KR0128543B1 - Method for preparing co removal catalysts - Google Patents

Abstract

The preparation method of the catalyst for removing carbon monooxide by carrying the metallic salt containing palladium ion and copper ion into porous carrier in 20~60deg.C is disclosed. Thereby, it is possible to simply and economically remove carbon monooxide in absence of special apparatus.

Description

Method for producing a catalyst for removing carbon monoxide

1 is an activity measuring device of the catalyst,

2 is a graph showing the activity (carbon monoxide conversion) of the catalyst prepared by Example 1 of the present invention as a function of temperature,

3 is a graph showing the activity (carbon monoxide conversion) of the catalyst prepared by Example 2 of the present invention at 25 ° C. as a function of time.

* Explanation of symbols for main parts of the drawings

1: reaction gas container 2: pressure regulator

3: flow meter 4: three-way valve

5: water jacket 6: reactor

7: thermocouple pair 8: electric resistance

9 porous filter made of sintered glass 10 6-port ring valve

11 gas chromatography 12 carrier gas

13: exhaust port

The present invention relates to a method for producing a catalyst for removing carbon monoxide, and more particularly, a metal salt containing piladium ions (Pd ²⁺ ) and copper ions (Cu ²⁺ ) supported on a porous carrier at a low temperature of 20 to 60 ° C. It relates to a method for producing a catalyst that can remove carbon monoxide from.

Conventional carbon monoxide removal catalysts usually have their efficacy at high temperatures of 150 ° C. [E.E. Miro, E. A. Lombardo, J. O. Petunchi, Rev. Lantinoam. Ing. guim. guim. apl. 1987, 17, 101], the recently developed catalyst for removing carbon monoxide at low temperatures is prepared by supporting precious metals such as gold or platinum on various metal oxides, but in this manufacturing method, expensive precious metals such as gold or platinum are manufactured. Since it is used as a raw material, it requires a lot of production cost, and also requires high technology to evenly distribute active metal ions such as gold or platinum to the carrier when producing catalyst [M. Haruta, S. Tsubota, T. Kobayashi, H. Kageyama, M. J. Genet, B. Delmon, J. Catal. 1993, 144 175.

As a catalyst for removing carbon monoxide at low temperatures, Hopcalite, which is composed of a mixture of tin oxide, manganese oxide, and copper oxide, is relatively economical and has a good effect of removing carbon monoxide, but the effect is greatly reduced in the presence of 10% or more moisture. Has a flaw [MI Brittan, H. Bilss, C. A. Walker, AIChE J. 1970, 16, 305].

Accordingly, the present inventors have researched to develop a new catalyst capable of removing carbon monoxide even at low temperatures as well as dispersing active metal ions easily and easily dispersing active metal ions in the carrier even though the production cost is low and moisture is high. The present invention was completed by introducing an active metal salt containing Pd ²⁺ and Cu ²⁺ into the.

It is an object of the present invention to provide a method for preparing a new catalyst having the above characteristics.

Hereinafter, the present invention will be described in detail.

The present invention relates to a method for producing a catalyst for removing carbon monoxide, characterized in that the support of the palladium ion (Pd ^{2 +} ) salt and copper ion (Cu ^{2 +} ) salt on a porous carrier.

Referring to the present invention in more detail as follows.

The present invention relates to a method for preparing a new catalyst which can easily remove toxic carbon monoxide at low temperature, and dissolves a certain amount of metal salt in water, and then mixes it with a porous carrier and removes water at a temperature of 60 to 70 ° C. Stir until until a solid product is obtained, or if the amount of water is reduced to some extent by stirring at a temperature of 60 ~ 70 ℃ by filtration under reduced pressure to obtain the catalyst of the present invention as a solid product.

Porous carriers that can be used in the present invention are those having an average particle diameter of 20 to 120 mesh, and examples thereof are a zeolite-based porous molecular sieve, activated carbon and alumina alone or a mixture of two or more thereof. ZSM-5, molecular sieve 13X and molecular sieve 5A are used.

At this time, the porosity of the zeolite-based porous molecular sieve is 10 kPa or less, and the porosity of activated carbon is 100 kPa on average.

In order to prepare the catalyst for removing carbon monoxide of the present invention, water-soluble salts of Pd ²⁺ and Cu ²⁺ are added to the porous carrier as described above. At this time, palladium chloride (PdCl ₂ ) is used as the palladium salt, and as the copper salt, A mixture of copper chloride (CuCl ₂ ) and copper nitrate [(Cu (NO ₃ ) ₂ ] is used.

In terms of the amount used, 2 to 18 x 10 ^-3 mol of the palladium salt is used for 100 g of the porous carrier. When the amount of the palladium salt is less than 2 x 10 ^-3 mol, the prepared catalyst shows low activity. ^If it exceeds ^-3 moles, the activity is good but uneconomical.

The copper salt mixture is used in 4 ~ 89 × 10 ^-3 moles per 100 g of porous carrier, there is a problem that the activity is lowered if the amount is out of the above range. In addition, copper nitrate in the copper salt mixture acts as a promoter to enhance catalyst activity and extend catalyst life. Any one of the copper salt mixtures may comprise at least 30 to 45 mol% of the total copper. When the carbon monoxide removal rate is the best.

As described above, the present invention is very useful as a method for preparing a catalyst which can remove toxic carbon monoxide easily and economically even at low temperature without a separate heating device.

Hereinafter, a method for preparing a carbon monoxide removing catalyst according to the present invention will be described in detail with reference to Examples, but the present invention is not limited by Examples.

[Examples 1 and 2]

In 50 ml of distilled water, the active metal salts are sequentially added to the following Table 1, and when a clear solution is obtained, 100 g of a carrier having the composition shown in Table 1 is added thereto.

The catalyst was prepared by stirring until all the remaining moisture was evaporated in a water bath at 65 ° C. and the obtained product was dried at 70 ° C. for 3 hours.

EXAMPLES 3-6

The catalyst was prepared by the same method as in Example 1, the composition of the following Table 1, but stirred for 7 hours in a water bath at 65 ℃ water and filtered using a vacuum flask.

EXAMPLES 7-10

In 300 ml of distilled water, the active metal salts of Table 1 are sequentially dissolved to make a transparent solution. Then, the solution is stirred hard while dropping the transparent solution into 100 g of the carrier.

The amount of water used is the minimum amount to wet the carrier. The product was prepared by drying at 70 ° C. for 3 hours.

[Comparative Examples 1 and 2]

In the same manner as in Example 1, a catalyst was prepared in the following composition ratio.

Comparative Example 3

In the same manner as in Example 3, a catalyst was prepared in the following composition ratio.

[Comparative Example 4]

A catalyst was prepared in the composition ratio of Table 1 by the same method as in Example 7.

The amount of distilled water used at this time is 150ml.

TABLE 1

Activated carbon: Japan Junsei Co., Ltd., surface area 1000㎡ / g

ZSM-5: Product by PQ Co., Ltd., surface area 430㎡ / g, SiO ₂ / Al ₂ O ₃ = 30 ~ 50 molar ratio

Alumina: Product made by Janssen of Belgium, surface area 150㎡ / g

Molecular sieve-5A: Aldrich, USA, surface area 750㎡ / g

Molecular sieve-13A: Made by Aldrich, USA, surface area 850㎡ / g

As the active metal ions supported on the porous carrier according to the method of the present invention as described above remove carbon monoxide while causing an oxidation / reduction reaction, the basic operation principle may be represented by the following formula.

CO + Pd ² + H ₂ O → CO ₂ + Pd + 2H ⁺ (A)

Pd + 2Cu ²⁺ → Pd ²⁺ + 2Cu ⁺ (I)

2Cu ⁺ + 2H ⁺ +1/20 ₂ → 2Cu ²⁺ + H ₂ O

CO + 1/20 ₂ → CO ₂ (D)

According to the formula (A), Pd ²⁺ is reduced to palladium metal (Pd) by carbon monoxide and at the same time carbon monoxide is oxidized to carbon dioxide. In addition, according to the formula (b), Pd is oxidized by Cu ²⁺ to be restored to Pd ²⁺ , and Cu ²⁺ is reduced to Cu ⁺ . In addition, according to the formula (C), Cu ⁺ is oxidized by hydrogen ions and oxygen gas to restore Cu ²⁺ .

Formula (D) is a general reaction to carbon monoxide removal occurring through Formulas (A) to (C), which eventually contributes to the conversion of toxic carbon monoxide into harmless carbon dioxide and Pd ²⁺ and Cu ^{2. Since +} is regenerated and recycled by oxidation / reduction reactions, carbon monoxide can be continuously removed by using an appropriate amount of Pd ²⁺ and Cu ²⁺ .

In addition, in the above chemical formula, although Cu ²⁺ actually introduced to the carrier in the present invention, although two different salts are different from each other, the two roles of Cu ²⁺ are not separately expressed, but in fact, they are complementary to each other. One of them acts as a promoter.

In order to measure the activity of the catalyst prepared by the preparation method as described above, the solid product was allowed to stand for one day in an airtight container under 30 to 40 ° C. water vapor pressure, and then measured by the catalytic activity measuring device shown in FIG. 1. Catalytic activity measurements are largely organically linked, including gas feeders, reactors and quantitative analysis of reaction products.

In FIG. 1, nitrogen, oxygen and carbon monoxide supplied from the reaction gas container 1 are respectively introduced into the reactor 6 directly through a three-way valve 4, or a water jacket. It is configured to pass through (5) and then enter the reactor (6). That is, a dry mixed gas flows directly into the reactor 6, or the mixed gas flows into the water and into the reactor 6 with water vapor saturated at room temperature. At this time, the amount and velocity of each gas flowing into the reactor 6 is controlled by a pressure regulator 2 and a floating ball flowmeter 3.

The reactor 6 was made of Pyrex glass material, 80 cm in length and 1.6 cm in diameter, and an electric resistance furnace 8 was attached to the outside for temperature control of the reactor 6. In the middle of the reactor 6, the catalyst particles in the form of powder were blocked with a porous filter 9 made of sintered glass so as not to fall below the reactor 6.

And in order to measure the actual reaction temperature, the end of the thermocouple pair (7) was placed in the middle of the sample.

The mixed gas introduced into the reactor 6, such as nitrogen, oxygen, carbon monoxide and water vapor, is adsorbed or oxidized / reduced by the active metal ions supported on the porous carrier while passing through the catalyst bed, and then the 6-port ring valve. The composition of the gas is quantitatively analyzed by passing through (10) and injecting it into the gas chromatography (11) to which a thermal conductivity detector (TCD) is attached. In the quantitative analysis, helium was used as a carrier gas 12, and after the analysis, the mixed gas was discharged into the atmosphere through the exhaust port 13.

Experimental Example

The solid products prepared in Examples 1 to 9 and Comparative Examples 1 to 4 were allowed to stand for one day in a closed vessel under a water vapor pressure of 30 to 40 ° C., and then the activity of the catalyst was measured using the catalytic activity measuring device of FIG. Measured. The amount of catalyst used for the catalytic activity measurement was 0.5 g, the raw material gas composition supplied from the reaction gas container 1 was 76% nitrogen, 4% carbon monoxide and 20% oxygen, and the temperature of the water passed through these mixed gases was about 20%. And flow rate is 40 cc / min. In addition, the filling material of the gas chromatography (11) column is molecular sieve 13X (manufactured by Hitachi, Japan), and the material of the column is stainless steel and its size is 6 feet x 18 inches. In the quantitative analysis, the temperature of the column was room temperature (20 ° C.), and the temperature of the thermal conductivity detector attached to the gas chromatography (11) was 110 ° C.

The activity measurement values for the various types of catalysts prepared in the present invention are shown in Table 2 below.The activity of the catalyst is measured by the size of the catalyst particles, the reaction temperature, the relative amount of active metal ions, the concentration of carbon monoxide, Relative activity varies depending on the speed of the reactor and the type of carrier.

TABLE 2

According to the results of Table 2, the catalyst prepared by the production method of the present invention showed very high activity as the conversion rate of carbon monoxide at 40 to 100% at a low temperature of 20 ~ 60 ℃.

In particular, in the case of Examples 1 to 6, although the same amount of palladium salt and copper salt were used, the removal rate of carbon monoxide, that is, the activity of the catalyst, was slightly different depending on the type of porous carrier. All high.

Figure 2 is a graph showing the relationship between the activity of the catalyst prepared in Example 1, that is, carbon monoxide conversion and temperature, the conversion rate of carbon monoxide in the temperature range of 20 ~ 60 ℃ was 88 ~ 95%.

3 is a graph showing the relationship between the activity and time of the catalyst prepared in Example 2 at a constant temperature of 25 ° C., showing the regeneration of the catalyst.

Therefore, the method for producing a catalyst for removing carbon monoxide of the present invention uses a metal salt of a relatively low price, and can also remove carbon monoxide at a temperature of 20 ~ 60 ℃ using the prepared catalyst.

Claims (5)

In preparing a catalyst for removing harmful gases by supporting a palladium ion (Pd ²⁺ ) salt and a copper ion (Cu ²⁺ ) salt on a porous carrier, palladium chloride (PdCl) is added to a porous carrier mixed with a zeolite-based molecular sieve and activated carbon. ₂ ) and a method for preparing a catalyst for removing carbon monoxide, characterized in that it is prepared by supporting a copper ion mixture of copper chloride (CuCl ₂ ) and copper nitrate (Cu (NO ₃ ) | ₂ . The method of claim 1, wherein the zeolite porous molecular sieve is a natural zeolite, ZSM-5, molecular sieve 13X, or molecular sieve 5A. The method of claim 1, wherein the palladium chloride is used in an amount of 2 to 18 × 10 ⁻³ moles based on 100 g of the porous carrier. The method of claim 1, wherein the copper ion salt is used in a range of 4 to 89 × 10 ⁻² with respect to 100 g of the porous carrier. Use of the catalyst prepared according to claim 1 for the removal of hydrogen monoxide at 20-60 ° C.