A metal organic framework material for separating carbon dioxide from a multi-component mixture and a preparation method thereof

Abstract

The present invention belongs to the field of new materials for gas adsorption and separation, and particularly proposes a metal organic framework material, a preparation method thereof, and its application in separating carbon dioxide from a multi-component mixture. The chemical formula of the metal organic framework material is [Co(ipa)(1dtab)], wherein Co represents metal center cobalt; ipa represents organic ligand isophthalic acid, and the structural formula is; 1dtab represents organic ligand 1,4-di(1H-1,2,4-triazole-1-yl)benzene, and the structural formula is; the metal organic framework material has a two-dimensional layered structure and periodic S-shaped one-dimensional pores, and the surface is rich in nitrogen atom action sites. The present invention aims to efficiently and selectively separate carbon dioxide from a variety of mixed gases. Under normal temperature conditions, the material has the highest adsorption of carbon dioxide in 10 mixed gases, and exhibits excellent performance in the selective separation of multi-component mixtures.

Description

Technical Field

[0001] The invention relates to the technical field of new materials for gas adsorption and separation, and in particular to a metal organic framework material and a preparation method thereof and an application thereof in separating carbon dioxide from a multi-component mixture. Background Art

[0002] The large amount of carbon dioxide produced in industrial processes not only has a profound impact on the climate, but may also lead to a waste of resources. Therefore, the development of efficient, economical and environmentally friendly carbon dioxide separation and capture technology is one of the important ways to achieve the goal of carbon neutrality. At present, although traditional separation technologies such as liquid amine absorption and low-temperature condensation are mature, they often have problems such as high energy consumption, complex equipment and secondary pollution to the environment, which makes it difficult to meet the needs of industrial-scale applications.

[0003] In recent years, Metal-Organic Frameworks (MOFs) have attracted widespread attention due to their high specific surface area, structural tunability and excellent gas adsorption performance. This type of material can regulate the pore size and chemical functionality by precisely designing the combination of coordinating metals and organic ligands, thereby giving it high selectivity and adsorption capacity for specific gas molecules. However, when separating carbon dioxide from complex mixed gases, conventional MOF materials face the challenge of competing with other gas molecules for adsorption, especially acetylene (C2H2). Due to the high polarity and adsorption activity of acetylene, its adsorption amount in MOF is usually higher than that of carbon dioxide, which seriously affects the preferential separation of carbon dioxide. In addition, when MOF materials separate carbon dioxide from multi-component mixtures, it is difficult to simultaneously take into account high selectivity and high adsorption capacity, which limits their performance in practical industrial applications. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a metal organic framework material and a preparation method thereof and its application in separating carbon dioxide from a multi-component mixture. By optimizing the pore structure and surface chemical functions of the material, the MOF material designed by the present invention significantly inhibits the adsorption of competitive gases such as acetylene, while improving the selectivity and adsorption capacity for carbon dioxide, and can preferentially adsorb carbon dioxide from 10 common small molecule gases, and can be applied to the separation of carbon dioxide in various mixtures. The present invention provides an innovative solution for achieving efficient capture and separation of carbon dioxide, and is expected to play an important role in the fields of industrial gas separation and greenhouse gas emission reduction.

[0005] The first object of the present invention is to provide a metal organic framework material, the metal organic framework material is named TJE-6, and the chemical structure is , where the arrow represents the coordination bond, and the lone pair of electrons on N coordinates to Co; the chemical formula is [Co(ipa)(1dtab)], where Co represents the metal center cobalt; ipa represents the organic ligand isophthalic acid, and the structural formula is ; 1dtab represents the organic ligand 1,4-di(1H-1,2,4-triazol-1-yl)benzene, the structural formula is .

[0006] In some embodiments of the present invention, the cobalt in the metal-organic framework material is 6-coordinated, and two cobalts are coordinated through the carboxyl bridge of two ipa ligands to form a one-dimensional chain structure. Subsequently, each cobalt is coordinated with the N of one triazole from two 1dtab ligands in a plane perpendicular to the chain to form a planar layered structure. Subsequently, the layered structures are interdigitated and stacked to form a spatial structure; the cobalt does not form an open metal site.

[0007] In some embodiments of the present invention, the metal organic framework material has a two-dimensional layered structure and periodic S-shaped one-dimensional channels, and nitrogen atom action sites are distributed on the surface of the one-dimensional channels.

[0008] In some embodiments of the present invention, the cross-sectional pore size of the one-dimensional channel is 4.1-3.0 Å. The channel size belongs to the ultra-micropore level.

[0009] The second object of the present invention is to provide a method for preparing a metal organic framework material for separating carbon dioxide from a multi-component mixture, comprising the following steps:

[0010] S1: dissolving organic ligands isophthalic acid and 4-di(1H-1,2,4-triazol-1-yl)benzene in an organic solvent, and adding a cobalt source to dissolve to obtain a mixed solution;

[0011] S2: heating the mixed solution obtained in step S1 for reaction, and after the reaction is completed, performing solid-liquid separation to obtain a solid phase, and washing the solid phase with a low boiling point solvent;

[0012] S3: vacuum drying and heating the solid phase obtained in step S2 to remove the solvent, thereby obtaining the metal organic framework material.

[0013] In some embodiments of the present invention, in step S1, the organic solvent includes N,N-dimethylacetamide and methanol, and the volume ratio of N,N-dimethylacetamide to methanol is (1:1) to (1:0).

[0014] In some embodiments of the present invention, in step S1, the cobalt source is selected from Co(NO3)2 hydrate and / or Co(NO3)2 hydrate.

[0015] In some embodiments of the present invention, in step S1, the molar ratio of the cobalt source to the organic ligands isophthalic acid and 4-di(1H-1,2,4-triazol-1-yl)benzene is (1:1:1) to (1:2:2).

[0016] In some embodiments of the present invention, in step S1, the dissolution method is a conventional method in the art, and any method can be used as long as it can achieve complete dissolution of the substance referred to in the present invention. Stirring and / or ultrasonic oscillation may be preferred.

[0017] In some embodiments of the present invention, in step S2, the temperature of the heating reaction is 90-130 °C, and the reaction time is not less than 24 hours.

[0018] In some embodiments of the present invention, in step S2, the reaction vessel for the heating reaction is a pressure-resistant closed container, which is a closed glass reaction bottle with a polytetrafluoroethylene gasket or a polytetrafluoroethylene-lined reaction kettle.

[0019] In some embodiments of the present invention, in step S2, the low boiling point solvent includes one or more of methanol, ethanol, dichloromethane or acetone.

[0020] In some embodiments of the present invention, in step S2, the solid-liquid separation is performed by suction filtration using an organic phase filter membrane or filter paper with a pore size of 0.2 to 5 μm. Further, a suction filtration device such as a Buchner funnel or a sand core filter device is used.

[0021] The third object of the present invention is to provide an application of the metal organic framework material in separating carbon dioxide from a multi-component mixture.

[0022] In some embodiments of the present invention, the method of application comprises the following steps:

[0023] A1: The metal organic framework material is loaded into an adsorption column and compacted, and activated by heating and purging with an inactive gas, and a mixed gas containing carbon dioxide is introduced into the adsorption column;

[0024] A2: After the metal organic framework material adsorbs and captures carbon dioxide in the mixed gas, other components in the mixed gas preferentially pass through the bed layer to achieve separation of carbon dioxide;

[0025] A3: The metal organic framework material used in step A2 is heated and purged with an inert gas to achieve the recycling of the metal organic framework material.

[0026] In some embodiments of the present invention, in step A1, the inner diameter of the adsorption column is 6-10 mm.

[0027] In some embodiments of the present invention, in step A1, the mixed gas containing carbon dioxide includes but is not limited to one or more of nitrogen, oxygen, methane, hydrogen, argon, acetylene, ethylene, ethane, and carbon monoxide.

[0028] In some embodiments of the present invention, in step A1, the volume content of carbon dioxide in the carbon dioxide-containing mixed gas is 1% to 99%.

[0029] In some embodiments of the present invention, in step A1, the mixed gas introduction rate is 2-4 mL·min -1 .

[0030] In some embodiments of the present invention, in steps A1 and A3, the inert gas is selected from nitrogen and / or helium, and the temperature of the heating and purging is 150-180 °C for no less than 30 minutes.

[0031] The above technical solution of the present invention has the following advantages compared with the prior art:

[0032] (1) The metal organic framework material TJE-6 obtained in the present invention has periodic one-dimensional channels with a cross-sectional pore size of 4.1~3.0 Å. The channel size is at the ultra-micropore level. Oxygen atom and nitrogen atom action sites are distributed on the pore surface, which can form hydrogen bond interactions with carbon dioxide. The synergistic effect of functional groups and ultra-micropore channels leads to the selective adsorption and separation effect of TJE-6 on carbon dioxide.

[0033] (2) The present invention provides a new method for the adsorption and separation of carbon dioxide based on metal organic framework materials. The new ultra-microporous metal organic framework material used in the method has a special pore structure and excellent gas selectivity. It can preferentially adsorb carbon dioxide in a complex mixture of ten small molecule gases, including acetylene, ethylene, ethane, methane, nitrogen, carbon monoxide, oxygen, hydrogen, argon, etc. This makes the present invention suitable for many fields such as industrial waste gas treatment, natural gas purification, raw gas separation in chemical production, carbon capture and storage (CCS), etc., and has significant economic and social benefits.

[0034] (3) The material used in the present invention can still maintain stable adsorption performance and structural integrity after multiple cycles of use, has good heat resistance and moisture resistance, and has a long service life.

[0035] (4) Compared with conventional porous adsorbents, the metal organic framework material used in the present invention has the advantages of high adsorption capacity, excellent desorption performance, repeated regeneration, high adsorption selectivity and low material cost. The material used is simple and safe in preparation, with high yield and basically no by-products.

[0036] (5) Compared with the traditional distillation method or gas phase adsorption separation method, the separation method provided by the present invention has the advantages of mild operating conditions, low energy consumption, and small equipment investment. Therefore, the present invention is expected to bring about an improvement in economic benefits for related petrochemical enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0038] Figure 1 Schematic diagram of the spatial structure of the TJE-6 material of the present invention (a structural diagram of a single layer and a layered stacking view and a schematic diagram of the pore structure observed along the b-axis of the unit cell. Atomic colors: dark blue, cobalt; gray, carbon; red, oxygen; lavender, nitrogen; atoms in the same layer in the layered stacking view are set to a uniform color, and the pores are represented by silver gray. Hydrogen atoms are omitted for clarity);

[0039] Figure 2 The X-ray powder diffraction experimental results of the activated TJE-6 materials obtained in Examples 1, 2 and 3 of the present invention and after long-term exposure to humid air;

[0040] Figure 3 This is the thermogravimetric curve of TJE-6 obtained in Example 1 of the present invention;

[0041] Figure 4 The adsorption isotherms of the activated TJE-6 material obtained in Example 1 of the present invention for 10 common gases at 25°C;

[0042] Figure 5 The ideal solution adsorption model selectivity (IAST selectivity) of the activated TJE-6 material obtained in Example 1 of the present invention for an equimolar binary mixture of carbon dioxide and various gases at 25°C;

[0043] Figure 6 This is a five-cycle adsorption and desorption experiment of carbon dioxide on the activated TJE-6 material obtained in Example 1 of the present invention at 25°C;

[0044] Figure 7 This is the penetration curve of the activated TJE-6 material obtained in Example 1 of the present invention under the conditions of an equimolar mixture of carbon dioxide and acetylene and water vapor with a relative humidity of 50% at 25°C;

[0045] Figure 8 : is the breakthrough curve of the activated TJE-6 material obtained in Example 2 of the present invention for an equimolar mixture of carbon dioxide and nitrogen at 25°C;

[0046] Fig. 9This is the penetration curve of the activated TJE-6 material obtained in Example 3 of the present invention for an equimolar mixture of carbon dioxide and four other gases at 25°C. DETAILED DESCRIPTION

[0047] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0048] Embodiment 1:

[0049] This embodiment provides a method for preparing a metal organic framework material, which specifically includes the following steps:

[0050] (1) Weigh 83.1 mg (0.5 mmol) of the organic ligand isophthalic acid (ipa) and 106.1 mg (0.5 mmol) of 1,4-di(1H-1,2,4-triazol-1-yl)benzene (1dtab) and dissolve them in 100 mL of pure N,N-dimethylacetamide solvent. Dissolve them fully under ultrasonic vibration to obtain a mixed solution.

[0051] (2) Add 145.5 mg (0.5 mmol) of Co(NO3)2·6H2O to the above mixed solution and stir to dissolve to obtain a clear solution. Then transfer the clear solution to a 110 mL sealed bottle with a polytetrafluoroethylene gasket, heat it at 100 °C for 48 hours, and filter it using a glass sand core suction filtration device equipped with an organic phase filter membrane with a pore size of 0.2 μm after cooling to obtain a rose-red newly synthesized TJE-6 single crystal.

[0052] (3) In order to obtain TJE-6 with complete solvent removal, the obtained sample was washed three times with 30 mL of fresh methanol. Finally, the sample was filtered and dried, and then heated to 180 °C under vacuum conditions for 12 hours to obtain the activated TJE-6 material. The structure of the activated TJE-6 material was characterized, and the results are shown in Figure 1~Figure 3 The spatial structure of the activated TJE-6 material prepared is as follows: Figure 1 As shown; X-ray powder diffraction was used to analyze the activated TJE-6 material, and the results were consistent with the powder diffraction obtained by analytical structure simulation ( Figure 2 ). Thermogravimetric curves of materials before and after vacuum drying ( Figure 3 ) indicates that the material is fully activated and that the thermal stability of the material reaches above 350 °C.

[0053] (4) Performance testing

[0054] A. Measure the adsorption isotherms of activated TJE-6 for 10 common gases at 25 °C. The results are as follows: Figure 4 As shown in Figure 2, the saturated adsorption capacity of TJE-6 for carbon dioxide reached 39.81 mL·g -1 , which is significantly higher than the saturated adsorption capacity of other gases: nitrogen (N2, 3.24 mL·g -1 ), oxygen (O2, 1.67 mL·g -1 ), methane (CH4, 9.97 mL·g -1 )、H2(H2,0.023mL·g -1 ), argon (Ar, 2.26 mL·g -1 ), acetylene (C2H2, 18.33 mL·g -1 )、ethylene(C2H4,22.70 mL·g -1 ), ethane (C2H6, 23.01 mL·g -1 ), carbon monoxide (CO, 4.50 mL·g -1 ), showing extremely high adsorption selectivity. The ideal solution adsorption model selectivity (IAST selectivity) of the activated TJE-6 material for an equimolar binary mixture of carbon dioxide and various gases at 25 °C is calculated as follows Figure 5 This result indicates that the adsorption selectivity of activated TJE-6 material for carbon dioxide is much higher than that for other gases.

[0055] B. Repeat the measurement of carbon dioxide adsorption and desorption curves at 25 °C for 5 times, and vacuum activate at 100 °C for 30 minutes between each cycle. The results are shown in Figure 6 This result indicates that the activated TJE-6 material can be recycled at 100 °C.

[0056] C. 1 gram of activated TJE-6 material was loaded into a fixed bed adsorption column with a diameter of 6 mm (the specifications of the fixed bed adsorption column are stainless steel adsorption columns with an inner diameter of 6 mm, a wall thickness of 1 mm, and a length of 20 cm) to conduct a penetration experiment. In order to activate the material in situ, a 20 mL min -1 The nitrogen gas was heated and purged at 180 °C for 50 min at a flow rate of 2 mL·min. -1 An equimolar mixture of carbon dioxide and acetylene was introduced into the system at a total flow rate of . The effluent phase was collected from the outlet of the adsorption column at different time points, and the product concentration in these effluents was accurately quantitatively analyzed using gas chromatography. After completing a round of testing, the metal organic framework material was regenerated by heating and purging with nitrogen again. The above experiment was then repeated using a mixture of carbon dioxide and acetylene containing 50% relative humidity. The experimental results are shown in Figure 2. Figure 7The results show that the material achieves efficient separation of acetylene and carbon dioxide, and acetylene flows out of the adsorption column preferentially.

[0057] Embodiment 2:

[0058] This embodiment provides a method for preparing a metal organic framework material, which specifically includes the following steps:

[0059] (1) Weigh 166.1 mg (1 mmol) of the organic ligand isophthalic acid (ipa) and 212.2 mg (1 mmol) of 1,4-di(1H-1,2,4-triazol-1-yl)benzene (1dtab) and dissolve them in 80 mL of a mixed solvent of N,N-dimethylacetamide and methanol in a volume ratio of 3:1. Dissolve them fully under ultrasonic vibration to obtain a mixed solution.

[0060] (2) Add 91.5 mg (0.5 mmol) of Co(NO3)2 to the mixed solution and stir to dissolve to obtain a clear solution. The clear solution was then transferred to a 100 mL polytetrafluoroethylene-lined reactor and heated at 130 °C for 24 hours. After cooling, it was filtered using a Buchner funnel equipped with filter paper with a pore size of 5 μm, and then washed four times with 50 mL of fresh ethanol. Finally, the sample was filtered and dried, and then heated to 190 °C under vacuum conditions and dried for 24 hours to obtain the activated TJE-6 material. The activated TJE-6 material was analyzed by X-ray powder diffraction, and the results were consistent with the powder diffraction obtained by analytical structure simulation ( Figure 2 ), proving that the synthesis was successful.

[0061] (3) Performance testing

[0062] One gram of activated TJE-6 material was loaded into a fixed bed adsorption column with a diameter of 10 mm (the specifications of the fixed bed adsorption column are stainless steel adsorption columns with an inner diameter of 8 mm, a wall thickness of 1 mm, and a length of 20 cm) for penetration experiments. In order to activate the material in situ, 30 mL min -1 The argon gas was heated and purged at 150 °C for 30 min. Then, the argon gas was heated and purged at a flow rate of 2.0 mL·min at 25 °C. -1 A mixture of equimolar carbon dioxide and nitrogen was introduced into the system at a total flow rate of . The effluent phase was collected from the outlet of the adsorption column at different time points, and the product concentration in these effluents was accurately quantitatively analyzed using gas chromatography technology. After completing a round of testing, the metal organic framework material was regenerated by heating and purging with argon again. The experimental results are shown in Figure 2. Figure 8 As shown, the results prove that the material achieves efficient separation of nitrogen and carbon dioxide, and the nitrogen flows out of the adsorption column in a very short time while the carbon dioxide is captured.

[0063] Example 3

[0064] This embodiment provides a method for preparing a metal organic framework material, which specifically includes the following steps:

[0065] (1) Weigh 166.1 mg (1.0 mmol) of the organic ligand isophthalic acid (ipa) and 169.7 mg (0.8 mmol) of 1,4-di(1H-1,2,4-triazol-1-yl)benzene (1dtab) and dissolve them in 80 mL of a 1:1 mixed solvent of N,N-dimethylacetamide and methanol, and heat them at 70 °C to fully dissolve them to obtain a mixed solution.

[0066] (2) Add 145.5 mg (0.5 mmol) of Co(NO3)2·6H2O to the above mixed solution and stir to dissolve to obtain a clear solution. Then transfer the clear solution to a 100 mL sealed bottle, heat it at 90 °C for 3 days, and after cooling, filter it using a Buchner funnel equipped with filter paper with a pore size of 5 μm, and then wash it 4 times with 50 mL of fresh acetone. Finally, filter the sample and dry it, then heat it to 200 °C under vacuum conditions and dry it for 24 hours to obtain the activated TJE-6 material. The activated TJE-6 material was analyzed by X-ray powder diffraction, and the results were consistent with the powder diffraction obtained by analytical structure simulation ( Figure 2 ), proving that the synthesis was successful. The activated TJE-6 material was placed in humid air for 90 days and then measured again, and the diffraction pattern did not change ( Figure 2 ), indicating that the activated TJE-6 material has good air stability.

[0067] One gram of activated TJE-6 material was loaded into a fixed bed adsorption column with a diameter of 8 mm (the specifications of the fixed bed adsorption column are stainless steel adsorption columns with an inner diameter of 10 mm, a wall thickness of 1 mm, and a length of 20 cm) for penetration experiments. In order to activate the material in situ, 30 mL min -1 The argon gas was heated and purged at 180 °C for 30 min. Then, the argon gas was heated and purged at a flow rate of 2.5 mL·min at 25 °C. -1 A mixed gas of equimolar carbon dioxide, acetylene, ethylene, ethane, and methane was introduced into the system at a total flow rate of . The effluent phase was collected from the outlet of the adsorption column at different time points, and the product concentration in these effluents was accurately quantitatively analyzed using gas chromatography technology. After completing a round of testing, the metal organic framework material was regenerated by heating and purging with argon gas again. The experimental results are shown in Figure 2. Fig. 9 As shown, the results prove that the material achieves efficient carbon dioxide separation, with methane, acetylene, ethylene, and ethane flowing out of the adsorption column first, and carbon dioxide flowing out last.

[0068] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A metal organic framework material, characterized in that: The metal organic framework material is named TJE-6, and its chemical structure is The arrows represent coordination bonds, and the lone pair of electrons on N coordinates to Co. The chemical formula is [Co(ipa)(1dtab)] n , where Co represents the metal center cobalt; ipa represents the organic ligand isophthalic acid, and the structural formula is 1dtab represents the organic ligand 1,4-di(1H-1,2,4-triazol-1-yl)benzene, with the structural formula n indicates that the metal organic framework material is a polymer.

2. The metal organic framework material according to claim 1, characterized in that: The cobalt in the metal organic framework material is 6-coordinated, and two cobalts are coordinated through the carboxyl bridge of two ipa ligands to form a one-dimensional chain structure. Then, each cobalt is coordinated with the N of one triazole from two 1dtab ligands in a plane perpendicular to the chain to form a planar layered structure. Then, the layered structures are interdigitated and stacked to form a spatial structure; the cobalt does not form an open metal site.

3. The metal organic framework material according to claim 1, characterized in that: The metal organic framework material has a two-dimensional layered structure and periodic S-shaped one-dimensional pores, and nitrogen atom action sites are distributed on the surface of the one-dimensional pores.

4. The metal organic framework material according to claim 3, characterized in that: The cross-sectional aperture of the one-dimensional channel is 5. The method for preparing the metal organic framework material according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: The organic ligand isophthalic acid and 1, 4-di(1H-1,2,4-triazol-1-yl)benzene is dissolved in an organic solvent, and a cobalt source is added to dissolve to obtain a mixed solution; S2: heating the mixed solution obtained in step S1 for reaction, and after the reaction is completed, performing solid-liquid separation to obtain a solid phase, and washing the solid phase with a low boiling point solvent; S3: vacuum drying and heating the solid phase obtained in step S2 to remove the solvent, thereby obtaining the metal organic framework material.

6. The preparation method according to claim 5, characterized in that: In step S1, the organic solvent includes N,N-dimethylacetamide and methanol, and the volume ratio of N,N-dimethylacetamide to methanol is 1:1 to 1:0; The cobalt source is selected from Co(NO3)2 hydrate and / or Co(NO3)2 hydrate; Cobalt source and organic ligand isophthalic acid, 1, The molar ratio of 4-di(1H-1,2,4-triazol-1-yl)benzene is (1:1:1) to (1:2:2).

7. The preparation method according to claim 5, characterized in that: In step S2, the heating reaction temperature is 90-130° C., and the reaction time is not less than 24 hours.

8. Use of the metal organic framework material according to any one of claims 1 to 4 in separating carbon dioxide from a multi-component mixture.

9. The use according to claim 8, characterized in that: The method of application includes the following steps: A1: The metal organic framework material is loaded into an adsorption column and compacted, and activated by heating and purging with an inactive gas, and a mixed gas containing carbon dioxide is introduced into the adsorption column; A2: After the metal organic framework material adsorbs and captures carbon dioxide in the mixed gas, other components in the mixed gas preferentially pass through the bed layer to achieve separation of carbon dioxide; A3: The metal organic framework material used in step A2 is heated and purged with an inert gas to achieve the recycling of the metal organic framework material.

10. The use according to claim 9, characterized in that: The inner diameter of the adsorption column is 6-10 mm; The mixed gas containing carbon dioxide includes one or more of nitrogen, oxygen, methane, hydrogen, argon, acetylene, ethylene, ethane, and carbon monoxide; The volume content of carbon dioxide in the carbon dioxide-containing mixed gas is 1% to 99%; The speed of introducing the mixed gas containing carbon dioxide is 2-4 mL·min -1 ; The inert gas is selected from nitrogen and / or helium; The temperature of the heating and purging is 150-180°C and the time is not less than 30 minutes.

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