KR20190009154A - Copper-Manganese oxides doped with palladium and preparation method thereof - Google Patents

Abstract

The present invention relates to a palladium-doped copper-manganese catalyst oxide and a method for manufacturing the same. More particularly, the present invention relates to a palladium-doped copper manganese catalyst oxide and a method for manufacturing the same in which a palladium metal (Pd) is doped and fixed on the surface of the copper-manganese oxide to effectively remove harmful gases such as carbon monoxide (CO) and nitrogen oxides (NO_x) and various malodor gases.

Description

[0001] Copper-manganese catalyst oxides doped with palladium and methods for preparing the same [0002]

The present invention relates to a palladium-doped copper-manganese catalyst oxide and a method for producing the same. More particularly, the present invention relates to a copper-manganese catalyst oxide doped with palladium (Pd) And a method for producing the copper-manganese catalyst oxide. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a palladium-doped copper-manganese catalyst oxide.

Noxious gas components such as carbon monoxide, nitrogen oxides, sulfur oxides and volatile organic compounds are contained in industrial sites, chemical plants, automobiles, power plants, incinerators, boilers, underpasses, tunnels, underground shopping malls and underground parking lots. An adsorbent or a catalyst material is mainly used for selective removal of the catalyst.

As the adsorbent, activated carbon, zeolite and the like are commonly used. However, the adsorbent has a limitation in the adsorption capacity, so that the adsorption capacity remarkably decreases or disappears after a certain period of time, and it is disadvantageous in that it is not easily reused and is one-time. In particular, there is a problem in that activated carbon can not adsorb various harmful gases.

As the catalyst material, noble metals such as platinum (Pt), gold (Au), and palladium (Pd) or transition metals such as manganese (Mn), cobalt (Co), and iron (Fe) Or the like is supported on a carrier such as a catalytic material for oxidation reaction.

On the other hand, the noble metal-containing catalyst shows excellent removal performance as compared with the transition metal-containing catalyst, but there is a limitation in the general application due to the unit price of the noble metal material. In recent years, catalysts using transition metals that are more economical than noble metals have been developed. Typically, catalysts for removing harmful gases such as carbon monoxide, volatile organic compounds (VOCs), ammonia, and hydrogen sulfide using copper- Is being developed.

However, copper-manganese oxides are catalytically active and are sensitive to the crystallinity of oxides. Also, when the catalyst is heat-treated for regeneration after a certain period of time, the catalyst characteristics are drastically lowered according to the change of the crystallinity and the catalyst characteristics are reduced in the presence of water.

Therefore, there is a need for a method for producing copper-manganese oxide having a good catalytic property in the copper-manganese catalyst oxide for removing harmful gas. Accordingly, the present inventors have succeeded in producing copper-manganese oxide which is economical in terms of cost as well as having excellent catalytic properties by doping palladium on copper-manganese oxide, and also a simple manufacturing process.

Korean Patent Laid-Open No. 10-2004-0097738 (entitled "Oxidized Manganese-based Catalyst for Ozone Decomposition and Method for Producing the Same", Applicant: Koatech Co., Ltd., Disclosure Date: November 18, 2004) Korean Patent Laid-Open No. 10-2007-0028102 (Title of the Invention: Process for producing copper-manganese catalyst oxide of nanoparticles and thus produced catalyst, Applicant: Keimyung University Industry-Academic Cooperation Foundation, Publication date: March 12, 2007) Korean Patent No. 10-0887545 (Title: Process for producing copper-manganese catalyst oxide for removal of volatile organic compounds, Applicant: Reedenex Co., Ltd., registered on Mar. 02, 2009)

It is an object of the present invention to provide a copper-manganese catalyst oxide having excellent ability to remove harmful gas by doping palladium on copper-manganese oxide in a simple manufacturing process and a copper-manganese catalyst oxide prepared thereby.

The present invention relates to a method for preparing a mixed solution, comprising: preparing a mixed solution by mixing a purified water and an inorganic layer compound to prepare an inorganic layered compound dispersion solution;

 A second step of adding a copper salt aqueous solution and a manganese salt aqueous solution to the mixed solution prepared in the first step and stirring to obtain a precipitate;

A third step of washing the precipitate obtained in the second step to remove unreacted materials and impurities and then drying to obtain a copper-manganese catalyst oxide hybridized with the inorganic layered compound; And

And a fourth step of dispersing the copper-manganese catalyst oxide hybridized with the inorganic layered compound obtained in the third step in distilled water, adding a palladium salt aqueous solution and stirring the mixture to obtain a precipitate, and drying and heat-treating the precipitate Manganese catalyst oxides which are doped with palladium.

In the first step, the inorganic layered compound is a smectite natural or synthetic clay, such as montmorillonite, bentonite, hectorite, saponite, beelliteellite, It is preferably at least one selected from the group consisting of nontronite, laponite, smecton, leucentite and swelling mica.

The first stage manganese salt is preferably at least one selected from the group consisting of manganese nitrate, manganese nitrate, manganese chloride, manganese iodide, manganese bromide, manganese sulfate, potassium permanganate and manganese acetate.

In the first step, the amount of the manganese salt is preferably 0.5 to 1.5 mol based on 100 g of the inorganic layer compound.

In the second step, it is preferable to use an aqueous solution of a copper salt which is at least one selected from the group consisting of copper acetate, copper nitrate, copper chloride, copper iodide, copper bromide, copper sulfate and copper acetate. More preferably 0.2 to 1 mol based on 100 g of the inorganic layered compound.

In the second step, it is preferable to use an aqueous solution of manganese salt, which is at least one selected from the group consisting of manganese nitrate, manganese chloride, manganese chloride, manganese chloride, manganese bromide, manganese sulfate, potassium permanganate and manganese acetate. It is preferable that the manganese salt as a raw material sample contains 1 to 2 mol based on 100 g of the inorganic layered compound.

In the fourth step, it is preferable to use an aqueous solution of a palladium salt which is at least one selected from the group consisting of palladium chloride, palladium fluoride, palladium iodide, palladium nitrate and palladium sulfate. The palladium salt as a raw material sample in the aqueous palladium salt solution is preferably an inorganic layer More preferably 0.001 to 0.01 mol based on 100 g of the copper-manganese catalyst oxide hybridized with the compound.

In the fourth step, the heat treatment is preferably performed at a temperature of 150 to 500 ° C for 0.5 to 12 hours.

Hereinafter, the present invention will be described in detail.

The present invention relates to a process for preparing palladium-doped copper-manganese catalyst oxides.

Preferably, the method comprises the steps of mixing a purified water and an inorganic layer compound to prepare an inorganic layered compound dispersion solution, adding a manganese salt and stirring to prepare a mixed solution;

 A second step of adding a copper salt aqueous solution and a manganese salt aqueous solution to the mixed solution prepared in the first step and stirring to obtain a precipitate;

A third step of washing the precipitate obtained in the second step to remove unreacted materials and impurities and then drying to obtain a copper-manganese catalyst oxide hybridized with the inorganic layered compound; And

And a fourth step of dispersing the copper-manganese catalyst oxide hybridized with the inorganic layered compound obtained in the third step in distilled water, adding a palladium salt aqueous solution and stirring the mixture to obtain a precipitate, and drying and heat-treating the precipitate Manganese catalyst oxides which are doped with palladium.

In the first step, the inorganic layered compound is a smectite natural or synthetic clay, such as montmorillonite, bentonite, hectorite, saponite, beelliteellite, It is preferably at least one selected from the group consisting of nontronite, laponite, smecton, leucentite and swelling mica.

In the first step, the concentration of the dispersion solution of the inorganic layer compound is preferably 1 to 3% by weight.

The first stage manganese salt is preferably at least one selected from the group consisting of manganese nitrate, manganese nitrate, manganese chloride, manganese iodide, manganese bromide, manganese sulfate, potassium permanganate and manganese acetate, more preferably potassium permanganate It is good to do.

In the first step, the amount of the manganese salt is preferably 0.5 to 1.5 mol based on 100 g of the inorganic layer compound. If the amount of the manganese salt is less than 0.5 mol based on 100 g of the inorganic layer compound, the noxious gas can not be sufficiently removed, and if it exceeds 1.5 mol, the catalytic property may be reduced in the presence of water, which is not preferable.

It is preferable that the manganese salt as the raw material sample of the first stage manganese salt or the second stage manganese salt aqueous solution has a particle size of 50 nm or less.

In the second step, it is preferable to use an aqueous solution of a copper salt which is at least one selected from the group consisting of copper acetate, copper nitrate, copper chloride, copper iodide, copper bromide, copper sulfate and copper acetate. More preferably 0.2 to 1 mol based on 100 g of the inorganic layered compound. If the amount of the copper salt is less than 0.1 mol based on 100 g of the inorganic layer compound, the harmful gas can not be sufficiently removed, and if it exceeds 1 mol, the catalytic property may be reduced in the presence of water, which is not preferable.

The copper salt as the raw material sample of the copper salt aqueous solution in the second step is preferably one having a particle size of 50 nm or less.

In the second step, it is preferable to use an aqueous solution of manganese salt, which is at least one selected from the group consisting of manganese nitrate, manganese chloride, manganese chloride, manganese iodide, manganese bromide, manganese sulfate, potassium permanganate and manganese acetate, It is better to use manganese acetate.

 In the second step, the manganese salt as a raw material sample in the aqueous solution of manganese nitrate preferably contains 1 to 2 mol based on 100 g of the inorganic layer compound. If the content of the manganese salt is less than 1 mol based on 100 g of the inorganic layer compound, the noxious gas can not be sufficiently removed, and if it exceeds 2 mol, the catalytic properties may be reduced in the presence of water.

In the fourth step, it is preferable to use an aqueous solution of a palladium salt which is at least one selected from the group consisting of palladium chloride, palladium fluoride, palladium iodide, palladium nitrate and palladium sulfate. The palladium salt as a raw material sample in the aqueous palladium salt solution is preferably an inorganic layer More preferably 0.001 to 0.01 mol based on 100 g of the copper-manganese catalyst oxide hybridized with the compound. When the content of the palladium salt is less than 0.001 mol based on 100 g of the copper-manganese catalyst oxide hybridized with the inorganic layer compound, the specific surface area of the catalyst is low and the noxious gas can not be sufficiently removed. When the amount exceeds 0.01 mol, The effect is insignificant.

In the fourth step, the heat treatment is preferably performed at a temperature of 150 to 500 ° C for 0.5 to 12 hours.

If the heat treatment temperature is lower than 150 ° C, palladium can not be sufficiently fixed, and if it exceeds 500 ° C, side reactions may occur between metal oxides, which is not preferable. If the heat treatment time is less than 0.5 hour, palladium can not be sufficiently fixed, and if it exceeds 12 hours, it is not economically advantageous.

The palladium-doped copper-manganese catalyst oxide of the present invention may further include an inorganic filler, activated carbon and a binder.

The inorganic filler is a porous and light-weight inorganic material, and inorganic minerals such as porous silica, alumina, titania, perlite and kaolin are preferable.

Activated carbon is a carbonaceous substance that exhibits adsorption to a solute in a gas or a solution, and has a role of improving porosity and specific surface area. There are no particular limitations on the powder that can be used as the activated carbon. For example, granular or powdered activated carbon may be used, preferably powdered activated carbon, more preferably powdered activated carbon having a particle size of about 500 mesh or less.

It is preferable that at least one of an inorganic binder and an organic binder is selected as the binder, and more preferably 5 wt% or less based on the total binder content.

At this time, the inorganic binder is preferably at least one selected from the group consisting of colloidal silica, titania, zirconia, water glass, alumina sol and inorganic layered compound.

The organic binder is selected from the group consisting of methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, methylethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, polyvinylalcohol, polyethylene glycol, polyacrylic acid, polymethyl Methacrylate, and hydroxypropyl. ≪ / RTI >

The copper-manganese catalyst oxides doped with palladium can provide copper-manganese catalyst oxides with improved performance by a simple process through the process for preparing palladium-doped copper-manganese catalyst oxides. It is possible to more effectively remove harmful gases such as carbon monoxide, nitrogen oxides, sulfur oxides, and volatile organic compounds at places such as plants, power plants, incinerators, underground roads and tunnels.

1 shows the nitrogen adsorption-desorption isotherm curves and porosity characteristics of the copper-manganese catalyst oxide hybridized with an inorganic layer compound before and after palladium doping.
FIG. 2 shows the results of carbon monoxide removal performance before and after palladium doping of the copper-manganese catalyst oxide hybridized with the inorganic layered compound.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

≪ Example 1 >

5 kg of a 2 wt% inorganic layered compound aqueous solution was prepared by adding an inorganic layered compound and distilled water into a reactor while stirring. 1 mol (158 g) of potassium permanganate (KMnO ₄ ) was added to the aqueous solution of the inorganic layered compound and stirred at room temperature for 1 hour. Next, 1.5 mol (367.75 g) of manganese acetate (Mn (CH ₃ COO) ₂ 4H ₂ O) was dissolved in 100 ml of distilled water to prepare an aqueous solution of manganese acetate. Then, the aqueous manganese acetate solution was added to an aqueous solution of an inorganic layered compound having potassium permanganate And the mixture was stirred at room temperature for 1 hour. Subsequently, 0.63 mol (125 g) of copper acetate (Cu (CH ₃ COO) ₂ H ₂ O) was dissolved in 2097.5 ml of distilled water to prepare a copper acetate aqueous solution, and the copper acetate aqueous solution was added to the aqueous solution of the inorganic layered compound to which manganese acetate had been added And the mixture was stirred at room temperature for 2 hours. After stirring, the reaction product was washed with distilled water to remove unreacted materials and impurities, and dried at 120 ° C for 4 hours to prepare a copper-manganese catalyst oxide hybridized with an inorganic layered compound.

Next, palladium was doped on the copper-manganese catalyst oxide hybridized with the inorganic layer compound. More specifically, first, 10 g of copper-manganese catalyst oxide hybridized with an inorganic layer compound was dispersed in 150 ml of distilled water, and 3 ml of 1 wt% PdCl ₂ solution was added to a solution in which copper-manganese catalyst oxide was dispersed. Lt; / RTI > Thereafter, it was filtered and vacuum-dried at 100 DEG C for 2 hours. Followed by heat treatment at 300 DEG C for 2 hours to prepare palladium-doped copper-manganese catalyst oxide.

≪ Examples 2 and 3 >

Copper-manganese catalyst oxide doped with palladium was prepared in the same manner as in Example 1, and the weight of the composition was prepared by referring to the values shown in Table 1 below.

≪ Comparative Example 1 &

5 kg of a 2 wt% inorganic layered compound aqueous solution was prepared by adding a low inorganic layer compound and distilled water into a reactor while stirring, and 1 mol (158 g) of potassium permanganate (KMnO ₄ ) was added to the inorganic layered compound aqueous solution and stirred at room temperature for 1 hour. Next, 1.5 mol (367.75 g) of manganese acetate (Mn (CH ₃ COO) ₂ 4H ₂ O) was dissolved in 100 ml of distilled water to prepare an aqueous solution of manganese acetate. Then, the aqueous manganese acetate solution was added to an aqueous solution of an inorganic layered compound having potassium permanganate And the mixture was stirred at room temperature for 1 hour. Subsequently, 0.63 mol (125 g) of copper acetate (Cu (CH ₃ COO) ₂ H ₂ O) was dissolved in 2097.5 ml of distilled water to prepare a copper acetate aqueous solution, and the copper acetate aqueous solution was added to the aqueous solution of the inorganic layered compound to which manganese acetate had been added And the mixture was stirred at room temperature for 2 hours. After stirring, the reaction product was washed with distilled water to remove unreacted materials and impurities, and dried at 120 ° C for 4 hours to prepare a copper-manganese catalyst oxide hybridized with an inorganic layered compound.

≪ Comparative Examples 2 to 6 >

The copper-manganese catalyst oxide doped with palladium was prepared in the same manner as in Example 1, and the weight of the composition and the heat treatment conditions were prepared by referring to the values shown in Table 1 below.

≪ Comparative Example 7 &

Copper-manganese catalyst oxide doped with palladium was prepared in the same manner as in Example 1 except that 3 ml of 0.1 wt% PdCl ₂ solution was used for palladium doping.

Condition Preparation conditions of copper-manganese catalyst oxide hybridized with an inorganic layered compound Heat treatment The inorganic layer compound (g) Manganitis Copper salt Potassium permanganate (mol) Manganese acetate (mol) Copper acetate (mol) Hour (hour) Temperature
(° C) Example 1 100 One
[158 g] 1.5
[367.75g] 0.63
[125 g] 2 300 Example 2 100 1.1
[173.90 g] 1.6
[392.16 g] 0.55
[109.81 g] 2 300 Example 3 100 0.8
[126.47 g] 1.3
[318.63 g] 0.75
[149.74 g] 2 300 Comparative Example 1 100 One
[158 g] 1.5
[367.75g] 0.63
[125 g] 2 300 Comparative Example 2 100 0.35
[55.33 g] 0.65
[159.32 g] One
[199.65 g] 2 300 Comparative Example 3 100 1.5
[237.14 g] 2
[490.2 g] 0.35
[69.88 g] 2 300 Comparative Example 4 100 One
[158 g] 1.5
[367.75g] 0.63
[125 g] 2 100 Comparative Example 5 100 One
[158 g] 1.5
[367.75g] 0.63
[125 g] 2 550 Comparative Example 6 100 One
[158 g] 1.5
[367.75g] 0.63
[125 g] 0.1 300 Comparative Example 7 100 One
[158 g] 1.5
[367.75g] 0.63
[125 g] 2 300

< Evaluation example  1. Porosity evaluation>

The porosity characteristics of the palladium-doped copper-manganese catalyst oxide prepared in Examples 1 to 3 and Comparative Examples 1 to 7 were evaluated through a nitrogen adsorption-desorption isotherm analysis method.

At this time, nitrogen adsorption-desorption isotherms were measured under liquid nitrogen (temperature 77K), and all samples were pretreated for 2 hours under a vacuum condition of 200 ° C. The results of nitrogen adsorption-desorption isotherms and specific surface area calculations are shown in Table 2 below. The specific surface area was determined by the BET (Brunauer-Emmett-Teller) method and the pore volume was determined by the BJH (Barrett-Joyner-Halenda) method.

Specific surface area (m ² / g) Porosity factor (cm ³ / g) Example 1 245 0.23 Example 2 249 0.24 Example 3 243 0.23 Comparative Example 1 215 0.22 Comparative Example 2 219 0.22 Comparative Example 3 214 0.22 Comparative Example 4 208 0.21 Comparative Example 5 203 0.20 Comparative Example 6 210 0.21 Comparative Example 7 218 0.22

Referring to Table 2, it can be seen that the palladium-doped copper-manganese catalyst oxide (Examples 1 to 3) has a high specific surface area and a large pore volume value, and thus it can be confirmed that it is a porous metal oxide having fine pores .

In contrast, in Comparative Examples 1 to 7, the specific surface area and pore volume value were low, and in Comparative Examples 4 to 6, in which the heat treatment temperature and time were out of the range of 150 to 500 ° C and 0.5 to 12 hours, The surface area and the pore volume were remarkably reduced.

&Lt; Evaluation Example 2 >

The CO removal efficiencies of the palladium-doped copper-manganese catalyst oxides prepared in Examples 1 to 3 and Comparative Examples 1 to 7 were evaluated.

The carbon monoxide removal efficiency was evaluated by adding 2 g of the copper-manganese catalyst oxide prepared in Examples 1 to 3 and Comparative Examples 1 to 7 to a 5 L tether bag at room temperature, injecting carbon monoxide at a concentration of 50 ppm, Plus) was used to measure changes in the concentration of carbon monoxide over time. The results of the carbon monoxide removal rate measurement are shown in Table 3 below.

Carbon Monoxide Removal Rate (%) 30 minutes 60 minutes Example 1 72 88 Example 2 75 90 Example 3 71 86 Comparative Example 1 36 56 Comparative Example 2 37 60 Comparative Example 3 34 58 Comparative Example 4 32 51 Comparative Example 5 30 49 Comparative Example 6 34 54 Comparative Example 7 38 62

Referring to Table 3, it was confirmed that the palladium-doped copper-manganese catalyst oxide (Examples 1 to 3) was removed by more than 70% of carbon monoxide within 30 minutes. On the other hand, in the case of Comparative Examples 1 to 7, carbon monoxide was hardly removed, and it was confirmed that the removal performance was not significantly improved after 60 minutes as compared with Examples 1 to 3.

Claims (8)

Preparing a mixed solution by mixing a purified water and an inorganic layered compound to prepare an inorganic layered compound dispersion solution, adding a manganese salt and stirring the mixed solution;
A second step of adding a copper salt aqueous solution and a manganese salt aqueous solution to the mixed solution prepared in the first step and stirring to obtain a precipitate;
A third step of washing the precipitate obtained in the second step to remove unreacted materials and impurities and then drying to obtain a copper-manganese catalyst oxide hybridized with an inorganic layered compound; And
And a fourth step of dispersing the copper-manganese catalyst oxide hybridized with the inorganic layered compound obtained in the third step in distilled water, adding a palladium salt aqueous solution and stirring to obtain a precipitate, and drying and heat-treating the precipitate By weight of palladium-doped copper-manganese catalyst oxide. The method according to claim 1,
In the first step, the inorganic layered compound is a smectite natural or synthetic clay, such as montmorillonite, bentonite, hectorite, saponite, beelliteellite, Doped copper-copper alloy, characterized in that it is at least one selected from the group consisting of nontronite, laponite, smecton, leucentite and swelling mica. Manganese catalyst oxide. The method according to claim 1,
The manganese salt of the first step is at least one selected from the group consisting of manganese nitrate, manganese nitrate, manganese chloride, manganese iodide, manganese bromide, manganese sulfate, potassium permanganate and manganese acetate. Oxide. The method according to claim 1,
The method for preparing palladium-doped copper-manganese catalyst oxide according to claim 1, wherein the manganese salt is contained in an amount of 0.5 to 1.5 mol based on 100 g of the inorganic layer compound. The method according to claim 1,
In the second step, it is preferable to use an aqueous solution of a copper salt which is at least one selected from the group consisting of copper acetate, copper nitrate, copper chloride, copper iodide, copper bromide, copper sulfate and copper acetate. Is contained in an amount of 0.2 to 1 mol based on 100 g of the inorganic layered compound. The method for producing a palladium-doped copper-manganese catalyst oxide according to claim 1, The method according to claim 1,
In the second step, it is preferable to use an aqueous solution of manganese salt, which is at least one selected from the group consisting of manganese nitrate, manganese chloride, manganese chloride, manganese chloride, manganese bromide, manganese sulfate, potassium permanganate and manganese acetate. Wherein the manganese salt as a raw material sample contains 1 to 2 mol based on 100 g of the inorganic layered compound. The method according to claim 1,
In the fourth step, it is preferable to use an aqueous solution of a palladium salt which is at least one selected from the group consisting of palladium chloride, palladium fluoride, palladium iodide, palladium nitrate and palladium sulfate. The palladium salt as a raw material sample in the aqueous palladium salt solution is preferably an inorganic layer Wherein the copper-manganese catalyst oxide comprises 0.001 to 0.01 mol based on 100 g of the copper-manganese catalyst oxide hybridized with the compound. The method according to claim 1,
Wherein the heat treatment in the fourth step is performed at a temperature ranging from 150 to 500 ° C. for 0.5 to 12 hours.

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