JP2012011387A - Method for manufacturing catalyst material, and catalyst material and catalyst body manufactured by the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a catalyst material which inhibits sintering of a catalyst component, and can raise heat resistance, and to provide a catalyst material and a catalyst body which are manufactured by the same.SOLUTION: The method for manufacturing a catalyst material includes: a first process which prepares a dispersion of a particle which has an oxygen occlusion discharge function, and consists of a composite oxide of two or more elements chosen from the group consisting of Ce, Zr, Al, Ti, Si, Mg, Y, and La, and a dispersion of a particle which has heat resistance, and consists of a composite oxide of Al and La; and a second process in which the dispersion of a particle which has an oxygen occlusion discharge function and the dispersion of a particle which has heat resistance are mixed, and which distributes the particle which has an oxygen occlusion discharge function, and the particle which has heat resistance in a mixed liquid, wherein low molecule amines are used as at least one dispersant of the particle which has an oxygen occlusion discharge function and the particle which has heat resistance.

Description

  The present invention relates to a method for producing a catalyst material used for harmful gas purification, fuel cell, environmental purification, and the like, and a catalyst material and a catalyst body produced thereby.

  Conventionally, noble metals such as Pt, Pd, and Rh are generally used as catalyst components for purifying harmful components such as HC, CO, and NOx contained in exhaust gas of an internal combustion engine. In such a catalyst component, a honeycomb carrier is used to carry the catalyst component on the surface of the honeycomb carrier with high dispersion. However, the surface area of the honeycomb carrier is not sufficient to support the catalyst component in a highly dispersed state, and a necessary loading amount cannot be ensured.

Therefore, conventionally, particulate oxide particles having a high specific surface area represented by γ-alumina (Al ₂ O ₃ ) are used as a carrier, and the oxide particles are supported on the honeycomb carrier before carrying the catalyst component. Then, the catalyst component was further supported on the coated layer of the coated oxide particles.

However, the conventional configuration in which a coating layer of oxide particles made of γ-alumina is formed on a honeycomb carrier and the catalyst component is supported on the coating layer of oxide particles has the following problems. .
First, γ-alumina has a high specific surface area, but itself has low heat resistance, so that the shape of γ-alumina changes due to long-term use, so that the catalyst component is buried in the inside of γ-alumina. The catalyst function was to be deactivated.

For this reason, in order to achieve the necessary exhaust gas purification performance, that is, sufficient catalyst function, it is necessary to carry an excess catalyst component from the initial stage, and the amount of catalyst component used is large and the utilization efficiency is low. There was a problem that.
In addition, when the conventional catalyst body is used as a catalyst body for exhaust gas purification of an internal combustion engine, it is used at a high temperature of about 1000 ° C. Therefore, with the use at this high temperature, the above-mentioned catalyst component γ -In addition to the problem of burying in the interior of alumina, there arises a problem that sintering due to heat occurs.

  Then, due to this sintering, the catalyst components move or the catalyst components are combined with each other, the reaction-active specific surface area is reduced, and the purification performance is deteriorated. For this reason as well, it is necessary to carry more catalyst components than the amount of catalyst required in the initial stage, and there are problems of environmental burden and high cost.

  On the other hand, a method of improving the catalyst performance by mixing the carrier particles and the catalyst component, separating the catalyst components with the carrier particles, and supporting them on the honeycomb carrier in a blocked state is considered. For example, when a catalyst component dispersed in a liquid phase and carrier particles are mixed, dried and calcined, the catalyst component is fixed and supported in the gaps between the carrier particles. If it can arrange | position uniformly, it will be thought that a support | carrier particle | grain plays the role of a blocking agent and can inhibit the movement of a catalyst component by a sintering etc., and the coupling | bonding of catalyst components.

  However, in order to realize the above-described method, it is necessary to dispose the catalyst component and the carrier particles separately precisely. Therefore, in the conventional method of dispersing two or more kinds of particles in a solution and then concentrating and drying or baking with reduced pressure or hot air, there is a problem that the two or more kinds of particles cannot be arranged uniformly.

  In view of the above points, an object of the present invention is to provide a method for producing a catalyst material capable of preventing sintering of catalyst components and improving heat resistance, a catalyst material produced thereby, and a catalyst body. .

  In order to achieve the above object, the present inventor prepared two or more kinds of dispersion liquids dispersed under the condition that the same kind of particles repel each other, and then mixed the two or more kinds of dispersion liquids. An experiment was conducted on the assumption that two or more kinds of particles should be uniformly dispersed in the mixed solution. As a result, it was found that two or more kinds of particles can be arranged so that the same kind of particles do not come into contact with each other, as shown in Examples described later.

  That is, in the first aspect of the invention, the particles having an oxygen storage / release function composed of a complex oxide of a plurality of elements selected from the group consisting of Ce, Zr, Al, Ti, Si, Mg, Y, and La. A first step of preparing a dispersion and a dispersion of heat-resistant particles made of a composite oxide of Al and La; a dispersion of particles having an oxygen storage / release function; and a dispersion of particles having heat resistance And a second step of dispersing the particles having the oxygen storage / release function and the heat-resistant particles in the mixed solution, and the particles having the oxygen storage / release function and the heat resistance. As a dispersant for at least one of the particles, low molecular amines are used.

  According to this, two or more kinds of particles (1, 2) can be uniformly arranged so that the same kind of particles do not contact each other. Here, when the catalyst component and the carrier particle are contained in two or more kinds of particles (1, 2), the catalyst component is uniformly arranged in the gap between the carrier particles, so that the carrier particle serves as a blocking agent. As a result, it is possible to inhibit the movement of the catalyst components and the binding between the catalyst components due to sintering and the like. Therefore, sintering of the catalyst component can be prevented and heat resistance can be improved. Further, when the particles having an oxygen storage / release function are a complex oxide of a plurality of elements selected from the element group consisting of Ce, Zr, Al, Ti, Si, Mg, Y, and La, the dispersant is an amine. It is good. At this time, since the surface potential of the particles having the oxygen storage / release function is positive, by using amines having a positive charge as the dispersant, the surface potential of the particles having the oxygen storage / release function can be further increased. Can be a plus. Thereby, particles having an oxygen storage / release function can be more effectively dispersed. Furthermore, when the particles having heat resistance are a composite oxide of Al and La, the dispersant may be an amine. At this time, since the surface potential of the particles having heat resistance is positive, the surface potential of the particles having heat resistance can be made more positive by using a positively charged amine as a dispersant. Can do. Thereby, the particles having heat resistance can be more effectively dispersed.

  Moreover, as a method of changing the repulsive force acting between two or more kinds of particles, it can be performed by changing the electrostatic repulsive force acting between two or more kinds of particles. The electrostatic repulsion can be described by a measurable ζ potential. When the ζ potentials of different particles are both positive or negative, repulsive force acts between the particles. On the other hand, when the ζ potentials of different particles are positive and negative, an attractive force acts between the particles.

  That is, as in the invention described in claim 2, by adjusting the amount of the dispersant, the particles having the oxygen storage / release function and the heat-resistant particles have the same ζ potential, so that two or more kinds can be obtained. A larger electrostatic repulsive force can be applied between the particles (1, 2). For this reason, the dispersibility of 2 or more types of particle | grains (1, 2) can be improved more.

  Further, as in the invention described in claim 3, the particles having an oxygen storage / release function may contain at least one noble metal.

  Moreover, like the invention of Claim 4, a catalyst material can be manufactured by the method of any one of Claims 1 thru | or 3. Further, as in the invention described in claim 5, the catalyst material may be coated on the surface layer or pores of the honeycomb-shaped carrier.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a figure which shows the typical structure of the catalyst material which concerns on 1st Embodiment, (a) at the time of dispersion | distribution, (b) at the time of arrangement | sequence, (c) has shown after drying and baking. FIG. 3 is a characteristic diagram showing the relationship between the pH of each dispersion and the ζ potential of particles in Example 1. FIG. 3 is a characteristic diagram showing the relationship between the amount of dispersant in the alumina particle dispersion and the ζ potential of alumina particles in Example 1.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of a catalyst material according to the first embodiment, where (a) shows a state after dispersion, (b) shows an arrangement, and (c) shows a state after drying and firing.

  In the present embodiment, particles 1 having a catalytic function (hereinafter also referred to as catalyst particles 1) and metal oxide particles 2 are employed as the two or more types of particles of the present invention.

Here, as the catalyst particles 1, promoter particles (promoter components) 4 to which the noble metal 3 and an alloy or oxide of the noble metal 3 or a composite oxide are attached can be employed. More specifically, the noble metal 3 may be Pt, Rh, Pd, Ru, Ir, Os, or the like. Further, as the cocatalyst particles 4, one or more selected from CeO ₂ , ZrO ₂ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , MgO, Y ₂ O ₃ , La ₂ O ₃ and derivatives thereof. Those composed of any of the compounds can be employed.

The metal oxide particles 2 may be one or more selected from CeO ₂ , ZrO ₂ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , MgO, Y ₂ O ₃ , La ₂ O ₃ and derivatives thereof. Those composed of any of the compounds can be employed.

  Next, the manufacturing method of the catalyst material of this embodiment is described.

  First, as shown in FIG. 1 (a), a dispersion of catalyst particles 1 (hereinafter also referred to as a first dispersion) uniformly dispersed under conditions such that the catalyst particles 1 repel each other, and a metal oxide Two types of dispersions of a dispersion of metal oxide particles 2 (hereinafter also referred to as a second dispersion) that are uniformly dispersed under conditions where the particles 2 repel each other are prepared.

  Here, as a method of uniformly dispersing each of the catalyst particles 1 and the metal oxide particles 2 in each dispersion, a state in which electrostatic repulsion acts between the same and different particles of the catalyst particles 1 and the metal oxide particles 2; That is, a method of adjusting the state of the dispersion so that the ζ potentials of the catalyst particles 1 and the metal oxide particles 2 are both positive or negative can be employed. More specifically, since the ζ potential of the particles generally changes depending on the pH, the pH of each dispersion is adjusted so that both the ζ potentials of the catalyst particles 1 and the metal oxide particles 2 are positive or negative. The adjustment method can be adopted.

  Subsequently, as shown in FIG. 1B, the first dispersion liquid and the second dispersion liquid are mixed to arrange the particles 1 and 2 so that the catalyst particles 1 do not contact each other. Thereby, catalyst composite particles composed of the catalyst particles 1 and the metal oxide particles 2 are generated.

  Subsequently, as shown in FIG. 1C, the catalyst composite particles obtained as described above are dried and calcined to obtain powdered catalyst composite particles, that is, a catalyst material.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the second embodiment, a new molecule having a charge (hereinafter also referred to as a dispersant) is attached to the surface of the particle dispersed in the solution, and the amount of the dispersant is adjusted to adjust the particle. Attempts were made to improve the dispersibility of two or more kinds of particles by changing the ζ potential. Description of the same parts as those in the first embodiment is omitted.

  First, in order to improve the dispersibility of two or more types of particles, a dispersant is added at the time of synthesis of each particle, and the amount of the dispersant adhering to the particle surface in the dispersion of each particle is adjusted. To do.

Here, as a method for adjusting the amount of the dispersing agent, the dispersing agent contained at the time of particle synthesis can be changed by changing the number of times of washing in centrifugation of the reaction solution.
Here, as a molecule having a positive charge, a material containing an amine, a quaternary ammonium salt, or a pyridinium salt can be employed. More specifically, a material containing polyethyleneimine, a material containing quaternary ammonium hydroxide, an alkanolamine, or the like can be employed.

  Moreover, as a molecule | numerator which has a negative charge, the material containing carboxylate, a sulfonate, a sulfate ester salt, a phosphate ester salt, etc. can be employ | adopted, Specifically, polycarboxylic acid ammonium salt is included. A material, a material containing sodium polycarboxylate, a material containing ammonium polycarboxylate, a material containing sodium polyacrylate, a material containing a polyacrylic maleic acid copolymer, or the like can be employed.

  Further, nonionic molecules whose potential changes with pH can be employed.

  In addition, as a dispersing agent, it is desirable to employ | adopt a thing with strong adsorption power with each particle | grain.

  Next, although it does not limit, the manufacturing method of the catalyst material of each said embodiment is demonstrated more concretely with reference to the following each Examples and comparative examples.

Example 1
Example 1 corresponds to the first and second embodiments.

  In Example 1, Pt was used as the noble metal, CeO2 / ZrO2 solid solution having an oxygen storage / release function was used as the promoter particles (promoter component), and alumina (Al2O3) was used as the metal oxide particles.

  The CeO2 / ZrO2 solid solution was synthesized by mixing diethanolamine as a coprecipitation agent in an aqueous solution in which cerium nitrate and zirconium oxynitrate were mixed by a liquid phase method and stirring at room temperature. Diethanolamine also acts as a dispersant for the synthetic particles.

  Then, the reaction solution is centrifuged, platinum chloride and a reducing agent are added to the resulting sol-dispersed solution, and Pt is supported on the CeO2 / ZrO2 solid solution to form catalyst particles having a particle diameter of about 5 nm. did.

  Further, alumina particles having a particle diameter of around 10 nm were formed by the same synthesis method as that for the CeO2 / ZrO2 solid solution.

  At this time, the dispersant for the catalyst particles (CeO2 / ZrO2 solid solution carrying Pt) and the dispersant for the alumina particles are both diethanolamine. For this reason, since the surface potential of the catalyst particles and the surface potential of the alumina particles are approximately the same, the dispersibility of the two types of particles can be further improved when the dispersion of the two types of particles is mixed. .

  Here, the zeta potential of the catalyst particles (CeO2 / ZrO2 solid solution carrying Pt) and alumina particles was measured. The measurement results are shown in FIG. In FIG. 2, the solid line a indicates the measurement result of the catalyst particle dispersion, and the broken line b indicates the measurement result of the alumina particle dispersion.

  As shown in FIG. 2, the catalyst particles had an electrostatic potential of 20 mV or higher in the pH 1-2 region where the particles can be stably dispersed, and the alumina particles had a positive potential of 30 mV or higher in the pH 1-3 region.

  Therefore, by mixing the dispersion of catalyst particles and the dispersion of alumina particles within the above pH range, catalyst particles (more specifically, noble metals and promoter particles) and alumina particles can be mixed. It is considered that composite catalyst particles arranged so as not to contact each other can be obtained.

  Therefore, in Example 1, first, pH 2 is used as a dispersion of catalyst particles, pHs 1, 2, and 3 are used as dispersions of alumina particles to be mixed, and mixing is performed so that each particle solid content is 1: 3. The dispersibility of the two kinds of particles was verified by observation with a transmission electron microscope of the obtained liquid mixture. As a result, the dispersion state of the catalyst particles differed depending on the difference in pH of the alumina particles during mixing, and the dispersibility was the best when the particles were mixed at pH 3.

  Subsequently, under the above mixed pH conditions, an experiment was conducted in which the amount of the dispersant adhering to the alumina particles was adjusted, the measurement of the ζ potential of the alumina particle dispersion, and the two types after mixing the dispersion of each particle The dispersion state of the particles was observed.

  FIG. 3 is a characteristic diagram showing the relationship between the amount of dispersant in the alumina particle dispersion and the ζ potential of the alumina particles. As shown in FIG. 3, it became clear that the ζ potential of the alumina particles changes depending on the amount of the dispersant in the alumina particle dispersion. Moreover, according to the observation result of the dispersion state of the two kinds of particles after mixing the dispersion liquid of each particle, it was found that the dispersion state of the catalyst particles also differs depending on the amount of the dispersant in the alumina particle dispersion liquid. . As indicated by point c in FIG. 3, the dispersibility of the two kinds of particles was the best when the amount of the dispersant in the dispersion of alumina particles was 33036 mV · s / mg.

  Various mixed liquids obtained as described above were dried by freeze drying and subjected to atmospheric firing at 800 ° C. for 5 hours to obtain catalyst composite particles (catalyst material).

(Comparative example)
A mixed slurry in which a slurry containing the same catalyst particles as in Example 1 (CeO ₂ / ZrO ₂ solid solution carrying Pt) and alumina were mixed so that the ratio of the number of each particle was 3: 1, The pH is adjusted to 3 to 4 with nitric acid and stirred for 2 hours to disperse the catalyst particles and alumina. This solution was concentrated by a rotary evaporator and dried. Further, the dried product was fired in the same manner as in the first example to obtain catalyst composite particles (catalyst material).

(Purification performance evaluation)
The catalyst composite particles obtained in Example 1 and the comparative example were each coated on a honeycomb carrier to prepare a catalyst body, and the purification performance of each catalyst composite particle was evaluated using a model gas.

  Specifically, a honeycomb carrier made of cordierite having a diameter of 30 mm and a length of 50 mm was used, and each catalyst composite particle was supported on the honeycomb carrier at a loading amount of 2 g / L. And in order to add the thermal history close | similar to actual use, the honeycomb support | carrier with which each catalyst composite particle was carry | supported was heat-treated at 950 degreeC for 5 hours, Then, each model gas was flowed and evaluated.

Here, as the model gas, a gas containing O ₂ , N ₂ , C ₃ H ₆ , C ₃ H ₈ , NO, and CO components was used. This model gas was flowed from the front part of the honeycomb carrier, and the components of the gas before and after the inflow of the honeycomb carrier were analyzed. Then, the purification rate is calculated from the ratio between the analysis value of the total gas amount of CO, NO, and HC components before the inflow of the honeycomb carrier and the analysis value of the total gas amount of CO, NO, and HC components after the inflow, The average of total NO and HC components was taken. It has been found that this purification rate improves as the temperature of the honeycomb carrier increases, and that the higher the purification rate at a lower temperature, the higher the catalyst performance.

  The evaluation was performed by heating the inflow gas and the honeycomb carrier, and measuring the relationship between the temperature of the inflow gas and the honeycomb carrier and the purification rate.

  As a result, the carrier coated with the catalyst composite particles obtained by mixing the catalyst composite particles obtained in Example 1 with the pH of the alumina particles having the poorest dispersion state being set to 1, has a purification rate. The temperature at which it reached 50% was 325 ° C. Moreover, among the catalyst composite particles obtained in Example 1, the pH of the alumina particles having the best dispersion state was set to 3, and the amount of the dispersant was further adjusted to 33036 mV · s / mg and mixed. In the carrier coated with the catalyst composite particles, the temperature at which the purification rate was 50% was 313 ° C. On the other hand, in the catalyst body coated with the catalyst composite particles obtained in the comparative example, the temperature at which the purification rate was 50% was 333 ° C.

  Thus, the catalyst body coated with the catalyst composite particles produced by improving the dispersibility by adjusting the pH of the dispersion of the two kinds of particles and the amount of the dispersant was coated with the catalyst composite particles obtained in the comparative example. Compared with the catalyst body, the temperature at which the purification rate reaches 50% is lowered, and it can be said that the catalyst performance is improved. That is, the catalyst particles are uniformly arranged in the gaps between the metal oxide particles, the metal oxide particles serve as a block material, and the catalyst particles move due to sintering during thermal history, or between the catalyst particles. The binding is thought to be inhibited.

  As described above, the two types of particles (catalyst particles and metal oxide particles) are made repulsive, the amount of the dispersant adhering to the particle surface is adjusted, and then the dispersion liquid of each particle is mixed. Thus, two or more kinds of particles can be arranged uniformly so that the same kind of particles do not contact each other.

  In each of the above embodiments, catalyst particles (catalyst components) and metal oxide particles (carrier particles) are employed as two or more kinds of particles, so that the catalyst particles can be uniformly arranged in the gaps between the metal oxide particles. . For this reason, the metal oxide particles serve as a blocking agent and can inhibit the movement of the catalyst particles due to sintering or the like and the bonding between the catalyst particles. Therefore, sintering of the catalyst particles can be prevented and the heat resistance can be improved.

(Example 2)
In Example 2, Rh was used as the noble metal, CeO ₂ / ZrO ₂ solid solution having an oxygen storage / release function was used as the promoter particles (catalyst component), and alumina was used as the metal oxide particles.

Then, a CeO ₂ / ZrO ₂ solid solution was synthesized by the same method as in Example 1, and Rh was supported on the synthesized CeO ₂ / ZrO ₂ solid solution, thereby obtaining catalyst particles having a particle diameter of about 5 nm. In addition, alumina particles having a particle diameter of around 10 nm were obtained by the same synthesis method as that for the CeO ₂ / ZrO ₂ solid solution.

  Here, when the ζ potential of the catalyst particles was measured, it was an electrostatic potential of 20 mV or more in the pH 1-2 region.

  Therefore, by mixing the dispersion of catalyst particles and the dispersion of alumina particles within the range where the pH of the dispersion of catalyst particles is 1-2 and the pH of the dispersion of alumina particles is 1-3, It is considered that composite catalyst particles arranged such that catalyst particles (more specifically, noble metals and promoter particles) and alumina particles do not contact each other can be obtained.

  Therefore, in Example 2, pH 1 is used as a dispersion of catalyst particles, pH 1, 2, and 3 are used as dispersions of alumina particles to be mixed, and mixing is performed so that the solid content of each particle is 1: 3. The dispersibility of the two kinds of particles was verified by observation with a transmission electron microscope of the obtained dispersion. As a result, it was found that the dispersibility was the best when the alumina dispersion was mixed at pH 3 and the amount of the dispersant was 33036 mV · s / mg.

(Example 3)
In Example 3, Pd was used as the noble metal, CeO ₂ / ZrO ₂ solid solution having an oxygen storage / release function was used as the promoter particles (catalyst component), and alumina was used as the metal oxide particles.

Then, a CeO ₂ / ZrO ₂ solid solution was synthesized by the same method as in Example 1, and Pd was supported on the synthesized CeO ₂ / ZrO ₂ solid solution to obtain catalyst particles having a particle diameter of about 5 nm. Further, alumina particles having a particle diameter of around 10 nm were obtained by the same synthesis method as that for the CeO ₂ / ZrO ₂ solid solution.

  Here, when the ζ potential of the catalyst particles was measured, it was an electrostatic potential of 20 mV or more in the pH range of 1 to 2.5.

  Therefore, the catalyst particle dispersion and the alumina particle dispersion are mixed within a range of pH 1 to 2.5 of the catalyst particle dispersion and pH 1 to 3 of the alumina particle dispersion. Thus, it is considered that composite catalyst particles arranged so that catalyst particles (more specifically, noble metals and promoter particles) and alumina particles do not contact each other can be obtained.

  Therefore, in Example 3, pH 1 is used as the dispersion of catalyst particles, pH 1, 2, and 3 are used as the dispersion of alumina particles to be mixed, and mixing is performed so that the solid content of each particle is 1: 3. The dispersibility of the two kinds of particles was verified by observation with a transmission electron microscope of the obtained dispersion. As a result, it was found that the dispersibility was the best when the alumina dispersion was mixed at pH 3 and the amount of the dispersant was 33036 mV · s / mg.

Example 4
In Example 4, Ru, Ir, and Os are used as noble metals, and CeO ₂ , ZrO ₂ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , MgO, Y ₂ O ₃ , and La are used as promoter particles (catalyst components). _Using one or two or more compounds selected from ₂ O ₃ and derivatives thereof, the metal oxide particles 2 are CeO ₂ , ZrO ₂ , Al ₂ O ₃ , TiO ₂ , SiO ₂ , MgO, Y ₂ O ₃ , La ₂ O ₃ and derivatives thereof were used. Even in this case, the same dispersion state as in Example 1 could be confirmed.

(Other embodiments)
In each of the above embodiments, the example in which the catalyst composite particles are supported on the honeycomb carrier made of cordierite has been described. However, the present invention is not limited to this, and the catalyst composite particles are supported on the honeycomb carrier made of ceramics such as SiC or alumina, or metal such as aluminum. May be.

1 catalyst particles 2 metal oxide particles

Claims (5)

A dispersion of particles having an oxygen storage / release function composed of a composite oxide of a plurality of types of elements selected from the group consisting of Ce, Zr, Al, Ti, Si, Mg, Y, La, and composite oxidation of Al and La A first step of preparing a dispersion of heat-resistant particles made of a material,
Secondly, the dispersion liquid of the particles having the oxygen storage / release function and the dispersion liquid of the heat resistant particles are mixed to disperse the particles having the oxygen storage / release function and the heat resistant particles in the mixed liquid. A process for producing a catalyst material comprising the steps of:
A method for producing a catalyst material, wherein a low molecular amine is used as a dispersant for at least one of the particles having an oxygen storage / release function and the heat-resistant particles.   2. The method for producing a catalyst material according to claim 1, wherein the amount of the dispersant is adjusted so that the ζ potential of the particles having the oxygen storage / release function and the particles having the heat resistance are substantially equal. .   The method for producing a catalyst material according to claim 1 or 2, wherein the particles having an oxygen storage / release function include at least one kind of noble metal.   A catalyst material produced by the method according to any one of claims 1 to 3.   5. A catalyst body, wherein the catalyst material according to claim 4 is coated on a surface layer or pores of a honeycomb-shaped carrier.

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