Ceramic unit body, honeycomb ceramic carrier and method for manufacturing the same, exhaust gas catalyst core

Abstract

The present invention provides a ceramic unit for exhaust gas catalysts that can improve gas flow efficiency and catalytic reaction uniformity, thereby enhancing purification performance. [Solution] The ceramic unit body has an air inlet end and an air outlet end at both ends, respectively, and has a plurality of partition chambers extending along the longitudinal direction. The partition chambers are separated by partition walls and include a first partition chamber and a second partition chamber that are alternately arranged in the cross-section. The first partition chamber has an open air inlet end and a closed outlet end, and the second partition chamber has a closed inlet end and an open outlet end. The partition walls are provided with a plurality of air holes that connect adjacent first and second partition chambers, and the average hole diameter Di of the openings on the first partition chamber side and the average hole diameter Do of the openings on the second partition chamber side of these air holes are set, Di

Description

[Technical Field]

[0001] This invention relates to a honeycomb ceramic catalyst, and more specifically to a ceramic unit body, a honeycomb ceramic carrier, a method for manufacturing the same, and an exhaust gas catalyst core. [Background technology]

[0002] Pollutants emitted from diesel vehicles mainly include carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and particulate matter (also known as PM, which consists of dry carbon soot, liquid hydrocarbons, and small amounts of sulfates). Typically, exhaust gas purification systems consist of carbon soot oxidation catalysts (DOC), diesel carbon soot filters (DPF), reducing agent injectors, and selective catalytic reduction (SCR) systems installed sequentially in the exhaust line from which the exhaust gas is discharged.

[0003] The exhaust gas generated from the engine is sequentially passed through a carbon soot oxidation catalyst, a diesel soot filter, and a selective catalytic reduction system to remove harmful substances contained in the exhaust gas. The DOC oxidizes carbon monoxide and hydrocarbons in the exhaust gas to carbon dioxide, and the filter collects particulate matter (PM) in the exhaust gas and selectively reduces it catalytically. This system adsorbs nitrogen oxides in the exhaust gas using a reducing agent or nitrogen groups injected from a reducing agent injector. Diesel particulate filters (DPFs) are generally coated with catalysts that have the function of oxidizing accumulated carbon soot and carbon monoxide and hydrocarbons. If the catalyst support level on the filter is sufficiently high, the function of the upstream carbon soot oxidation catalyst can be integrated into the DPF.

[0004] Therefore, it is urgently necessary to find solutions to improve the exhaust gas conversion rate and the efficiency of capturing particles in the exhaust gas. [Prior art documents] [Patent Documents]

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0006] The object of the present invention is to provide a ceramic unit body, a honeycomb ceramic carrier and a manufacturing method thereof, and an exhaust gas catalyst core that can improve the conversion rate of exhaust gas and the capture efficiency of particles in the exhaust gas by coating both a carbon soot oxidation catalyst and a DPF oxidation catalyst.

Means for Solving the Problems

[0007] To achieve the above object, the present invention provides the following technical solutions. In the ceramic unit body, both ends in the longitudinal direction of the ceramic unit body are an air inlet end and an air outlet end respectively, and the ceramic unit body has a plurality of partition chambers that extend along the longitudinal direction of the ceramic unit body and are partitioned by partition walls.

[0008] The partition chambers include a first partition chamber and a second partition chamber that are alternately arranged within the cross-section of the ceramic unit body. The first partition chamber is open on the side of the air inlet end and closed on the side of the air outlet end, and the second partition chamber is closed on the side of the air inlet end and open on the side of the air outlet end. Here, the partition wall is provided with a plurality of air holes that connect the first partition chamber and the second partition chamber, the average diameter of the openings of the air holes on the side of the first partition chamber is Di, the average diameter of the openings of the air holes on the side of the second partition chamber is Do, and Di <Doである。

[0009] In some embodiments of the present invention, in at least one of the air holes, the number of openings on the side of the first partition chamber of the air hole is at least two, and the diameter of at least one of the openings on the side of the first partition chamber is smaller than the diameter of the opening on the side of the second partition chamber of the air hole. and / or, in at least one of the air vents, the number of openings on the second partition chamber side is at least two, and the diameter of at least one of the openings on the second partition chamber side is greater than the diameter of the opening of that air vent on the first partition chamber side.

[0010] In some embodiments of the present invention, the average pore diameter of the air holes on the first partition chamber side is Di∈[8,20] in micrometers, preferably Di∈[12,20] in micrometers. And / or, the average diameter of the opening of the air vent on the side of the second partition chamber is Do∈[11,23] in micrometers, preferably Do∈[15,23] in micrometers.

[0011] In some embodiments of the present invention, the cross-sectional shapes of the first partition chamber and the second partition chamber are both square or rectangular. And / or, the first partition chamber and the second partition chamber are arranged alternately in a cardboard grid pattern within the cross-section of the ceramic unit body. In some embodiments of the present invention, the thickness of the partition wall is 75 to 250 μm, preferably 125 to 200 μm. And / or, the cross-sectional area of ​​the first partitioned room is greater than the cross-sectional area of ​​the second partitioned room, or the cross-sectional area of ​​the first partitioned room is less than the cross-sectional area of ​​the second partitioned room, or the cross-sectional area of ​​the first partitioned room is equal to the cross-sectional area of ​​the second partitioned room.

[0012] In some embodiments of the present invention, the distribution density of the air pores in the partition wall, i.e., the porosity, is 35-55%. And / or, the pore density of the partition chamber in the ceramic unit body is 200 to 500 mesh.

[0013] To achieve the above objectives, the present invention further provides the following technical solutions. In the method for manufacturing the ceramic unit body described above, the method comprises the following steps: Step A1 involves dry mixing silicon carbide powder, silicon powder, alkaline earth metal carbonate, metal oxide powder, auxiliary agents, binders, and pore-forming agents to obtain a dry blend. Step A2 involves wet-mixing the dry blend obtained in step A1 with water and a lubricant to obtain a wet blend. Step A3 includes kneading, clayizing, extruding, drying, pore-filling, degreasing, and sintering the wet blend obtained in step A2 to obtain the ceramic unit body.

[0014] Here, the sintering in step A3 includes sequential anaerobic sintering and oxidative sintering. In the oxidative sintering process, the air inlet end of the molded body after anaerobic sintering is exposed to air, and the air is extracted under negative pressure at the air outlet end of the molded body. As a result, the air passes sequentially from the air inlet end of the molded body through the first partition chamber, the air vent, and the second partition chamber, and leaves the molded body from the air outlet end to form the air vent. This causes the average pore diameter Do of the opening on the second partition chamber side of the air vent to be larger than the average pore diameter Di of the opening on the first partition chamber side.

[0015] Preferably, the dry mixing is performed using a plow-type high-speed mixer, the dry mixing time is 10 to 30 minutes, and the dry mixing rotation speed is 50 to 200 rpm. Preferably, the wet mixing time is 1 to 20 minutes, and the wet mixing rotation speed is 50 to 200 rpm.

[0016] Preferably, the mixture is kneaded using a twin-screw kneader, and the kneading time is 30 to 180 minutes. In some embodiments of the present invention, in step A1, the magnitude of the negative pressure used for negative pressure extraction is (-0.05) to (-0.02) MPa. In some embodiments of the present invention, in step A1, the silicon carbide powder comprises a first silicon carbide powder having an average particle size of 20 to 30 μm and a second silicon carbide powder having an average particle size of 3 to 8 μm.

[0017] In some embodiments of the present invention, in step A1, when the total amount of silicon carbide powder is calculated as 100% by weight, the proportion of the first silicon carbide powder in the total silicon carbide powder is 70-95% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 5-30% by weight. In some embodiments of the present invention, in step A1, when the total mass of the raw materials is calculated as 100% by weight, the proportion of silicon carbide powder is 50-75% by weight, preferably 50-65% by weight, the proportion of silicon powder is 15-25% by weight, preferably 15-20% by weight, the proportion of alkaline earth metal carbonate is 1-2% by weight, the proportion of metal oxide powder is 0.2-1% by weight, the proportion of auxiliary agent is 0.5-1.5% by weight, the proportion of binder is 6-15% by weight, the proportion of pore-forming agent is 3-18% by weight, and the proportion of lubricant is 5-11% by weight.

[0018] In some embodiments of the present invention, the average particle size of the silicon powder is 3 to 10 μm, the average particle size of the alkaline earth metal carbonate is 2 to 6 μm, the average particle size of the metal oxide is 3 to 8 μm, and the average particle size of the pore-forming agent is 8 to 40 μm.

[0019] In some embodiments of the present invention, the alkaline earth metal carbonate is selected from at least one of magnesium carbonate, strontium carbonate, barium carbonate, and calcium carbonate.

[0020] In some embodiments of the present invention, the metal oxide is aluminum oxide. In some embodiments of the present invention, the auxiliary agent is selected from at least one of bentonite and kaolin.

[0021] In some embodiments of the present invention, the binder is selected from at least one of organic alcohols, potassium laurate, modified cellulose, polyethylene oxide, and polyvinylpyrrolidone.

[0022] In some embodiments of the present invention, the pore-forming agent is selected from at least one of walnut powder, graphite, benzoic acid, starch, ammonium bicarbonate, ammonium chloride, polymethyl methacrylate, and expanded microspheres. In some embodiments of the present invention, the lubricant is glycerol. To achieve the above objectives, the present invention further provides the following technical solutions. In the honeycomb ceramic carrier, the honeycomb ceramic carrier is composed of the ceramic unit body described above, or a ceramic unit body manufactured by the method described above, and each of the ceramic unit bodies is distributed and connected within the cross-section of the honeycomb ceramic carrier, and the longitudinal direction of the ceramic unit body coincides with the longitudinal direction of the honeycomb ceramic carrier.

[0023] In some embodiments of the present invention, the thermal conductivity of the honeycomb ceramic carrier is 5 to 30 W / m·K, preferably 10 to 30 W / m·K, and more preferably 13 to 25 W / m·K. In some embodiments of the present invention, the honeycomb ceramic carrier is cylindrical or polygonal prismatic.

[0024] To achieve the above objectives, the present invention further provides the following technical solutions. A method for manufacturing a honeycomb ceramic carrier, the method comprising the following steps: Step B1 provides the ceramic unit body described above, or provides a ceramic unit body obtained by manufacturing by the method described above. The process includes step B2, which involves sequentially joining, grinding, and skin grafting the ceramic unit body to obtain the honeycomb ceramic carrier. To achieve the above objectives, the present invention further provides the following technical solutions.

[0025] An exhaust gas catalyst core, wherein the exhaust gas catalyst core is The above-mentioned honeycomb ceramic carrier, or a honeycomb ceramic carrier obtained by the above-mentioned method, The first catalyst applied to the inner wall surface of the first partition chamber of the honeycomb ceramic carrier, The honeycomb ceramic carrier includes a second catalyst applied to the inner wall surface of the second partition chamber.

[0026] In some embodiments of the present invention, the exhaust gas catalyst core is used to catalyst exhaust gas containing soot carbon particles, the first catalyst is used to promote the oxidation of the soot carbon particles, and the second catalyst is used to catalyst the conversion of carbon monoxide, hydrocarbons, and nitrogen oxides. Other areas of application will become apparent from the descriptions provided in this disclosure. The descriptions and specific examples in the invention are for illustrative purposes only and are not intended to limit the scope of this disclosure. [Effects of the Invention]

[0027] The technical solutions provided by the present invention have the following beneficial effects compared to the prior art.

[0028] This invention provides a wall-flow type honeycomb ceramic carrier capable of supporting both a DOC oxidation catalyst (i.e., a carbon soot oxidation catalyst) and a DPF oxidation catalyst. This carrier has a low regeneration temperature equilibrium point after loading, and its collection efficiency and exhaust gas conversion rate approach those of a DOC+DPF exhaust gas treatment system, while saving volume and cost in the diesel vehicle exhaust gas lowering system. Specifically, by controlling the pore density of the carrier, the opening area on the carrier outlet side is increased, increasing the contact area between the catalyst and the reaction gas, allowing both the DOC catalyst and the DPF catalyst to be coated simultaneously. This brings the exhaust gas conversion rate and particle capture efficiency closer to that of a DOC+DPF exhaust system, saving volume and cost in the diesel vehicle exhaust gas lowering system. [Brief explanation of the drawing]

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings that are necessary for describing the embodiments are briefly introduced below. The accompanying drawings in the following description represent only a portion of the embodiments of the present invention, and it will be apparent to those skilled in the art that other drawings can be obtained based on these accompanying drawings without requiring any creative effort.

[0030] [Figure 1] This is a schematic diagram showing the appearance of a honeycomb ceramic carrier provided by a first embodiment of the present invention, in which the cross-sectional area of ​​the first partition chamber is larger than the cross-sectional area of ​​the second partition chamber. [Figure 2] Figure 1 is a schematic diagram showing the structure of the honeycomb ceramic carrier as viewed from a first viewpoint. [Figure 3] This is a schematic diagram showing a magnified view of a localized area A in Figure 2. [Figure 4] This is a schematic diagram showing the structure of a honeycomb ceramic carrier, provided by a second embodiment of the present invention, in which the cross-sectional area of ​​the first partition chamber and the cross-sectional area of ​​the second partition chamber are equal, as viewed from a second viewpoint. [Figure 5] This is a schematic diagram showing a magnified view of a localized area B in Figure 4. [Figure 6] Figure 1 is a schematic diagram showing the cross-sectional structure of the honeycomb ceramic carrier when it is cut along its longitudinal direction. [Figure 7] This is a schematic diagram showing a cross-section of an air vent in a part of the partition wall in Figure 6. [Figure 8] This is a flowchart of a method for manufacturing a ceramic unit body provided by a third embodiment of the present invention. [Figure 9] This is a flowchart of a method for manufacturing a honeycomb ceramic carrier provided by a fourth embodiment of the present invention. [Figure 10] This is an SEM schematic diagram of air pores in a pore diameter sampling area on the side of the first partition chamber in a honeycomb ceramic carrier provided by a fifth embodiment of the present invention. [Figure 11] This is an SEM schematic diagram of air pores in a pore size sampling area on the side of the second partition chamber in a honeycomb ceramic carrier provided by a fifth embodiment of the present invention. [Figure 12] This is a magnified SEM schematic of a localized air pore in the pore diameter sampling area on the side of the first partition chamber in a honeycomb ceramic carrier provided by a fifth embodiment of the present invention. [Figure 13] This is a magnified SEM schematic of a localized air pore in the pore diameter sampling area on the side of the first partition chamber in a honeycomb ceramic carrier provided by a fifth embodiment of the present invention. [Figure 14] This is an SEM morphological view of a partition wall of a honeycomb ceramic carrier provided according to a fifth embodiment of the present invention. [Modes for carrying out the invention]

[0031] The technical solutions of embodiments of the present invention are described below clearly and completely, but it is clear that the embodiments described are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments that can be obtained by those skilled in the art without creative effort based on embodiments of the present invention are within the scope of the present invention. It should be understood that the specific embodiments described herein are used solely to illustrate and interpret the present invention and are not intended to limit the present invention.

[0032] Any specific numerical value disclosed herein (including the endpoints of numerical ranges) should be understood not to be limited to the correct value of that numerical value, but to also cover values ​​close to the correct value, such as any possible numerical value within ±5% of the correct value. Furthermore, one or more new numerical ranges can be obtained from the disclosed numerical ranges by any combination of endpoint values ​​within the range, between endpoint values ​​and specific point values ​​within the range, and between each specific point value, and these new numerical ranges should also be considered to be specifically disclosed herein.

[0033] The terms used in this disclosure are intended solely to describe, and not to limit, specific exemplary embodiments. Unless explicitly indicated in the context, the singular forms “one,” “one kind,” and “this” used in this disclosure may also be intended to include the plural. The terms “consist of,” “contains,” “includes,” and “have” are inclusive and describe the existence of the described features, elements, compositions, steps, integers, operations, and / or components, but do not preclude the existence or addition of one or more other features, integers, steps, operations, elements, components, and / or sets thereof. The open-ended term “consist of” should be understood as a non-restrictive term to describe the various embodiments described in this disclosure and to assert their protection; however, in some embodiments, this term may instead be understood as a more restrictive and limiting term, such as “consisting of…” or “essentially consisting of….” Accordingly, with respect to any given embodiment that refers to a composition, material, component, element, feature, integer, operation and / or process step, the disclosure also specifically includes embodiments that consist of, or essentially consist of, such referred composition, material, component, element, feature, integer, operation and / or process step. In the case of “consisting of,” the alternative embodiment excludes additional compositions, materials, components, elements, features, integers, operation and / or process steps. However, in the case of “essentially consisting of…,” additional compositions, materials, components, elements, features, integers, operation and / or process steps that substantially affect the essential and novel properties are excluded from such embodiments, but compositions, materials, components, elements, features, integers, operation and / or process steps that do not substantially affect the essential and novel properties may be included in this embodiment.

[0034] The steps, processes, and operations of the methods described herein should not be construed as necessarily requiring them to be performed in a specific order described or shown unless explicitly specified as such. Furthermore, unless otherwise stated, additional or alternative steps may be used.

[0035] In the present invention, any matters or items not mentioned, except those expressly described, can be directly applied without modification to matters or items known in the art. Furthermore, any embodiment described herein may be freely combined with one or more other embodiments described herein, and any technical solution or technical idea formed thereby shall all be considered part of the original disclosure or original record of the present invention, and shall not be considered new content not disclosed or anticipated in the disclosure unless the combination is clearly unreasonable to a person skilled in the art.

[0036] Unless otherwise stated, terms used herein have the same meaning as those generally understood by those skilled in the art. If a term is defined herein and that definition differs from that generally understood by those skilled in the art, the definition herein shall prevail.

[0037] Unless otherwise stated, when % is mentioned herein, it refers to weight percent. It should be noted that in the specification of this invention, DOC refers to a Diesel Oxidation Catalyst, and DPF refers to a Diesel Particulate Filter.

[0038] It should be noted that the carbon soot particles, also referred to as PM, as described in the specification of this invention, consist of dry carbon soot, liquid hydrocarbons, and small amounts of sulfates. Carbon soot particles can be considered a product of the inadequate combustion process of diesel. The ceramic unit body, honeycomb ceramic carrier, and exhaust gas catalyst core provided by this invention can facilitate the passive regeneration efficiency of these soot particles. Here, “passive regeneration” means “achieving the removal of particulate matter in the particle trap by reducing the activation energy of the oxidation reaction of carbon soot particles without the need to supply or intervene with external energy, and completing the reaction using only the heat provided by the exhaust gas.”

[0039] In the context of this disclosure, Di represents the average diameter of the opening of the air vent on the side of the first partition chamber, and Do represents the average diameter of the opening of the air vent on the side of the second partition chamber.

[0040] In the context of this disclosure, perforation density refers to the number of partition chambers per square inch, in units of mesh. Here, the partition chambers include both a first partition chamber and a second partition chamber.

[0041] It should be noted that in some embodiments of the present invention, the exhaust gas catalyst core can catalyze the treatment of exhaust gas or exhaust gases, and more specifically, it can be used to catalyze the treatment of exhaust gas or exhaust gases produced by the incomplete combustion of diesel engines.

[0042] First aspect Referring to Figures 1 to 7, this is the ceramic unit body. Referring to Figure 6, both ends of the ceramic unit body in the longitudinal direction are an air inlet end 01 and an air outlet end 02, respectively. The ceramic unit body has a plurality of partitioned chambers that extend along the longitudinal direction of the ceramic unit body and are separated by partition walls. Referring to Figures 2 to 5, the partitioned chambers consist of a first partitioned chamber 11 and a second partitioned chamber 12 that are alternately arranged within the cross-section of the ceramic unit body. Referring to Figures 6 and 7, the first partitioned chamber 11 is open on the side of the air inlet end 01 and closed on the side of the air outlet end 02, while the second partitioned chamber 12 is closed on the side of the air inlet end 01 and open on the side of the air outlet end 02. Referring to Figure 7, the average diameter of the opening of the air vent on the side of the first partition chamber 11 is Di, the average diameter of the opening of the air vent on the side of the second partition chamber 12 is Do, and Di <Doである。

[0043] The present invention further provides a honeycomb ceramic carrier composed of a plurality of the above-mentioned ceramic unit bodies. Therefore, when describing the structure of the above-mentioned ceramic unit bodies in the specification of the present invention, a schematic diagram showing the structure of the honeycomb ceramic carrier may be referenced.

[0044] Specifically, the ceramic unit body provided by the present invention has a unique structural design in the partition wall between the two partition chambers inside it. Referring to Figures 6 and 7, the average pore diameter Di of the air vent opening on the side of the first partition chamber 11 is smaller than the average pore diameter Do of the air vent opening on the side of the second partition chamber 12. In other words, each air vent in the partition wall has a substantially conical structure, meaning that the pore diameter of each air vent tends to "gradually expand along the direction of airflow movement." Here, the small-diameter air inlets can block carbon soot particles that have not yet completed the combustion oxidation reaction from the outside of the conical air vents, thus temporarily retaining these carbon soot particles inside the first partition chamber 11. In some embodiments of the present invention, the inside of the first partition chamber 11 is coated with a catalyst capable of catalyzing the oxidation reaction of these carbon soot particles to be carried out completely. After these carbon soot particles are catalyzed by the catalyst in the first partition chamber 11 and the oxidation reaction is fully completed, they are carried by the airflow into the conical air vents and reach the second partition chamber 12. Furthermore, because the air outlets of the conical air vents have a large diameter, on the one hand, particles carried by the airflow can remain inside the air vents and prevent clogging, and on the other hand, a portion of the catalyst coated inside the second partition chamber 12 can be coated around the air outlets of the conical air vents, that is, the coating area of ​​the catalyst coated inside the second partition chamber 12 can be increased. Thus, it can be understood that the larger the coating area of ​​the catalyst, the more effectively the reaction can be promoted.

[0045] In some embodiments of the present invention, in at least one of the air vents, the number of openings on the side of the first partition chamber 11 is at least two, and the diameter of at least one of the openings on the side of the first partition chamber 11 is smaller than the diameter of the opening of the air vent on the side of the second partition chamber 12. Specifically, referring to the air vent on the left side of Figure 7, it has two air intake openings on the side of the first partition chamber 11 and one air exhaust opening on the side of the second partition chamber 12. That is, gas from the first partition chamber 11 enters the air vent through these two air intake openings and finally enters the second partition chamber 12 through the single air exhaust opening of the air vent.

[0046] In some embodiments of the present invention, in at least one of the air vents, the number of openings on the side of the second partition chamber 12 is at least two, and the diameter of at least one of the openings on the side of the second partition chamber 12 is greater than the diameter of the opening of the air vent on the side of the first partition chamber 11. Specifically, referring to the air vent on the right side of Figure 7, it has only one air intake opening on the side of the first partition chamber 11, but has two air exhaust openings on the side of the second partition chamber 12. That is, gas from the first partition chamber 11 enters the interior of the air vent through this single air intake opening and finally enters the second partition chamber 12 through the two air exhaust openings of the air vent.

[0047] In some embodiments of the present invention, the average diameter of the opening of the air vent on the side of the first partition chamber 11 is Di∈[8,20] in micrometers, preferably Di∈[12,20] in micrometers. With respect to the size range of Di, it is understood that it is best to select such a range so that carbon soot particles produced by the incomplete combustion of the diese can be isolated to the outside of the air vent. Thus, in some embodiments of the present invention, if the inside of the first partition chamber 11 is coated with a catalyst that can promote the complete oxidative combustion of the above carbon soot particles, the air vent that satisfies the above Di size design principle can first temporarily isolate the carbon soot particles inside the first partition chamber 11, and then, after the carbon soot particles have completely burned, can be carried by the airflow through the air vent to reach the second partition chamber 12.

[0048] In some embodiments of the present invention, the average pore diameter of the opening of the air pores on the side of the second partition chamber 12 is Do∈[11,23] in micrometers, preferably Do∈[15,23] in micrometers. A larger pore diameter structure of the conical air pores increases the area to which the catalyst can be coated when the catalyst is later coated onto the second partition chamber 12, and a larger coating area of ​​the catalyst is advantageous for catalyzing and advancing the reaction.

[0049] In some embodiments of the present invention, the cross-sectional shapes of the first partition chamber 11 and the second partition chamber 12 are both square or rectangular. The first partition chamber 11, having a square or rectangular cross-sectional shape, has four sides all adjacent to the second partition chamber 12. This allows gas that has entered the first partition chamber 11 to enter the second partition chamber 12 directly after it has left, improving the compactness of the ceramic unit body structure and reducing waste of space and material.

[0050] In some embodiments of the present invention, the first partition chamber 11 and the second partition chamber 12 are alternately arranged in a cardboard grid pattern within the cross-section of the ceramic unit body. This design concept improves the compactness of the ceramic unit body structure and reduces waste of space and material.

[0051] In some embodiments of the present invention, the thickness of the partition wall is 3 to 10 mil (approximately 75 to 250 μm), preferably 5 to 8 mil (approximately 125 to 200 μm). It should be noted that by setting the thickness of the partition wall of the ceramic unit body within this range, the pressure difference between the air inlet side 01 and the air outlet side 02 of the ceramic unit body can be reduced. It can be understood that the smaller this pressure difference, the more the gas flow and purification reaction are promoted, and the thicker the wall, the greater the depth of the air holes, the longer the flow path of the gas flow within the air holes, and ultimately the greater the pressure difference between the air inlet side 01 and the air outlet side 02 of the ceramic unit body. On the other hand, an appropriate wall thickness can ensure that the ceramic unit body has sufficient rigidity, preventing problems such as deformation and brittle fracture from occurring during use.

[0052] In some embodiments of the present invention, the porosity of the ceramic unit body is 35-55%, preferably 35-45%. Porosity is the ratio of the volume of pores to the total volume of the material. It should be noted that by setting the porosity of the ceramic unit body within this range, on the one hand, the pressure difference between the air inlet side 01 and the air outlet side 02 of the ceramic unit body can be reduced. It is understood that the smaller this pressure difference, the more the gas flow and purification reaction are promoted. On the other hand, an appropriate porosity can ensure that the ceramic unit body has sufficient rigidity, preventing problems such as deformation and brittle fracture from occurring during use.

[0053] In some embodiments of the present invention, the distribution density (also called porosity) of the air pores in the partition wall is 35-55%. This "distribution density" refers to the ratio of the area of ​​the cross-section of the air pores to the area of ​​the partition wall. It should be noted that by setting the distribution density of the air pores in the ceramic unit body within this range, the pressure difference between the air inlet side 01 and the air outlet side 02 of the ceramic unit body can be reduced. It is understood that the smaller this pressure difference, the more the gas flow and purification reaction are promoted. On the other hand, an appropriate distribution density of air pores can ensure that the ceramic unit body has sufficient rigidity, preventing problems such as deformation and brittle fracture from occurring during use.

[0054] In some embodiments of the present invention, the partition chamber density, i.e., the pore density, of the partition chambers in the cross-section of the ceramic unit body is 200 to 500 mesh. It should be noted that setting the partition chamber density of the ceramic unit body within this range reduces the pressure difference between the air inlet side 01 and the air outlet side 02 of the ceramic unit body. It is understood that the smaller this pressure difference, the more the gas flow and purification reaction are promoted. On the other hand, an appropriate partition chamber density can ensure that the ceramic unit body has sufficient rigidity, preventing problems such as deformation and brittle fracture during use. Furthermore, under certain conditions, a higher partition chamber density is advantageous because it increases the coating area of ​​the catalyst, which is beneficial for sufficiently promoting the reaction.

[0055] In some embodiments of the present invention, the cross-sectional area of ​​the first partition chamber is larger than that of the second partition chamber. It should be noted that the larger size of the first partition chamber allows for a sufficient reduction in back pressure on the honeycomb ceramic after the filter has captured soot and carbon particles, thereby reducing energy consumption. At the same time, since the first partition chamber is coated with a high-concentration oxidation catalyst, the captured soot and carbon particles are effectively converted, and the active regeneration of the filter can be reduced by passively regenerating and converting more soot and carbon particles at a lower temperature.

[0056] In some embodiments of the present invention, the cross-sectional area of ​​the first partition chamber is smaller than the cross-sectional area of ​​the second partition chamber. In some embodiments of the present invention, the cross-sectional area of ​​the first partition chamber is equal to the cross-sectional area of ​​the second partition chamber.

[0057] Second aspect Referring to Figure 8, the method for manufacturing the ceramic unit body described above includes the following steps: step A1 of dry mixing silicon carbide powder, silicon powder, alkaline earth metal carbonate, metal oxide powder, auxiliary agent, binder and pore-forming agent; step A2 of wet mixing the dry blend obtained in step A1 with water and lubricant; and step A3 of kneading, clayifying, extruding, drying, pore-filling, degreasing and sintering the wet blend obtained in step A2 to obtain the ceramic unit body. Here, the sintering in step A3 includes sequential anaerobic sintering and oxidative sintering. In the oxidative sintering process, the air inlet end (01) of the molded body that has completed anaerobic sintering is exposed to air, and negative pressure is extracted from the air outlet end 02 of the molded body. As a result, air flows sequentially from the air inlet end 01 of the molded body through the first partition chamber 11, the air vent, and the second partition chamber 12, leaving the molded body from the air outlet end 02 to form the air vent. This causes the average hole diameter Do of the opening of the air vent on the second partition chamber 12 side to be larger than the average hole diameter Di of the opening on the first partition chamber 11 side.

[0058] In the manufacturing of the ceramic unit body described above, pores are formed by "adding a pore-forming agent to the raw material," which explains why the shape of each air pore in the partition wall of the final product differs. However, in the present invention, the ceramic unit body is manufactured by "first anaerobic sintering, then oxidative sintering," so one end of the air pore closest to the air inlet side 01 is oxidized first, and the smaller silicon atoms at this location are oxidized to become larger silicon dioxide atoms. As a result, most of the air pores have the effect of "having a smaller diameter for the air inlet than for the air outlet, resulting in conical air pores."

[0059] In some embodiments of the present invention, the dry mixing is performed using a plow-blade type high-speed mixer, the dry mixing time is 10 to 30 minutes, and the rotation speed for dry mixing is 50 to 200 rpm.

[0060] In some embodiments of the present invention, the wet mixing time is 1 to 20 minutes, and the wet mixing rotation speed is 50 to 200 rpm.

[0061] In some embodiments of the present invention, the mixture is kneaded using a twin-screw kneader, and the kneading time is 30 to 180 minutes. In some embodiments of the present invention, in step A1, the magnitude of the negative pressure used for negative pressure extraction is (-0.05) to (-0.02) MPa.

[0062] In some embodiments of the present invention, in step A1, the silicon carbide powder includes a first silicon carbide powder having an average particle size of 20 to 30 μm and a second silicon carbide powder having an average particle size of 3 to 8 μm.

[0063] In some embodiments of the present invention, in step A1, when the total amount of silicon carbide powder is calculated as 100% by weight, the proportion of the first silicon carbide powder in the total silicon carbide powder is 70-95% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 5-30% by weight.

[0064] In some embodiments of the present invention, in steps A1 and A2, when the total mass of the raw materials is calculated as 100% by weight, the proportion of silicon carbide powder is 50-75% by weight, preferably 50-65% by weight, the proportion of silicon powder is 15-25% by weight, preferably 15-20% by weight, the proportion of alkaline earth metal carbonate is 1-2% by weight, the proportion of metal oxide powder is 0.2-1% by weight, the proportion of auxiliary agent is 0.5-1.5% by weight, the proportion of binder is 6-15% by weight, the proportion of pore-forming agent is 3-18% by weight, and the proportion of lubricant is 5-11% by weight. The total mass percentage of the raw materials is the sum of the mass percentages of each raw material excluding the mass of water.

[0065] In some embodiments of the present invention, the average particle size of the silicon powder is 3 to 10 μm, the average particle size of the alkaline earth metal carbonate is 2 to 6 μm, the average particle size of the metal oxide is 3 to 8 μm, and the average particle size of the pore-forming agent is 8 to 40 μm.

[0066] In some embodiments of the present invention, the alkaline earth metal carbonate is selected from at least one of magnesium carbonate, strontium carbonate, barium carbonate, and calcium carbonate.

[0067] In some embodiments of the present invention, the metal oxide is selected from at least one of aluminum oxide and titanium oxide.

[0068] In some embodiments of the present invention, the auxiliary agent is selected from at least one of bentonite and kaolin.

[0069] In some embodiments of the present invention, the binder is selected from at least one of organic alcohols, potassium laurate, modified cellulose, polyethylene oxide, and polyvinylpyrrolidone. Examples of the organic alcohol include monohydric alcohols, dihydric alcohols, and polyhydric alcohols, preferably C1-C8, and more preferably C1-C4 monohydric, dihydric, and polyhydric alcohols. Examples of the organic alcohol include, but are not limited to, 1,2-propylene glycol, ethylene glycol, butanediol, 1,3-propylene glycol, and pentaerythritol. Examples of the modified cellulose include, but are not limited to, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, and propylcellulose.

[0070] In some embodiments of the present invention, the pore-forming agent is selected from at least one of walnut powder, graphite, benzoic acid, starch, ammonium bicarbonate, ammonium chloride, polymethyl methacrylate, and expanded microspheres.

[0071] In some embodiments of the present invention, the lubricant is glycerol.

[0072] Third aspect The honeycomb ceramic carrier is composed of the ceramic unit body described above or a ceramic unit body manufactured by the method described above, and each of the ceramic unit bodies is distributed and connected within the cross-section of the honeycomb ceramic carrier, and the longitudinal direction of the ceramic unit body coincides with the longitudinal direction of the honeycomb ceramic carrier.

[0073] In some embodiments of the present invention, the thermal conductivity of the honeycomb ceramic carrier is 5 to 30 W / m·K, preferably 10 to 30 W / m·K, and more preferably 13 to 25 W / m·K.

[0074] In some embodiments of the present invention, the honeycomb ceramic carrier is cylindrical or polygonal prismatic.

[0075] Fourth aspect Referring to Figure 9, the present invention provides a method for manufacturing the above-mentioned honeycomb ceramic carrier. This method includes the following steps: step B1 of providing the above-mentioned ceramic unit body or providing a ceramic unit body obtained by the above-mentioned method; and step B2 of obtaining the honeycomb ceramic carrier after sequentially subjecting the ceramic unit body to joining, grinding and skin grafting.

[0076] Fifth aspect The present invention provides an exhaust gas catalyst core comprising the above-described honeycomb ceramic carrier, or a honeycomb ceramic carrier manufactured by the above-described method, a first catalyst applied to the inner wall surface of a first partition chamber 11 of the honeycomb ceramic carrier, and a second catalyst applied to the inner wall surface of a second partition chamber 12 of the honeycomb ceramic carrier. Referring to Figures 6 and 7, the first partition chamber 11 is open on the side of the air inlet end 01 and closed on the side of the air outlet end 02, and the second partition chamber 12 is closed on the side of the air inlet end 01 and open on the side of the air outlet end 02.

[0077] In some embodiments of the present invention, the exhaust gas catalyst core is used to catalyst exhaust gas containing soot carbon particles, the first catalyst is used to promote the oxidation of the soot carbon particles, and the second catalyst is used to catalyst carbon monoxide, hydrocarbons, and nitrogen oxides.

[0078] In some embodiments of the present invention, the first catalyst is a DPF, i.e., a Diesel Particle Filter, and the second catalyst is a DOC, i.e., a Diesel Oxidation Catalyst.

[0079] This invention designs the above-mentioned ceramic unit body, honeycomb ceramic carrier, and exhaust gas catalyst core. The concept is to integrate the functions of DPF and DOC while providing a perforated tube structure that fully utilizes wall-flow type honeycomb ceramic. Simultaneously, the silicon carbide DPF and DOC honeycomb ceramic carrier, which supports both the DPF and DOC oxidation catalysts, is crucial for efficiently reducing the overall volume and cost of the aftertreatment system. It achieves a lower regeneration temperature point after loading, and capture efficiency and exhaust gas conversion rates approach those of a DPF+DOC exhaust gas treatment system. At the same time, it saves volume and cost in the blowdown system of diesel vehicles.

[0080] The silicon carbide honeycomb ceramic carrier, which is coated with an oxidation catalyst provided by the present invention, increases the opening area on the carrier outlet side by controlling the pore density of the carrier, thereby increasing the contact area between the catalyst and the reaction gas. Both DPF and DOC catalysts can be coated simultaneously, and its exhaust gas conversion rate and particle capture efficiency approach that of a DPF+DOC exhaust system, saving volume and cost in diesel vehicle blowdown systems.

[0081] Example 1 In this embodiment, the silicon carbide powder is 54.5% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 88% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 12% by weight. 19% metallic silicon powder, 1% alkaline earth metal carbonate, 0.5% metal oxide powder, 1% auxiliary agent, 10% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry mixing is complete, 10% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is added to a twin-screw kneader and kneaded for 60 minutes. After the kneaded pug is turned into clay, it is fed into an extruder and the unit body is extruded using a 300-mesh mold with a wall thickness of 3 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.02 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.946 mm². 2 The cross-sectional area of ​​the second partitioned chamber is 1.177 mm². 2 That is the case.

[0082] Example 2 In this example, the silicon carbide powder was 56.5% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder was 88.5% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder was 11.5% by weight. 20% metallic silicon powder, 1% alkaline earth metal carbonate, 0.5% metal oxide powder, 1% auxiliary agent, 9% binder, and 4% pore-forming agent were added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 8% lubricant and 35% of the mass fraction of the raw materials in water were added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture was put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder was turned into clay, it was put into an extruder, and the unit body was extruded using a 300-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.946 mm². 2 The cross-sectional area of ​​the second partitioned chamber is 1.177 mm². 2 That is the case.

[0083] Example 3 In this example, the silicon carbide powder is 59% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 88% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 12% by weight. 20% metallic silicon powder, 1% alkaline earth metal carbonate, 1% metal oxide powder, 1% auxiliary agent, 7% binder, and 3% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 8% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 300-mesh mold with a wall thickness of 8 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.946 mm². 2 The cross-sectional area of ​​the second partitioned chamber is 1.177 mm². 2 That is the case.

[0084] Example 4 In this example, the silicon carbide powder is 61% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 86% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 14% by weight. 20% metallic silicon powder, 1.5% alkaline earth metal carbonate, 0.5% metal oxide powder, 0.5% auxiliary agent, 6.5% binder, and 3% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 7% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 400-mesh mold with a wall thickness of 3 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.04 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1,550 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.912 mm². 2 That is the case.

[0085] Example 5 In this example, the silicon carbide powder is 60% by weight. Here, the proportion of the first silicon carbide powder in the total silicon carbide powder is 91.7% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 8.3% by weight. 18% of metallic silicon powder, 2% of alkaline earth metal carbonate, 0.5% of metal oxide powder, 1.5% of auxiliary agent, 7% of binder, and 3% of pore former are added to a hoe-type mixer and dry-mixed for 15 minutes at a rotation speed of 95 rpm. After dry mixing, 8% of lubricant and 35% of water based on the raw material mass fraction are added to conduct wet mixing. The time for wet mixing is 5 minutes and the rotation speed is 95 rpm. The obtained raw material mixture is put into a biaxial kneader and kneaded for 60 minutes. After the kneaded pug is clayified, it is put into an extruder, and the unit body is extruded using a mold with 400 mesh and a wall thickness of 6 mil. Then, microwave drying, pore plugging, degreasing, anaerobic sintering, and oxidation sintering are carried out. In the process of oxidation sintering, by means of negative pressure extraction at the outlet end of the unit body, air passes through the inlet side, porous partition wall, and outlet side of the unit body in sequence. Here, the negative pressure at the outlet end is -0.03 MPa. Then, through steps such as joining, grinding, and skin grafting in sequence, a silicon carbide honeycomb ceramic carrier capable of coating the above oxidation catalyst is obtained. The cross-sectional area of the first partition chamber of the honeycomb ceramic unit body provided by this example is 1.550 mm 2 and the cross-sectional area of the second partition chamber is 0.912 mm 2 respectively.

[0086] Example 6 In this example, the silicon carbide powder is 63% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 90% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 10% by weight. 19% metallic silicon powder, 1% alkaline earth metal carbonate, 0.5% metal oxide powder, 0.5% auxiliary agent, 6% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 6% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 400-mesh mold with a wall thickness of 8 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1,550 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.912 mm². 2 That is the case.

[0087] Example 7 In this example, the silicon carbide powder is 60% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 75% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 25% by weight. 16% metallic silicon powder, 2% alkaline earth metal carbonate, 1% metal oxide powder, 1.5% auxiliary agent, 7.5% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 8% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 500-mesh mold with a wall thickness of 3 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.188 mm². 2 The cross-sectional area of ​​the second partitioned chamber is 0.176 mm². 2 That is the case.

[0088] Example 8 In this example, the silicon carbide powder is 61% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 84% ​​by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 16% by weight. 17% metallic silicon powder, 1.5% alkaline earth metal carbonate, 0.5% metal oxide powder, 1% auxiliary agent, 7% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 8% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 500-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.05 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.188 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.716 mm². 2 That is the case.

[0089] Example 9 In this example, the silicon carbide powder is 61% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 75% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 25% by weight. 15% metallic silicon powder, 2% alkaline earth metal carbonate, 1% metal oxide powder, 1% auxiliary agent, 8% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 8% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 500-mesh mold with a wall thickness of 8 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.05 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.188 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.716 mm². 2 That is the case.

[0090] Example 10 In this example, the silicon carbide powder is 58% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 86% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 14% by weight. 16% metallic silicon powder, 2% alkaline earth metal carbonate, 0.5% metal oxide powder, 1% auxiliary agent, 9% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 9.5% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 300-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.946 mm². 2 The cross-sectional area of ​​the second partitioned chamber is 1.177 mm². 2 That is the case.

[0091] Example 11 In this example, the silicon carbide powder is 55% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 93% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 17% by weight. 15% metallic silicon powder, 1% alkaline earth metal carbonate, 0.5% metal oxide powder, 0.5% auxiliary agent, 7% binder, and 15% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 6% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 300-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.946 mm². 2 The cross-sectional area of ​​the second partitioned chamber is 1.177 mm². 2 That is the case.

[0092] Example 12 In this example, the silicon carbide powder is 59% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 87% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 13% by weight. 18% metallic silicon powder, 2% alkaline earth metal carbonate, 0.5% metal oxide powder, 1% auxiliary agent, 13.5% binder, and 5% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 8% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 400-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1,550 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.912 mm². 2 That is the case.

[0093] Example 13 In this example, the silicon carbide powder is 51% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 84% ​​by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 16% by weight. 15% metallic silicon powder, 2% alkaline earth metal carbonate, 1% metal oxide powder, 1% auxiliary agent, 7% binder, and 15% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 8% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 400-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1,550 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.912 mm². 2 That is the case.

[0094] Example 14 In this example, the silicon carbide powder is 56% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 82% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 18% by weight. 18% metallic silicon powder, 2% alkaline earth metal carbonate, 0.5% metal oxide powder, 1% auxiliary agent, 9% binder, and 3% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 10.5% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 500-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.188 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.716 mm². 2 That is the case.

[0095] Example 15 In this example, the silicon carbide powder is 54% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 89% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 11% by weight. 16% metallic silicon powder, 1% alkaline earth metal carbonate, 0.5% metal oxide powder, 1% auxiliary agent, 6.5% binder, and 15% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 6% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 500-mesh mold with a wall thickness of 8 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.188 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.716 mm². 2 That is the case.

[0096] Example 16 In this example, the silicon carbide powder is 56% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 82% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 18% by weight. 17% metallic silicon powder, 2% alkaline earth metal carbonate, 0.5% metal oxide powder, 1% auxiliary agent, 9.5% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 10% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 200-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 2.372 mm². 2 The cross-sectional area of ​​the second partitioned chamber is 1.428 mm². 2 That is the case.

[0097] Example 17 In this example, the silicon carbide powder is 54% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 84% ​​by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 16% by weight. 17% metallic silicon powder, 1.5% alkaline earth metal carbonate, 1% metal oxide powder, 1% auxiliary agent, 9% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 10.5% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded pug is turned into clay, it is put into an extruder and the unit body is extruded using a 300-mesh mold with a wall thickness of 12 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.946 mm². 2 The cross-sectional area of ​​the second partitioned chamber is 1.177 mm². 2 That is the case.

[0098] Example 18 In this example, the silicon carbide powder is 58% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 83% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 17% by weight. 18% metallic silicon powder, 1.5% alkaline earth metal carbonate, 0.5% metal oxide powder, 1% auxiliary agent, 10% binder, and 2% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 9% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 400-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1,550 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.912 mm². 2 That is the case.

[0099] Example 19 In this example, the silicon carbide powder is 50% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 90% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 10% by weight. 15% metallic silicon powder, 1% alkaline earth metal carbonate, 0.5% metal oxide powder, 0.5% auxiliary agent, 6% binder, and 20% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 7% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 400-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1,550 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.912 mm². 2 That is the case.

[0100] Comparative Example 1 In this example, the silicon carbide powder is 57% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 86% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 14% by weight. 16% metallic silicon powder, 2% alkaline earth metal carbonate, 1% metal oxide powder, 1% auxiliary agent, 9% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 10% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 600-mesh mold with a wall thickness of 3 mil. Subsequently, microwave drying, pore sealing, degreasing, anaerobic sintering, and oxidative sintering are performed. During the oxidative sintering process, air is sequentially passed through the inlet side, porous partition wall, and outlet side of the unit body by negative pressure extraction at the outlet end of the unit body. Here, the negative pressure at the outlet end is -0.03 MPa. Subsequently, steps such as bonding, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 0.884 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.531 mm². 2 That is the case.

[0101] Comparative Example 2 In this example, the silicon carbide powder is 57% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 84% ​​by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 16% by weight. 17% metallic silicon powder, 2% alkaline earth metal carbonate, 1% metal oxide powder, 1% auxiliary agent, 9% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry mixing, 9% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 300-mesh mold with a wall thickness of 3 mil. Subsequently, microwave drying, pore plugging, degreasing, anaerobic sintering, and oxidative sintering are performed, resulting in oxidative sintering without negative pressure extraction. Then, steps such as bonding, grinding, and skin grafting are sequentially followed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1.946 mm². 2 The cross-sectional area of ​​the second partitioned chamber is 1.177 mm². 2 That is the case.

[0102] Comparative Example 3 In this example, the silicon carbide powder is 57% by weight, where the proportion of the first silicon carbide powder in the total silicon carbide powder is 86% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 14% by weight. 16% metallic silicon powder, 2% alkaline earth metal carbonate, 1% metal oxide powder, 1% auxiliary agent, 9% binder, and 4% pore-forming agent are added to a plow-type mixer and dry-mixed at a rotation speed of 95 rpm for 15 minutes. After dry-mixing, 10% lubricant and 35% of the mass fraction of the raw materials are added and wet-mixed for 5 minutes at a rotation speed of 95 rpm. The resulting raw material mixture is put into a twin-screw kneader and kneaded for 60 minutes. After the kneaded powder is turned into clay, it is put into an extruder and the unit body is extruded using a 400-mesh mold with a wall thickness of 6 mil. Subsequently, microwave drying, pore plugging, degreasing, anaerobic sintering, and oxidative sintering are performed, resulting in oxidative sintering without negative pressure extraction. Then, steps such as joining, grinding, and skin grafting are sequentially performed to obtain a silicon carbide honeycomb ceramic carrier to which the above-mentioned oxidation catalyst can be coated. The cross-sectional area of ​​the first partition chamber of the honeycomb ceramic unit body provided in this embodiment is 1,550 mm². 2 The cross-sectional area of ​​the second partitioned room is 0.912 mm². 2 That is the case.

[0103] The types of raw materials used in Examples 1-19 and Comparative Examples 1-3 are shown in Table 1 below.

[0104] Table 1. Types of raw materials used in Examples 1-19 and Comparative Examples 1-3 (Silicon carbide powder, silicon powder, and lubricants are omitted from the description) JPEG0007849554000001.jpg255169

[0105] The porosity of the honeycomb ceramic carriers obtained in each of the above examples and comparative examples was obtained by testing using the drainage method. Pore volume was tested using the mercury intrusion method, with the unit body prepared as a sample block with a length, width, and height of 10 mm*10 mm*15 mm, and measured using a MicroActive AutoPore V 9600 Version 2.03.00 mercury pressure gauge from Mike Corporation, USA. Tests were performed according to the national standard: GB / T21650.1-2008, and the results are shown in Table 2 below.

[0106] The average pore diameters of the openings located on the air intake side and the average pore diameters of the openings located on the air exhaust side of the air pores for the honeycomb ceramic carriers obtained in each of the above examples and comparative examples were obtained by the following method: (1) The partitions of the honeycomb ceramic carrier were fabricated on multiple 1 mm * 1 mm sample wafers. The sample wafers were divided into an inlet side and an outlet side, and the same side was tested during the testing process. The surface awaiting testing was placed on a scanning electron microscope (model: JS / YQ SEM-101) and scanned at a magnification of 400x. 5 to 8 sample wafers were randomly sampled, and a 500 μm * 500 μm area was taken from each sample wafer. (2) The pore diameters of the 1st to Nth (N is 5 to 8) regions were measured, and the average value D of the pore diameters of each region was measured. n Calculate (n is 1 to N). (3) D1 to D N Calculate the mean D, and the standard deviation σ of the above mean data set is σ = sqrt(((D1-D) 2 +(D2-D) 2 +......+(D n -D) 2 Calculate () / N), where n is 1 to N. (4) If the standard deviation σ is less than 1.5 μm, this mean value is valid, i.e., D is the average pore diameter on this partition side. Obtain the average pore diameters on the inlet and outlet sides, and refer to Table 2 below for the results.

[0107] The method for testing the thermal conductivity of the honeycomb ceramic carriers obtained in each of the above examples and comparative examples involved using an LFA467 laser thermal conductivity meter to test the thermal conductivity of the honeycomb ceramic carriers according to the above invention under conditions of a temperature range of 25 to 500°C and a heating interval of 50 K / min, and the results are shown in Table 2 below.

[0108] In Table 2, "Average hole diameter Di at the air intake end" refers to "the average hole diameter of the opening located on the air intake side of the air vent," "Average hole diameter Do at the air exhaust end" refers to "the average hole diameter of the opening located on the air exhaust side of the air vent," and "Difference in hole diameter between air exhaust end and air intake end" refers to "the difference between the average hole diameter of the opening located on the air intake side of the air vent and the average hole diameter of the opening located on the air exhaust side of the air vent."

[0109] Table 2 Performance parameters of honeycomb ceramic carriers obtained in each example and comparative example JPEG0007849554000002.jpg220170

[0110] The carriers prepared in Examples 1-19 were coated with catalysts, and back pressure amplification tests were performed. The PN23 test method for carriers coated with DOC catalyst and DPF catalyst was measured using the World Harmonized Transient Cycle (WHTC), and data with PN > 23 nm was obtained. The test results are shown in Table 3.

[0111] The conversion rates of NO, CO, and HC, as well as the regeneration equilibrium temperature point and ignition temperature, were tested. The test results are shown in Table 3. Catalyst coating: DOC oxidation catalysts and DPF oxidation catalysts are catalyst slurries containing noble metals, and the slurry coating layer contains oxides composed of aluminum oxide and / or rare earth elements.

[0112] The DPF oxidation catalyst is coated on the walls of the air-vent tubes. The noble metals in the slurry coating include Pt and Pd, with a mass ratio of Pt to Pd of 1:0 to 5:1, and a concentration of noble metals of 10 g / ft. 3 ~20g / ft 3 That is the case.

[0113] The DOC oxidation catalyst is coated into the filter wall of the particle filter from the air outlet end. The noble metals in the catalyst within the filter wall include Pt and Pd, with a mass ratio of Pt to Pd of 5:1 to 0:1, and a concentration of noble metals of 10 g / ft. 3 ~20g / ft 3 That is the case.

[0114] Table 3 Catalytic performance of honeycomb ceramic carriers obtained in each example and comparative example. JPEG0007849554000003.jpg203170

[0115] As can be seen from Table 3 above, in Examples 1 to 19 of the present invention, the Do (pore diameter of the outlet side partition) - Di (pore diameter of the inlet side partition) is greater than 3 μm, meaning that the filter of the present invention satisfies high capture efficiency, can simultaneously support DOC oxidation catalyst and DPF oxidation catalyst, and after support, the conversion rate of NOx, CO, and HC is high.

[0116] Specifically, Comparative Example 1 has a high mesh count, and its NOx and HC conversion rates are close to those of the Examples. However, the high mesh count significantly increases the amount of catalyst coating, thus not leading to cost reduction. In Comparative Examples 2 and 3, compared to the Examples, a negative pressure method was not used when extracting air from the outlet side of the unit body. As a result, the oxidation effect was less noticeable, and oxidation sintering at the pore diameter on the inlet side was reduced in the same amount of time. Due to the larger pore diameter, the PN value measured in the WHTC cycle was higher, and the NOx and HC conversion rates were slightly lower. In Examples 16 and 1, the reduction in mesh count leads to an increase in the active regeneration conversion temperature and the regeneration equilibrium temperature point, which is disadvantageous in terms of energy consumption. Compared to Example 1, Example 17 has a thicker wall, which is disadvantageous in reducing back pressure. The thicker wall also results in slower heat conduction, leading to an increase in the active regeneration conversion temperature and the regeneration equilibrium temperature point. The low porosity in Example 18 similarly leads to high back pressure, while the high porosity in Example 19 destabilizes the honeycomb ceramic structure, resulting in low compressive strength. Simultaneously, the increased porosity reduces the thermal conductivity of the honeycomb ceramic carrier, raising the active regeneration conversion temperature and regeneration equilibrium temperature point of this catalyst-coated carrier.

[0117] Therefore, in this invention, by improving the oxidation sintering means in the manufacturing process and the difference in diameter between the inlet and outlet, and by manufacturing a filter equipped with both a DOC oxidation catalyst and a DPF oxidation catalyst, it is possible to effectively improve the filtration efficiency and exhaust gas conversion efficiency, reduce the amplification of the catalyst coating back pressure, and ultimately reduce the energy consumption of the vehicle.

[0118] The above-described details are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Modifications or substitutions that are readily conceivable to those skilled in the art within the technical scope disclosed herein should be included within the scope of protection of the present invention. Accordingly, the scope of protection of the present invention shall be subject to the scope of protection of the claims described herein. Furthermore, specific examples are applied in this specification to illustrate the principles and embodiments of the present invention, and the above-described examples are used only to aid in understanding the methods and core ideas of the present invention, and the contents of this specification should not be construed as limiting the present invention. [Explanation of Symbols]

[0119] 01 Air intake side 02 Air discharge side 11. First partitioned room 12. Second partition room

Claims

1. The ceramic unit body, The ends of the ceramic unit body in the longitudinal direction are a gas inlet end and a gas outlet end, respectively, and the ceramic unit body has a plurality of partitioned chambers that extend along the longitudinal direction of the ceramic unit body and are separated by partition walls. The partition chamber includes a first partition chamber and a second partition chamber alternately arranged within the cross-section of the ceramic unit body, wherein the first partition chamber is open on the side of the gas inlet and closed on the side of the gas outlet, and the second partition chamber is closed on the side of the gas inlet and open on the side of the gas outlet. The partition wall is provided with a plurality of air holes that connect the first partition chamber and the second partition chamber, the average diameter of the openings of the air holes on the side of the first partition chamber is Di, the average diameter of the openings of the air holes on the side of the second partition chamber is Do, and Di < Do. Furthermore, in micrometer units, Di ∈ [8, 20], Do ∈ [11, 23], and Do - Di > 3 μm. The ceramic unit body is characterized in that the density of the pores in the partition chamber in the ceramic unit body is 200 to 500 mesh.

2. In at least one of the air vents, the number of openings on the side of the first partition chamber is at least two, and the diameter of at least one of the openings on the side of the first partition chamber is smaller than the diameter of the opening of that air vent on the side of the second partition chamber. and / or, in at least one of the air holes, the number of openings on the second partition chamber side is at least two, and the diameter of at least one of the openings on the second partition chamber side is greater than the diameter of the opening of the air hole on the first partition chamber side.

3. The average diameter of the air pores on the first partition chamber side is Di ∈ [12, 20] in micrometers, The ceramic unit body according to claim 2, characterized in that and / or, the average diameter of the opening of the air vent on the second partition chamber side is Do ∈ [15, 23] in micrometers.

4. The cross-sectional shapes of the first partition chamber and the second partition chamber are both square or rectangular. The ceramic unit body according to claim 1, characterized in that the first partition chamber and the second partition chamber are alternately arranged in a checkerboard pattern within the cross-section of the ceramic unit body.

5. The thickness of the partition wall is 75 to 250 μm. The ceramic unit body according to claim 1, characterized in that and / or, the cross-sectional area of ​​the first partition chamber is greater than the cross-sectional area of ​​the second partition chamber, or the cross-sectional area of ​​the first partition chamber is less than the cross-sectional area of ​​the second partition chamber, or the cross-sectional area of ​​the first partition chamber is equal to the cross-sectional area of ​​the second partition chamber.

6. The porosity of the ceramic unit body is 35-55%. The ceramic unit body according to claim 1, characterized in that...

7. A method for manufacturing the ceramic unit body described in claim 1, The above method involves the following steps: Step A1 involves dry mixing silicon carbide powder, silicon powder, alkaline earth metal carbonate, metal oxide powder, auxiliary agents, binders, and pore-forming agents to obtain a dry blend. Step A2 involves wet-mixing the dry blend obtained in step A1 with water and a lubricant to obtain a wet blend. Step A3 involves kneading, clayifying, extruding, drying, pore-filling, degreasing, and sintering the wet blend obtained in step A2 to obtain the ceramic unit body. Includes, The sintering in step A3 includes sequential anaerobic sintering and oxidative sintering. In the oxidative sintering process, the gas inlet end of the molded body after anaerobic sintering is exposed to air, and negative pressure extraction is performed against the gas outlet end of the molded body. As a result, the air travels sequentially from the gas inlet end of the molded body through the first partition chamber, the air vent, and the second partition chamber, leaving the molded body from the gas outlet end to form the air vent. This causes the average hole diameter Do of the opening on the second partition chamber side of the air vent to become larger than the average hole diameter Di of the opening on the first partition chamber side. Furthermore, Di ∈ [8, 20], Do ∈ [11, 23], and Do-Di > 3 μm in micrometer units, and after the kneaded pug is turned into clay, it is fed into an extruder and extruded using a mold with an appropriate number of meshes, so that the pore density of the partition chamber in the ceramic unit body is 200 to 500 meshes. The dry mixing is performed using a plow-blade type high-speed mixer, with a dry mixing time of 10 to 30 minutes and a dry mixing rotation speed of 50 to 200 rpm. The wet mixing time is 1 to 20 minutes, and the wet mixing rotation speed is 50 to 200 rpm. A method characterized by mixing using a twin-screw mixer, with a mixing time of 30 to 180 minutes.

8. The method according to claim 7, characterized in that, in step A3, the magnitude of the negative pressure used for negative pressure extraction is (-0.05) to (-0.02) MPa.

9. The method according to claim 7, characterized in that, in step A1, the silicon carbide powder comprises a first silicon carbide powder having an average particle size of 20 to 30 μm and a second silicon carbide powder having an average particle size of 3 to 8 μm.

10. The method according to claim 9, characterized in that, in step A1, when the total amount of silicon carbide powder is calculated as 100% by weight, the proportion of the first silicon carbide powder in the total silicon carbide powder is 70 to 95% by weight, and the proportion of the second silicon carbide powder in the total silicon carbide powder is 5 to 30% by weight.

11. The method according to claim 7, characterized in that, in step A1, when the total mass of the raw materials is calculated as 100% by weight, the proportion of silicon carbide powder is 50 to 75% by weight, the proportion of silicon powder is 15 to 25% by weight, the proportion of alkaline earth metal carbonate is 1 to 2% by weight, the proportion of metal oxide powder is 0.2 to 1% by weight, the proportion of auxiliary agent is 0.5 to 1.5% by weight, the proportion of binder is 6 to 15% by weight, the proportion of pore-forming agent is 3 to 18% by weight, and the proportion of lubricant is 5 to 11% by weight.

12. The method according to claim 7, characterized in that the average particle size of the silicon powder is 3 to 10 μm, the average particle size of the alkaline earth metal carbonate is 2 to 6 μm, the average particle size of the metal oxide is 3 to 8 μm, and the average particle size of the pore-forming agent is 8 to 40 μm.

13. The above method has the following characteristics: The aforementioned alkaline earth metal carbonate is selected from at least one of magnesium carbonate, strontium carbonate, barium carbonate, and calcium carbonate. The aforementioned metal oxide is selected from at least one of aluminum oxide and titanium oxide. The aforementioned auxiliary agent is selected from at least one of bentonite and kaolin. The binder is selected from at least one of the following: organic alcohol, potassium laurate, modified cellulose, polyethylene oxide, and polyvinylpyrrolidone. The pore-forming agent is selected from at least one of walnut powder, graphite, benzoic acid, starch, ammonium bicarbonate, ammonium chloride, polymethyl methacrylate, and expanded microspheres. The lubricant is glycerol. The method according to claim 7, characterized by having one or more of the following.

14. A honeycomb ceramic carrier, The honeycomb ceramic carrier is characterized in that it is composed of ceramic unit bodies obtained by manufacturing by the method of claim 7, each of the ceramic unit bodies is distributed and connected within the cross-section of the honeycomb ceramic carrier, and the longitudinal direction of the ceramic unit bodies coincides with the longitudinal direction of the honeycomb ceramic carrier.

15. A honeycomb ceramic carrier, The honeycomb ceramic carrier is characterized in that the honeycomb ceramic carrier is composed of the ceramic unit body described in claim 1, each of the ceramic unit bodies is distributed and connected within the cross-section of the honeycomb ceramic carrier, and the longitudinal direction of the ceramic unit body coincides with the longitudinal direction of the honeycomb ceramic carrier.

16. The honeycomb ceramic carrier according to claim 15, characterized in that the thermal conductivity of the honeycomb ceramic carrier is 5 to 30 W / m·K.

17. The honeycomb ceramic carrier according to claim 15, characterized in that the honeycomb ceramic carrier is cylindrical or polygonal prismatic.

18. A method for manufacturing a honeycomb ceramic carrier according to claim 15, The above method involves the following steps: Step B1 provides the ceramic unit body, Step B2 involves sequentially joining, grinding, and skin grafting the ceramic unit body to obtain the honeycomb ceramic carrier. A method characterized by including

19. It is an exhaust gas catalyst core, The exhaust gas catalyst core is The honeycomb ceramic carrier according to claim 15, The first catalyst applied to the inner wall surface of the first partition chamber of the honeycomb ceramic carrier, The second catalyst applied to the inner wall surface of the second partition chamber of the honeycomb ceramic carrier and An exhaust gas catalyst core characterized by containing [a certain component].

20. The exhaust gas catalyst core according to claim 19, characterized in that the exhaust gas catalyst core is used to catalyst exhaust gas containing soot carbon particles, the first catalyst is used to promote the oxidation of the soot carbon particles, and the second catalyst is used to catalyst the conversion of carbon monoxide, hydrocarbons and nitrogen oxides.

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