KR102226766B1 - Method of ceramic filter for purifying exhaust gas and ceramic filter produced from the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a ceramic filter for purifying exhaust gas, and the ceramic filter manufactured thereby. More specifically, the present invention relates to a method for manufacturing a ceramic filter for exhaust gas, in which an iron oxide is deposited on an existing platinum-based catalyst, and a catalyst to convert a harmful substance of the exhaust gas to a harmless substance is used from a room temperature, such that structural stability is obtained even in an exhaust gas environment at a higher temperature of 500 °C as well as the room temperature. The ceramic filter for purifying the exhaust gas, which is manufactured according the manufacturing method of the present invention, may efficiently make an oxidation reaction of carbon monoxide (CO) at a high conversion rate even at a low temperature (30 °C). The conversion rate of CO is greatly increased at a lower temperature for a shorter time. The increased higher conversion rate is stably maintained over time.

Description

A method for manufacturing a ceramic filter for purifying exhaust gas, and a ceramic filter manufactured by the method TECHNICAL FIELD [METHOD OF CERAMIC FILTER FOR PURIFYING EXHAUST GAS AND CERAMIC FILTER PRODUCED FROM THE SAME}

The present invention relates to a method of manufacturing a ceramic filter for purifying exhaust gas and a ceramic filter manufactured thereby, and specifically, a catalyst capable of converting harmful substances of exhaust gas into harmless substances at room temperature by depositing iron oxide on an existing platinum-based catalyst. Using, it relates to a method for manufacturing a ceramic filter for purifying exhaust gas having structural stability not only at room temperature but also in a high temperature exhaust gas environment of 500°C.

Carbon monoxide and various other hydrocarbons, which are harmful to the human body and the environment, are formed due to incomplete combustion of fossil fuels. Accordingly, automobile exhaust gas is converted into a harmless substance, such as carbon monoxide converted to carbon dioxide through an appropriate treatment device, and then into the atmosphere. Should be discharged.

Generally, catalysts such as platinum nanoparticles are used in automobile exhaust gas treatment units to convert harmful substances into harmless substances. The catalyst has high catalytic activity and structural stability, but is expensive and catalytic activity only at temperatures above 150℃. There is a problem of showing. This causes a widely known cold start-up problem, especially after starting a car in a cold winter, and before the engine temperature rises, the cold exhaust gas is discharged into the atmosphere without being converted into harmless substances as it passes through the catalytic treatment section. Air pollution caused by automobile exhaust gas is mostly caused by exhaust gas emitted within 5 minutes immediately after starting the engine.

Because of this problem, studies on catalysts that operate from room temperature have been conducted, and gold and cobalt oxide catalysts having a particle size of less than 5 nanometers have been shown to have high activity in the carbon monoxide oxidation reaction at room temperature.

However, in the case of automobile exhaust gas treatment catalysts, it is also important to show high catalytic activity from room temperature, but on the other hand, when the temperature of the engine rises when the car is running sufficiently, the structure changes at that temperature when the exhaust gas temperature reaches 500℃. It is important to maintain the catalytic activity without causing catalytic activity. In the case of the above-mentioned room temperature catalyst, there is a problem in that the structure of the catalyst is easily deformed at a high temperature and thus catalytic activity is not maintained.

Republic of Korea Patent Publication No. 10-2019-0003799

An object of the present invention is to deposit iron oxide on an existing platinum-based catalyst, so that it is possible to convert harmful substances from exhaust gas into harmless substances at room temperature, and a method of manufacturing a new catalyst having structural stability even in a high temperature exhaust gas environment of 500°C. It provides, and relates to a method of manufacturing a ceramic filter for purification of exhaust gas comprising the catalyst prepared by the manufacturing method.

In order to solve the above technical problem, the present invention comprises the steps of: 1) _{placing Pt/Al 2} O ₃ and an iron precursor in a sealed reactor, respectively; 2) vaporizing an iron precursor by heating the reactor to a temperature of 50 to 70°C; 3) preparing a catalyst _{(Fe-Pt / Al 2 O} 3) to heat the temperature of the reactor at a temperature of 150 ~ 250 ℃ by depositing iron oxide on Pt / Al ₂ O ₃ surface; 4) heat-treating the prepared catalyst by heating it in air at a temperature of 400 to 500°C; 5) preparing a coating composition by mixing the catalyst with silicate, a filler, cellulose, a dispersant, and a flame retardant; and 6) coating the coating composition on the ceramic filter. do.

Steps 1) to 4) are a method of preparing a catalyst for a carbon monoxide oxidation reaction using a temperature-controlled chemical vapor deposition method.

In the case of manufacturing using conventional CVD performed at a single temperature, the metal catalyst precursor vaporizes and reacts with surrounding oxygen to form a metal oxide and is deposited on the carrier, so that the metal catalyst precursor vapor cannot be transferred to the inside of the carrier and is oxidized on the surface. Therefore, it is difficult to fully utilize the advantages of the porous carrier because it can be deposited and agglomerated to cover the pores of the carrier.

Accordingly, the present invention has a characteristic that it is possible to prepare a catalyst in which the completely oxidized iron oxide is deposited by controlling the temperature in two stages and performing additional heat treatment.

Step 1) is a step of _{placing the Pt/Al 2} O ₃ and the iron precursor inside the sealed reactor, respectively, the Pt/Al ₂ O ₃ and the iron precursor do not contact each other, and Pt/Al ₂ O ₃ is more than the iron precursor. It is advantageous to be positioned higher.

Step 2) is a step of vaporizing the iron precursor by heating it to a temperature of 50 to 70°C in the reactor, and is preferably carried out for 1 to 3 hours, and by inducing only the vaporization of the iron precursor, the vapor pressure of the iron precursor is reduced in the sealed chamber. By increasing the amount, the iron precursor gas can be evenly diffused into _{the Pt/Al 2} O _{3 interior through the pores.}

3) The step is a step of heating the temperature of the reactor at a temperature of 150 ~ 250 ℃ by depositing the oxide on the surface and inside the Pt / Al ₂ O ₃ to obtain a catalyst _{(Fe-Pt / Al 2 O} 3), 10 It is preferably carried out for ~ 14 hours, Pt / Al ₂ O _{3 It} is possible to form iron oxide by reacting with oxygen and the iron precursor diffused in the surface and inside.

Step 4) is an additional heat treatment step, and it is preferable that the catalyst prepared in step 3) is taken out of the reactor and carried out in dried air at a temperature of 400 to 500° C. higher than the temperature of step 3) for 1 to 3 hours. In the step of forming iron oxide in step 3), the iron precursor may not be completely oxidized due to a relatively low temperature and may remain in the form of an iron precursor. It can be completely oxidized.

In the case of the catalyst without additional heat treatment (step 4), the minimum temperature with catalytic activity of 100% carbon monoxide consumption rate was found to be 110°C, and the catalyst (Fe-Pt/Al _{2) without additional heat treatment (step 4)} When O ₃ ) and the catalyst subjected to the additional heat treatment were compared, it was confirmed that the activity of _{the catalyst (Fe-Pt/Al 2} O ₃ ) subjected to the additional heat treatment at a temperature of 400 to 500°C was more excellent.

The iron precursor is preferably ferrocene, and the catalyst (Fe-Pt/Al ₂ O ₃ ) prepared by the above method has a characteristic that catalytic activity is regenerated when heat-treated at 300 to 500° C. after use.

Step 5) is a step of preparing a coating composition for coating the catalyst on a ceramic filter, characterized in that the catalyst is mixed with a silicate, a filler, a cellulose, and a dispersant.

The ceramic filter may be prepared by mixing 90% by weight of cordierite having an average particle size of 150 μm, 5% by weight of methylcellulose, 3% by weight of glycerin, and 2% by weight of graphite, but is not limited thereto.

The coating composition is silicate 50 to 70 wt%, Fe-Pt/Al ₂ O ₃ catalyst 20 to 40 wt%, filler 1 to 5 wt%, cellulose 1 to 3 wt%, dispersant 1 to 3 wt%, and flame retardant 1 to It may contain 5% by weight, but is not limited thereto.

The silicate is preferably potassium silicate, and may be added in an amount of 50 to 70% by weight based on the total weight of the coating composition. Silicate is used as an adhesive, and if it is added in an amount of less than 50% by weight, adhesive strength may be weakened, and if it is added in an amount exceeding 70% by weight, the amount of the catalyst is relatively small, so that the catalytic activity is deteriorated.

The Fe-Pt/Al ₂ O ₃ catalyst may be added in 20 to 40% by weight, and if it is added in less than 20% by weight, the catalytic activity cannot be properly exhibited, and if it is added in excess of 40% by weight, Since the amount of silicate is relatively small, there is a disadvantage that coating may not be properly performed.

The filler was made of titanium oxide, and as a result of testing the adhesion by adding various substances to improve the adhesion of the silicate, it was found that when using the photocatalyst titanium oxide, it has very high initial adhesion and strong final bonding. Confirmed. It is preferable that the filler is added in an amount of 1 to 5% by weight based on the total weight of the coating composition.

Cellulose is also preferably added in an amount of 1 to 3% by weight based on the total weight of the coating composition to improve the adhesion of the silicate.

The dispersant is added to avoid agglomeration of the powder added to the coating liquid, and is preferably naphthalene or an unsaturated fatty acid having 16 to 18 carbon atoms, and is preferably added in an amount of 1 to 3% by weight based on the total weight of the coating composition.

The fatty acid is preferably an unsaturated fatty acid, and an unsaturated fatty acid having 16 or 18 carbon atoms is preferred. Specifically, any one of palmitoleic acid, which is an unsaturated fatty acid having 16 carbon atoms, oleic acid, which is a fatty acid having 18 carbon atoms, linoleic acid, and linolenic acid, may be used, preferably oleic acid. (oleic acid).

The fatty acid has an excellent affinity with silicate and has an effect of improving the dispersion effect by preventing the aggregation of silicate.Refer to the following experimental example, when oleic acid is added as a dispersant, compared to the case where naphthalene is added as a dispersant. It was confirmed that the catalytic activity was improved.

The flame retardant is added to impart heat resistance to the coating layer, so that the coating layer is not damaged even at high temperatures, preferably magnesium hydroxide or montmorillonite may be added, and the flame retardant is added in an amount of 1 to 5% by weight based on the total weight of the coating composition. It is desirable to be. In addition, the present inventors have confirmed that when magnesium hydroxide and montmorillonite are mixed in a weight ratio of 1:1 than that of magnesium hydroxide and montmorillonite, respectively, excellent heat resistance is imposed and the activity of the catalyst is also increased.

Existing platinum catalysts do not operate near room temperature, so there is a problem that environmental pollutants are discharged into the atmosphere without being converted from exhaust gases into harmless substances for the first 5 minutes after starting the car. The ceramic filter for purification of exhaust gas manufactured by the manufacturing method of the present invention can efficiently proceed with the oxidation reaction of carbon monoxide (CO) at a high conversion rate even at a low temperature (30°C), so that the conversion rate of CO at a relatively short time and low temperature In addition to this significant increase, there is an advantage in that the high conversion rate thus increased is stably maintained over time.

1 is a graph showing the nitrogen adsorption analysis results of Comparative Example Pt/Al ₂ O _3.
Figure 2 is a graph showing the result of a carbon monoxide oxidation reaction experiment according to the reaction temperature of Fe-Pt / Al ₂ O ₃ prepared through the Example and Comparative Example Pt / Al ₂ O _3.
3 is a graph showing the results of repeated carbon monoxide oxidation reaction experiments of Fe-Pt/Al ₂ O _{3 prepared through Examples and the results of recovering catalytic activity through the regeneration process.}

Most automobiles obtain energy required for power through an exothermic reaction of fossil fuels (gasoline, diesel, etc.). At this time, carbon monoxide and various other hydrocarbons are formed due to incomplete combustion of gasoline, which is mainly composed of carbon and hydrogen, which can cause a fatal effect on the human body primarily when discharged into the atmosphere, which is subject to environmental regulations.

Secondly, they react with light and ozone to form fine dust. Accordingly, automobile exhaust gas must be discharged into the atmosphere after the substances harmful to the human body are converted into harmful substances through an appropriate treatment device.

Exhaust gas treatment reactions (for example, oxidation of carbon monoxide, 2CO + O ₂ → 2CO ₂ ) can only take place above 1000°C in the absence of a catalyst due to high activation energy, and activation energy using catalysts such as platinum nanoparticles If lowered, it may occur at a temperature of 150°C or higher.

The role of platinum, etc., used as a catalyst for automobile exhaust gas treatment, is to form low-energy intermediates that are good for forming the products of the above-mentioned chemical reactions through adsorption of harmful substances such as oxygen molecules and carbon monoxide.

Although the catalytic activity and stability of platinum nanoparticles have been proven and commercialized, platinum catalysts have fatal disadvantages. The platinum catalyst does not operate near room temperature and can cause a catalytic reaction of the conversion reaction of the above harmful compounds only when the temperature is above 150℃.

In the case of carbon monoxide oxidation, this is known to be associated with a high adsorption energy of carbon monoxide. This causes a widely known cold-start up problem, especially in the cold winter, after starting the car, the cold exhaust gas that is released for the first 5 minutes before the engine temperature rises is converted to harmless substances as it passes through the catalytic treatment section. It is discharged into the atmosphere without being carried out. It is well known that air pollution caused by automobile exhaust gas is mostly caused by exhaust gas emitted within 5 minutes immediately after starting the engine.

Due to this problem, research on oxidation catalysts operating from room temperature has been actively conducted for the past 30 years, and gold catalysts, cobalt oxide catalysts, and copper/manganese oxide catalysts with a particle size of less than 5 nanometers (nm) are high in carbon monoxide oxidation reactions at room temperature. It was found to be active.

In the case of automobile exhaust gas treatment catalyst, it is important on the one hand to show high catalytic activity at room temperature, but on the other hand, when the temperature of the engine rises when the vehicle is sufficiently running and the temperature of the exhaust gas reaches 400 ~ 500℃, It is important to maintain the stability of the catalytic activity without causing structural deformation at that temperature.

As mentioned above, catalysts operating from room temperature easily undergo structural deformation at high temperatures, and thus do not satisfy the conditions of catalysts that must have high durability in the environment of automobile exhaust gas treatment units that are repeatedly exposed to room temperature and high temperatures. For example, gold nanoparticles with high activity in the carbon monoxide oxidation reaction at room temperature aggregate together at a high temperature to form large particles, and catalytic activity is lost due to a decrease in the specific surface area of the catalyst and loss of intrinsic properties of the gold nanoparticles.

Recently, the present inventors have developed a technology to uniformly apply inexpensive iron oxide in the form of fine particles of 1-2 nanometers to mesoporous alumina with a high specific surface area by using a temperature regulated-chemical vapor deposition method. Was developed and the carbon monoxide oxidation reaction using this was implemented at room temperature. In the case of the iron oxide nanoparticle-based catalyst, it was confirmed that not only the activity at room temperature but also structural stability and durability of the catalytic activity were exhibited even in heat treatment at 500°C.

As a result of introducing the iron oxide deposition technology into the platinum/alumina structure, which is an existing automobile exhaust gas treatment catalyst, the activity at room temperature increased compared to the existing platinum/alumina catalyst, and the minimum temperature (T ₁₀₀ ) showing 100% activity was also reduced. (Existing platinum/alumina-activity at room temperature: 10% or less, T ₁₀₀ : 150℃, platinum/alumina deposited with iron oxide-room temperature activity: 50%, T ₁₀₀ : 80°C).

In the case of a carbon monoxide oxidation reaction at a low temperature, poisoning on the surface of a catalyst, in which the catalytic activity remarkably decreases as the reaction time increases, may be a major problem. In the case of the platinum/alumina catalyst structure incorporating this iron oxide, the catalyst activity at room temperature decreased slightly when it was repeatedly exposed to room temperature and high temperature and used for the carbon monoxide oxidation reaction, but the catalyst activity was improved through heat treatment in the absence of carbon monoxide. I was able to recover.

The platinum/alumina catalyst supported with iron oxide prepared by the temperature-controlled vapor deposition method can solve the aforementioned cold-start up problem and secure economic efficiency, so it can be seen that there is a high possibility of practical use. Silver can have potential because it can be linked to carbon monoxide treatment leaking from boilers.

Hereinafter, the present invention will be described in detail by the following examples. However, the following examples are merely illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

1. Temperature control-Fe-Pt/Al loaded with iron oxide using chemical vapor deposition method ₂ O ₃ Preparation of catalyst

_{A catalyst (Fe-Pt/Al 2} O ₃ ) in which nano-sized iron oxide particles are deposited on _{Pt/Al 2} O ₃ (platinum content 5 wt%) is prepared using the following temperature-controlled chemical vapor deposition method. On the inner bottom of the reactor made of stainless steel surrounded by a heating band, 0.01 g of ferrocene, a precursor of iron, is placed in a container made of quartz. After placing 1 g of Pt/Al ₂ O ₃ (platinum content 5 wt%, Sigma aldrich) in the center of the reactor in a container made of stainless steel wire mesh, the reactor is sealed with polyimide tape. After maintaining the temperature of the reactor at 60° C. for 2 hours, the temperature is raised to 200° C. and maintained for 12 hours. Subsequently, the catalyst is taken out and further heat-treated at 450° C. for 2 hours in a dry air atmosphere to finally prepare _{Pt/Al 2} O _{3 on which iron oxide nanoparticles are deposited.} Under the conditions, the _{amount of iron deposited on Pt/Al 2} O ₃ was added at 1.24 wt% based on the total weight of the catalyst.

<Experimental Example 1> Fe-Pt/Al ₂ O ₃ Carbon monoxide oxidation reaction using catalyst

_{The catalytic activity of Fe-Pt/Al 2} O ₃ prepared through the above method for the carbon monoxide oxidation reaction was compared with that of the comparative example. The catalytic activity was evaluated by the consumption rate of carbon monoxide and the generation rate of carbon dioxide, which is a product of the oxidation reaction of carbon monoxide. 2 is a result of a carbon monoxide oxidation experiment according to the reaction temperature of Fe-Pt/Al ₂ O ₃ prepared through the above method and conventional commercialized Pt/Al ₂ O _3. Using an electric furnace, the temperature of the reactor was increased from room temperature to 450°C at a rate of 1°C/min, and the gas mixture passed through the catalyst was quantitatively analyzed by gas chromatography, and 1% carbon monoxide gas diluted with dry air was used.

_{To compare catalytic activity, commercialized platinum/alumina (Pt/Al 2} O ₃ ) catalyst particles with a specific surface area of about 96 m ² /g and an average pore size of about 10 nm as a control (platinum content 5 wt%, Sigma aldrich G) was used (Fig. 1).

Carbon monoxide consumption rate (%) 30℃ 50℃ 100℃ 150℃ 200℃ 250℃ 300℃ Fe-Pt/Al ₂ O ₃ 49 53 100 100 100 100 100 Pt/Al ₂ O ₃ 9 14 30 100 100 100 100

_{Unlike the control group (Pt/Al 2} O ₃ ) showing a carbon monoxide consumption rate of 10% or less at room temperature (30° C.) and a carbon dioxide generation rate, in the case of the Example, the carbon monoxide consumption rate and carbon dioxide generation rate were about 50% in the same temperature range. The minimum temperature with 100% catalytic activity was found to be 150° C. and 80° C. in Comparative Examples and Examples, respectively.

<Experimental Example 2>

The catalytic activity of the Fe-Pt/Al ₂ O ₃ prepared through the above method was checked for repetitive carbon monoxide oxidation reactions, and when the surface of the catalyst was poisoned, it was investigated whether the catalytic activity can be recovered through the regeneration process. (Fig. 3). The carbon monoxide oxidation reaction proceeded in the same manner as in Experimental Example 1, and was repeated a total of 4 times without changing the catalyst. After that, the catalyst was heat-treated at 500° C. for 8 hours in a dry air atmosphere without carbon monoxide, and the catalyst was further utilized for the carbon monoxide oxidation reaction. As a result of the experiment, it was confirmed that the catalytic activity at room temperature decreased little by little as the carbon monoxide oxidation reaction was repeatedly performed, but the catalytic activity could be recovered after the heat treatment.

2. Fe-Pt/Al ₂ O ₃ Coated ceramic filter

<Example>

90% by weight of cordierite with an average particle size of 150㎛, 5% by weight of methylcellulose, 3% by weight of glycerin, and 2% by weight of graphite are mixed to form a molded product having a honeycomb structure, and put into an electric furnace at a temperature of 1,420°C. The ceramic filter was prepared by firing at for 1 hour.

Thereafter, in order to coat the prepared Fe-Pt/Al ₂ O ₃ on the ceramic filter, potassium silicate 60% by weight, the prepared Fe-Pt/Al ₂ O ₃ catalyst 30% by weight, a filler titanium oxide 3% by weight, Methylcellulose 2% by weight, dispersant naphthalene 2% by weight, and flame retardant magnesium hydroxide 3% by weight were mixed, and coated on the surface of the ceramic filter using a vacuum impregnation method. At this time, the degree of vacuum is less than ^{1×10 -3 torr.}

<Comparative Example 1>

A ceramic filter was manufactured in the same manner as in Example, except that 30% by weight of the potassium silicate and _{60% by weight of the prepared Fe-Pt/Al 2} O _{3 catalyst were mixed.}

<Comparative Example 2>

A ceramic filter was manufactured in the same manner as in Example, except that 45% by weight of the potassium silicate and 45% by weight of the prepared Fe-Pt/Al ₂ O _{3 catalyst were mixed.}

<Comparative Example 3>

A ceramic filter was manufactured in the same manner as in the above Example, except that 3% by weight of montmorillonite was added as a flame retardant instead of the magnesium hydroxide.

<Comparative Example 4>

A ceramic filter was manufactured in the same manner as in Example, except that 1.5% by weight of montmorillonite was added as a flame retardant (magnesium hydroxide and montmorillonite in a 1:1 weight ratio) instead of 1.5% by weight of magnesium hydroxide.

<Comparative Example 5>

A ceramic filter was manufactured in the same manner as in Comparative Example 4, except that 2% by weight of oleic acid was added as a dispersant instead of 2% by weight of naphthalene as a dispersant.

<Experimental Example 3>

In order to check the catalytic activity of the prepared ceramic filter according to the carbon monoxide oxidation reaction, the carbon monoxide oxidation reaction for the ceramic filters prepared in Examples and Comparative Examples 1 to 5 was performed in the same manner as in the conditions of Experimental Example 1, and 100% The minimum temperature with the catalytic activity of is shown in Table 2.

Having 100% catalytic activity
Minimum temperature (℃) Carbon monoxide consumption rate (%) at room temperature (30 ^{o C)} Example 90℃ 55% Comparative Example 1 130℃ 30% Comparative Example 2 110℃ 40% Comparative Example 3 95℃ 49% Comparative Example 4 86℃ 56% Comparative Example 5 82℃ 59%

Referring to Table 2, it was confirmed that the catalytic activity was the most excellent in Examples. In the case of Comparative Examples 1 and 2, a relatively large amount of Fe-Pt/Al ₂ O ₃ catalyst was included compared to the Examples, but the content of silicate was relatively decreased, so that the catalyst was not efficiently coated on the ceramic filter. It is judged to have a lower catalytic activity than that.

When montmorillonite was added as the flame retardant (Comparative Example 3), the catalytic activity was observed to decrease compared to the Example, but when magnesium hydroxide and montmorillonite were added in a weight ratio of 1:1 (Comparative Example 4), Example It was confirmed that the catalytic activity was improved compared to that.

In addition, in the case of using oleic acid instead of naphthalene as a dispersant (Comparative Example 5), it was confirmed that the catalytic activity slightly increased compared to Comparative Example 4, which was found that oleic acid having excellent affinity with silicate was It is believed that this is because the dispersion effect was improved by preventing agglomeration.

Claims (11)

1) placing the Pt/Al ₂ O ₃ and iron precursors inside the sealed reactor, respectively;
2) vaporizing an iron precursor by heating the reactor to a temperature of 50 to 70°C;
3) preparing a catalyst _{(Fe-Pt / Al 2 O} 3) to heat the temperature of the reactor at a temperature of 150 ~ 250 ℃ by depositing the oxide on the surface and inside the Pt / Al ₂ O _3;
4) heat-treating the prepared catalyst by heating it in air at a temperature of 400 to 500°C;
5) preparing a coating composition by mixing the catalyst with silicate, titanium oxide as a filler, naphthalene as a dispersant, or unsaturated fatty acid having 16 to 18 carbon atoms, and magnesium hydroxide or montmorillonite as a flame retardant; And
6) A method of manufacturing a ceramic filter for purifying exhaust gas comprising the step of coating the coating composition on a ceramic filter.
The method of claim 1,
The iron precursor is ferrocene (ferrocene) method of manufacturing a ceramic filter for purification of exhaust gas.
The method of claim 1,
When the prepared catalyst (Fe-Pt/Al ₂ O ₃ ) is heat-treated at 300 to 500°C after use, the catalyst activity is regenerated.
delete The method of claim 1,
The flame retardant is magnesium hydroxide and montmorillonite is added in a weight ratio of 1: 1 to the exhaust gas purification ceramic filter manufacturing method.
The method of claim 1,
The coating composition is silicate 50 to 70 wt%, Fe-Pt/Al ₂ O ₃ catalyst 20 to 40 wt%, filler 1 to 5 wt%, cellulose 1 to 3 wt%, dispersant 1 to 3 wt%, and flame retardant 1 to A method for manufacturing a ceramic filter for purifying exhaust gas containing 5% by weight.
The method of claim 1,
The step of vaporizing the iron precursor is a method of manufacturing a ceramic filter for purification of exhaust gas performed for 1 to 3 hours.
The method of claim 1,
The step of preparing the catalyst (Fe-Pt/Al ₂ O ₃ ) is a method of manufacturing a ceramic filter for purifying exhaust gas that is performed for 10 to 14 hours.
The method of claim 1,
The heat treatment step is a method of manufacturing a ceramic filter for purifying exhaust gas performed for 1 to 3 hours.
The method of claim 1,
The ceramic filter is prepared by mixing 90% by weight of cordierite having an average particle size of 150 μm, 5% by weight of methylcellulose, 3% by weight of glycerin, and 2% by weight of graphite.
A ceramic filter for purifying exhaust gas manufactured according to any one of claims 1 to 3 and 5 to 10.

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