Metal-organic structures and methods of making the same

Abstract

The present application provides a MOF having high CO2 adsorption capacity and composed of inexpensive materials. One embodiment of the present application relates to a metal organic structure represented by formula (I) [in the formula, M a2+ is a divalent copper ion (Cu 2+ ), L is a pyrazine ligand, M b3+ is a trivalent aluminum ion (Al 3+ ) or gallium ion (Ga 3+ ), and n is 0 or 1]. Another embodiment of the present application relates to a method for producing a metal organic structure having the above characteristics. M a (L)2M b F5(H2O) n (I)

Description

Technical Field

[0001] This invention relates to a metal-organic structure and its manufacturing method. Background Technology

[0002] Metal-organic structures (hereinafter also referred to as "MOFs") are crystalline porous materials composed of metals and organic ligands. Depending on the combination of metals and organic ligands used, the pore size and surface shape of MOFs can be designed at the molecular level. MOFs are expected to be used in applications such as adsorption and storage materials for gases such as CO2, heterogeneous catalysts, and conductive materials.

[0003] For example, Patent Document 1 describes a method for capturing chemical species, comprising the step of contacting a metal-organic structure with a fluid composition containing one or more of SO2, CO2, and H2O, wherein the metal-organic structure comprises a square lattice of columnar inorganic structural blocks, the square lattice being Ni(pyrazine)2, and the inorganic structural blocks being selected from [NbOF5]. 2- Or [AlF5(H2O)] 2- The steps in the process, and the steps of adsorbing one or more of SO2, CO2 and H2O from the fluid composition onto the metal-organic structure.

[0004] Patent Document 1: Japanese Patent Publication No. 2021-527557 Summary of the Invention

[0005] As mentioned above, techniques for using MOFs as CO2 adsorption materials are known. However, in the case of the MOF described in Patent Document 1, for example, represented by Ni(pyrazine)₂AlF₅(H₂O), the Ni-pyrazine-Ni distance is large. Therefore, in the case of the MOF described in Patent Document 1, the size of the pores for CO2 adsorption becomes larger, resulting in weak CO2 adsorption capacity. Furthermore, in the case of the MOF described in Patent Document 1, the high cost of raw materials due to the inclusion of expensive Ni is a problem.

[0006] Therefore, the object of the present invention is to provide an MOF with high CO2 adsorption capacity and made of inexpensive materials.

[0007] The inventors have conducted various studies on methods for solving the aforementioned problem. The inventors have discovered that in MOFs containing divalent metal ions and pyrazine ligands as described in Patent Document 1, inexpensive copper ions (Cu) can be used... 2+ ) as a divalent metal ion and using aluminum ions (Al 3+ ) or gallium ions (Ga 3+As a trivalent metal ion contained in inorganic anions, it is possible to obtain a MOF with high CO2 adsorption capacity capable of adsorbing low concentrations of CO2. The inventors completed this invention based on the aforementioned insights.

[0008] That is, the present invention includes the following methods and embodiments.

[0009] (Implementation Method 1) A metal-organic structure, wherein,

[0010] The metal-organic structure is represented by formula (I).

[0011] M a (L) 2M b F5 (H2O) n (I)

[0012] [In the formula,

[0013] M a2+ Copper ions with a valence of divalent (Cu) 2+ ),

[0014] L is a pyrazine ligand.

[0015] M b3+ aluminum ions with a valence of 3 (Al) 3+ ) or gallium ions (Ga 3+ ),

[0016] n is 0 or 1.

[0017] (Embodiment 2) According to the metal-organic structure described in Embodiment 1, wherein M b3+ aluminum ions with a valence of 3 (Al) 3+ ).

[0018] (Embodiment 3) The method for manufacturing a metal-organic structure according to Embodiment 1 or 2 includes:

[0019] Material preparation process, prepare L and M a2+ Hydrofluoric acid (HF) and M b3+ ;

[0020] The aqueous solution preparation process involves preparing an aqueous solution containing HF and an aqueous solution containing M. b3+ Aqueous solutions; and

[0021] The reaction process involves mixing an aqueous solution containing HF and a solution containing M. b3+ An aqueous solution, making L and M a2+ HF and M b3+ reaction.

[0022] (Embodiment 4) According to the method of Embodiment 3, the aqueous solution preparation step includes an aqueous solution containing hydrofluoric acid (HF) or an aqueous solution containing M. b3+ M is further mixed in the aqueous solution a2+ .

[0023] (Embodiment 5) According to the method of Embodiment 3 or 4, the aqueous solution preparation step includes an aqueous solution containing hydrofluoric acid (HF) or an aqueous solution containing M. b3+ The solution was further mixed with L.

[0024] Invention Effects

[0025] This invention provides a MOF with high CO2 adsorption capacity and made of inexpensive materials. Attached Figure Description

[0026] Figure 1 The crystal structure of an embodiment of the MOF of the present invention is shown.

[0027] Figure 2 The figures show the X-ray diffraction patterns of the powders containing the products obtained in Example 1, Reference Example 1, Reference Example 2, Example 2, and Comparative Example 3. In the figures, the horizontal axis represents 2θ (Cu K). α The vertical axis represents the intensity (au), with the vertical axis representing the intensity (°).

[0028] Figure 3 The figure shows the CO2 adsorption isotherms of the powders from Example 1 and Comparative Example 3 at 298 K. In the figure, the horizontal axis represents the CO2 pressure P. CO2 (Pa), with the vertical axis representing the CO2 adsorption capacity V. CO2 (mL(STP)·g) -1 ).

[0029] Figure 4 The figure shows the CO2 adsorption isotherms of the powders from Examples 1 and 2, and Reference Examples 1 and 2, at 298 K. In the figure, the horizontal axis represents the CO2 pressure P. CO2 (Pa), with the vertical axis representing the CO2 adsorption capacity V. CO2 (mL(STP)·g) -1 ). Detailed Implementation

[0030] The preferred embodiments of the present invention will now be described in detail.

[0031] <1: Metal-organic structures>

[0032] One aspect of the present invention relates to a metal-organic structure (MOF). The MOF of this aspect is represented by formula (I), M a (L) 2Mb F5 (H2O) n (I). In formula (I), M a2+ Copper ions with a valence of divalent (Cu) 2+ L is a pyrazine ligand. M b3+ aluminum ions with a valence of 3 (Al) 3+ ) or gallium ions (Ga 3+ Al) is preferred. 3+ n is 0 or 1, preferably 1. The MOF of this method, represented by formula (I), can have high CO2 adsorption capacity.

[0033] In equation (I), M b3+ Formation with 5 fluoride ions (F - )5-coordinated bitrigonal pyramidal divalent anion ((M b F5) 2- ) or a divalent anion with an octahedral structure having a further 6-coordinate to 1 water molecule (H2O) ((M b F5(H2O)) 2- ).

[0034] The MOF of this method is preferably Cu(pyrazine)₂AlF₅(H₂O) or Cu(pyrazine)₂GaF₅(H₂O), more preferably Cu(pyrazine)₂AlF₅(H₂O). The MOF of this method having the structure represented by the above formula can have particularly high CO₂ adsorption capacity.

[0035] The crystal structure of Cu(pyrazine)₂AlF₅(H₂O) (Example 1), which is one embodiment of the MOF of this method, is shown below. Figure 1 .like Figure 1 As shown, the MOF of this method is similar to the MOF of the prior art (Ni(pyrazine)2AlF5(H2O) described in Comparative Example 3 and Patent Document 1), (AlF5(H2O)). 2- F at the octahedral vertices of the anion - Facing inwards towards the pores. In this crystal structure, F - The δ - The δ value of carbon (C) in CO2 + They interact and adsorb CO2. Furthermore, Cu... 2+ For Ni 2+ The ions exhibit a strong Young-Taylor effect. Therefore, compared to the Ni-pyrazine-Ni distance of the prior art MOF (Comparative Example 3), the Cu-pyrazine-Cu distance of the MOF in this method is shorter. As a result, the MOF in this method has narrower pores and exhibits stronger CO2 adsorption capacity compared to the prior art MOF (Comparative Example 3).

[0036] The composition and crystal structure of the MOF obtained in this manner can be determined, for example, by measuring the X-ray diffraction pattern of the MOF. Furthermore, the pyrazine ligand contained in the MOF obtained in this manner can be determined, for example, by dissolving the MOF in a solvent and then... 1 The pyrazine ligands contained in the solution were identified by 1H-NMR analysis.

[0037] The CO2 adsorption capacity of the MOF in this method can be evaluated, for example, by measuring the CO2 adsorption isotherm of the MOF and calculating the amount of CO2 adsorbed under a specified CO2 pressure.

[0038] <2: Manufacturing methods of metal-organic structures>

[0039] Another aspect of the present invention relates to a method for manufacturing a metal-organic structure according to one aspect of the present invention. This method includes a material preparation step, an aqueous solution preparation step, and a reaction step. The steps of this method will be described below.

[0040] [2-1: Material Preparation Process]

[0041] This process includes preparing L and M. a2+ Hydrofluoric acid (HF) and M b3+ .

[0042] The pyrazine ligand L and divalent copper ion M prepared in this process a2+ HF and trivalent metal ions M b3+ Inorganic salts containing the metal ion can be purchased to prepare the substance itself. a2+ Inorganic salts, exemplified by copper(II) nitrate trihydrate (Cu(NO3)2·3H2O). As a component of M... b3+ Inorganic salts, such as aluminum nitrate nonahydrate (Al(NO3)3·9H2O) and gallium nitrate octahydrate (Ga(NO3)3·8H2O), can be cited.

[0043] [2-2: Aqueous solution preparation process]

[0044] This process includes preparing an aqueous solution containing HF and containing M. b3+ An aqueous solution.

[0045] trivalent metal ion M b3+ Fluorides (e.g., AlF3) have low solubility in water. Therefore, in the manufacture of MOF according to one aspect of the present invention, if the pyrazine ligand L and / or divalent copper ion M... a2+ The preparation of a mixture containing HF and M does not exist. b3+ An aqueous solution may generate M. b3+The fluoride precipitate does not form MOF. In contrast, in this process, an aqueous solution containing HF and an aqueous solution containing M are prepared separately. b3+ An aqueous solution can substantially avoid M b3+ The MOF of the present invention is obtained by the formation of fluoride precipitates.

[0046] In the aqueous solution containing HF prepared in this process, the concentration of HF is preferably between 0.1 and 2 mol·L⁻¹. -1 More preferably, it is within the range of 0.5 to 1.5 mol·L⁻¹. -1 Within the range.

[0047] The product containing M prepared in this process b3+ In aqueous solution, M b3+ The preferred concentration is between 0.1 and 1 mol·L⁻¹. -1 More preferably, it is within the range of 0.1 to 0.7 mol·L⁻¹. -1 Within the range.

[0048] This process may further include reacting with an aqueous solution containing HF and a solution containing M. b3+ Aqueous solutions containing M were prepared separately. a2+ The process of using an aqueous solution may also include using an aqueous solution containing HF or containing M. b3+ M is further mixed in the aqueous solution a2+ The process includes, in one embodiment, an aqueous solution containing HF or containing M. b3+ M is further mixed in the aqueous solution a2+ In another embodiment, the process further includes reacting with an aqueous solution containing HF and M. b3+ Aqueous solutions containing M were prepared separately. a2+ The process of preparing an aqueous solution. In the case of the described embodiment, M a2+ The preferred concentration is between 0.1 and 1 mol·L⁻¹. -1 More preferably, it is within the range of 0.1 to 0.7 mol·L⁻¹. -1 Within the range.

[0049] This process may further include reacting with an aqueous solution containing HF and a solution containing M. b3+ The process of separately preparing an aqueous solution containing pyrazine ligand L may also include an aqueous solution containing HF or containing M. b3+ The step involves further mixing pyrazine ligand L in an aqueous solution. In one embodiment, this step includes mixing the pyrazine ligand L in an aqueous solution containing HF or containing M. b3+ The pyrazine ligand L is further mixed in an aqueous solution. In another embodiment, this step includes containing M b3+The pyrazine ligand L is further mixed into the aqueous solution. In the case of the described embodiment, the concentration of the pyrazine ligand L is preferably from 0.1 to 1 mol·L⁻¹. -1 More preferably, it is within the range of 0.1 to 0.7 mol·L⁻¹. -1 Within the range.

[0050] [2-3: Reaction Process]

[0051] This process includes mixing an aqueous solution containing HF and an aqueous solution containing M. b3+ An aqueous solution, making L and M a2+ HF and M b3+ reaction.

[0052] In the aqueous solution preparation process described herein, the aqueous solution contains HF and contains M b3+ Aqueous solutions containing M were prepared separately. a2+ In embodiments where an aqueous solution containing HF and / or an aqueous solution containing pyrazine ligand L is used, this step preferably includes, in addition to, an aqueous solution containing HF and an aqueous solution containing M... b3+ In addition to the aqueous solution, it also contains M a2+ An aqueous solution of the mixture and / or an aqueous solution containing pyrazine ligand L is reacted with the mixture.

[0053] In the aqueous solution preparation process described herein, the aqueous solution contains HF or contains M b3+ M is further mixed in the aqueous solution a2+ And / or in an aqueous solution containing HF or containing M b3+ In embodiments where pyrazine ligand L is further mixed into an aqueous solution, this step preferably includes mixing M in addition to HF. a2+ or an aqueous solution of pyrazine ligand L and containing M b3+ Or M a2+ Or an aqueous solution of pyrazine ligand L is reacted. In the case of this embodiment, M a2+ And pyrazine ligand L only needs to be contained in an aqueous solution containing HF or containing M b3+ It can be in at least one of the aqueous solutions.

[0054] This process preferably involves mixing an aqueous solution containing each material in a solvent and reacting it. Various solvents used in the art for manufacturing MOFs can be cited as solvents used in this process. Polytetrafluoroethylene (PTFE) is preferably used as the solvent in this process. PTFE has high chemical resistance and is therefore substantially stable even to highly corrosive HF. Therefore, by using the solvent exemplified herein, the reaction can be carried out efficiently to obtain a MOF according to one aspect of the present invention.

[0055] In this process, the reaction temperature is preferably room temperature, more preferably in the range of 10 to 40°C. The reaction time is preferably in the range of 1 to 100 hours. By carrying out this process under the conditions described above, the reaction can be carried out efficiently to obtain a MOF of one aspect of the present invention.

[0056] As detailed above, the MOF of the present invention has narrower pores and exhibits stronger CO2 adsorption capacity compared to prior art MOFs. Therefore, the MOF of the present invention is suitable as a CO2 adsorption material in CO2 adsorption systems, CO2 separation systems, or CO2 storage systems. Furthermore, the manufacturing method of the present invention can obtain the MOF of the present invention having the characteristics described herein in high yield. Therefore, the manufacturing method of the present invention can effectively provide materials suitable for the applications exemplified herein.

[0057] Example

[0058] The present invention will be further described in detail below using examples. However, the technical scope of the present invention is not limited to these examples.

[0059] <I: Fabrication of Metal-Organic Structures>

[0060] [I-1: Reagent]

[0061] Aluminum nitrate nonahydrate (Al(NO3)3·9H2O) (manufactured by FUJIFILM Wako Pure Chemical Corporation) 98.0+ wt%

[0062] Scandium(III) nitrate tetrahydrate (Sc(NO3)3·4H2O) (manufactured by JUNSEI CHEMICAL CO.,LTD.) 99.9% by weight

[0063] Chromium(III) nitrate nonahydrate (Cr(NO3)3·9H2O) (manufactured by KANTO CHEMICAL CO.,INC.) 98.0 to 103.0% by weight

[0064] Ferric(III) nitrate nonahydrate (Fe(NO3)3·9H2O) (manufactured by FUJIFILM Wako Pure Chemical Corporation) 99.0+ wt%

[0065] Nickel(II) nitrate hexahydrate (Ni(NO3)2·6H2O) (manufactured by FUJIFILM Wako Pure Chemical Corporation) 98.0+ wt%

[0066] Copper(II) nitrate trihydrate (Cu(NO3)2·3H2O) (manufactured by FUJIFILM Wako Pure Chemical Corporation) 99.0 to 104.0% by weight

[0067] Gallium nitrate octahydrate (Ga(NO3)3·8H2O) (manufactured by Daito Corporation) 99% by weight

[0068] Yttrium(III) nitrate hexahydrate (Y(NO3)3·6H2O) (manufactured by KANTO CHEMICAL CO.,INC.) >99.99% by weight

[0069] Pyrazine (manufactured by Tokyo Chemical Industry Co., Ltd.) >98.0% by weight

[0070] Hydrofluoric acid (55% by weight HF) (manufactured by Hayashi Pure Chemical Ind., Ltd.) 55% by weight

[0071] [I-2: Experiment 1 (Example 1)]

[0072] Distilled water was added to Al(NO3)3·9H2O and pyrazine as solutes to prepare a solution with a concentration of 0.64 mol·L⁻¹. -1 The concentration includes Al(NO3)3·9H2O, at 5.12 mol·L⁻¹. -1 The concentration contained in the aqueous solution of pyrazine was 1. Distilled water was added to hydrofluoric acid (55% HF) as a solute to prepare a solution with a concentration of 1.2 mol·L⁻¹. -1 The concentration includes an aqueous solution of HF. Distilled water was added to Cu(NO3)2·3H2O as a solute to prepare a solution with a concentration of 0.64 mol·L⁻¹. -1 The concentration of the aqueous solution contained in Cu(NO3)2·3H2O was 3 (aqueous solution preparation step). 1 mL of aqueous solution 1, 0.5 mL of aqueous solution 2, and 0.5 mL of aqueous solution 3 were added to 3 mL of polytetrafluoroethylene (PTFE) solution, and the solution was left at room temperature for 72 hours (reaction step). The precipitate was recovered. After washing the precipitate with aqueous solution 2, it was further washed with ethanol. The washed precipitate was dried under reduced pressure at 60 °C overnight to obtain the product.

[0073] [I-3: Experiment 2 (Refer to Example 1)]

[0074] In I-2, the solute in aqueous solution 1 was changed to Sc(NO3)3·4H2O and pyrazine of the same concentration, and the product was obtained under the same conditions as described above.

[0075] [I-4: Experiment 3 (Comparative Example 1)]

[0076] In I-2, the solute in aqueous solution 1 was changed to Cr(NO3)3·9H2O and pyrazine of the same concentration, and the product was obtained under the same conditions as described above.

[0077] [I-5: Experiment 4 (Refer to Example 2)]

[0078] In I-2, the solute in aqueous solution 1 was changed to Fe(NO3)3·9H2O and pyrazine of the same concentration, and the product was obtained under the same conditions as described above.

[0079] [I-6: Experiment 5 (Example 2)]

[0080] In I-2, the solute in aqueous solution 1 was changed to Ga(NO3)3·8H2O and pyrazine of the same concentration, and the product was obtained under the same conditions as described above.

[0081] [I-7: Experiment 6 (Comparative Example 2)]

[0082] In I-2, the solute in aqueous solution 1 was changed to Y(NO3)3·6H2O and pyrazine of the same concentration, and the product was obtained under the same conditions as described above.

[0083] [I-8: Experiment 7 (Comparative Example 3)]

[0084] In I-2, the solute in aqueous solution 3 was changed to Ni(NO3)2·6H2O of the same concentration, and the product was obtained under the same conditions as described above.

[0085] [I-9: Experiment 8 (Comparative Example 4)]

[0086] In I-2, the solute in aqueous solution 1 is changed to Al(NO3)3·9H2O of the same concentration and 0.6 mol·L⁻¹. -1 The concentration of HF was changed to 10.24 mol·L⁻¹. -1 The product was obtained under the same conditions as described above, except that a certain concentration of pyrazine was used.

[0087] [I-10: Experiment 9 (Comparative Example 5)]

[0088] In I-2, the solute in aqueous solution 1 is changed to Sc(NO3)3·4H2O of the same concentration and 0.6 mol·L⁻¹. -1 The concentration of HF was changed to 10.24 mol·L⁻¹. -1The product was obtained under the same conditions as described above, except that a certain concentration of pyrazine was used.

[0089] [I-11: Experiment 10 (Comparative Example 6)]

[0090] In I-2, the solute in aqueous solution 1 is changed to Y(NO3)3·6H2O of the same concentration and 0.6 mol·L⁻¹. -1 The concentration of HF was changed to 10.24 mol·L⁻¹. -1 The product was obtained under the same conditions as described above, except that a certain concentration of pyrazine was used.

[0091] <II: Analysis of Metal-Organic Structures>

[0092] [II-1: Appearance of Metal-Organic Structures]

[0093] The appearance of the products from tests 1 to 10 (Examples 1 and 2, Reference Examples 1 and 2, and Comparative Examples 1 to 6) is shown in Table 1.

[0094] [Table 1]

[0095]

[0096] As shown in Table 1, no precipitation occurred in Comparative Example 1. Based on this result, it is speculated that it is difficult to form Cr-containing precipitates. 3+ The pentafluorochromate ion (CrF5) 2- ) or its hydrate ((CrF5(H2O)) 2- In Comparative Example 2, a white powder precipitate was formed. Since it was white, it was presumed that the product did not contain Cu. 2+ YF3 was generated. In Comparative Examples 4 to 6, Al containing trivalent metal ions was prepared. 3+ ,Sc 3+ Or Y 3+ In the stage of preparing aqueous solution 1 with HF, a white powder precipitate was formed. Based on this result, it is speculated that fluorides with low solubility, such as AlF3, ScF3, or YF3, were generated during the preparation of aqueous solution 1.

[0097] [II-2: Analysis of the Crystal Structure of Metal-Organic Structures]

[0098] X-ray diffraction (XRD) measurements were performed on the powders of the products obtained in Example 1, Reference Example 1, Reference Example 2, Example 2, and Comparative Example 3. The measuring apparatus and conditions are shown below. The XRD patterns of the powders of each product are also shown below. Figure 2 In the figure, the horizontal axis represents 2θ (Cu K). αThe vertical axis represents the intensity (au), with the vertical axis representing the intensity (°).

[0099] Measurement apparatus: RINT RAPID II (Rigaku Corporation)

[0100] Measurement conditions: Voltage 50V, Current 100mA, Collimator diameter φ0.3mm, Sample angle ω5°

[0101] according to Figure 2 The X-ray diffraction patterns shown suggest that these products all have similar crystal structures. In the X-ray diffraction patterns of the products of Reference Example 2, Example 2, and Comparative Example 3, the intensity of the 100 diffraction line is stronger than that of the 001 diffraction line. Based on this result, it is speculated that among these products, the intensity of the 100 diffraction line is stronger than that of the 001 diffraction line. a -M b F6(H2O)-M a In terms of direction, in M a -Pyrazine-M a Crystals preferentially grow in the direction of growth.

[0102] In the X-ray diffraction patterns of the products of Example 1, Reference Example 1, Reference Example 2, and Example 2, the 100 diffraction line appears at almost the same angle. This result is presumed to be because the 100 diffraction line corresponds to the distance of the Cu-pyrazine-Cu bond regardless of the type of trivalent metal ion. On the other hand, in the case containing Ni... 2+ Instead of Cu 2+ In the X-ray diffraction pattern of the product of Comparative Example 3, the 100 diffraction line appears slightly at a lower angle compared to the X-ray diffraction pattern of the product described above. This result is presumed to reflect that the Ni-pyrazine-Ni bond is longer than the Cu-pyrazine-Cu bond.

[0103] [II-3: Determination of CO2 adsorption isotherms in metal-organic structures]

[0104] CO2 adsorption isotherm measurements were performed on the powders of the products obtained in Example 1, Reference Example 1, Reference Example 2, Example 2, and Comparative Example 3. The measuring apparatus and conditions are shown below. Furthermore, the CO2 adsorption isotherms of the powders from Example 1 and Comparative Example 3 at 298 K are shown below. Figure 3 In the figure, the horizontal axis represents the CO2 pressure P. CO2 (Pa), with the vertical axis representing the CO2 adsorption capacity V. CO2 (mL(STP)·g) -1 ).

[0105] Pretreatment unit: BELPREP VACII (MicrotracBEL Corp.)

[0106] Pretreatment conditions: Vacuum exhaust at 60℃ for 3 hours

[0107] Measurement device: BELSORP MINIX (MicrotracBEL Corp.)

[0108] Measurement conditions: CO2 adsorption capacity was measured at 298 K.

[0109] The product of Example 1 was a MOF represented by Cu(pyrazine)₂AlF₅(H₂O), and the product of Comparative Example 3 was a MOF represented by Ni(pyrazine)₂AlF₅(H₂O). 2+ For Ni 2+ The ions exhibit a strong Young's-Taylor effect. Therefore, compared to the Ni-pyrazine-Ni distance of Ni(pyrazine)₂AlF₅(H₂O) in Comparative Example 3, the Cu-pyrazine-Cu distance of Cu(pyrazine)₂AlF₅(H₂O) in Example 1 is shorter. This can also be seen from... Figure 2 The angle difference of the 100° diffraction line in the X-ray diffraction patterns of the products of Example 1 and Comparative Example 3 shown is supported. As a result, it is speculated that the MOF of Example 1 has narrower pores than the MOF of Comparative Example 3, exhibiting stronger CO2 adsorption capacity. Figure 3 ).

[0110] The CO2 adsorption isotherms of the powders from Examples 1 and 2, and Reference Examples 1 and 2, at 298 K are shown below. Figure 4 In the figure, the horizontal axis represents the CO2 pressure P. CO2 (Pa), with the vertical axis representing the CO2 adsorption capacity V. CO2 (mL(STP)·g) -1 ).

[0111] like Figure 4 As shown, various CO2 adsorption characteristics are clearly demonstrated based on the types of trivalent metal ions constituting the MOF. These trivalent metal ions include Al... 3+ or Ga 3+ MOFs containing Sc in Examples 1 and 2 3+ or Fe 3+ Compared to MOFs in Reference Examples 1 and 2, it showed stronger CO2 adsorption capacity.

[0112] Furthermore, the present invention is not limited to the described embodiments, but includes various modifications. For example, the embodiments described in detail are for the purpose of illustrating the present invention and are not necessarily limited to embodiments having all the described structures. Moreover, it is possible to add, delete, and / or replace other structures in a part of the structure of each embodiment.

Claims

1. A metal-organic structure, characterized in that, The metal-organic structure is represented by formula (I). M a (L)2M b F5(H2O) n (I) In the formula, M a2+ Copper ions with a valence of divalent (Cu) 2+ ), L is a pyrazine ligand. M b3+ aluminum ions with a valence of 3 (Al) 3+ ) or gallium ions (Ga 3+ ), n is 0 or 1.

2. The metal-organic structure according to claim 1, characterized in that, M b3+ aluminum ions with a valence of 3 (Al) 3+ ).

3. The method for manufacturing a metal-organic structure according to claim 1, characterized in that, include: Material preparation process, including the preparation of L and M a2+ Hydrofluoric acid (HF) and M b3+ ; The aqueous solution preparation process includes the preparation of an aqueous solution containing HF and an aqueous solution containing M. b3+ Aqueous solutions; and The reaction process involves mixing an aqueous solution containing HF and a solution containing M. b3+ An aqueous solution, making L, M a2+ HF and M b3+ reaction.

4. The method according to claim 3, characterized in that, In the aqueous solution preparation process, the aqueous solution includes hydrofluoric acid (HF) or an aqueous solution containing M... b3+ M is further mixed in the aqueous solution a2+ .

5. The method according to claim 3, characterized in that, In the aqueous solution preparation process, the aqueous solution includes hydrofluoric acid (HF) or an aqueous solution containing M... b3+ The solution was further mixed with L.

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