in an amount of 85 grams per liter of filter body and filtration particles present in or on the inlet surface of the filter body in an amount of 7.1 grams of filtration particles per liter of filter body (wherein the TWC washcoat was applied to a filter body already comprising filtration particles that had been heat treated at a temperature of up to 350°C (i.e., heat treated to preserve hydrophobicity), such that the filtration material including the filtration particles was hydrophobic when the TWC washcoat was applied, and the filter body was heat treated at a higher temperature (>550°C) sufficient to calcinate the TWC material (i.e., the hydrophobicity of the filtration material including the filtration particles was removed by calcination after the TWC material was deposited on or in the filter body)). The filter body was 4.66 inches (approximately 11.84 cm) in diameter, 6 inches (approximately 15.24 cm) long (axially), with 300 cells per square inch (cpsi) and a matrix wall thickness of 8 mils (approximately 0.203 mm).

[0083] FIG. 12 shows that the filter body (G) has a higher clean (at 0.0 soot particle loading) pressure drop that is 27% higher than the clean pressure drop for the bare filter body (A), and that the filter body (G) has a higher clean (at 0.0 soot particle loading) pressure drop that is 17.8% higher than the clean pressure drop for the wash-coated filter body (B).

[0084] FIG. 12 shows filter body G, having 7.1 grams of filtration particles per liter of filter body, after being subjected to a low to medium temperature hydrophobicity-retaining heat treatment (e.g., a maximum heat treatment temperature of 500° C., i.e., exposure to one or more temperatures of 500° C. or less, more specifically 200 to 500° C., or in some embodiments 300 to 500° C.) so that the filtration particles become hydrophobic when the catalytic material is applied to the filter body, and then heat treated at a high temperature above 500° C. sufficient to calcine the catalytic material and remove the hydrophobicity of the filtration particles, resulting in a 27% higher pressure drop at a particulate loading at or near 0.0 compared to the pressure drop for filter body A.

[0085] FIG. 13 graphically illustrates the filtration efficiency in % versus particle loading (soot loading) in grams per liter (g / l) for filter bodies (A), (B), (F), and (G).

[0086] FIG. 13 shows filter body G having 7.1 grams of filtration particles per liter of filter body after being subjected to a low to medium temperature hydrophobicity-retaining heat treatment (such as a maximum heat treatment temperature of 350°C), which becomes hydrophobic when the catalyst material is applied to the filter body, and which is loaded with 6.4 grams of filtration particles per liter of filter body, but which has the same or only a slightly lower clean filtration efficiency (92% clean FE for filter body G) compared to filter body F which does not contain the catalyst material (96% clean FE for filter body F).

[0087] Furthermore, the embodiments disclosed herein have a nearly complete knee in the soot-loaded pressure drop curve (the "SLdP knee"), suggesting that the deeper filtration mechanism corresponding to the higher pressure drop is avoided and that the filter particles and catalyst material are processed and functioning properly. In FIG. 12, Filter Body B exhibits a ratio of pressure drop at 0.5 g / L soot particle loading to pressure drop at 0 g / L soot particle loading of 1.22, indicating a significant knee. Meanwhile, Filter Body G according to this disclosure exhibits a ratio of pressure drop at 0.5 g / L soot particle loading to pressure drop at 0 g / L soot particle loading of only 1.07, indicating a nearly complete knee. For example, in FIG. 12, filter body B exhibited a pressure drop gradient of approximately 0.32 kPa pressure drop per g / l soot loading between 0.00 g / l soot loading and 1.25 g / l soot loading, and approximately 0.29 kPa pressure drop per g / l soot loading between 1.25 g / l soot loading and 3.0 g / l soot loading, such that the change in pressure drop gradient was less than 30%, preferably less than 20%, and more preferably less than 15% (absolute value) (here, approximately 11%) for soot loadings between 0.00 and 3.00 g / l. In contrast, filter body G had a significant bend and exhibited a pressure drop gradient of approximately 1.00 kPa pressure drop per g / l soot loading between 0.00 g / l soot loading and 1.25 g / l soot loading, and approximately 0.4 kPa pressure drop per g / l soot loading between 1.25 g / l soot loading and 3.00 g / l soot loading, such that the change in pressure drop gradient was approximately 40% (absolute value) in the soot loading range of 0.00 to 3.00 g / l. The filter bodies disclosed herein, such as filter body B of FIG. 12, exhibit a pressure drop gradient of less than about 1.00 kPa pressure drop per g / L of soot loading, preferably less than 0.70 kPa pressure drop per g / L of soot loading, more preferably less than 0.50 kPa pressure drop per g / L of soot loading, even more preferably less than 0.40 kPa pressure drop per g / L of soot loading, and even more preferably less than 0.35 kPa pressure drop per g / L of soot loading, for all soot loadings between 0.00 g / L and 3.00 g / L soot loading.The filter bodies disclosed herein, such as filter body B of FIG. 12, exhibit a pressure drop gradient of less than about 1.00 kPa pressure drop per g / l soot loading, preferably less than 0.70 kPa pressure drop per g / l soot loading, more preferably less than 0.50 kPa pressure drop per g / l soot loading, even more preferably less than 0.40 kPa pressure drop per g / l soot loading, and even more preferably less than 0.35 kPa pressure drop per g / l soot loading, for all soot loadings between 0.00 g / l soot loading and 1.00 g / l soot loading.

[0088] FIG. 13 corresponds to a filter body including a porous honeycomb structure for a filter structure consisting of porous filter walls, wherein the filter structure includes a matrix of filter walls configured as a cellular honeycomb structure consisting of cells, the surfaces of the filter walls defining channels extending from an inlet end to an outlet end of the filter structure, the channels including inlet channels and outlet channels, the filter structure including a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end, and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end; The porous filter wall includes opposing first and second wall surfaces, the filter wall of the filter structure carrying filtration particles disposed within and / or on the filter wall at or near the first wall surface, in some embodiments near the first surface, and a catalyst material disposed within and / or on a second surface of the porous filter wall, the second surface defining an outlet channel, and the filter body having a clean filtration efficiency at a particle loading of 0.0, greater than 80%, in some embodiments greater than 85%, and in some embodiments greater than 90%, as shown, for example, in FIG. 13 .

[0089] FIG. 14 schematically illustrates the % increase in clean filtration efficiency (first set of bars), clean pressure drop (second set of bars), and particulate / soot loading pressure drop (third set of bars), where the first bar in each set corresponds to (1) a filter body coated with TWC catalyst material through the outlet channels at a loading of 90 g / L followed by a loading of 2 g / L of filtration particles through the inlet channels, (2) a filter body loaded with 7.1 g / L of filtration particles through the inlet channels and then heat treated at 350° C. followed by a TWC catalyst coating through the outlet channels at a loading of 85 g / L, and (3) a filter body loaded with 7.1 g / L of filtration particles through the inlet channels and then heat treated at 600° C. followed by a TWC catalyst coating through the outlet channels at a loading of 85 g / L. FIG. 14 shows that both higher clean filtration efficiency and lower pressure drop are associated with applying a hydrophobic filtration material containing filtration particles, followed by heat treatment at a temperature low enough to retain at least some hydrophobicity, and then applying a catalytic material via a washcoat while the filtration material containing filtration particles is still hydrophobic.

[0090] FIG. 15A shows a schematic of the setup used to measure filtration efficiency. This setup involves the generation of soot using a propane burner (a reproducible exhaust simulator (REXS burner, Matter Engineering Inc.)) and then mixing the soot with primary air before the air is introduced into the input pipe to the particulate filter. The particulate matter or soot generated by the REXS / CAST burner may have similar soot morphology, chemistry, and size distribution to soot generated by diesel engines, although for evaluation purposes such soot can also be injected into other types of particulate filters, such as gasoline particulate filters. See, for example, SAE Paper No. 2008-01-0759(2008) Kasper and Mosimann reported that the mobility size distribution of REXS-generated soot is comparable to diesel soot, with a mobility mode diameter of 80 nm, a lognormal geometric standard deviation of 1.8, and a primary particle diameter of 20-35 nm. The soot concentration level and primary air flow rate can be selected so that the total gas mass flow rate is similar to the velocity of interest in engine applications, such as those encountered in light- and heavy-duty diesel engine applications or gasoline particulate filter applications. To estimate mass-based filtration efficiency, soot mass concentrations are measured upstream and downstream of the filter using AVL's photoacoustic microsoot sensor (MSS). Prior to the test, the two microsoot sensors are calibrated against each other by measuring the upstream soot concentration at different levels of primary gas dilution. The particulate filter is cleaned with compressed air and loaded onto the measurement bench. The system is set to bypass mode and the primary air is gradually increased to the desired level. The REXS burner is turned on and the system is allowed to stabilize while remaining in bypass mode. The soot concentration level and primary air flow rate are determined according to the test requirements. For the data reported here, the combined burner and primary air flow rate used is 365 SLPM (standard liters per minute). The soot concentration level used is approximately 7 mg / m 3 It can be seen that the soot concentration downstream of the filter measured by MSS starts at a certain value and then gradually decreases to zero, as the deposited (accumulated) soot plays a role in enhancing filtration. The time step of the MSS measurement is set to δt = 1 s. The downstream concentration data from MSS is taken as (t’ κ C down,κ ;κ=1,2,…N), then at any time t ’ κ The mass-based filtration efficiency at is calculated as follows:

[0091]

number

[0092] where C up is the upstream concentration measured by the microsoot sensor. κ The corresponding filter soot loading SL per unit filter volume at is estimated using the following relationship:

[0093]

number

[0094] Here, Q T is the volumetric flow rate into the filter, and V フィルタ is the volume of the filter. As soot accumulates within the filter, the soot itself acts as additional filtering media, improving filtration efficiency over time. Filtration efficiency gradually increases from clean filter efficiency to a steady-state efficiency, asymptotically reaching 100% efficiency at higher soot (particulate) loadings. Figure 15B shows a schematic of a pressure drop (dP) measurement rig, or test bench, suitable for measuring the pressure drop across a particulate filter. The bench includes an arrangement for loading a can-shaped filter body or "component" with flanges associated with pressure sensors upstream (filter inlet face) and downstream (filter outlet face) of the filter. The difference in pressure measured by the upstream and downstream sensors is the pressure drop ("Δp" or "dP"). The filter is cleaned with compressed air and loaded onto the measurement bench. The air flow rate is selected depending on the test requirements. For the data reported here, the air flow rate used was 210 SCFM (standard ft 3 / min), with standard conditions specified at 21.1°C and 1 ATM. The pressure drop measured without soot can be referred to as clean dP or clean pressure drop. The pressure drop measured with soot can be referred to as SLdP or soot-loaded pressure drop. To measure the pressure drop of a filter with soot, the filter is individually loaded with a measured amount of soot and tested in the rig described above. Figure 15C shows a schematic of the soot-loaded rig. Artificial soot (Printex-U) was deposited on the filter using compressed nitrogen (N2) as a carrier. A Torrit dust collector was placed downstream of the filter to capture soot that passed through or penetrated the test filter. Each rig had a designated soot feeder connected to a funnel. The soot was sent to the funnel by the auger screw, where it was drawn into the main exhaust pipe by a venturi system. The corresponding weight and pressure drop measured at each level can be used to generate incremental soot loadings in the filter to generate SLdP profiles. For the data reported here, the nitrogen flow rate used to load the soot was 16 ft. 3 / min.

[0095] In some embodiments, the filter bodies disclosed herein comprise a porous filter wall or porous wall portion of the filter body comprising a bulk porosity of 40 to 75% as measured by mercury porosimetry.

[0096] In some embodiments, the porous wall portion comprises a wall made of cordierite, aluminum titanate, silicon carbide, mullite, spinel, silica, alumina, silicon nitride, and combinations thereof.

[0097] In some embodiments, the porous wall portion comprises walls arranged in a honeycomb structure having between 100 and 900 cells per square inch (approximately 645.16 square millimeters).

[0098] Referring now to FIG. 16 , a honeycomb body 300 is shown according to one or more embodiments shown and described herein. In an embodiment, the honeycomb body 300 may include a plurality of walls 306 defining a plurality of interior channels 301. The plurality of interior channels 301 and intersecting channel walls 306 extend between a first end 302, which may be an inlet end, and a second end 304, which may be an outlet end, of the plugged honeycomb body. The honeycomb body may have one or more channels plugged at one or both of the first end 302 and the second end 304. The pattern of plugged channels in the honeycomb body is not limited. In some embodiments, the pattern of plugged and unplugged channels at one end of the plugged honeycomb body may be a checkerboard pattern, for example, where alternate channels at one end of the plugged honeycomb body are plugged. In some embodiments, plugged channels at one end of the plugged honeycomb body have corresponding unplugged channels at the other end, and unplugged channels at one end of the plugged honeycomb body have corresponding plugged channels at the other end.

[0099] In one or more embodiments, the plugged honeycomb body may be comprised of cordierite, aluminum titanate, enstatite, mullite, forsterite, corundum (SiC), spinel, sapphirine, or periclase, or combinations thereof. Generally, cordierite has the formula MgAlSiO 18 In some embodiments, the pore size of the ceramic material, the porosity of the ceramic material, and the pore size distribution of the ceramic material are obtained in a controlled manner, for example, by varying the particle size of the ceramic raw materials. Additionally, a pore former can be included in the ceramic batch used to form the plugged honeycomb body.

[0100] In some embodiments, the walls of the plugged honeycomb body can have an average thickness of 25 μm to 400 μm, e.g., 50 μm to 375 μm, 75 μm to 350 μm, 100 μm to 325 μm, 125 μm to 300 μm, 150 μm to 300 μm, 150 μm to 275 μm, 150 μm to 250 μm, or 175 μm to 225 μm. The walls of the plugged honeycomb body can be described as having a base portion, consisting of a bulk portion (also referred to herein as bulk) and a surface portion (also referred to herein as surface). The surface portion of the wall extends from the surface of the wall of the plugged honeycomb body into the wall toward the bulk portion of the plugged honeycomb body. The surface portion may extend to a depth of 0 to about 5 μm into the base portion of the wall of the plugged honeycomb body. In some embodiments, the surface portion may extend into the base portion of the wall about 5 μm, about 7 μm, or about 9 μm (i.e., a depth of 0 μm). The bulk portion of the plugged honeycomb body comprises the wall thickness minus the surface portion. Thus, the bulk portion of the plugged honeycomb body may be determined by the following formula: t 全体 -2t 表面 , where t 全体 is the total thickness of the wall, and t 表面 is the wall thickness.

[0101] In one or more embodiments, the bulk of the plugged honeycomb body (before any filtration material is applied) has a bulk median pore size of from 7 μm to 25 μm, e.g., from 12 μm to 22 μm, or from 12 μm to 18 μm. For example, in some embodiments, the bulk of the plugged honeycomb body can have a bulk median pore size of about 10 μm, about 11 μm, about 12 μm, about 13 μm, about 14 μm, about 15 μm, about 16 μm, about 17 μm, about 18 μm, about 19 μm, or about 20 μm. Generally, the pore sizes of a given material exist in a statistical distribution. Thus, the term "median pore size" or "d50" (before any filtration material is applied) refers to the length measurement above which 50% of the pores lie and below which the remaining 50% of the pores lie, based on a statistical distribution of all pores. The pores in a ceramic body can be created by at least one of the following: (1) the particle size and size distribution of the inorganic batch materials; (2) the firing time and temperature schedule of the furnace / heat treatment; (3) the furnace atmosphere (e.g., low or high oxygen and / or moisture content); and (4) pore formers, such as, for example, polymers and polymer particles, starch, wood flour, hollow inorganic particles, and / or graphite / carbon particles.

[0102] In some specific embodiments, the median pore size (d50) of the bulk of the plugged honeycomb body (before any filtration material is applied) ranges from 10 μm to about 16 μm, e.g., 13-14 μm, where d10 refers to the length measurement above which 90% of the pores lie and below which the remaining 10% of the pores lie, based on a statistical distribution of all pores, and is about 7 μm. In certain embodiments, d90 refers to the length measurement above which 10% of the pores in the bulk of the plugged honeycomb body (before any filtration material is applied) lie and below which the remaining 90% of the pores lie, based on a statistical distribution of all pores, and is about 30 μm. In certain embodiments, the median diameter (D50) of the secondary particles or agglomerates is about 2 micrometers (μm, or "microns"). In certain embodiments, it has been determined that excellent filtration efficiency results and low pressure drop results are achieved when the median aggregate size D50 and the median wall pore diameter d50 of the bulk honeycomb body are such that the ratio of the median aggregate size D50 to the median wall pore diameter d50 of the bulk honeycomb body is in the range of 5:1 to 16:1. In more specific embodiments, the ratio of the median aggregate size D50 to the median wall pore diameter d50 of the bulk honeycomb body (before any filtration material is applied) is in the range of 6:1 to 16:1, 7:1 to 16:1, 8:1 to 16:1, 9:1 to 16:1, 10:1 to 16:1, 11:1 to 16:1, or 12:1 to 6:1, resulting in excellent filtration efficiency results and low pressure drop results.

[0103] In some embodiments, the bulk of the plugged honeycomb body can have a bulk porosity, excluding the coating, of 50% or more to 75% or less, as measured by mercury intrusion porosimetry. Other methods for measuring porosity include scanning electron microscopy (SEM) and X-ray tomography, two methods that are particularly useful for measuring surface and bulk porosity independently of one another. In one or more embodiments, the bulk porosity of the plugged honeycomb body can be, for example, in the range of about 50% to about 75%, about 50% to about 70%, about 50% to about 65%, about 50% to about 60%, about 50% to about 58%, about 50% to about 56%, or about 50% to about 54%.

[0104] In one or more embodiments, the surface portion of the plugged honeycomb body has a surface median pore diameter of from 7 μm to 20 μm, e.g., from 8 μm to 15 μm, or from 10 μm to 14 μm. For example, in some embodiments, the surface of the plugged honeycomb body can have a surface median pore diameter of about 8 μm, about 9 μm, about 10 μm, about 11 μm, about 12 μm, about 13 μm, about 14 μm, or about 15 μm.

[0105] In some embodiments, the surface of the plugged honeycomb body may have a surface porosity of 35% or more and 75% or less, prior to application of the filtration material deposition, as measured by mercury intrusion porosimetry, SEM, or X-ray tomography. In one or more embodiments, the surface porosity of the plugged honeycomb body may be less than 65%, e.g., less than 60%, less than 55%, less than 50%, less than 48%, less than 46%, less than 44%, less than 42%, less than 40%, less than 48%, or less than 36%.

[0106] 16 and 17, a honeycomb body in the form of a particulate filter 300 is shown schematically. The particulate filter 300 may be used as a wall flow filter for filtering particulate matter from an exhaust gas stream, such as an exhaust gas stream emitted from a gasoline engine, in which case the particulate filter 300 is a gasoline particulate filter. The particulate filter 300 generally includes a honeycomb body having a plurality of channels 310 or cells extending between an inlet end 302 and an outlet end 304 and defining an overall length thereof. The channels 310 of the particulate filter 300 are formed by, and at least partially defined by, a plurality of intersecting channel walls 306 that extend from the inlet end 302 to the outlet end 304. The particulate filter 300 may also include a skin layer 305 that surrounds the matrix of walls 306 and the plurality of channels 310. This skin layer 305 may be extruded during the formation of the channel walls 306, or may be formed in a later process as a subsequently applied skin layer, such as by applying a skin cement to the perimeter of the channel.

[0107] In some embodiments described herein, the channel walls 306 of the particulate filter 300 may have a thickness greater than about 2 mils (50 micrometers, or "microns"), or in some embodiments, greater than about 4 mils (101.6 micrometers). For example, in some embodiments, the thickness of the channel walls 306 may range from about 4 mils up to about 30 mils (762 micrometers). In other embodiments, the thickness of the channel walls 306 may range from about 6 mils (152 micrometers) to about 10 mils (253 micrometers). In some other embodiments, the thickness of the channel walls 306 may range from about 7 mils (177 micrometers) to about 9 mils (228 micrometers).

[0108] In some embodiments of the particulate filter 200 described herein, the channel walls 306 of the particulate filter 300 can have a bare open porosity P≧35% before any coatings are applied to the particulate filter 300 (i.e., the porosity before any coatings are applied to the plugged honeycomb body). In some embodiments, the bare open porosity of the channel walls 306 can be such that 40%≦P≦75%. In other embodiments, the bare open porosity of the channel walls 306 can be such that 45%≦P≦75%, 50%≦P≦75%, 55%≦P≦75%, 60%≦P≦75%, 45%≦P≦70%, 50%≦P≦70%, 55%≦P≦70%, or 60%≦P≦70%.

[0109] Furthermore, in some embodiments, the channel walls 306 of the particulate filter 300 are formed so that the pore distribution within the channel walls 206 has a median pore size of 30 μm (“microns”) or less, before any coatings are applied (i.e., bare). For example, in some embodiments, the median pore size can be 8 microns or more and less than 30 microns or less. In other embodiments, the median pore size can be 10 microns or more and less than 30 microns or less. In other embodiments, the median pore size can be 10 microns or more and less than 25 microns or less. In some embodiments, particulate filters produced with a median pore size greater than about 30 microns have reduced filtration efficiency, while particulate filters produced with a median pore size less than about 8 microns may have difficulty penetrating the pores with a washcoat containing a catalyst. Therefore, in some embodiments, it is desirable to maintain the median pore size of the channel walls in the range of about 8 microns to about 30 microns, e.g., 10 microns to about 20 microns.

[0110] In one or more embodiments described herein, the plugged honeycomb body of the particulate filter 300 is formed from a metal or ceramic material, such as cordierite, silicon carbide, aluminum oxide, aluminum titanate, or any other ceramic material suitable for use in high-temperature particulate filtration applications. For example, the particulate filter 300 can be formed from cordierite by mixing a batch of ceramic precursor materials, which can include building blocks suitable for producing ceramic articles containing primarily cordierite crystalline phase. Generally, building blocks suitable for cordierite formation include a combination of inorganic components including talc, a silica-forming source, and an alumina-forming source. The batch composition can further include a clay, such as kaolin clay. The cordierite precursor batch composition can also include organic components, such as organic pore formers, which are added to the batch mixture to achieve the desired pore size distribution. For example, the batch composition can include starch suitable for use as a pore former and / or other processing aid. Alternatively, the build materials may include one or more cordierite powders suitable for forming a sintered cordierite honeycomb structure upon firing, as well as an organic pore former material.

[0111] The batch composition may further include one or more processing aids, such as a binder, and a liquid vehicle, such as water or a suitable solvent. Processing aids are added to the batch mixture to plasticize the batch mixture and generally improve processing, reduce drying time, reduce cracking during firing, and / or aid in producing desired properties in the plugged honeycomb body. For example, the binder may include an organic binder. Suitable organic binders include water-soluble cellulose ether binders, such as methyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose derivatives, hydroxyethyl acrylate, polyvinyl alcohol, and / or any combination thereof. Incorporating an organic binder into the plasticized batch composition may facilitate extrusion of the plasticized batch composition. In some embodiments, the batch composition may include one or more optional molding or processing aids, such as a lubricant to aid in extrusion of the plasticized batch mixture. Exemplary lubricants may include tall oil, sodium stearate, or other suitable lubricants.

[0112] After the batch of ceramic precursor material is mixed with appropriate processing aids, the batch of ceramic precursor material is extruded and dried to form a green honeycomb body including an inlet end and an outlet end with a plurality of channel walls extending between the inlet end and the outlet end. The green honeycomb body is then fired according to a firing schedule suitable for producing a fired honeycomb body. At least a first set of channels of the fired honeycomb body may then be plugged with a ceramic plugging composition in a predefined plugging pattern, and the honeycomb body is dried and / or heated to secure the plugs within the channels.

[0113] In various embodiments, the plugged honeycomb body is configured to filter particulate matter from a gas stream, such as, for example, an exhaust stream from a gasoline engine. Accordingly, the median pore size, porosity, shape, and other design aspects of both the bulk and surface of the plugged honeycomb body are selected with these filtration requirements of the plugged honeycomb body in mind. By way of example, as shown in FIGS. 16 and 17 , a honeycomb body in the form of a particulate filter 300 is shown schematically. The particulate filter 300 can be used as a wall-flow filter for filtering particulate matter from an exhaust gas stream 350, such as an exhaust gas stream emitted from a gasoline engine, in which case the particulate filter 300 is a gasoline particulate filter. The particulate filter 300 generally includes a honeycomb body having a plurality of channels 301 or cells extending between an inlet end 302 and an outlet end 304 and defining an overall length La. The channels 301 of the particulate filter 300 are formed, and at least partially defined, by a plurality of intersecting channel walls 306 extending from an inlet end 302 to an outlet end 304. The particulate filter 300 may also include a skin layer 305 surrounding the plurality of channels 301. This skin layer 305 may be extruded during the formation of the channel walls 306, or may be formed in a subsequent process as a subsequently applied skin layer, such as by applying a skin cement to the periphery of the channels. An axial cross-section of the particulate filter 300 of FIG. 16, i.e., a cross-section taken along a plane perpendicular to the longitudinal axis extending from the inlet face to the outlet face of the honeycomb body, is shown in FIG. 17. In some embodiments, certain channels are designated as inlet channels 308 and certain other channels are designated as outlet channels 310. In some embodiments of the particulate filter 300, at least a first set of the channels may be plugged with plugs 312. Generally, the plugs 312 are placed proximate to the ends (i.e., the inlet end or the outlet end) of the channels 301. The plugs are generally placed in a predefined pattern, such as the checkerboard pattern shown in Figure 16, where every other end of the channel is plugged.The inlet channels 308 may be plugged at or near the outlet end 304, and the outlet channels 310 may be plugged at or near the inlet end 302 of the channel that does not correspond to the inlet channel. Thus, each cell may be plugged at or near only one end of the particulate filter. While FIG. 17 generally depicts a checkerboard plugging pattern, alternative plugging patterns may be used in the porous ceramic honeycomb article. In some embodiments disclosed herein, the particulate filter 300 may be formed with a channel density of up to about 600 channels per square inch (cpsi). For example, in some embodiments, the particulate filter 300 may have a channel density of about 100 cpsi (about 15.5 cells / cm). 3 ) to approximately 600 cpsi (approximately 93.0 cells / cm 3 In some other embodiments, the particulate filter 300 may have a channel density in the range of about 100 cpsi (about 15.5 cells / cm). 3 ) ~ approx. 400 cpsi (approx. 62.0 cells / cm 3 ), or even about 200 cpsi (about 31.0 cells / cm 3 ) ~ approx. 300 cpsi (approx. 46.5 cells / cm 3) In some embodiments disclosed herein, the channel walls 306 of the particulate filter 300 may have a thickness greater than about 4 mils (101.6 micrometers). For example, in some embodiments, the thickness of the channel walls 306 may range from about 4 mils up to about 30 mils (762 micrometers). In some other embodiments, the thickness of the channel walls 306 may range from about 6 mils (152 micrometers) to about 10 mils (253 micrometers). In some other embodiments, the thickness of the channel walls 306 may range from about 7 mils (177 micrometers) to about 9 mils (228 micrometers). FIG. 18 schematically illustrates the relative position of a filtration material 360 including filtration particles 350 supported by honeycomb body walls 306 that also support catalytic material 380, most of which are disposed within the walls of the walls 306 and spaced apart from the filtration particles 350, such that at least a portion of the solid particulate matter 400 carried by the exhaust flow 350 is captured by the filtration particles 350.

[0114] The filtering particles or material, which may be an inorganic layer in some portions or in some embodiments, on the wall of the plugged honeycomb body is preferably very thin in some embodiments compared to the thickness of the base portion of the wall of the plugged honeycomb body. The material, which may be an inorganic layer on the plugged honeycomb body, may be formed by a method that allows the deposited material to be applied to the surface of the wall of the plugged honeycomb body in a very thin coating or in some portions in a layer. In embodiments, the average thickness of the material, which may be a deposition region or inorganic layer, on the base portion of the wall of the plugged honeycomb body is from 0.5 μm to 50 μm, or from 0.5 μm to 45 μm, or from 0.5 μm to 40 μm, or from 0.5 μm to 35 μm, or from 0.5 μm to 30 μm, or from 0.5 μm to 25 μm, or from 0.5 μm to 20 μm, or from 0.5 μm to 15 μm, or from 0.5 μm to 10 μm. In one or more embodiments, the inorganic material comprises alumina.

[0115] In another set of embodiments disclosed herein, a filter body is disclosed that includes a porous honeycomb structure comprising porous filter walls, filtration particles carried by the porous filter walls, and a catalyst material, wherein the structure includes a matrix of filter walls configured as a cellular honeycomb structure, the surfaces of the filter walls defining channels extending from an inlet end to an outlet end of the filter structure, the channels including an inlet channel and an outlet channel, the filter structure including a first group of plugs disposed within the outlet end and sealing the inlet channel at or near the outlet end, and a second group of plugs disposed within the inlet end that seal the inlet channel at or near the outlet end. and a second group of plugs positioned at or near the inlet end and sealing the outlet channel, wherein the porous filter wall includes opposing first and second wall surfaces, filtration particles disposed within and / or on the filter wall at or near the first wall surface, catalytic material disposed within and / or on a second surface of the porous filter wall, a catalytic load disposed within the filter wall primarily within the wall, and the second surface defining the outlet channel; in some of these embodiments, the filter body has a clean filtration efficiency of greater than 80% at a particle load of 0.0, and the filter body , a catalyst loading of 40 to 50 g of catalyst material per liter of filter body volume, the catalyst loading being primarily intramurally disposed within the filter walls, the filter body exhibiting a clean filtration efficiency of greater than 92% at a particulate loading of 0.0 g / L, the filter body exhibiting a ratio of pressure drop at a soot particulate loading of 0.5 g / L to pressure drop at a soot particulate loading of 0 g / L of 1.01 to 1.15; in some of these embodiments, the filter body has a catalyst loading of 50 to 90 g of catalyst material per liter of filter body volume, the catalyst loading being primarily intramurally disposed within the filter walls. and the filter body exhibits a clean filtration efficiency of greater than 88% at a particulate loading of 0.0 g / L, and the filter body exhibits a ratio of pressure drop at a soot particulate loading of 0.5 g / L to pressure drop at a soot particulate loading of 1.01 to 1.20; in some of these embodiments, the filter body has a catalyst loading of 90 to 150 g of catalyst material per liter of filter body volume, the catalyst loading being disposed primarily intramurally within the filter walls, and the filter body exhibits a clean filtration efficiency of greater than 85% at a particulate loading of 0.0 g / L, and the filter body exhibits a ratio of pressure drop at a soot particulate loading of 1.01 to 1.20.In some of these embodiments, the filter body has a catalyst loading of 40 to 50 g of catalyst material per liter of filter body volume, the catalyst loading being primarily disposed within the filter walls, and the filter body exhibits a clean filtration efficiency of greater than 94% at a particulate loading of 0.0 g / L, and the filter body exhibits a ratio of pressure drop at 0.5 g / L soot particle loading to pressure drop at 0 g / L soot particle loading of 1.01 to 1.10; in some of these embodiments, the filter body has a catalyst loading of 50 to 90 g of catalyst material per liter of filter body volume, the catalyst loading being primarily disposed within the filter walls. In some of these embodiments, the filter body has a catalyst loading of 90 to 150 g of catalyst material per liter of filter body volume, the catalyst loading being disposed primarily within the filter walls, and the filter body exhibits a clean filtration efficiency of greater than 90% at a particulate loading of 0.0 g / L, and the filter body exhibits a ratio of pressure drop at 0.5 g / L soot particulate loading to pressure drop at 0 g / L soot particulate loading of 1.01 to 1.15; in some of these embodiments, the filter body has a catalyst loading of 90 to 150 g of catalyst material per liter of filter body volume, the catalyst loading being disposed primarily within the filter walls, and the filter body exhibits a clean filtration efficiency of greater than 88% at a particulate loading of 0.0 g / L, and the filter body exhibits a ratio of pressure drop at 0.5 g / L soot particulate loading to pressure drop at 0 g / L soot particulate loading of 1.01 to 1.20.

[0116] As noted above, the performance characteristics of the reference filter body were a filter size of 4.66 inches (approximately 11.84 cm) (diameter) by 5 inches (approximately 12.7 cm) (length), CPSI 300, web thickness of 8 mils (approximately 203 micrometers), and TWC bulk density of 1600 g / m 3 For filter performance characteristics of filters of other filter geometries, microstructures, and / or catalytic materials, the product performance characteristics claimed herein may be determined by normalization.

[0117] As used herein, "reference filter body" means a filter body having the characteristics of the porous honeycomb structure present in the subject filter body, except that the reference filter body has reference geometric and microstructural characteristics (i.e., a reference cell density of 300 cells per square inch (approximately 645.16 square millimeters) and a reference average wall thickness of 8 mils (approximately 0.203 mm)), the reference filter body having a diameter of 4.66 inches (approximately 11.84 cm) and an axial length of 5 inches (approximately 12.7 cm), and a catalyst loading bulk density of 1600 g / m 3 Thus, for filter bodies that differ from the reference filter body, in order to evaluate the subject filter body with respect to the characteristics and / or performance claimed in this disclosure, the filter performance can be normalized to reflect differences in filter size, CPSI, web thickness, and / or catalyst loading per filter matrix volume.

[0118] Thus, one skilled in the art can, if necessary, normalize the results for a given filter body to account for differences in size, CPSI, and web thickness, as well as the effects of washcoat density, allowing for comparative evaluation of the FE (filtration efficiency) and dP (pressure drop) performance of filters with different shapes and sizes. For such normalization, channel-scale 1D FE (SAE 2012-01-0363) and dP (SAE 200-01-0184) models are used for filtration efficiency and pressure drop normalization, respectively. Pressure drop normalization for a given filter body begins by selecting an initial estimate of the coated wall permeability; the SAE 200-01-0184 dP model is then used, along with inputs for the specific shape, size, and test conditions of the given filter body, to predict the pressure drop. If the model's predicted pressure drop does not match the (“experimental”) measured pressure drop for the given filter body, the difference between these pressure drop values ​​is used to calculate a new estimate of the wall permeability. This iterative process continues until a wall permeability value is reached that results in agreement between experimental and modeling results. This equivalent or "extracted" permeability therefore provides a reasonable representation of the actual permeability of the subject filter wall. This extracted wall permeability is then used as an input to the model in combination with the subject filter size, shape, and test conditions described in this disclosure (4.66 inch diameter x 5 inch length, CPSI 300, 8 mil web thickness) to calculate pressure drop performance under these conditions. Normalization of filtration efficiency (FE) is performed similarly, except that instead of extracting the coated permeability as in the case of dP, the coated equivalent d50 is extracted for FE and used for normalization. Thus, one skilled in the art will understand that a subject filter body may be constructed to a standard bulk density (i.e., 1600 g / m) as described in this disclosure. 3 When a catalyst material includes a bulk density different from the bulk density of the filter matrix (bulk density of the filter matrix), the catalyst (washcoat) loading can be normalized to arrive at an equivalent catalyst loading (g / L filter matrix volume) for comparison to the claimed features / performance of the present disclosure.

[0119] References throughout this specification to "one embodiment," "a particular embodiment," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "one or more embodiments," "a particular embodiment," "one embodiment," or "an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0120] Although the disclosure herein has been described with reference to particular embodiments, it is to be understood that the described embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed method and apparatus without departing from the spirit and scope of the disclosure. Accordingly, the present disclosure may include modifications and variations that come within the scope of the appended claims and their equivalents.

[0121] Preferred embodiments of the present invention will be described below in detail.

[0122] Embodiment 1 A filter body including a porous honeycomb structure consisting of a porous filter wall, filtering particles supported on the porous filter wall, and a catalyst material, the structure includes a matrix of filter walls configured as a cellular honeycomb structure of cells having an average wall thickness WT (in mils) and a cell density CD (cells per square inch (approximately 645.16 square millimeters)), wherein surfaces of the filter walls define channels extending from an inlet end to an outlet end of the filter structure, the channels including inlet channels and outlet channels; the filter body has an effective diameter D (in inches) and a length L (in inches) extending axially from the inlet end to the outlet end; the filter structure includes a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end, and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end; the porous filter wall includes opposing first and second wall surfaces; the filtering particles are deposited in and / or on the filter wall at or near the first wall surface; The catalytic material is deposited within the porous filter wall and / or on the second surface of the porous filter wall, and the catalytic material has a bulk density (BD) (g / m 3 filter matrix volume unit), the catalytic load is disposed primarily within the filter wall; the second surface defines the outlet channel; and the filter body has a clean filtration efficiency of greater than 80% at a particle loading of 0.0, normalized to a reference filter body having a reference cell density of 300 cells per square inch (approximately 645.16 square millimeters) and a reference average wall thickness of 8 mils (approximately 0.203 mm); Filter body.

[0123] Embodiment 2 2. The filter body of embodiment 1, wherein the filter body has a normalized clean filtration efficiency of greater than 85% at a particle loading of 0.0.

[0124] Embodiment 3 2. The filter body of embodiment 1, wherein the filter body has a normalized clean filtration efficiency of greater than 90% at a particle loading of 0.0.

[0125] Embodiment 4 the filter body has a catalyst loading of 150 to 200 grams of catalyst material per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 92% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized clean pressure drop of less than 2.81 kPa at 0.0 g / L; 2. The filter body of embodiment 1.

[0126] Embodiment 5 the filter body has a catalyst loading of 200 to 350 grams of catalyst material per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 88% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized clean pressure drop of less than 3.24 kPa at 0.0 g / L; 2. The filter body of embodiment 1.

[0127] Embodiment 6 the filter body has a catalyst loading of 350 to 580 grams of catalyst material per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 85% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized clean pressure drop of less than 3.60 kPa at 0.0 g / L; 2. The filter body of embodiment 1.

[0128] Embodiment 7 the walls of the matrix are configured to define 300 cells per square inch (approximately 645.16 square millimeters) in an axial cross section of the honeycomb structure; the filter wall having an average thickness of 8 mils (203 micrometers); the filter body has a catalyst loading of greater than 350 grams of catalyst material per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 85% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized clean pressure drop of less than 3.24 kPa at 0.0 g / L; 2. The filter body of embodiment 1.

[0129] Embodiment 8 the filter body has a catalyst loading of 150 to 200 grams of catalyst material per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 94% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized clean pressure drop of less than 2.6 kPa at 0.0 g / L; 2. The filter body of embodiment 1.

[0130] Embodiment 9 the filter body has a catalyst loading of 200 to 350 grams of catalyst material per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 90% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized clean pressure drop of less than 3.02 kPa at 0.0 g / L; 2. The filter body of embodiment 1.

[0131] Embodiment 10 the filter body has a catalyst loading of 350 to 580 grams of catalyst material per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 88% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized clean pressure drop of less than 3.40 kPa at 0.0 g / L; 2. The filter body of embodiment 1.

[0132] Embodiment 11 the walls of the matrix are configured to define 300 cells per square inch (approximately 645.16 square millimeters) in an axial cross-section of the honeycomb structure; the filter wall having an average thickness of 8 mils (203 micrometers); the filter body has a catalyst loading of greater than 350 grams of catalyst material per liter of filter matrix volume; the filter body exhibits a clean filtration efficiency of greater than 88% at a particulate load of 0.0 g / L; and the filter body exhibits a clean pressure drop of less than 3.0 kPa at 0.0 g / L; 2. The filter body of embodiment 1.

[0133] Embodiment 12 the catalytic material is present at a catalyst loading of 40 to 50 grams per liter of filter body; the filter body exhibits a normalized clean filtration efficiency of greater than 92% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized pressure drop at a particulate load of 0.5 g / L that is less than 115% of its normalized pressure drop at a particulate load of 0.0 g / L. 2. The filter body of embodiment 1.

[0134] Embodiment 13 the catalytic material is present at a catalyst loading of 150 to 200 grams per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 92% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized pressure drop at a particulate load of 0.5 g / L that is less than 115% of its normalized pressure drop at a particulate load of 0.0 g / L. 2. The filter body of embodiment 1.

[0135] Embodiment 14 the catalytic material is present at a catalyst loading of 200 to 350 grams per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 88% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized pressure drop at a particulate load of 0.5 g / L that is less than 120% of its normalized pressure drop at a particulate load of 0.0 g / L. 2. The filter body of embodiment 1.

[0136] Embodiment 15 the catalytic material is present at a catalyst loading of 350 to 580 grams per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 85% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized pressure drop at a particulate load of 0.5 g / L that is less than 125% of its normalized pressure drop at a particulate load of 0.0 g / L; 2. The filter body of embodiment 1.

[0137] Embodiment 16 the catalytic material is present at a catalyst loading of greater than 350 grams per liter of filter matrix volume; the filter body exhibits a clean filtration efficiency of greater than 85% at a particulate load of 0.0 g / L; and the filter body exhibits a pressure drop at a particulate load of 0.5 g / L that is less than 125% of its pressure drop at a particulate load of 0.0 g / L; 2. The filter body of embodiment 1.

[0138] Embodiment 17 the catalytic material is present at a catalyst loading of 150 to 200 grams per liter of filter matrix volume; the filter body exhibits a clean filtration efficiency of greater than 94% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized pressure drop at a particulate load of 0.5 g / L that is less than 110% of its normalized pressure drop at a particulate load of 0.0 g / L. 2. The filter body of embodiment 1.

[0139] Embodiment 18 the catalytic material is present at a catalyst loading of 200 to 350 grams per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 90% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized pressure drop at a particulate load of 0.5 g / L that is less than 115% of its normalized pressure drop at a particulate load of 0.0 g / L. 2. The filter body of embodiment 1.

[0140] Embodiment 19 the catalytic material is present at a catalyst loading of 350 to 580 grams per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 88% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized pressure drop at a particulate load of 0.5 g / L that is less than 120% of its normalized pressure drop at a particulate load of 0.0 g / L. 2. The filter body of embodiment 1.

[0141] Embodiment 20 2. The filter body of embodiment 1, wherein the filter body has a cell density of 300 cells per square inch (about 645.16 square millimeters) and an average wall thickness of 8 mils (about 203 micrometers).

[0142] Embodiment 21 1. A method for manufacturing a porous ceramic honeycomb filter body, said method comprising: depositing a filtration material including filtration particles onto porous filter walls of a filter structure, the filter structure including a matrix of filter walls configured as a cellular honeycomb structure, wherein surfaces of the filter walls define channels extending from an inlet end to an outlet end of the filter structure, the channels including inlet channels and outlet channels, the filter structure including a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end, and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end, the porous filter walls including opposing first and second wall surfaces, the filtration particles being carried by the filter walls on, within, or both on and within the first wall surfaces; heat treating the filter structure to provide heat treatment of the filtration material by heating the filter structure at one or more filtration heat treatment temperatures of 500°C or less for a time sufficient to reduce the hydrophobicity of the filtration material, wherein the filtration material is hydrophobic prior to the deposition and / or the hydrophobicity is imparted to the filtration material after the deposition and prior to the heat treatment; depositing a catalytic material on a second surface of the porous filter wall such that the catalytic material is disposed within the filter wall and / or on the second surface of the filter wall, the second surface defining the outlet channel. A method comprising:

[0143] Embodiment 22 22. The method of embodiment 21, wherein the filtration material is hydrophobic prior to said depositing.

[0144] Embodiment 23 22. The method of embodiment 21, wherein the filtration material is hydrophobic prior to the heat treatment.

[0145] Embodiment 24 22. The method of claim 21, wherein the mixture of filter particles and carrier gas is transported through a duct toward the filter body at a downstream end of the duct and enters the inlet end of the filter body.

[0146] Embodiment 25 25. The method of embodiment 24, wherein the filtration material comprises filtration particles and one or more hydrophobic organic materials.

[0147] Embodiment 26 26. The method of embodiment 25, wherein the filtering particles are mixed with at least one hydrophobic organic material prior to mixing with the carrier gas.

[0148] Embodiment 27 27. The method of embodiment 26, wherein the organic material and filtering particles are injected into the carrier gas through a nozzle.

[0149] Embodiment 28 22. The method of claim 21, wherein at least some of the hydrophobicity of the filtration material remains after heat treatment of the filtration material.

[0150] Embodiment 29 22. The method of embodiment 21, wherein the filter structure is heat treated for more than 0.5 hours and less than 10 hours to provide heat treatment of the filtration material.

[0151] Embodiment 30 22. The method of embodiment 21, further comprising reducing the hydrophobicity of the filtration material after the catalytic material is deposited.

[0152] Embodiment 31 22. The method of embodiment 21, further comprising eliminating the hydrophobicity of the filtration material after the catalytic material is deposited.

[0153] Embodiment 32 22. The method of embodiment 21, further comprising heat treating the filter structure after depositing the catalytic material.

[0154] Embodiment 33 22. The method of embodiment 21, further comprising heat treating the filter structure after deposition of the catalytic material for a time and at one or more temperatures sufficient to calcine the catalytic material.

[0155] Embodiment 34 22. The method of embodiment 21, wherein the step of depositing the catalytic material comprises depositing the catalytic material in successive loads.

[0156] Embodiment 35 35. The method of embodiment 34, wherein the filter structure is heated between loadings of the catalytic material without removing the hydrophobicity of the filtration material.

[0157] Embodiment 36 22. The method of embodiment 21, wherein the step of depositing the catalytic material comprises depositing the catalytic material in successive loads, the catalytic material being dried between the loads of the catalytic material.

[0158] Embodiment 37 22. The method of embodiment 21, further comprising heat treating the filter structure after the selected amount of catalytic material has been deposited by heating the filter structure to a heat treatment temperature of greater than 500°C for more than one hour.

[0159] Embodiment 38 22. The method of embodiment 21, wherein a selected amount of catalytic material is deposited, the resulting catalyst loading being between 1 and 500 g of catalytic material per liter of filter structure volume.

[0160] Embodiment 39 22. The method of embodiment 21, wherein the step of depositing the catalytic material comprises applying a catalytic material slurry to the second surface of the filter wall.

[0161] Embodiment 40 22. The method of claim 21, wherein the filtration material consists of inorganic filtration particles and a binder material.

[0162] Embodiment 41 41. The method of embodiment 40, wherein the binder material exhibits hydrophobic properties.

[0163] Embodiment 42 41. The method of embodiment 40, wherein the binder material comprises a silicon-containing material.

[0164] Embodiment 43 41. The method of embodiment 40, wherein the binder material comprises a silicone material.

[0165] EMBODIMENT 44 41. The method of embodiment 40, wherein the binder material comprises a silicone resin.

[0166] Embodiment 45 41. The method of embodiment 40, wherein the binder material comprises a siloxane or polysiloxane.

[0167] Embodiment 46 41. The method of embodiment 40, wherein the binder material comprises an alkali siloxane.

[0168] Embodiment 47 41. The method of embodiment 40, wherein the binder material comprises an alkoxysiloxane.

[0169] Embodiment 48 41. The method of embodiment 40, wherein the filtering particles comprise inorganic nanoparticles.

[0170] Embodiment 49 41. The method of embodiment 40, wherein the inorganic nanoparticles comprise refractory nanoparticles.

[0171] Embodiment 50 50. The method of embodiment 49, wherein the refractory nanoparticles comprise alumina, aluminum titanate, cordierite, silicon carbide, mullite, spinel, silica, zeolite, zirconia, silicon nitride, zirconium phosphate, or a combination thereof.

[0172] Embodiment 51 41. The method of embodiment 40, wherein the filtration material comprises an aggregate of inorganic nanoparticles and a binder material that exhibits hydrophobicity.

[0173] Embodiment 52 22. The method of claim 21, wherein the filtration particles are not hydrophobic and the filtration material is rendered hydrophobic prior to deposition of the catalytic material.

[0174] Embodiment 53 22. The method of claim 21, wherein the filtration particles are not hydrophobic and hydrophobicity is imparted to the filtration material by mixing the filtration particles with a hydrophobic material prior to deposition of the catalytic material.

[0175] EMBODIMENT 54 54. The method of embodiment 53, wherein the hydrophobic material comprises a hydrophobic organic material.

[0176] Embodiment 55 1. A method for manufacturing a porous ceramic honeycomb filter body, the method comprising: depositing a filtration material including filtration particles on a porous filter wall of a filter structure, the filtration material being disposed on or within the filter wall, the filtration material being hydrophobic, the filter structure including a matrix of the filter wall configured as a cellular honeycomb structure, wherein a surface of the filter wall defines channels extending from an inlet end to an outlet end of the filter structure, the channels including inlet channels and outlet channels, the filter structure including a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end, and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end, the porous filter wall including opposing first and second wall surfaces, the filtration material being carried by the filter wall on, within, or both on and within the first wall surface; heat treating the filter structure to provide heat treatment of the filtration material by heating the filter structure to one or more filtration heat treatment temperatures to maintain at least some hydrophobicity of the filtration particles; and depositing a catalytic material on the second surface of the porous filter wall such that the filtering material is hydrophobic while the catalytic material is disposed within the filter wall and / or on the second surface of the filter wall, the second surface defining the outlet channel. A method comprising:

[0177] Embodiment 56 A filter body having a porous honeycomb structure including a porous filter wall, filtering particles supported on the porous filter wall, and a catalyst material, the structure includes a matrix of filter walls configured as a cellular honeycomb structure of cells having an average wall thickness WT (in mils) and a cell density CD (cells per square inch (approximately 645.16 square millimeters)), wherein surfaces of the filter walls define channels extending from an inlet end to an outlet end of the filter structure, the channels including inlet channels and outlet channels; the filter body has an effective diameter D (in inches) and a length L (in inches) extending axially from the inlet end to the outlet end; the filter structure includes a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end, and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end; the porous filter wall includes opposing first and second wall surfaces; the filtering particles are deposited in and / or on the filter wall at or near the first wall surface; The catalytic material is deposited within the porous filter wall and / or on a second surface of the porous filter wall, and the catalytic material has a bulk density (BD) (g / m 3 filter matrix volume unit), the catalytic load is disposed primarily within the filter wall; the second surface defines the outlet channel; and the filter body has a clean filtration efficiency of greater than 80% at a particle loading of 0.0, normalized to a reference filter body having a reference cell density of 300 cells per square inch (approximately 645.16 square millimeters) and a reference average wall thickness of 8 mils (approximately 203 micrometers); Filter body.

[0178] Embodiment 57 the filter body has a catalyst loading of 350 to 580 grams of catalyst material per liter of filter matrix volume; the filter body exhibits a normalized clean filtration efficiency of greater than 85% at a particulate load of 0.0 g / L; and the filter body exhibits a normalized clean pressure drop of less than 3.60 kPa at 0.0 g / L; 57. A filter body as described in embodiment 56.

[0179] Embodiment 58 the catalytic material is present at a catalyst loading of greater than 350 grams per liter of filter matrix volume; the filter body exhibits a clean filtration efficiency of greater than 85% at a particulate load of 0.0 g / L; and the filter body exhibits a pressure drop at a particulate load of 0.5 g / L that is less than 125% of its pressure drop at a particulate load of 0.0 g / L; 57. A filter body as described in embodiment 56.

[0180] Embodiment 59 1. A method for manufacturing a porous ceramic honeycomb filter body, said method comprising: depositing a filtration material including filtration particles onto porous filter walls of a filter structure, the filter structure including a matrix of filter walls configured as a cellular honeycomb structure, wherein surfaces of the filter walls define channels extending from an inlet end to an outlet end of the filter structure, the channels including inlet channels and outlet channels, the filter structure including a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end, and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end, the porous filter walls including opposing first and second wall surfaces, the filtration particles being carried by the filter walls on, within, or both on and within the first wall surfaces; heat treating the filter structure to provide heat treatment of the filtration material by heating the filter structure at one or more filtration heat treatment temperatures of 500°C or less for a time sufficient to reduce the hydrophobicity of the filtration material, wherein the filtration material is hydrophobic prior to the deposition and / or the hydrophobicity is imparted to the filtration material after the deposition and prior to the heat treatment; depositing a catalytic material on a second surface of the porous filter wall such that the catalytic material is disposed within the filter wall and / or on the second surface of the filter wall, the second surface defining the outlet channel. A method comprising:

[0181] Embodiment 60 60. The method of embodiment 59, wherein at least some of the hydrophobicity of the filtration material remains after heat treatment of the filtration material.

[0182] Embodiment 61 60. The method of embodiment 59, wherein the filtration material comprises an aggregate of inorganic nanoparticles and a binder material that exhibits hydrophobicity. [Explanation of symbols]

[0183] 300 Particulate Filter 301 Channel 302 Inlet end 304 Outlet end 305 Outer skin layer 306 Channel Wall 308 Entrance Channel 310 Exit Channel 312 Plug 350 exhaust flow / filtered particles 360 filtration material 380 Catalytic Materials 400 Solid particulate matter

Claims

[Claim 1] A filter body having a porous honeycomb structure including a porous filter wall, filtering particles supported on the porous filter wall, and a catalyst material, the structure includes a matrix of filter walls configured as a cellular honeycomb structure of cells having an average wall thickness WT (in mils) and a cell density CD (cells per square inch (approximately 645.16 square millimeters)), wherein surfaces of the filter walls define channels extending from an inlet end to an outlet end of the filter structure, the channels including inlet and outlet channels; the filter body has an effective diameter D (in inches) and a length L (in inches) extending axially from the inlet end to the outlet end; the filter structure includes a first group of plugs disposed within the outlet end and sealing the inlet channels at or near the outlet end, and a second group of plugs disposed within the inlet end and sealing the outlet channels at or near the inlet end; the porous filter wall includes opposing first and second wall surfaces; the filtering particles are deposited in and / or on the filter wall at or near the first wall surface; The catalytic material is deposited within the porous filter wall and / or on a second surface of the porous filter wall, and the catalytic material has a bulk density (BD) (g / m ３ filter matrix volume units), the catalytic load is disposed primarily within the filter wall; the second surface defines the outlet channel; and the filter body has a clean filtration efficiency of greater than 80% at a particle loading of 0.0, normalized to a reference filter body having a reference cell density of 300 cells per square inch (approximately 645.16 square millimeters) and a reference average wall thickness of 8 mils (approximately 203 micrometers); Filter body.

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