KR102241779B1 - A mixed metal oxide catalyst for amine-based carbon dioxide absorbent, amine-based carbon dioxide absorbent, and apparatus for absorption and desorption using thereof - Google Patents

Abstract

The present invention relates to a composite metal oxide catalyst for an amine-based carbon dioxide adsorbent, an amine-based carbon dioxide adsorbent and an adsorption and desorption device including the same. By using a catalyst represented by the following [Chemical Formula 1] and having a pyrochlore structure, carbon dioxide It improves the reaction rate related to absorption and desorption of and can be used while continuously circulating the absorption and desorption reaction.

Description

A mixed metal oxide catalyst for amine-based carbon dioxide absorbent, amine-based carbon dioxide absorbent, and apparatus for absorption and desorption using thereof }

The present invention relates to a composite metal oxide catalyst which improves the reaction rate related to absorption and desorption of carbon dioxide and improves the function to be used while continuously circulating the absorption and desorption reaction, an amine-based carbon dioxide adsorbent and an adsorption and desorption device including the same. will be.

Carbon dioxide capture and storage (CCS) technology is a technology that captures a large amount of carbon dioxide generated after combustion of fossil fuels and stores the captured carbon dioxide in the crust or ocean, or converts it into chemical materials and fuel. It is a generic term.

The CCS technology has become more important as the Paris Agreement was adopted in 2015 to reduce the emission of carbon dioxide, which has been pointed out as a major cause of climate change caused by global warming as a global problem. It is increasing. Korea, the world's seventh-largest greenhouse gas emitter, aims to reduce greenhouse gas emissions by 37% compared to the forecast by 2030.

Among the methods of collecting carbon dioxide, the post-combustion capture technology uses a method of absorbing and desorbing carbon dioxide contained in a flue gas using an absorbent after burning fossil fuels. Although there are various methods for the principle of such absorbent absorbing carbon dioxide from flue gas, chemisorption is mainly used because chemisorption is easy to selectively absorb carbon dioxide among various gases. However, such a chemical adsorption method has a problem in that the reaction rate, especially desorption is slow.

Until now, various absorbents using chemical adsorption have been researched and developed, but what is mainly considered in practical terms is an amine absorbent using aqueous solutions such as MEA, DEA, MDEA, and DIPA. The concentration of amines generally used is 32% for MEA, 20-25% for DEA, and 30-50% for MDEA. These amine-based absorbent is carbamate (RNHCOO ^-) in an aqueous solution when it reacts with the carbon dioxide (CO ₂₎ at a lower temperature, bicarbonate (HCO ₃ ^-) representative reaction scheme for forming the carbamate (carbamate) to form the various compounds of the form below: same.

According to the above reaction formula, 0.5 mol of carbon dioxide can be absorbed per 1 mol of amine. In addition, the reaction proceeds in the reverse direction at a high temperature. By utilizing this point, the amine that has absorbed carbon dioxide can be regenerated and used for carbon dioxide absorption again.

In general, MEA has an excellent absorption rate of carbon dioxide and its molecular weight is small, so it is most often used because of its high carbon dioxide absorption per unit weight.However, in the process of regenerating it in a regenerator after the MEA absorbent absorbs carbon dioxide, the reaction speed of carbon dioxide desorption is slow. A high temperature of ~130 °C is required. Since the MEA absorbent is composed of a mixed solution of MEA and water, when the temperature is heated to 110° C. or higher for regeneration, there is a problem of consuming excessive thermal energy due to vaporization of water (heat of vaporization, 2.255 kJ/g) generated at 100° C. The cost for such regeneration is large enough to account for more than 70% of the total operating cost, and it is known that the amine-based absorbent is partially decomposed at a high temperature of 100° C. or higher to generate a carcinogen.

In order to solve this problem, when MDEA, which is a tertiary amine capable of degassing at a low temperature, is used as an absorbent, the amount of thermal energy required for regeneration is low, but there is a problem in that the carbon dioxide absorption rate is low at room temperature.

Accordingly, research is being conducted in the direction of improving the economic efficiency and safety of the entire process by improving the slow carbon dioxide desorption rate of MEA so that the desorption reaction proceeds below 100 ℃. Silica gel, HZSM-5, γ-Al ₂ O ₃ , TiO ₂ , V ₂ O ₅ , MoO ₃ , FeOOH, TiO(OH) ₂ Various inorganic-based catalysts such as, etc. have been reported. For the carbon dioxide is absorbed MEA carbon dioxide is mainly (MEAH ⁺⁾ (MEACOO ^-) or ^{_{(MEAH +) (HCO 3 -}} ) known to exist in the form and with the hydrolysis (hydrolysis) of water to carbon dioxide occurs again therefrom The exchange of hydrogen ions (H ⁺ ) between cations and anions is very important.

Accordingly, there is a need for a catalyst that enables the exchange of ^{H +} ions to be easily performed so that the reaction rate can be drastically improved.

Catalyst-TiO(OH)2 could drastically reduce the energy consumption of CO2 capture, M. Fan et al., Nat Commun., 2018 Metal oxide catalyst-aided solvent regeneration: A promising method to economize post-combustion CO2 capture process, H. Baek et al., J Taiwan Inst Chem Eng., 2018

An object of the present invention is to provide a composite metal oxide catalyst that improves the reaction rate related to the absorption and desorption of carbon dioxide and improves the function so that the absorption and desorption reaction can be used while continuously circulating.

In addition, another object of the present invention is to provide an amine-based carbon dioxide adsorbent comprising the composite metal oxide catalyst.

In addition, another object of the present invention is to provide an adsorption and desorption device comprising the composite metal oxide catalyst.

The composite metal oxide catalyst for an amine-based carbon dioxide adsorbent of the present invention for achieving the above object is represented by the following [Chemical Formula 1], and has a pyrochlore structure;

[Formula 1]

A ₂ [B _2-x A _x ]O _7-y

In the [Formula 1], A is Pb (plumbum) or Bi (bismuth), B is Ru (ruthenium) or Ir (iridium), O is oxygen,

The x is a prime number of 0≦x≦1, and y is a prime number of 0≦y≦1.

The specific surface area of the composite metal oxide catalyst ^{may be 1 to 300 m 2} /g.

In addition, the amine-based carbon dioxide adsorbent of the present invention for achieving the above-described other object may include the composite metal oxide catalyst and an amine-based aqueous solution.

The amine-based aqueous solution is monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), diisopropanolamine (DIPA), and aminoethoxyethanol (DGA). It may be one or more aqueous solutions selected from the group consisting of.

In addition, the carbon dioxide adsorption and desorption apparatus of the present invention for achieving the another object described above may include the composite metal oxide catalyst.

The composite metal oxide catalyst of the present invention improves the reaction rate related to absorption and desorption of carbon dioxide when used in an amine-based carbon dioxide absorbent, and can be used while continuously circulating the absorption and desorption reaction.

In addition, conventional amine-based carbon dioxide absorbents require a high temperature of 110 to 130 ℃ due to the slow reaction rate of carbon dioxide desorption, and accordingly, some decompose to produce carcinogenic substances, but amine-based carbon dioxide using the composite metal oxide catalyst of the present invention The absorbent has excellent desorption of carbon dioxide at a temperature lower than the boiling point of water, preferably at a temperature of 90° C. or less, and thus carcinogenic substances are not generated and energy consumption can be significantly reduced.

1A is a view _{showing a B 2} O ₆ structure, FIG. 1B is a view showing an O` (AO`) ₄ tetrahedral structure, and FIG. 1C is a view showing the catalyst crystal structure of the present invention in which FIGS. 1A and 1B are combined. Structure.
_{Figure 2a shows the (i) Pb 2} [Ru _1.83 Pb _0.17 ]O ₆ O` <sub>0.5</sub> catalyst having a grain size of 10 nm or less prepared in Example 1 of the present invention and (ii) Pb having a grain size of 20 to 40 nm. <sub>2</sub> [Ru <sub>1.83</sub> Pb <sub>0.17</sub> ]O <sub>6</sub> O` _{0.5 This} is a graph showing the X-ray diffraction pattern for the catalyst.
_{FIG. 2b is a (i) Bi 2} [Ru _1.53 Bi _0.47 ]O _7-y catalyst having a grain size of 10 nm or less prepared in Example 2 of the present invention _{and (ii) Bi 2} having a grain size of 20 to 40 nm. It is a graph showing the X-ray diffraction pattern for the [Ru _1.53 Bi _0.47 ]O _{7-y catalyst.
3A is a photograph taken by TEM of a Pb 2} [Ru _1.83 Pb _0.17 ]O ₆ O` <sub>0.5</sub> catalyst having a size of 10 nm or less prepared according to Example 1 of the present invention, and FIG. 3B is an example of the present invention. <sub>A photo of a Pb 2</sub> [Ru <sub>1.83</sub> Pb <sub>0.17</sub> ]O <sub>6</sub> O` _0.5 catalyst having a size of 20 to 40 nm prepared according to 1 was taken by SEM.
_{3C is a photograph of a Bi 2} [Ru _1.53 Bi _0.47 ]O _7-y catalyst having a size of 10 nm or less prepared according to Example 2 of the present invention by TEM, and FIG. 3D is a photograph of Example 2 of the present invention. This is a photograph of a Bi ₂ [Ru _1.53 Bi _0.47 ]O _7-y catalyst having a size of 20 to 40 nm prepared according to the SEM by SEM.
4 shows a system for a carbon dioxide absorption and desorption test using MEA.
_{5A is a graph showing the carbon dioxide absorption rate of a carbon dioxide absorbent using a Pb 2} [Ru _1.83 Pb _0.17 ]O ₆ O` _0.5 catalyst prepared according to Example 1 of the present invention, and FIG. 5B is a graph showing the carbon dioxide absorbed in FIG. 5A. It is a graph showing the desorption rate, and FIG. 5C is a graph showing the amount of desorption when carbon dioxide absorbed in FIG. 5A is desorbed.
_{6A is a graph showing the carbon dioxide absorption rate of a carbon dioxide absorbent using a Bi 2} [Ru _1.53 Bi _0.47 ]O _7-y catalyst prepared according to Example 2 of the present invention, and FIG. 6B is a graph showing the absorption of carbon dioxide absorbed in FIG. 6A. It is a graph showing the desorption rate, and FIG. 6C is a graph showing the amount of desorption when the carbon dioxide absorbed in FIG. 6A is desorbed.

The present invention relates to a composite metal oxide catalyst which improves the reaction rate related to absorption and desorption of carbon dioxide and improves the function to be used while continuously circulating the absorption and desorption reaction, an amine-based carbon dioxide adsorbent and an adsorption and desorption device including the same. will be.

Hereinafter, the present invention will be described in detail.

The composite metal oxide catalyst for an amine-based carbon dioxide adsorbent of the present invention is represented by the following [Chemical Formula 1], and has a pyrochlore structure.

[Formula 1]

A ₂ [B _2-x A _x ]O _7-y

In [Chemical Formula 1], A is Pb (plumbum) or Bi (bismuth), B is Ru (ruthenium) or Ir (iridium), and O is oxygen.

In addition, x is a prime number of 0 ≤ x ≤ 1, and y is a prime number of 0 ≤ y ≤ 1 to improve the reaction rate related to the absorption and desorption of carbon dioxide, and can be used while continuously circulating the absorption and desorption reaction. So that the function can be improved. In addition, it is possible to lower the temperature required for desorption of carbon dioxide. If the x and y values are within the above range, there is no significant difference in effect.

The compound of [Chemical Formula 1] is specifically a _{pyrochlore structure formed in a structure of A 2} [B _2-x A _x ]O ₆ O` <sub>y</sub> , and the pyrochlore structure is shown in FIG. 1 As described above, the hexagonal ring-shaped structure formed by the corners of the <sub>BO 6</sub> octahedron is in the [111] direction, or the inside <sub>of the B 2</sub> O <sub>6 framework formed in a cage shape is O`-</sub> It is a complex structure filled with O`(AO`) _{4 tetrahedrons connected linearly with AO`.} At this time, all or part of the O′ is eliminated to form a defect (vacancy), and both O and O′ are oxygen.

Specifically, FIG. 1A is a view _{showing a B 2} O ₆ structure, FIG. 1B is a view showing an O` (AO`) ₄ tetrahedral structure, and FIG. 1C is a catalyst crystal structure of the present invention in which FIGS. 1A and 1B are combined. It is a structure showing. In other words, FIG. 1B shows that some oxygen in the O'-AO' linear structure is replaced with a vacancy to actually _{show a tetrahedral structure in the form of O'A 4} , and this vacancy exists in the crystal structure. The site can be used as an active site for carbon dioxide absorption and desorption.

Due to this structural specificity, the catalyst of the present invention can contain many oxygen vacancy in the structure, and when placed in an aqueous solution, the oxygen vacancy site present on the catalyst surface acts as a local positive charge center. Because of this, a strong electrostatic interaction can occur with water molecules absorbed into the vacancy or water molecules adsorbed near the vacancy.

In addition, the A element present in the catalyst of the present invention has a very high average oxidation number of +4 or more (Ru ^{4 +} , Ru ^{5 +} , Pb ^{4 +} , Ir ^{4 +} , Ir ^{5 +,} etc.) oxygen vacancy. Water molecules inside or near are strongly polarized due to this, resulting in acidic properties (Scheme 2).

Accordingly, the catalyst of the present invention has ^{a property of providing or accepting H +} to the outside through hydrolysis of water in some cases, and thereby can be used as an active site for absorption and desorption reactions of carbon dioxide. _{That is, the exchange of hydrogen ions between RNH 3} ⁺ and RNHCO ₂ ^- is essential in order to activate the reverse reaction of carbon dioxide desorption reaction (Scheme 3) from an amine, and the catalyst of the present invention is a hydrogen ion as shown in Scheme 3 and Scheme 4 above. It can act as a medium for exchange.

In the above reaction formula, MH ₂ O and M-OH ^- represent water and hydroxide ions present at vacancy sites of the pyrochlore structure, respectively.

The catalyst of the present invention can be synthesized through a high-temperature sintering process or a low-temperature solution-based process, and can be prepared in a ^{form with a very large specific surface area (50 to 300 m 2 /g) through a low-temperature synthesis process to maximize carbon dioxide desorption reaction.} In addition, in order to improve the stability in the amine-based aqueous solution, it is possible to prepare a larger particle form through heat treatment or the like.

In addition, the catalyst of the present invention can be prepared not only in a form with a large specific surface area as described above, but also in a form with a small specific surface area (1 to 49 m ² /g), so that the specific surface area is 1 to 300 m ² /g. It can be formed freely in, and there is no difference in the effect between the materials within the range as long as the range is satisfied.

In addition, the present invention may provide an amine-based carbon dioxide adsorbent including the catalyst represented by [Chemical Formula 1].

The amine-based carbon dioxide adsorbent performs a reaction by adding the catalyst represented by the [Chemical Formula 1] to the amine-based aqueous solution, thereby improving the reaction rate related to absorption and desorption of carbon dioxide, and can continuously circulate the absorption and desorption reaction. have.

The amine-based aqueous solution is not particularly limited as long as it is an amine-based material capable of absorbing and desorbing carbon dioxide, but preferably monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine, MDEA), diisopropanolamine (DIPA), and aminoethoxyethanol (DGA).

In addition, the present invention can provide a carbon dioxide adsorption and desorption apparatus including the catalyst represented by the above [Chemical Formula 1].

Hereinafter, a preferred embodiment is presented to aid in the understanding of the present invention, but it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the present invention and the scope of the technical idea, but the following examples are only illustrative of the present invention, It is natural that such modifications and modifications fall within the scope of the appended claims.

Example 1. Lead-ruthenium composite metal oxide catalyst

3.303 g of ruthenium nitrosyl nitrate solution (Ru 1.5% by weight) and 0.134 g of Pb acetate (lead subacetate) were added to 6.0 g of distilled water and stirred for 1 hour, followed by adding 3.3 ml of a 2.0 M NaOH solution, followed by stirring for 3 hours. Then, 0.25 ml of a 13% NaOCl solution was added and stirred for 24 hours _{to synthesize Pb 2} [Ru _1.83 Pb _0.17 ]O ₆ O` _0.5 having a grain size of 10 nm or less (specific surface area 152 m ² /g).

Then, the solution was put back into a hydrothermal synthesizer and heat-treated at 150° C. for 24 hours to synthesize a bulk Pb ₂ [Ru _1.83 Pb _0.17 ]O ₆ O` _0.5 having a grain size of 20 to 40 nm (ratio The surface area was 3.5 m ² /g).

Example 2. Bismuth-ruthenium composite metal oxide catalyst

3.303 g of Ruthenium nitrosyl nitrate solution (Ru 1.5% by weight) and 0.364 g of Bi(NO) ₃ ·5H ₂ O were added to 1.0 g of distilled water _{, stirred for 30 minutes, and 0.6 g of concentrated HNO 3} solution was added and stirred for an additional 30 minutes. Then, 10 ml of a 2.0 M NaOH solution was added and stirred at 70° C. for 3 hours, and then 0.75 ml of 13% NaOCl was added and stirred at 70° C. for 24 hours to obtain Bi ₂ [Ru _1.53 Bi _0.47 ]O having a crystal grain size of 10 nm or less. _{A 7-y} catalyst was synthesized (specific surface area 103 m ² /g).

Then, the solution was put back into a hydrothermal synthesizer and heat-treated at 150° C. for 24 hours to synthesize a bulk Bi ₂ [Ru _1.53 Bi _0.47 ]O _7-y with a grain size of 20 to 40 nm (specific surface area 2.1 m ² /g). The y value was difficult to accurately measure, but it did not exceed 1.

Washed with distilled water and ethanol, and dried in a vacuum oven at 100° C. for 12 hours.

Example 3. Lead-iridium composite metal oxide catalyst

In the same manner as in Example 1 _{, using 0.149 g of iridium chloride (IrCl 3} ) and 0.134 g of Pb acetate (lead subacetate) to synthesize a _{Pb 2} [Ir _1.73 Pb _0.27 ]O _{7-y catalyst of 10 nm or less (ratio} The surface area was 101 m ² /g).

_{In addition, a bulk Pb 2} [Ir _1.73 Pb _0.27 ]O _7-y having a grain size of 20 to 40 nm was synthesized (specific surface area 2.1 m ² /g). The y value was difficult to accurately measure, but it did not exceed 1.

Example 4. Bismuth-iridium composite metal oxide catalyst

But the same procedure as in Example _{2, iridium chloride (IrCl 3)} 0.149 g and _{Bi (NO) 3 · 5H 2} O 0.364 g or less to 10 nm by using _{Bi 2 [Ir 1 .45 Bi 0} .55] O 7 _-y catalyst was synthesized (specific surface area 130 m ² /g).

_{In addition, a bulk form of Bi 2} [Ir _1.45 Bi _0.55 ]O _7-y having a crystal grain size of 20 to 40 nm was synthesized (specific surface area 5.1 m ² /g). The y value was difficult to accurately measure, but it did not exceed 1.

<Test Example>

Test Example 1. X-ray diffraction measurement

Figure 2a embodiment, the size of the (i) crystal grains prepared in 1 10 nm or less _{Pb 2 [Ru 1.83 Pb 0.17]} O 6 O` 0.5 catalyst and (ii) the size of the crystal grains of 20 to 40 nm Pb <sub>2</sub> [Ru <sub>1.83</sub> Pb <sub>0.17</sub> ]O <sub>6</sub> O` _0.5 is a graph showing the X-ray diffraction pattern for the catalyst.

_{In addition, Figure 2b shows the (i) Bi 2} [Ru _1.53 Bi _0.47 ]O _7-y catalyst having a grain size of 10 nm or less prepared in Example 2 _{and (ii) Bi 2} [having a grain size of 20 to 40 nm] It is a graph showing the X-ray diffraction pattern for the _{Ru 1.53} Bi _0.47 ]O _{7-y catalyst.}

As shown in FIGS. 2A and 2B, no change in the X-ray diffraction pattern according to the difference in grain size was observed, and the Pb ₂ [Ru _1.83 Pb _0.17 ]O ₆ O` _0.5 catalyst of Example 1 was determined. It was confirmed that the structure belongs to the space group P-43m by vacancy ordering and that Bi ₂ [Ru _1.53 Bi _0.47 ]O _7-y belongs to Fd-3m.

Test Example 2. Taken by TEM and SEM

_{3A is a photograph of a Pb 2} [Ru _1.83 Pb _0.17 ]O ₆ O` <sub>0.5</sub> catalyst having a size of 10 nm or less prepared according to Example 1 by TEM, and FIG. 3B is a photo of a crystal grain prepared according to Example 1 This is a photograph of a Pb <sub>2</sub> [Ru <sub>1.83</sub> Pb <sub>0.17</sub> ]O <sub>6</sub> O` _0.5 catalyst having a size of 20 to 40 nm by SEM.

In addition, FIG. 3C is a photograph of a Bi ₂ [Ru _1.53 Bi _0.47 ]O _7-y catalyst having a size of 10 nm or less prepared according to Example 2 by TEM, and FIG. 3D is This is a photograph of a Bi ₂ [Ru _1.53 Bi _0.47 ]O _7-y catalyst having a grain size of 20 to 40 nm by SEM.

As shown in FIGS. 3A to 3D, it can be seen that the composite metal oxide particles having an initial uniform size of several nm have grown into particles having a size of several tens of nm after the hydrothermal reaction.

Test Example 3. Carbon dioxide absorption and desorption test using 20% MEA aqueous solution

4 shows a system for a carbon dioxide absorption and desorption test using MEA.

4 is a system used to confirm the performance of the catalyst of the present invention, and was used to measure the evaluation of the carbon dioxide absorbent using the catalyst of the present invention in an aqueous MEA solution on carbon dioxide absorption and desorption reaction rates. To simulate the flue gas including carbon dioxide, a mixed gas consisting of a volume ratio of _{CO 2} : O ₂ : N _{2 = 10: 10: 80 was used.}

200 g of an aqueous solution containing 20% MEA was prepared, and then added to the reactor of FIG. 4, and the composite metal oxide catalyst prepared according to Example 1 or 2 was added by 2.0 g, corresponding to 1% by weight of the MEA solution. Was put in. For the test for absorption of carbon dioxide, the temperature of the solution was heated to 40° C. and the amount of carbon dioxide absorbed by the MEA was measured while flowing a mixed gas including carbon dioxide.

_{5A is a graph showing the carbon dioxide absorption rate of a carbon dioxide absorbent using a Pb 2} [Ru _1.83 Pb _0.17 ]O ₆ O` _0.5 catalyst prepared according to Example 1, and FIG. 5B is a desorption rate for desorbing carbon dioxide absorbed in FIG. 5A 5C is a graph showing the amount of desorption when the carbon dioxide absorbed in FIG. 5A is desorbed.

In addition, Figure 6a is a _{graph showing the carbon dioxide absorption rate of the carbon dioxide absorbent using the Bi 2} [Ru _1.53 Bi _0.47 ]O _7-y catalyst prepared according to Example 2, Figure 6b is a desorption of the carbon dioxide absorbed in Figure 6a It is a graph showing the rate, and FIG. 6C is a graph showing the amount of desorption when the carbon dioxide absorbed in FIG. 6A is desorbed.

5A and 6A, in the case of using the catalyst prepared according to Example 1 or Example 2, the time that the carbon dioxide input to the reactor is absorbed by 90% or more of the absorbent is using the absorbent without using the catalyst. It was confirmed that it was longer than that of the case. This means that when the catalyst prepared according to Example 1 or Example 2 is used, the amount of carbon dioxide absorbed by MEA is increased.

After absorption of carbon dioxide, MEA (spent MEA) in which carbon dioxide was absorbed for 6000 seconds under the same conditions was put into a reactor and heated with a heater to keep the temperature of the solution at 90 ℃, and the amount of carbon dioxide generated while maintaining the temperature was 6000. Measurements were made continuously for seconds. As a result, as shown in FIGS. 5B and 6B, in the case of using the catalyst prepared according to Example 1 or Example 2, the temperature at which the carbon dioxide desorption rate is the highest is lower than that in the absence of the catalyst, and FIG. 5C And as shown in Figure 6c it was confirmed that the final amount of desorption also increased significantly.

In order to confirm the stability of the catalyst when performing the carbon dioxide absorption-desorption cycle using the catalyst prepared according to Examples 1 and 2, the above process was repeated at least 30 times. As a result, the absorption amount and the amount of desorption were determined according to the cycle. It was confirmed that the catalysts prepared according to Examples 1 and 2 were stable because there was no significant change.

Claims (5)

A composite metal oxide catalyst for carbon dioxide adsorption and desorption reaction in an amine-based aqueous solution represented by the following [Chemical Formula 1] and having a pyrochlore structure;
[Formula 1]
A ₂ [B _2-x A _x ]O _7-y
In the [Formula 1], A is Pb (plumbum) or Bi (bismuth), B is Ru (ruthenium) or Ir (iridium), O is oxygen,
The x is a prime number of 0≦x≦1, and y is a prime number of 0≦y≦1. The composite metal oxide catalyst according to claim 1, wherein the specific surface area of the composite metal oxide catalyst is 1 to 300 m ² /g. An amine-based carbon dioxide adsorbent comprising the composite metal oxide catalyst of claim 1 or 2 and an amine-based aqueous solution. The method of claim 3, wherein the amine-based aqueous solution is monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine (MDEA), diisopropanolamine (DIPA), and amino. An amine-based carbon dioxide adsorbent, characterized in that it is an aqueous solution selected from the group consisting of oxyethanol (aminoethoxyethanol, DGA). A carbon dioxide adsorption and desorption apparatus comprising the composite metal oxide catalyst of claim 1 or 2.

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