JP2007144359A - Method for carrying catalyst on honeycomb structure body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst carrying method for a honeycomb structure body which is capable of evenly carrying a catalyst with desirable composition as a catalyst and distribution property in fine pores inside of fine pores of a honeycomb structure body. <P>SOLUTION: The catalyst carrying method for a honeycomb structure body 1 is for carrying a catalyst in a honeycomb structure body 1 provided with porous partitioning walls 4 installed in a manner that a plurality of cells 3 communicating with two end faces and having a large number of fine pores are formed and sealing parts 10 installed for sealing one end face of the cells 3. The catalyst carrying method for a honeycomb structure body involves impregnating fine pores of the honeycomb structure body with a component which occupies 50% by volume or higher in the entire constituent components of the catalyst among constituent components except noble metals of the catalyst in a precursor state or sol state, carrying out gelation of the impregnated component, and drying the gelled component. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention is a carbon monoxide (CO), hydrocarbon (HC), nitrogen oxide (NO _x ) contained in exhaust gas discharged from automobiles, construction machinery, industrial stationary engines, combustion equipment, and the like, In manufacturing a honeycomb catalyst body suitably used for purification of components to be purified such as sulfur oxide (SO _x ) and a filter for removing fine particles from a diesel engine, a honeycomb structure as a catalyst carrier is used. The present invention relates to a catalyst supporting method for a honeycomb structure supporting a catalyst.

  Currently, a catalyst body (honeycomb catalyst body) using a honeycomb structure as a catalyst carrier is used in order to purify exhaust gas discharged from various engines and the like. As shown in FIG. 6, this honeycomb catalyst body has a structure in which a catalyst layer 15 is supported on the surface of the partition walls 4 forming the cells 3 of the honeycomb structure 11. As shown in FIGS. 4 and 5, when the exhaust gas is purified using the honeycomb catalyst body 60, the exhaust gas is caused to flow into the cells 3 of the honeycomb catalyst body 60 from the one end face 2a side, The exhaust gas is brought into contact with a catalyst layer (not shown), and then is discharged from the other end surface 2b side to the outside (see, for example, Patent Document 1).

Conventionally, when a catalyst is supported on a honeycomb structure, a raw material powder to be a catalyst is separately synthesized to obtain a catalyst powder, and the resulting catalyst powder is slurried, impregnated into the honeycomb structure, and then dried. Was done by. This catalyst powder contains alumina, titania, metal components, etc. that function as a catalyst.
JP 2003-33664 A

  However, the conventional catalyst loading method described above has a problem that the catalyst powder does not enter the small pores of the honeycomb structure and is not loaded when the particle size of the particles constituting the catalyst powder is large.

  Also, when the honeycomb structure is impregnated with the catalyst powder and dried, the catalyst component (catalyst powder) moves from the pores of the honeycomb structure to the partition wall surface along with the movement of water. There is also a problem that the catalyst becomes non-uniform, resulting in an increase in pressure loss and a catalyst that is not effectively used.

  Furthermore, once synthesized catalyst powder can achieve a good composition and pore distribution as a catalyst, this catalyst powder is slurried and impregnated into a honeycomb structure, and then dried. However, there is a problem that structural changes occur in the catalyst, and the supported catalyst does not have a good composition and pore distribution.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to provide a catalyst having a good composition and fine pore distribution as a catalyst and to make a fine structure of the honeycomb structure. An object of the present invention is to provide a catalyst supporting method for a honeycomb structure that can be uniformly supported in pores.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have determined that one component having a volume ratio of 50% by volume or more in the entire component of the catalyst, excluding the precious metal of the catalyst, is a precursor. By impregnating the pores of the honeycomb structure in a body state or a sol state, gelling one component impregnated in the pores, and drying the gelled one component, the above problem Has been found to be possible to achieve the present invention.

  That is, according to the present invention, the following method for supporting a catalyst for a honeycomb structure is provided.

[1] A porous partition wall having a large number of pores arranged so that a plurality of cells communicating between two end faces are formed, and the cells are plugged at any one of the end faces. A catalyst supporting method for a honeycomb structure in which a catalyst is supported on a honeycomb structure having a plugged portion disposed therein, and occupies the entire constituent components of the catalyst among the constituent components excluding the noble metal of the catalyst One component having a volume ratio of 50% by volume or more is impregnated into the pores of the honeycomb structure in a precursor state or a sol state, the impregnated one component is gelled, and the gel A method for supporting a catalyst of a honeycomb structure, comprising a step of drying the one component that has been made into a solid.

[2] The method for supporting the catalyst of the honeycomb structure according to [1], wherein the method for drying the one component that has been gelled is freeze-drying.

[3] When the one component is impregnated into the pores of the honeycomb structure in a precursor state or a sol state, the entire component of the catalyst is added to the solution containing the one component. The method for supporting a catalyst of a honeycomb structure according to the above [1] or [2], wherein a solution containing another component having a volume ratio of less than 50% by volume and / or a constituent component of the catalyst made of the noble metal is used.

[4] After impregnating the one component into the pores of the honeycomb structure and drying, the other component having a volume ratio of less than 50% by volume of the total component of the catalyst, and / or the Using a solution containing a constituent component of a catalyst made of a noble metal, the other component having a volume ratio of less than 50% by volume in the total constituent components of the catalyst and / or a constituent component of the catalyst made of the noble metal are added to the honeycomb. The method for supporting a catalyst of a honeycomb structure according to the above [1] or [2], wherein the pores of the structure are impregnated and the impregnated components are dried.

[5] Three-way catalyst for purifying gasoline engine exhaust gas, oxidation catalyst for hydrocarbon, carbon monoxide or soot purification, SCR catalyst for NO _x selective reduction, NO _x storage catalyst, three-way purification function and soot Any one of the above [1] to [4], wherein at least one catalyst selected from the group consisting of a quaternary catalyst having a purification function and a catalyst used for purifying oxide-based harmful components in combustion exhaust gas is used. A method for supporting a catalyst for a honeycomb structure according to claim 1.

[6] The catalyst supporting method for a honeycomb structure according to any one of [1] to [5], wherein the honeycomb structure is made of a material mainly composed of ceramics or a sintered metal.

[7] The method for supporting a catalyst of the honeycomb structure according to any one of [1] to [6], wherein the honeycomb structure is a diesel particulate filter.

  According to the method for supporting a catalyst of a honeycomb structure of the present invention, a catalyst having a good composition and pore distribution as a catalyst can be uniformly supported in the pores of the honeycomb structure. For this reason, the catalyst can be favorably supported even on a honeycomb structure having a small pore diameter, which has conventionally been difficult to support the catalyst.

  In addition, according to the catalyst supporting method of the honeycomb structure of the present invention, the catalyst can be uniformly supported in the pores, so that the pressure loss of the resulting honeycomb catalyst body can be reduced.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

  FIG. 1 is a front view schematically showing a honeycomb structure (honeycomb catalyst body) on which a catalyst is supported according to an embodiment of the catalyst supporting method of the honeycomb structure of the present invention. FIG. 2 is a cross-sectional view schematically showing the honeycomb structure. FIG. FIG. 3 is a partially enlarged view of the honeycomb structure of FIG. As shown in FIGS. 1 to 3, the honeycomb structure catalyst supporting method of the present embodiment (hereinafter sometimes simply referred to as a catalyst supporting method) includes a plurality of cells 3 communicating between two end faces 2 a and 2 b. A porous partition wall 4 having a large number of pores 25 and a plugging portion 10 disposed so as to plug the cell 3 at one of the end faces 2a and 2b. The catalyst supporting method of the honeycomb structure in which the catalyst 5 is supported on the honeycomb structure 1 having the above. In addition, the code | symbol 20 in FIG. 1 has shown the outer wall of the honeycomb structure.

  The honeycomb catalyst body 1a carrying the catalyst 5 on the honeycomb structure 1 allows the fluid (for example, exhaust gas) flowing into the predetermined cell 3 from the one end face 2a to pass through the pores of the partition walls 4, Purified by the catalyst 5 supported in the pores 25, the purified fluid passes through the cell 3 adjacent to the predetermined cell 3 and is discharged from the other end face 2a side. The catalyst supporting method of the present embodiment is not limited to a honeycomb structure having a function only as a catalyst carrier, but also to a diesel particulate filter for removing fine particles from a diesel engine by the porous partition walls of the honeycomb structure. However, the catalyst can be supported well.

  In the catalyst supporting method of the honeycomb structure according to the present embodiment, when the catalyst 5 is supported on the honeycomb structure 1, the ratio of the volume to the total components of the catalyst among the components excluding the noble metal of the catalyst is 50. Impregnating the pores of the honeycomb structure with one component of volume% or more in the precursor state or sol state, gelling the impregnated component, and drying the gelled component A method for supporting a catalyst of a honeycomb structure including a step.

  By comprising in this way, the synthesis | combination and carrying | support of the catalyst to carry | support can be performed simultaneously, Furthermore, the ratio of the volume which occupies for the whole component except a noble metal of a catalyst becomes 50 volume% or more, In order to impregnate the pores of the honeycomb structure in a precursor state or sol state such as alkoxide, a catalyst having a good composition and pore distribution as a catalyst can be uniformly supported in the pores. .

  Further, the honeycomb catalyst body obtained by the catalyst supporting method for the honeycomb structure of the present embodiment has a small pressure loss. In particular, when purifying exhaust gas containing soot or the like, a reduction in pressure loss appears prominently. For example, in a state where 3 g / L of soot is stored, the increase in pressure loss of the honeycomb catalyst body carrying the catalyst is 50% or less with respect to the honeycomb structure before carrying the catalyst.

  Hereinafter, the catalyst supporting method for the honeycomb structure of the present embodiment will be described in more detail for each step. First, of the constituent components excluding the noble metal of the catalyst, one component having a volume ratio of 50% by volume or more in the entire constituent components of the catalyst is made into a precursor state or a sol state.

As the catalyst to be supported by the catalyst supporting method of the honeycomb structure of the present embodiment, the three-way catalyst for gasoline engine exhaust gas purification, hydrocarbons, carbon monoxide, or soot purifying oxidation catalyst, NO _X selective reduction for SCR catalyst, NO _X storage catalyst, a three-way purification function and soot four yuan catalyst having a purification function, and at least one selected from the group consisting of catalysts used for purifying oxide harmful components in the combustion exhaust gas Mention may be made of catalysts.

  In addition, among the constituent components excluding the noble metal of the catalyst described above, one component having a volume ratio of 50% by volume or more with respect to the total constituent components of the catalyst is representative of, for example, a three-way catalyst for purifying gasoline engine exhaust gas Such as alumina in platinum (Pt) -rhodium (Rh) / alumina-ceria catalyst, platinum (Pt) as a catalyst for hydrocarbon oxidation / titania in titania, silica in palladium (Pd) / silica catalyst Can be mentioned.

  In addition, the precursor state referred to in the present invention is a state of a compound in which the reaction does not proceed to a compound that is originally used as a catalyst in a chemical sense. For example, an alkoxide in an anhydrous alcohol solvent, water, This refers to the state of alkoxide in anhydrous alcohol in the hydrolysis reaction.

  For example, when one component is alumina, the state of aluminum isopropoxide dissolved in anhydrous isopropanol solution can be a precursor state, and when one component is titania, The state of titanium tetrachloride dissolved in the precursor can be a precursor state.

  The sol state referred to in the present invention means that one component is in a state of fine particles such as a colloid and dispersed in a liquid and in a fluid state. For example, when one component is alumina. May include boehmite sol (AlOOH) dispersed in a solvent.

  Next, one component of the precursor state or the sol state is impregnated in the pores of the honeycomb structure as a catalyst carrier. Examples of the impregnation method include a method in which the honeycomb structure is immersed in a solution containing one component in a precursor state or a sol state, and the solution enters the pores of the honeycomb structure.

  The honeycomb structure used in the catalyst supporting method of the honeycomb structure of the present embodiment can be manufactured, for example, according to a manufacturing method according to a conventionally known method for manufacturing a diesel particulate filter (DPF).

  Although there is no restriction | limiting in particular as a material which comprises a honeycomb structure, For example, the material which has ceramics as a main component, or a sintered metal etc. can be mentioned as a suitable example. Further, when the honeycomb structure is made of a material mainly composed of ceramics, the ceramics include silicon carbide, cordierite, alumina titanate, sialon, mullite, silicon nitride, zirconium phosphate, zirconia, Titania, alumina, silica, or a combination thereof can be cited as a suitable example. In particular, ceramics such as silicon carbide, cordierite, mullite, silicon nitride, and alumina are preferable in terms of alkali resistance. Of these, oxide ceramics are preferable from the viewpoint of cost.

There is no restriction | limiting in particular in the shape of the honeycomb structure used as a support | carrier, The honeycomb structure used for a conventionally well-known diesel particulate filter (DPF) can be used suitably. For example, the cell density (cell density) of the honeycomb catalyst body to be used is preferably 0.775 to 155 cells / cm ² (5 to 1000 cpsi), and 3.1 to 77.5 cells / cm ² (20 -500 cpsi) is more preferable, and 4.65-46.5 pieces / cm ² (30-300 cpsi) is particularly preferable. When the cell density is less than 0.775 cells / cm ² , the contact efficiency of the resulting honeycomb catalyst body with the exhaust gas tends to be insufficient. On the other hand, when the cell density exceeds 155 cells / cm ² , the pressure loss tends to increase. Note that “cpsi” is an abbreviation for “cells per square inch” and is a unit representing the number of cells per square inch. 10 cpsi is about 1.55 / cm ² .

In addition, the thermal expansion coefficient of the honeycomb structure in the cell communication direction at 40 to 800 ° C. is preferably less than 1.0 × 10 ⁻⁶ / ° C., and preferably 0 to 0.8 × 10 ⁻⁶ / More preferably, it is 0 degreeC, and it is especially preferable that it is 0-0.5 * 10 < ^-6 > / degreeC. When the thermal expansion coefficient in the direction of cell communication at 40 to 800 ° C. is less than 1.0 × 10 ⁻⁶ / ° C., the thermal stress when exposed to high-temperature exhaust gas can be kept low, and destruction due to thermal stress can be prevented. Can be prevented.

  The average pore diameter of the partition walls in the state where the catalyst is supported is preferably 5 to 500 μm, and more preferably 10 to 200 μm. If the average pore diameter is less than 5 μm, the pressure loss is too large, which is not suitable. On the other hand, when the average pore diameter is more than 500 μm, it tends to be difficult to ensure a sufficient contact area between the exhaust gas and the catalyst layer. The “pore diameter” in the present specification is a physical property value measured by image analysis. Specifically, the SEM photograph of the partition cross section is observed at least 20 fields with respect to the field of length × width = t × t, where the partition wall thickness is “t”. Next, within each observed visual field, the maximum linear distance in the void was measured, and the average value of the maximum linear distances measured for all visual fields was defined as “average pore diameter”.

  In addition, the shape of the cross section cut in the radial direction on the plane perpendicular to the cell communication direction of the honeycomb structure is preferably a shape suitable for the inner shape of the exhaust system to be installed. Specific examples include a circle, an ellipse, an ellipse, a trapezoid, a triangle, a quadrangle, a hexagon, and a deformed shape that is asymmetrical to the left and right. Of these, a circle, an ellipse, and an ellipse are preferable.

  Further, in the catalyst supporting method of the honeycomb structure of the present embodiment, one component is included when impregnating the pores of the honeycomb structure in the precursor state or the sol state. In the solution, other components with a volume ratio of less than 50% by volume based on the total components other than the noble metal of the catalyst and / or components of the catalyst made of noble metal (hereinafter sometimes referred to as “noble metal component”) A containing solution may be used. By comprising in this way, since the other component and / or noble metal component can be impregnated in the pores simultaneously with the one component, the catalyst supporting step can be simplified. Of course, the honeycomb structure may be immersed in a solution containing only one component.

  Next, if necessary, solification of one component impregnated in the pores of the honeycomb structure is advanced. For example, when a dehydrated isopropanol solution containing the above-described aluminum, iso, propoxide is used, the solution reacts with moisture to cause hydrolysis to generate boehmite sol. For this reason, one component impregnated in the pores by adding a few drops of deionized water to the above solution, or taking out the honeycomb structure from the above solution and reacting with moisture in the atmosphere. Can be allowed to proceed.

  Moreover, when using the solution which melt | dissolved titanium tetrachloride in solutions, such as water, sol-ization can be advanced by boiling a solution at about 80 degreeC.

  In addition, the method for solification can be appropriately selected depending on the type of one component and the type of solvent used.

  When performing the solification, for example, the pore distribution of the supported catalyst layer can be adjusted by controlling the solation process.

  Next, the sol-formed one component is gelled to advance into a solidified state containing liquid or air. As a specific gelation method, various drying methods are suitable. For this drying, in the conventional catalyst supporting method, a method similar to the method of drying the catalyst slurry can be used. However, in the catalyst supporting method of the honeycomb structure of the present embodiment, drying is performed by freeze drying. It is preferable. By performing such freeze-drying, the migration of the gelled catalyst component (one component, etc.) in the pores during drying can be suppressed, and the precursor or sol state is impregnated uniformly. The held state can be maintained well.

  Next, in the step of impregnating the pores of the above-mentioned one component into the pores of the honeycomb structure, when there are other components not included in the solution or a constituent component of the catalyst made of a noble metal (noble metal component), The proportion of the volume in the total constituent components of the catalyst using a solution containing the constituent components of the catalyst composed of the other constituents of less than 50% by volume and / or the noble metal in the total constituent components excluding the noble metal of the catalyst. Is impregnated in the pores of the honeycomb structure with other components and / or noble metal components of less than 50% by volume, and the impregnated components are dried.

  In addition, when impregnating one component into the pores of the honeycomb structure, the proportion of the volume in the total constituent components excluding the precious metal of the catalyst in the solution containing the one component is less than 50% by volume. When a solution containing a component and / or a noble metal component is used, since these components are impregnated and dried simultaneously with one component, it is not necessary to impregnate the pores separately.

  Next, a catalyst component is generated by synthesizing the catalyst components in the pores (that is, one component, or another component or noble metal component depending on the catalyst component). As described above, the catalyst can be supported on the honeycomb structure. In particular, the catalyst loading method of the present embodiment can load the catalyst well even on a diesel particulate filter or the like, which has conventionally been difficult to load the catalyst in its small pores.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In addition, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

  [Identification of catalyst loading position]: The catalyst loading position was identified by cutting out the honeycomb structure (honeycomb catalyst body) carrying the catalyst and analyzing the composition distribution image of the cross-sectional observation result to determine the amount and position of the catalyst. . The uniformity of the catalyst after loading is compared with the amount of catalyst loaded near the center in the thickness direction of the partition and near the surface of the partition (about 10 μm from the surface of the partition). Was judged as “no difference”, and when the difference in the amount carried was 20% or more, it was judged as “difference”.

[Pressure loss measurement]: Since the influence of the honeycomb catalyst body on the pressure loss appears remarkably when the soot is stored, the pressure loss was evaluated in a state where the soot was attached. As a measurement method, 3 g / L of soot was supported on the honeycomb structure before supporting the catalyst in advance and the honeycomb structure (honeycomb catalyst body) after supporting the catalyst, and each honeycomb structure or honeycomb was supported. Pressure loss was measured by flowing air through the catalyst body at room temperature under a flow rate of 2.0 m ³ / min. The pressure loss was evaluated by setting the pressure loss of the honeycomb structure before supporting the catalyst as P ₁ and the pressure loss of the honeycomb structure (honeycomb catalyst body) after supporting the catalyst as P _2. From “P _1” and “P ₂ ”, the “pressure loss increase rate (%)” was calculated according to the following formula (1). The case where the pressure loss increase rate was less than 50% was judged as “◯”, and the case where it was 50% or more was judged as “x”.
Pressure loss increase rate (%) = {(P ₂ −P ₁ ) / P ₁ } × 100 (1)

Example 1
Honeycomb structure having a diameter of 144 mm and a length of 152 mm (partition wall thickness: 12 mil (0.3048 mm), cell density: 300 cpsi (46.5 cells / cm ² ), porosity: 55%, average pore diameter: 15 μm, plugging Depth: 10 mm) was prepared. First, a dehydrated isopropanol solution containing aluminum, iso, propoxide is generated as an alumina (one component) source as a constituent material of the catalyst, and the prepared honeycomb structure is immersed in this solution and then taken out as it is in the atmosphere. It was hydrolyzed by contact with water, and one component was made into a sol.

  Next, the honeycomb structure including the boehmite sol generated by hydrolysis was freeze-dried and gelled, and then calcined in the atmosphere at 500 ° C. to finish loading alumina. Next, in order to support platinum as a noble metal, the above honeycomb structure supporting alumina was impregnated with a dinitrodiammine platinum nitric acid aqueous solution prepared in advance at a predetermined concentration and dried at room temperature. Thereafter, the honeycomb structure containing alumina and platinum was calcined at 300 ° C. to prepare a honeycomb structure (honeycomb catalyst body) supporting platinum / alumina. The amount of each catalyst component supported is shown in Table 1.

(Example 2)
Example except that the honeycomb structure was immersed in a dehydrated isopropanol solution containing aluminum, iso, propoxide, and then hydrolyzed by adding a few drops of deionized water to the solution to form one component in sol. 1 was used to prepare a honeycomb structure (honeycomb catalyst body) carrying platinum / alumina. The amount of each catalyst component supported is shown in Table 1.

(Example 3)
Honeycomb structure having a diameter of 191 mm and a length of 170 mm (partition wall thickness: 12 mil (0.3048 mm), cell density: 300 cpsi (46.5 / cm ² ), porosity: 60%, average pore diameter: 19 μm, plugging Depth: 10 mm) was prepared. First, a solution containing titanium tetrachloride as a titania (one component) source as a constituent material of the catalyst, chloroplatinic acid as a platinum (noble metal component) source, and water was prepared, and this solution was prepared. The honeycomb structure was immersed. Thereafter, this solution was boiled at 80 ° C. to make one component into a sol. A honeycomb structure containing titania and platinum was freeze-dried and gelled, and then calcined in the atmosphere at 300 ° C. to prepare a honeycomb structure (honeycomb catalyst body) carrying platinum / titania. . The amount of each catalyst component supported is shown in Table 1. Note that 1 mil is one thousandth of an inch and 0.0254 mm.

(Comparative Example 1)
Honeycomb structure having a diameter of 144 mm and a length of 152 mm (partition wall thickness: 12 mil (0.3048 mm), cell density: 300 cpsi (46.5 cells / cm ² ), porosity: 55%, average pore diameter: 15 μm, plugging Depth: 10 mm) was prepared. First, activated alumina, dinitrodiammine platinum nitric acid as a noble metal component and water were mixed and then wet pulverized to prepare a catalyst coating solution. The prepared honeycomb structure was impregnated with this catalyst coating solution to coat the catalyst and dried to prepare a honeycomb structure (honeycomb catalyst body) carrying platinum / alumina. The amount of each catalyst component supported is shown in Table 1.

  As is apparent from the results shown in Table 1, all the honeycomb structures (honeycomb catalyst bodies) on which the catalysts are supported by the catalyst supporting methods of Examples 1 to 3 are determined to have no difference in the identification results of the catalyst supporting positions. The catalyst could be supported uniformly. Also in the pressure loss measurement, it was found that the pressure loss increase rate was less than 50%, and the pressure loss was reduced. On the other hand, the honeycomb structure (honeycomb catalyst body) of Comparative Example 1 in which the catalyst is supported by the conventional catalyst supporting method has a difference in supported amount of 20% or more as a result of identifying the catalyst supporting position, and the pressure loss increase rate is It was 50% or more.

  The method for supporting a honeycomb structure of the present invention can uniformly support a catalyst having a good composition and pore distribution as a catalyst in the pores of the honeycomb structure. A method for manufacturing a honeycomb catalyst body used for purification of components to be purified contained in exhaust gas discharged from mechanical and industrial stationary engines and combustion equipment, and a filter for removing particulates from a diesel engine It can be used suitably.

1 is a front view schematically showing a honeycomb structure (honeycomb catalyst body) on which a catalyst is supported according to an embodiment of a catalyst support method for a honeycomb structure of the present invention. FIG. Fig. 2 is a cross-sectional view schematically showing the honeycomb structure of Fig. 1. FIG. 3 is a partially enlarged view of the honeycomb structure of FIG. It is a front view which shows typically one Embodiment of the conventional honeycomb catalyst body. It is sectional drawing which shows typically one Embodiment of the conventional honeycomb catalyst body. It is the elements on larger scale which show typically one embodiment of the conventional honeycomb catalyst body.

Explanation of symbols

1: honeycomb structure, 1a: honeycomb catalyst body, 2a, 2b: end face, 3: cell, 4: partition, 5: catalyst, 10: plugged portion, 11: honeycomb structure, 15: catalyst layer, 20: Outer wall, 25: pore, 60: honeycomb catalyst body.

Claims (7)

A porous partition wall having a large number of pores arranged so as to form a plurality of cells communicating between two end faces, and arranged so as to plug the cells at any of the end faces. A method for supporting a catalyst in a honeycomb structure in which a catalyst is supported in a honeycomb structure having a plugging portion,
Among the constituent components excluding the precious metal of the catalyst, one component having a volume ratio of 50% by volume or more in the total constituent components of the catalyst is added in the precursor state or the sol state in the fine structure of the honeycomb structure. A method for supporting a catalyst of a honeycomb structure, comprising the steps of impregnating pores, gelling the impregnated one component, and drying the gelled one component.   The method for supporting a catalyst of a honeycomb structure according to claim 1, wherein the method for drying the one component that has been gelled is freeze-drying.   When the one component is impregnated into the pores of the honeycomb structure in a precursor state or a sol state, the volume of the catalyst component in the solution containing the one component The method for supporting a catalyst of a honeycomb structure according to claim 1 or 2, wherein a solution containing another component having a ratio of less than 50% by volume and / or a constituent component of the catalyst composed of the noble metal is used.   After the one component is impregnated into the pores of the honeycomb structure and dried, the proportion of the volume in the total component of the catalyst is less than 50% by volume and / or the noble metal. Using the solution containing the catalyst component, the other component having a volume ratio of less than 50% by volume to the total component of the catalyst and / or the component of the catalyst made of the noble metal is added to the honeycomb structure. The method for supporting a catalyst of a honeycomb structure according to claim 1 or 2, wherein the pores are impregnated and the impregnated components are dried. As the catalyst, a three-way catalyst for gasoline engine exhaust gas purification, an oxidation catalyst for hydrocarbon, carbon monoxide, or soot purification, an SCR catalyst for NO _x selective reduction, an NO _x storage catalyst, a three-way purification function and a soot purification function A honeycomb structure according to any one of claims 1 to 4, wherein at least one catalyst selected from the group consisting of a quaternary catalyst having a catalyst and a catalyst used for purifying oxide-based harmful components in combustion exhaust gas is used. A method for supporting a catalyst in a body.   The method for supporting a catalyst of a honeycomb structure according to any one of claims 1 to 5, wherein the honeycomb structure is made of a material mainly composed of ceramics or a sintered metal.   The method for supporting a catalyst on a honeycomb structure according to any one of claims 1 to 6, wherein the honeycomb structure is a diesel particulate filter.

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