KR20190076891A - Polymer-coated amine-grafted MOF adsorbents for carbon dioxide capture and their preparation - Google Patents

Abstract

The present invention relates to a carbon dioxide adsorbent based on amine-grounded MOF coated with polymer. More specifically, the carbon dioxide adsorbent based on amine-grounded MOF coated with polymer is able to: effectively reduce renewable energy generated during carbon dioxide adsorption and desorption processes; and collect carbon dioxide effectively in an actual fluidized bed by maintaining structural stability from moisture present in exhaust gas. The carbon dioxide adsorbent and the producing method thereof: use Mg, Mn, Fe, Co, Ni, Cu, or Zn as the metal of a porous metal-organic framework; effectively reduce renewable energy generated in carbon dioxide adsorption and desorption processes by coating the surface of the porous metal-organic framework with a hydrophobic polymer; and maintain structural stability from moisture.

Description

TECHNICAL FIELD [0001] The present invention relates to an amine-ground MOF-based carbon dioxide adsorbent coated with a polymer material and a method for producing the same,

The present invention relates to an amine ground MOF-based carbon dioxide adsorbent coated with a polymer material, and more particularly to a carbon dioxide adsorbent which is capable of effectively reducing the renewable energy generated during the carbon dioxide adsorption and desorption process and maintaining the structural stability from the water present in the exhaust gas. Based MOF-based carbon dioxide adsorbent coated with a polymer material capable of effectively capturing carbon dioxide in an actual fluidized bed.

30-40% of CO ₂ emissions, which are the main cause of global warming, are generated in thermal power plants and the CO ₂ concentration in the flue gas is 150 mbar. In the fluidized bed for efficient adsorption between the gas and the solid adsorbent, the adsorption process proceeds from the bottom of the bed, and the CO ₂ concentration decreases to about 30 mbar when it reaches the top of the bed. Therefore, the solid adsorbent used in the fluidized bed should be able to adsorb at a wide range of CO ₂ concentrations.

In addition, after the adsorption process, the adsorbent is transferred to the regenerator and reactivated. However, the conventional adsorbents have problems in the reuse because the desorption process is not performed well in the high concentration CO ₂ and low temperature environment. Therefore, researches have been made actively on adsorbents capable of high desorption at high concentration as well as high adsorption ability at low concentration.

Metal-Organic Frameworks (MOF) in solid adsorbents are crystalline solids composed of coordination of metals and ligands. They have a large surface area and can regulate the pores. As an effective adsorbent for CO ₂ capture Research has been carried out to use this catalyst and it has been reported that introduction of an amine group into MOF greatly improves the adsorption ability through chemical bonding between carbon atoms of amine group and carbon dioxide.

However, in order to apply the MOF to the actual CO2 capture process, the following conditions must be satisfied.

The first is to reduce capture energy. This is a matter that must be considered for practical application, and it is necessary to reduce the energy of capturing carbon dioxide by exchanging heat generated during adsorption and desorption. That is, when the difference between the carbon dioxide adsorption temperature and the desorption temperature is small, it is possible to effectively reduce the renewable energy generated in the process of absorbing and desorbing carbon dioxide. If the adsorption and desorption temperature difference (ΔT) can be made at a level of 30 ° C. or lower, it is not necessary to exchange sensible heat, so that the carbon dioxide capture energy can be drastically reduced.

Second, stability should be maintained under moisture conditions. Carbon dioxide, which is the main cause of global warming, is emitted mainly through thermal power plants. The composition of the exhaust gas emitted from the power plant is about 15% of carbon dioxide and about 75% of nitrogen, and carbon dioxide and nitrogen have 90% About 10% of the combustion gas is also present. Among them, water occupies about 5 to 7%. When water vapor is present in the process of adsorbing carbon dioxide, MOF may cause a substitution reaction between the adsorbed carbon dioxide and water, and the metal-ligand bond breaks, Can be lost. In addition, acidic gases such as sulfur dioxide (SO ₂ ), nitrogen dioxide (NO ₂ ), and the like, which are present in a trace amount, may change into strong acids when they are in contact with water, thereby affecting the MOF structure. As a result, these components can affect the MOF structure and consequently have a direct impact on the carbon dioxide adsorption capacity. Therefore, it is required to develop a carbon dioxide adsorbent capable of maintaining structural stability from the moisture and acid gas contained in the power plant flue gas.

Korean Patent Publication No. 10-2015-0007484

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-mentioned problems, and an object of the present invention is to provide a carbon dioxide adsorbent capable of effectively reducing the renewable energy generated during carbon dioxide adsorption and desorption processes and maintaining structural stability from moisture, .

In order to solve the above problems,

A polyhydric amine is introduced into the porous metal containing a primary amine-organic framework material; including, and the porous metal-organic framework material is _{M 2 (dobpdc), M 2} (dobdc), M 2 (dondc) and M ₂ ( dotpdc). < / RTI >< RTI ID = 0.0 >

Wherein dobpdc is 4,4'-dioxido-3,3'-biphenyldicarboxylate, and dobdc is 2,5-di Oxydo-1,4-benzenedicarboxylate, dondc is 1,5-dioxide-2,6-naphthalenedicarboxylate, and dotpdc is 4,4'-dioxido-3,3'-triphenyldicarboxylate It is a decay rate.

According to the present invention, the surface of the porous metal-organic skeleton may be selected from the group consisting of polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF) Or at least one selected hydrophobic polymer material may be coated.

The present invention also relates to a process for preparing a poly (organophosphazene) comprising the steps of: (a) mixing a poly (organophosphazene) with a poly (organophosphazene), an organic solvent and a polyamine having a primary amine group; And (b) obtaining a porous metal-organic skeleton in which a polyamine having a primary amine group is introduced from the reactant, wherein the porous metal-organic skeleton is selected from the group consisting of M ₂ (dobpdc), M ₂ ), M ₂ (dondc), and M ₂ (dotpdc). The carbon dioxide adsorbent is preferably selected from the group consisting of:

Wherein dobpdc is 4,4'-dioxido-3,3'-biphenyldicarboxylate, and dobdc is 2,5-di Oxydo-1,4-benzenedicarboxylate, dondc is 1,5-dioxide-2,6-naphthalenedicarboxylate, and dotpdc is 4,4'-dioxido-3,3'-triphenyldicarboxylate It is a decay rate.

According to the present invention, the step (b) comprises the steps of: (b1) centrifuging the reaction product to obtain a white solid; And (b2) washing and pretreating the white solid.

According to the present invention, after the step (b), (c) the surface of the porous metal-organic skeleton into which the polyamine having the primary amine group is introduced is polydimethylsiloxane (PDMS), polytetrafluoroethylene , Polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and the like.

According to the present invention, the polyhydric amine may be selected from compounds represented by the following general formulas (1) to (15).

[Chemical Formula 1 to Chemical Formula 15]

According to the present invention, by using Mg, Mn, Fe, Co, Ni, Cu, or Zn as the metal of the porous metal-organic skeleton and coating the surface of the porous metal-organic skeleton with the hydrophobic polymer, The present invention can provide a carbon dioxide adsorbent capable of effectively reducing the regeneration energy generated from the carbon dioxide adsorbent and maintaining the structural stability from moisture and a method for producing the carbon dioxide adsorbent.

Figure 1 is a graph of CO ₂ adsorption isotherms according to temperature of amine-functionalized MOFs per metal ((a) een-Mg ₂ (dobpdc) linear scale, (c) een-Mn ₂ (dobpdc) linear scale, _{Co 2 (dobpdc) linear scale,} (g) een-Ni 2 (dobpdc) linear scale, (i) een-Zn 2 (dobpdc) linear scale, (b) een-Mg 2 (dobpdc) log scale, (d) _{een-Mn 2 (dobpdc) log} scale, (f) een-Co 2 (dobpdc) log scale, (h) een-Ni 2 (dobpdc) log scale, (j) een-Zn 2 (dobpdc) log scale graph) .
FIG. 2 is a graph showing carbon dioxide adsorption curves through thermogravimetric analysis (TGA) of amine functionalized MOFs per metal. FIG.
3 is a Thermer step graph for measuring the desorption temperature of een-Mn ₂ (dobpdc) (a) and een-Mg ₂ (dobpdc) (b).
4 is a graph showing adsorption isotherms of een-Mn ₂ (dobpdc) (a) and een-Mg ₂ (dobpdc) (b) at 60 and 120 ° C.
5 is a graph showing the working capacity of een-Mn ₂ (dobpdc) according to the adsorption and desorption temperatures.
FIG. 6 is a graph showing a TSA (Temperature-Swing Adsorption) cycle of een-Mn ₂ (dobpdc) under the condition that the temperature difference between adsorption and desorption is 30 ° C.
7 is a view showing the structure of the PDMS used in the present invention.
8 is IR spectra of een-Mn ₂ (dobpdc) and een-Mn @ PDMS5D, 10D, 20D, 50D (a), een-Mn @ PDMS5S, 10S, 20S and 50S (b).
9 is a PXRD graph of een-Mn ₂ (dobpdc) and een-Mn @ PDMS5D, 10D, 20D, 50D (a), een-Mn @ PDMS5S, 10S, 20S and 50S (b).
10 is a TEM image of een-Mn ₂ (dobpdc) (a), een-Mn @ PDMS20D (b), and een-Mn @ PDMS20S (c).
Figure 11 is _{een-Mn 2 (dobpdc) (} a), een-Mn @ PDMS5D (b), een-Mn @ PDMS10D (c), een-Mn @ PDMS20D (d), een-Mn @ PDMS50D (e), The contact angles of een-Mn @ PDMS5S (f), een-Mn @ PDMS10S (g), een-Mn @ PDMS20S (h) and een- Mn @ PDMS50S (i).
(D), een-Mn @ PDMS5S (e), een-Mn @ PDMS5D (b), een- Mn @ PDMS10S (f), een-Mn @ PDMS20S (g), and een-Mn @ PDMS50S (h).
Figure 13 shows the STEM image of een-Mn ₂ (dobpdc) (a), een-Mn @ PDMS20D (c), een-Mn @ PDMS20S (e), een- , and een-Mn @ PDMS20S (f).
FIG. 14 shows line scan results of een-Mn @ PDMS20D (a) and een-Mn @ PDMS20S (b).
15 is a graph showing adsorption amount of carbon dioxide before and after PDMS coating by thermogravimetric analysis (TGA) of een-Mn @ PDMSD series adsorbent (a) and een-Mn @ PDMSS series adsorbent (b).
FIG. 16 shows the water exposure test results of een-Mn @ PDMS20D (a) and een-Mn @ PDMS20S (b).
Figure 17 shows the adsorbent deposited at temperatures of 140 ° C (a), 200 ° C (b), and 235 ° C (c), respectively, as a result of testing the moisture resistance of the adsorbent coated by vapor deposition at different deposition temperatures.
18 is a schematic view showing a method of coating a surface of a MOF by a deposition method using PDMS according to the present invention.
19 is a schematic view showing a method of coating a surface of a MOF by a dipping method using PDMS according to the present invention.
20 is a graph of carbon dioxide adsorption performance using TEN of een-Mn ₂ (dobpdc), een-Mn @ PFTE and een-Mn @ PVDF.

Hereinafter, the present invention will be described in more detail.

The present invention provides a carbon dioxide adsorbent capable of effectively reducing the regeneration energy generated during carbon dioxide adsorption and desorption processes and maintaining structural stability from moisture, and a method for producing the same.

The porous metal-organic skeleton includes M ₂ (dobpdc), M ₂ (dobdc), M ₂ (dondc), and the like. ) And M < ₂ > (dotpdc).

Wherein dobpdc is 4,4'-dioxido-3,3'-biphenyldicarboxylate, and dobdc is 2,5-di Oxydo-1,4-benzenedicarboxylate, dondc is 1,5-dioxide-2,6-naphthalenedicarboxylate, and dotpdc is 4,4'-dioxido-3,3'-triphenyldicarboxylate It is a decay rate.

As described above, the present invention can reduce the temperature difference when the carbon dioxide is adsorbed and desorbed by using Mn, Co, Ni, Zn or the like in addition to Mg, which is conventionally widely used as the metal material of the porous metal-organic skeleton, And carbon dioxide capture energy can be reduced through the reduction of renewable energy generated in the desorption process.

Further, in order to ensure structural stability from the moisture and acid gas contained in the exhaust gas, it is preferable to coat the surface of the porous metal-organic skeleton with a hydrophobic polymer material. At this time, the hydrophobic polymer material may be at least one selected from the group consisting of polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF) Preferably PDMS.

The porous metal-organic skeleton is preferably one having a polyamine introduced with a primary amine group. The amine functionalization of these porous metal-organic skeletons allows the carbon dioxide sorbent to capture low concentrations of carbon dioxide. Particularly, in order to trap carbon dioxide in the air, it is preferable to use a porous metal-organic skeleton in which a high-density amine group is introduced. The enthalpy of adsorption due to the interaction between the amine group and the carbon atom of CO ₂ can be remarkably improved through the introduction of the high density amine group. This amine functionalization is accomplished by grafting amine groups to the open metal sites of the porous metal-organic skeleton and the open metal sites serve as Lewis acids. In this case, the primary amine group can be well coordinated to open metal sites by containing two hydrogen groups. In addition, the remaining free amine groups can effectively trap the incoming CO ₂ .

The polyamines according to the present invention may have two, three, or more amine-terminated ends. More specifically, the polyhydric amines may include primary amine groups at each of the two ends. In the case of polyamines having primary amine groups at both ends, it is possible to introduce various substituents into the side branches. At low pressure, the carbon dioxide adsorption can be easily controlled through the primary amine group and the carbon dioxide desorption can be easily controlled through the side branches. In particular, the side chain present in the polyvalent amine can play an important role in improving the structural stability of the adsorbent by interfering with the decomposition of the bond between the porous metal-organic skeleton and the amine. On the other hand, the free amine group of the polyvalent amine may be a primary amine.

Specifically, the polyvalent amine of the present invention can be selected from the compounds represented by the following general formulas (1) to (15).

[Chemical Formula 1 to Chemical Formula 15]

Also, the present invention provides a method for producing a carbon dioxide adsorbent capable of effectively reducing the regenerated energy generated in the process of adsorbing and desorbing carbon dioxide and maintaining the structural stability from moisture, and a method of producing the carbon dioxide adsorbent according to the present invention And includes the following steps.

(a) mixing with a polyvalent amine containing a porous metal-organic skeleton, an organic solvent and a primary amine group, followed by reaction with an ultrasonic mill; And

(b) obtaining a porous metal-organic skeleton into which a polyamine containing a primary amine group is introduced from the reaction product.

At this time, the contents of the porous metal-organic skeleton and the polyvalent amine are the same as those described in the carbon dioxide adsorbent.

The step (b) may further include: (b1) centrifuging the reaction product to obtain a white solid; And (b2) washing and pretreating said white solid.

(C) the surface of the porous metal-organic skeleton into which the polyamine having a primary amine group is introduced is polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), fluorine And at least one hydrophobic polymer material selected from the group consisting of polyvinylidene fluoride (PVDF).

At this time, the hydrophobic polymer material can be coated by any conventional method known in the art, but a vapor deposition method or a dipping method may be used.

In addition, when the hydrophobic polymer material is coated using a deposition method, the deposition temperature is preferably 220 to 240 ° C. The amount of the hydrophobic polymer used is preferably 15-30 parts by weight based on 100 parts by weight of the porous metal-organic skeleton obtained through the step (b).

When the hydrophobic polymer material is coated using the immersion method, hexane, toluene, diethyl ether, or a mixture thereof may be used as the solvent. The solvent may be a porous material obtained through the step (b) It is preferred to use 1 to 3 mL based on 100 mg of the metal-organic skeleton. The amount of the hydrophobic polymer used is preferably 15-30 parts by weight based on 100 parts by weight of the porous metal-organic skeleton obtained through the step (b).

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments and the like. It will be apparent to those skilled in the art, however, that these examples are provided for further illustrating the present invention and that the scope of the present invention is not limited thereto.

Example .

[M ₂ ( dobpdc )] (M = Mg, Mn, Co, Ni  Or Zn)

The skeleton of M ₂ (dobpdc) was prepared by dissolving H ₄ dobpdc (4,4'-Dihydroxy- [1,1'-byphenyl-3,3'-dicarboxylic acid]) and MX ₂ · yH ₂ O in DMF and ethanol , And synthesized by microwave reaction under different conditions. Since DMF is coordinated to the metal in the synthesized M ₂ (dobpdc) -DMF, the amine is easily grounded by replacing it with methanol. Specific synthesis conditions are shown in Table 1 below.

[ een -M ₂ ( dobpdc )] (M = Mn, Co, Ni , Zn)

 (1) een-Mn ₂ (dobpdc)

[Mn ₂ (dobpdc) (DMF) ₂ ] was placed in MeOH for 3 days, and the sample and MeOH were separated and dried using a vacuum filtration apparatus. 100 ml of dry Mn ₂ (dobpdc) was added to a 1-necked flask, and 100 ml of toluene and 50 equivalents of N-ethylethylenediamine (hereinafter referred to as een; 1.4 ml, 13.22 mmol) were mixed and reacted for 12 hours using an ultrasonic mill. After completion of the reaction, a white solid was separated using a centrifuge, washed several times with toluene and hexane, and then pre-treated at 100 ° C under vacuum to obtain 144 mg of een-Mn ₂ (dobpdc) Respectively.

(2) een-Co ₂ (dobpdc)

[Co ₂ (dobpdc) (DMF) ₂ ] was placed in MeOH for 3 days, and the sample and MeOH were separated and dried using a vacuum filtration apparatus. 100 ml of dry Co ₂ (dobpdc) was added to a 1-necked flask, and 100 ml of toluene and 50 equivalents of N-ethylethylenediamine (hereinafter referred to as een; 1.36 ml, 12.95 mmol) were mixed and reacted for 12 hours using an ultrasonic grinder. After completion of the reaction, a white solid was separated using a centrifuge, washed several times with toluene and hexane, and then pre-treated at 120 ° C under vacuum to obtain een-Co ₂ (dobpdc).

(3) een-Ni ₂ (dobpdc)

[Ni ₂ (dobpdc) (DMF) ₂ ] was placed in MeOH for 3 days, and the sample and MeOH were separated and dried using a vacuum filtration apparatus. 100 ml of dry Ni ₂ (dobpdc) was added to a 1-necked flask, and 100 ml of toluene and 50 equivalents of N-ethylethylenediamine (hereinafter referred to as een; 1.37 ml, 12.96 mmol) were mixed and reacted for 12 hours using an ultrasonic grinder. After completion of the reaction, a white solid was separated using a centrifuge, washed several times with toluene and hexane, and then pre-treated at 120 ° C under vacuum to obtain een-Ni ₂ (dobpdc).

(4) een-Zn ₂ (dobpdc)

[Zn ₂ (dobpdc) (DMF) ₂ ] was placed in MeOH for 3 days, and the sample and MeOH were separated and dried using a vacuum filtration apparatus. 100 ml of dry Zn ₂ (dobpdc) was added to a 1-necked flask, and 100 ml of toluene and 50 equivalents of N-Ethylethylenediamine (hereinafter referred to as een; 1.38 ml, 12.95 mmol) were mixed and reacted for 12 hours using an ultrasonic mill. After completion of the reaction, a white solid was separated using a centrifuge, washed several times with toluene and hexane, and then pre-treated at 120 ° C under vacuum to obtain een-Zn ₂ (dobpdc).

PDMS  Coated [ een -M ₂ ( dobpdc )] [Een-Mn @ PDMSD] (vapor deposition method)

100 mg of the synthesized een-Mn ₂ (dobpdc) was placed in a test tube, and the same test tube (PDMS 5 mg, 10 mg, 20 mg, and 50 mg) After the test tube was vacuumed, the test tube inlet was heated and sealed. The sealed test tube was heated so that PDMS was deposited on the surface of een-Mn ₂ (dobpdc), and the reaction time was 6 hours to prepare [een-Mn @ PDMSD] (see FIG.

At this time, the deposition temperature was determined to be 235 ° C (c), which is the highest stability temperature after exposure to 100% relative humidity for 1 hour when the moisture stability test was performed after synthesis. PDMS The samples synthesized using 5 mg of een-Mn @ PDMS5D and 10 mg of PDMS were synthesized using een-Mn @ PDMS10D and PDMS 20 mg. The samples were synthesized using een-Mn @ PDMS20D and PDMS 50 mg. One sample was named een-Mn @ PDMS50D.

PDMS  Coated [ een -M ₂ ( dobpdc )] [Een-Mn @ PDMSS] ( Dipping method )

PDMS was dissolved in the solvent by adjusting the ratio (weight ratio) of een-Mn ₂ (dobpdc) PDMS (PDMS 5 mg, 10 mg, 20 mg, and 50 mg). A 100 mg sample of een-Mn ₂ (dobpdc) was added to the mixed solvent, which was sufficiently dissolved, and the mixture was evenly mixed using an ultrasonic grinder. The solvent mixed with een-Mn ₂ (dobpdc) was dried under a nitrogen condition, and a solid powder sample was taken and stored (see FIG. 18).

At this time, samples synthesized using PDMS 5 mg according to the amount of PDMS used in synthesis were een-Mn @ PDMS5S and PDMS 10 mg, and samples synthesized using een-Mn @ PDMS10S and PDMS 20 mg were een -Mn @ PDMS20S and PDMS 50 mg were designated as een-Mn @ PDMS50S.

een -M ₂ ( dobpdc ) Carbon Dioxide Adsorption Capacity Evaluation

Measuring the Mn, Co, Ni, carbon dioxide absorption curves of one een-M ₂ (dobpdc) and een-Mg ₂ (dobpdc) synthesized by using a Mg synthesized using Zn was shown in Figure 1 to the result. Measurement results, 25 ℃, carbon dioxide absorption amount in 1 atmosphere of carbon dioxide adsorption amount of een-Mg ₂ (dobpdc) widely used as a conventional carbon dioxide adsorbent is 4.76 mmol / g (17.3 wt% ) and, een-Mn ₂ (dobpdc) Was 4.65 mmol / g (17.0 wt%).

The adsorption performance of een-Mn ₂ (dobpdc) at 25 ° C and 0.15 atmospheric pressure is 3.72 mmol / g (14.1 wt%) in the range of partial pressure of carbon dioxide (0.15 atm) in general postcombustion. (3.75 mmol / g (14.2 wt%)) than that of een-Mg ₂ (dobpdc) (Fig. 1).

Next, thermogravimetric analysis (TGA) of the amine functionalized MOF for each metal was carried out, and the results are shown in FIG. Specifically, after putting the sample in the TGA equipment, it was heated for 120 minutes at each pretreatment condition temperature to remove all the carbon dioxide and water in the sample exposed to the air. After cooling the sample to 40 ° C, 15% And the adsorption amount was measured. As a result, it was confirmed that the adsorption amount of een-Mn ₂ (dobpdc) was similar to that of een-Mg ₂ (dobpdc).

een - Mn ₂ (dobpdc)  Working capacity and Absorption / desorption  Behavior control

Working capacity refers to the actual amount of carbon dioxide adsorbed during the TSA measurement and represents the actual determinant of the material properties in post-combustion carbon dioxide capture. For this reason, it is desirable to select the adsorbent based on the working capacity rather than the net carbon dioxide adsorption amount.

To measure the working capacity, pretreatment was carried out at 100% CO 2 condition and at the pretreatment temperature of MOF. Next, the process of obtaining the optimum desorption temperature of the MOF adsorbent for measuring the working capacity was performed. Specifically, the MOF adsorbent was pretreated in accordance with each pretreatment condition, and then subjected to a process of adsorbing carbon dioxide by exposure to 100% carbon dioxide at 40 ° C. for 1 hour. The optimum desorption temperature of MOF was derived by analyzing the desorption characteristics of carbon dioxide while increasing the temperature to 200 ° C by 10 ° C. This een-Mg ₂ (dobpdc) proper desorption temperature is in the proper desorption temperature is een-Mn ₂ (dobpdc) a low desorption temperature of 100-110 ℃ _{130-140 ℃, een-Mn 2 (} dobpdc) working capacity of (Fig. 3).

Next, the isotherms of een-Mg ₂ (dobpdc) and een-Mn ₂ (dobpdc) were compared with adsorption at 60 ° C and 120 ° C. As a result of the measurement, it was confirmed that the working capacity of een-Mn ₂ (dobpdc) according to the present invention was superior to that of een-Mg ₂ (dobpdc) under the same conditions (FIG. 4).

Based on these results, the working capacity of een-Mn ₂ (dobpdc) according to the present invention was investigated according to the adsorption and desorption temperature differences. The desorption temperature was fixed at 80, 90, 100, and 110 ℃ and the working capacity was investigated while increasing the adsorption temperature. The larger the ΔT, the higher the working capacity. As a result, it was confirmed that the working capacity was more than 10 wt% at the adsorption temperature of 70 ℃ and the desorption temperature of 100 ℃, ΔT = 30 ℃. As a result, the een-Mn ₂ (dobpdc) adsorbent according to the present invention exhibits excellent working capacity under the condition of ΔT = 30 ° C., and thus it is possible to effectively capture carbon dioxide while minimizing sensible heat exchange (FIG. 5).

Temperature-Swing Adsorption ( TSA ) cycle

The temperature-swing adsorption (TSA) cycle of een-Mn ₂ (dobpdc) was measured under the condition that the temperature difference between adsorption and desorption was 30 ° C. (ΔT = 30 ° C.), and the results are shown in FIG. Specifically, when for 5 minutes adsorption in 15% CO _2, 70 ℃ with respect to the sample and for 1 minute desorption from the CO ₂ 100%, 100 ℃ and hayeoteul repeated measures more than 600 times, showed only a degradation of 0.34 wt% 14 wt % Higher working capacity.

Investigation of the components of een-Mn @ PDMSD and een-Mn @ PDMSS

(Een-Mn @ PDMSD) by evaporating PDMS having the structure shown in Fig. 7 as a silicon-based organic polymer on the MOF surface or removing solvent molecules from a solution containing PDMS (een-Mn @ The adsorbent with improved stability from moisture was prepared through PDMSS and experiments were conducted to confirm that PDMS was coated on the MOF surface.

Fig. 8 is an IR spectrum of een-Mn ₂ (dobpdc), een-Mn @ PDMSD (a), and een-Mn @ PDMSS (b). This was observed for Si-CH ₃ rocking mode in the Si-CH ₃ symmetric bending mode, 850-860cm ^-1 in the vicinity of the CH stretching mode and 1250-1260cm ^-1 2900-3000cm ^-1 near the methyl group.

9 is a PXRD graph of een-Mn ₂ (dobpdc), een-Mn @ PDMSD (a), and een-Mn @ PDMSS (b). As a result, it was confirmed that the structure of MOF remains stable even after PDMS coating.

10 is a TEM image of een-Mn ₂ (dobpdc) (a), een-Mn @ PDMS20D (b), and een-Mn @ PDMS20S (c). Through this, it was visually confirmed that PDMS was well coated on the MOF surface. Unlike the een-Mn ₂ (dobpdc) shown in FIG. 10A, the een-Mn @ PDMS20D, een-Mn @ PDMS20S shown in FIGS. 10B and 10C, Was deposited on the surface and was found to surround the surface.

11 shows the contact angles of een-Mn ₂ (dobpdc) and een-Mn ₂ (dobpdc) @PDMSD, een-Mn ₂ (dobpdc) @PDMSS. As a result, een-Mn ₂ (dobpdc) absorbed water immediately after (a) dropping water droplets, confirming that een-Mn ₂ (dobpdc) was made of a hydrophilic material. However, in the case of een-Mn ₂ (dobpdc) @PDMSD (be), een-Mn ₂ (dobpdc) @PDMSS (fi) which have been coated with PDMS, the droplets are not absorbed Respectively. As a result, it was confirmed that the hydrophobic material was well coated on the MOF surface.

Fig. 12 is a comparison of XPS graphs of een-Mn ₂ (dobpdc) and een-Mn ₂ (dobpdc) @ PDMSD (ad) and een-Mn ₂ (dobpdc) @PDMSS (eh). As a result, the peak of Si, which is the main component of PDMS, was observed for the coated samples, and it was confirmed that the MOF surface contained Si material.

Next, the element distribution of een-Mn ₂ (dobpdc) and een-Mn ₂ (dobpdc) @PDMSD and een-Mn ₂ (dobpdc) @PDMSS was observed through TEM (transmission electron microscopy) 13 are shown in Fig. (A) of Figure 13 is PDMS coating former STEM image of _{een-Mn 2 (dobpdc),} (b) is a PDMS coating former EDS mapping image of _{een-Mn 2 (dobpdc),} (c) is een-Mn ₂ (dobpdc ) @ STEM image of PDMS20D, (d) is _{een-Mn 2 (dobpdc) @} EDS mapping image of PDMS20D, (e) is _{een-Mn 2 (dobpdc) @} STEM image of PDMS20S, (d) is een-Mn ₂ (dobpdc) This is the EDS mapping image of @ PDMS20S. As a result, it was confirmed that Si (green) of PDMS was distributed around een-Mn ₂ (dobpdc) (red), and PDMS was well coated on the surface of een-Mn ₂ (dobpdc) Respectively.

Next, linescan was performed based on the above EDS mapping result, and the results are shown in FIG. This in een-Mn @ PDMSD (a) , een-Mn @ PDMSS (b) high and a relatively outer surface, the intensity of Si in all, a central portion is measured by the intensity of Mn high een-Mn ₂ (dobpdc) outer surface by Si element was observed to be distributed, and it was confirmed that PDMS was well coated on the surface of een-Mn ₂ (dobpdc).

Performance of een-Mn @ PDMSD and een-Mn @ PDMSS

Fig. 15 shows the results of adsorption of een-Mn2 (dobpdc), een-Mn @ PDMSD, and een-Mn @ PDMSS on carbon dioxide, which was measured using a thermogravimetric analyzer.

In the case of een-Mn @ PDMSD (a), een-Mn @ PDMS5D and een-Mn @ PDMS10D, which have low content of PDMS, showed a low carbon dioxide adsorption amount, which was vaporized into the sealed test tube in the high- It is because it came out. In the case of een-Mn @ PDMS20D, it was confirmed that vaporized PDM molecules can reduce the loss of een by filling the inside of the test tube, and thus it is possible to synthesize a coating adsorbent exhibiting a carbon dioxide adsorption amount of 10 wt% or more. On the other hand, in the case of een-Mn @ PDMS50D, it was confirmed that the amount of PDMS was too large to reduce the amount of carbon dioxide adsorbed by weight.

In the case of een-Mn @ PDMSS (b), as the content of PDMS increased, the amount of adsorbed carbon dioxide was decreased due to the high proportion of the polymer in the absorbent. In Fig. 11, it was confirmed that hydrophobicity was generated from een-Mn @ PDMS20S. Therefore, it was confirmed that the adsorbent having moisture resistance due to polymer coating and carbon dioxide adsorption capability of 10 wt% or more was een-Mn @ PDMS20S.

Water stability of een-Mn @ PDMSD and een-Mn @ PDMSS

Figure 16 shows the results of water exposure stability tests of een-Mn ₂ (dobpdc) and een-Mn @ PDMSD, een-Mn @ PDMSS. The adsorbent coated at 100% relative humidity was exposed, And the change of the carbon dioxide adsorption amount was measured.

In the case of een-Mn @ PDMSD (a), there was no decrease in performance as compared to een-Mn ₂ (dobpdc), which decreased carbon dioxide adsorption performance up to one hour. As a result, it was confirmed that the polymer coating film synthesized by the vapor deposition method effectively prevented penetration of water molecules.

In the case of een-Mn @ PDMSS (b), there was no decrease in performance as compared to een-Mn ₂ (dobpdc), in which the adsorption capacity of carbon dioxide was reduced by up to one hour. As a result, it was confirmed that the polymer coating film synthesized by the immersion method effectively prevented the penetration of water molecules.

Claims (7)

A porous metal-organic skeleton into which a polyamine having a primary amine group is introduced,
Wherein the porous metal-organic skeleton is selected from the group consisting of M ₂ (dobpdc), M ₂ (dobdc), M ₂ (dondc) and M ₂ (dotpdc)
Wherein dobpdc is 4,4'-dioxido-3,3'-biphenyldicarboxylate, and dobdc is 2,5-di Oxydo-1,4-benzenedicarboxylate, dondc is 1,5-dioxide-2,6-naphthalenedicarboxylate, and dotpdc is 4,4'-dioxido-3,3'-triphenyldicarboxylate It is a decay rate. The method according to claim 1,
The surface of the porous metal-organic skeleton may be at least one selected from the group consisting of polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF) A carbon dioxide adsorbent characterized by being coated with a hydrophobic polymer material. The method according to claim 1,
Wherein the polyvalent amine is selected from compounds represented by the following general formulas (1) to (15).
[Chemical Formula 1 to Chemical Formula 15]

(a) mixing with a polyvalent amine containing a porous metal-organic skeleton, an organic solvent and a primary amine group, followed by reaction with an ultrasonic mill; And
(b) obtaining a porous metal-organic skeleton into which a polyamine having a primary amine group is introduced from the reaction product,
Wherein the porous metal-organic skeleton is selected from the group consisting of M ₂ (dobpdc), M ₂ (dobdc), M ₂ (dondc) and M ₂ (dotpdc)
Wherein dobpdc is 4,4'-dioxido-3,3'-biphenyldicarboxylate, and dobdc is 2,5-di Oxydo-1,4-benzenedicarboxylate, dondc is 1,5-dioxide-2,6-naphthalenedicarboxylate, and dotpdc is 4,4'-dioxido-3,3'-triphenyldicarboxylate It is a decay rate. 5. The method of claim 4,
Wherein the step (b) comprises: (b1) centrifuging the reaction product to obtain a white solid; And (b2) washing and pre-treating the white solid. 5. The method of claim 4,
(c) the surface of the porous metal-organic skeleton into which the polyamine having the primary amine group is introduced is polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), polyvinylidene fluoride fluoride, and PVDF). The method for producing a carbon dioxide adsorbent according to claim 1, wherein the hydrophobic polymer is selected from the group consisting of fluorine, fluoride, and PVDF. 5. The method of claim 4,
Wherein the polyvalent amine is selected from compounds represented by the following general formulas (1) to (15).
[Chemical Formula 1 to Chemical Formula 15]

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