Method for producing metal-organic structure

Abstract

A method for producing a metal-organic structure, the method comprising: a step for preparing an aqueous zirconium complex solution containing zirconium atoms; and a step for obtaining a metal-organic structure by sequentially or simultaneously mixing the zirconium complex aqueous solution, an organic ligand, and an alcohol.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a metal-organic structure. Background Art

[0002] A metal-organic structure refers to a porous three-dimensional structure formed by a central metal and an organic ligand, and is also called MOF (Metal Organic Framework), and has been widely studied in recent years (hereinafter, also referred to as "MOF"). MOF is characterized by a high specific surface area and a high degree of design freedom. In addition, due to having many and uniform micropores, it is used as a gas adsorbent and absorbent.

[0003] As a conventional method for manufacturing MOF, there is a solvothermal synthesis method. Specifically, metal ions, an organic ligand, and a solvent are added to a reaction vessel and heated to manufacture.

[0004] In the solvothermal method, usually in order to promote the reaction, a reaction at a high temperature exceeding 100 °C is required.

[0005] Non-Patent Document 1 describes a method for manufacturing UiO-66, a metal-organic structure of zirconium.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Non-Patent Document 1: Cryst. Growth Des., 2020, 20, 10, 6787-6795 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] Water is a general and inexpensive solvent, but it easily coordinates with metals and hinders the synthesis reaction of metal-organic structures, so there are few examples of using it as a synthesis solvent for metal-organic structures.

[0011] Non-Patent Document 1 describes the synthesis of a zirconium-based metal-organic structure using water, but the crystallinity and specific surface area are low. In addition, there is room for improvement in the yield.

[0012] The problem to be solved by the present invention is to provide a method for manufacturing a metal-organic structure that can obtain a metal-organic structure with excellent crystallinity in a high yield.

[0013] Means for Solving the Problems

[0014] The means for solving the above problems includes the following methods.

[0015] <1>A method for manufacturing a metal-organic structure, comprising: a step of preparing an aqueous zirconium complex solution containing a zirconium complex; and

[0016] a step of obtaining a metal-organic structure by mixing the aqueous zirconium complex solution, an organic ligand, and an alcohol sequentially or simultaneously.

[0017] <2>The method for manufacturing a metal-organic structure according to <1>, wherein the liquid temperature during mixing in the step of obtaining the metal-organic structure is 80 °C or lower.

[0018] <3>The method for manufacturing a metal-organic structure according to <1> or <2>, further comprising a step of adjusting the pH of the aqueous zirconium complex solution to 2 to 9 before the step of obtaining the metal-organic structure.

[0019] <4>The method for manufacturing a metal-organic structure according to any one of <1> to <3>, wherein the organic ligand is a polycarboxylic acid or a salt thereof.

[0020] <5>The method for manufacturing a metal-organic structure according to any one of <1> to <4>, wherein the organic ligand is a polycarboxylic acid having a benzene skeleton or a salt thereof.

[0021] <6>The method for manufacturing a metal-organic structure according to any one of <1> to <5>, wherein the molar ratio of zirconium atoms to the organic ligand is zirconium atoms:organic ligand = 1:0.1 to 1:3.

[0022] <7>The method for manufacturing a metal-organic structure according to any one of <1> to <6>, wherein in the step of obtaining the metal-organic structure, the mass ratio of water to alcohol in the solvent after mixing the alcohol is water:alcohol = 1:0.1 to 1:3.

[0023] <8>The method for manufacturing a metal-organic structure according to any one of <1> to <7>, wherein in the step of obtaining the metal-organic structure, the content of the compound having a nitrogen atom in the solvent after mixing the aqueous zirconium complex solution, the organic ligand, and the alcohol is 1% by mass or less.

[0024] Effects of the Invention

[0025] By the present invention, a method for manufacturing a metal-organic structure with excellent crystallinity can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a powder X-ray diffraction measurement (PXRD) pattern of the metal-organic structure obtained in Example 1.

[0027] Figure 2 Powder X-ray diffraction (PXRD) pattern of the metal-organic structure obtained in Example 2.

[0028] Figure 3 Powder X-ray diffraction (PXRD) pattern of the metal-organic structure obtained in Comparative Example 1. Detailed Description of the Invention

[0029] The description of the technical features described below is based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. It should be noted that in the specification of the present application, "~" means including the values described before and after it as the lower limit value and the upper limit value.

[0030] In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in one numerical range can also be replaced with the upper limit value or the lower limit value of other stepwise-described numerical ranges. In addition, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range can also be replaced with the value shown in the examples.

[0031] In the present invention, when there are multiple substances corresponding to each component in the composition, unless otherwise specified, the amount of each component in the composition refers to the total measurement of the multiple substances present in the composition.

[0032] In the present invention, the term "process" includes not only independent processes, but also includes cases where it cannot be clearly distinguished from other processes, as long as the purpose expected by the process can be achieved.

[0033] In the present invention, "mass%" and "weight%" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0034] In addition, in the present invention, a combination of two or more preferred modes is a more preferred mode.

[0035] Hereinafter, the content of the present invention will be described in detail.

[0036] (Method for Producing Metal-Organic Structure)

[0037] The method for producing a metal-organic structure of the present invention includes: a step of preparing an aqueous solution of a zirconium complex containing zirconium atoms; and a step of mixing the aqueous solution of the zirconium complex, an organic ligand, and an alcohol sequentially or simultaneously to obtain a metal-organic structure.

[0038] In addition, the metal-organic structure produced by the method for producing a metal-organic structure of the present invention is preferably used as a gas adsorbent or storage agent, or a deodorant.

[0039] Alternatively, it can be compounded with fibers, resins, liquids (such as water, organic solvents, etc.), etc., and used as a raw material for manufacturing gas adsorption products.

[0040] Examples of the use as a gas adsorption product include a deodorizing processing liquid, deodorizing fibers, a deodorizing resin composition, deodorizing fabric, and a deodorizing filter material.

[0041] As a result of intensive research by the present inventors, it has been found that by adopting the above configuration, a composition with excellent crystallinity can be provided.

[0042] The mechanism of action of the excellent effects based on this is not yet clear, but it can be presumed as follows.

[0043] Presumption: When manufacturing a metal-organic structure by mixing an aqueous solution of a zirconium complex and an organic ligand, an alcohol is added to make a mixed solvent of water and alcohol, so that the alcohol with hydrogen-donating properties promotes the cleavage of the bond between the zirconium complex and the ligand of the metal-organic structure in a metastable structure and the re-coordination to a stable structure, thereby obtaining a metal-organic structure with excellent crystallinity.

[0044] <Process for preparing an aqueous solution of a zirconium complex>

[0045] The method for manufacturing a metal-organic structure of the present invention includes a process for preparing an aqueous solution of a zirconium complex.

[0046] In the process for preparing an aqueous solution of a zirconium complex, it is preferable to prepare a zirconium complex from a metal salt containing a zirconium atom or a hydrate of a metal salt.

[0047] There is no particular limitation on the metal salt containing a zirconium atom, and examples thereof include metal halides (including metal oxohalides) such as metal chlorides, metal bromides, metal iodides, and metal fluorides; metal nitrates; metal sulfates; metal carbonates; metal formates; metal phosphates; organic metal compounds such as metal carboxylates and metal alkoxides, metallocene compounds, metal sulfides; metal hydroxides, etc.

[0048] More specifically, examples include zirconium tetrachloride, zirconyl chloride or zirconyl chloride octahydrate, zirconium nitrate or zirconium nitrate dihydrate, zirconyl nitrate or zirconyl nitrate dihydrate, zirconium tetrapropyl, zirconium tetrabutyl, or dichlorodicyclopentadienylzirconium (ZrCp2Cl2), etc., but are not limited thereto.

[0049] Among them, as the metal salt containing a zirconium atom or the hydrate of a metal salt, zirconyl chloride or its hydrate is preferable.

[0050] In the step of preparing an aqueous solution of a zirconium complex, the solvent used is not particularly limited as long as it is a water-containing solvent. However, from the viewpoints of complex-forming ability and crystallinity of the obtained metal-organic structure, a solvent containing 30% by mass or more of water is preferred, 80% by mass or more of water is more preferred, 90% by mass or more of water is still more preferred, and 99% by mass or more and 100% by mass or less of water is particularly preferred.

[0051] In the step of preparing an aqueous solution of a zirconium complex, an acid is preferably added from the viewpoint of complex-forming ability.

[0052] As the acid, an inorganic acid or an organic acid may be used. However, from the viewpoint of complex-forming ability, an organic acid is preferred, and a monocarboxylic acid compound is more preferred. The monocarboxylic acid compound is not particularly limited, and examples thereof include acetic acid and formic acid.

[0053] From the viewpoint of complex-forming ability, when the amount of zirconium atoms used is 1 molar equivalent, the addition amount of the acid is preferably 1 molar equivalent to 1000 molar equivalents, more preferably 5 molar equivalents to 800 molar equivalents, and particularly preferably 10 molar equivalents to 500 molar equivalents.

[0054] In addition, it is speculated that the acid will form a salt by performing the step of adjusting the pH of the aqueous solution of the zirconium complex to 2 to 9 described below.

[0055] In addition, there are no particular restrictions on the usage amount of the metal salt or metal salt hydrate containing zirconium atoms and the amount of the solvent, and they can be appropriately selected.

[0056] Among them, from the viewpoint of complex-forming ability, the usage amount of the metal salt or metal salt hydrate containing zirconium atoms is preferably 0.5% by mass to 30% by mass, more preferably 1% by mass to 20% by mass, based on the total mass of the aqueous solution of the zirconium complex.

[0057] There are no particular restrictions on the reaction temperature in the step of preparing an aqueous solution of a zirconium complex, and it is preferably 80 °C or lower. The lower limit value of the reaction temperature can be appropriately set, for example, it can be set to 5 °C or higher, and in order to improve the reactivity, it can also be set to 20 °C or higher. The upper limit value of the reaction temperature can be appropriately set, and it can also be set to 60 °C or lower, for example.

[0058] There are no particular restrictions on the reaction time in the step of preparing an aqueous solution of a zirconium complex, and it is preferably 0.1 hour to 72 hours, more preferably 1 hour to 36 hours.

[0059] <Step of Adjusting the pH of the Aqueous Solution of the Zirconium Complex to 2 to 9>

[0060] The method for manufacturing the metal-organic structure of the present invention preferably further includes a step of adjusting the pH of the zirconium complex aqueous solution to 2 to 9 before the step of obtaining the metal-organic structure.

[0061] In the step of adjusting the pH of the zirconium complex aqueous solution, it is preferable to add a basic compound to adjust the pH.

[0062] There is no particular limitation on the basic compound, and examples thereof include alkali metal salt compounds and alkaline earth metal salt compounds.

[0063] Among them, from the viewpoint of complex formation, alkali metal salt compounds are preferred, alkali metal carbonate compounds are more preferred, and sodium carbonate is particularly preferred.

[0064] The addition amount of the basic compound can be appropriately selected according to the desired pH.

[0065] In the step of adjusting the pH of the zirconium complex aqueous solution to 2 to 9, from the viewpoint of complex formation, it is preferable to adjust the pH to 3 to 8, and more preferably to 4 to 7.

[0066] The pH in the present invention is the value at 25 °C, and the pH is measured at 25 °C using a pH measuring device (device name: Compact pH Meter LAQUA twin AS-pH-22, HORIBA Advanced Techno, Co., Ltd.).

[0067] Before the step of obtaining the metal-organic structure, there is no particular limitation on the reaction temperature in the step of adjusting the pH of the zirconium complex aqueous solution to 2 to 9, and it is preferably 80 °C or lower.

[0068] Before the step of obtaining the metal-organic structure, there is no particular limitation on the reaction time in the step of adjusting the pH of the zirconium complex aqueous solution to 2 to 9, and it is preferably 0.1 hour to 24 hours, and more preferably 0.1 hour to 3 hours.

[0069] <Step of obtaining the metal-organic structure>

[0070] In the method for manufacturing the metal-organic structure of the present invention, alcohol can be added after mixing the zirconium complex aqueous solution and the organic ligand, or the organic ligand and alcohol can be mixed and then the zirconium complex is added, or the zirconium complex and alcohol can be mixed and then the organic ligand is added.

[0071] The organic ligand used is not particularly limited as long as it can form a metal-organic structure by coordinating with the zirconium complex. For example, the organic ligand may also have multiple functional groups capable of coordinating with metal ions. Examples of the functional groups capable of coordinating with metal ions include carboxyl group, glycidyl group, carboxylic anhydride group, CS2H, OH, SH, SO, SO2, SO3H, -S-, -SS-, Si(OH)3, Ge(OH)3, Sn(OH)3, Si(SH)4, Ge(SH)4, Sn(SH)4, PO3H, CH(SH)2, C(SH)3, CH(NH2)2, C(NH2)3, CH(OH)2, C(OH)3, CH(CN)2, C(CN)3, CH(RSH)2, C(RSH)3, CH(RNH2)2, C(RNH2)3, CH(ROH)2, C(ROH)3, etc. It should be noted that those that can form salts with these functional groups may also be in the form of salts.

[0072] The organic ligand can be, for example, an aromatic compound, a heteroaromatic compound, or a heterocyclic compound.

[0073] An aromatic compound refers to a compound of a monocyclic or polycyclic system formed by a 5- or 6-membered aromatic hydrocarbon ring. Specific examples include benzene, naphthalene, 1,4-dihydronaphthalene, fluorene, anthracene, phenanthrene, biphenyl, terphenyl, acenaphthylene, acenaphthene, tetrahydronaphthalene, chromane, 2,3-dihydro-1,4-dioxinaphthalene, pyrene, indane, indene, and phenanthrene.

[0074] A heteroaromatic compound refers to a compound of a monocyclic or polycyclic system formed by a 5- or 6-membered aromatic ring containing 1 to 3 heteroatoms selected from O and S. In the case of a polycyclic system, at least one ring being a heteroaromatic ring is sufficient.

[0075] Examples of the heterocyclic compound include morpholine, pyrrolidine, piperidine, methylpiperazine, tetrahydrofuran, and dioxane.

[0076] Among them, polycarboxylic acids having an ethylene skeleton and polycarboxylic acids having a benzene skeleton are preferred.

[0077] Examples of the polycarboxylic acid having an ethylene skeleton include fumaric acid, maleic acid, etc., but are not limited thereto.

[0078] Examples of the polycarboxylic acid having a benzene skeleton include phthalic acid, isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, etc., but are not limited to these.

[0079] Among them, from the viewpoints of complex-forming ability and crystallinity of the obtained metal-organic structure, dicarboxylic acids or their salts formed by carboxyl groups and divalent hydrocarbon groups are preferred, dicarboxylic acids or their salts formed by carboxyl groups and divalent aromatic hydrocarbon groups are more preferred, and terephthalic acid or its salts are particularly preferred. There is no particular limitation on the cation forming the salt, and examples of monovalent cations include alkali metal ions and ammonium ions.

[0080] Here, the "divalent hydrocarbon group" and the "divalent aromatic hydrocarbon group" refer to the hydrocarbon group and the aromatic hydrocarbon group obtained by removing two functional groups from an organic ligand having two functional groups capable of coordinating with metal ions.

[0081] The amount of the organic ligand used can be appropriately adjusted in combination with the amount of the zirconium complex. Among them, from the viewpoint of the crystallinity of the obtained metal-organic structure, the molar ratio of zirconium atoms to the organic ligand contained in the zirconium complex aqueous solution is preferably zirconium atoms:organic ligand = 1:0.05 to 1:5, more preferably zirconium atoms:organic ligand = 1:0.1 to 1:3, and particularly preferably zirconium atoms:organic ligand = 1:0.5 to 1:2.

[0082] In addition, in the step of obtaining the metal-organic structure, the organic ligand can be added directly in the form of a compound, dispersed in a liquid and added, or added in the form of a solution containing the organic ligand.

[0083] Examples of the solvent used in the solution containing the organic ligand include water and alcohols, and water is preferred.

[0084] There is no particular limitation on the alcohol used, and examples include methanol, ethanol, propanol, isopropanol, etc.

[0085] Among them, from the viewpoint of the crystallinity of the obtained metal-organic structure, ethanol is preferably used.

[0086] The alcohol can be used alone or in combination of two or more.

[0087] In the step of obtaining the metal-organic structure, there is no particular limitation on the mass ratio of water to alcohol in the solvent after mixing the alcohol, but from the viewpoints of the crystallinity, specific surface area and yield of the obtained metal-organic structure, it is preferably water:alcohol = 1:0.1 to 1:3, more preferably water:alcohol = 1:0.1 to 1:2, and particularly preferably water:alcohol = 1:0.2 to 1:2.

[0088] In addition, in the step of obtaining the metal-organic structure, from the viewpoint of the crystallinity of the obtained metal-organic structure, the total content of water and alcohol in the solvent after mixing the alcohol is preferably 50% by mass or more, may be 80% by mass or more, and may also be 100% with respect to the total mass of the solvent.

[0089] In the step of obtaining the metal-organic structure, from the viewpoints of the crystallinity and yield of the obtained metal-organic structure, the content of the nitrogen atom-containing compound in the solvent after mixing the alcohol is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 1% by mass or less. It should be noted that the lower limit is 0% by mass.

[0090] Examples of the nitrogen atom-containing compound include compounds containing nitrogen functional groups such as amino groups, amide groups, and imide groups, such as N,N-dimethylformamide (DMF), N,N-diethylformamide (DEF), N,N-dimethylacetamide (DMAc), ammonia, and triethylamine.

[0091] Regarding the reaction temperature in the step of obtaining the metal-organic structure, from the viewpoints of the crystallinity, specific surface area, and yield of the obtained metal-organic structure, it is preferably 80°C or lower. The lower limit of the reaction temperature can be appropriately set. For example, it is preferably 5°C or higher, and in order to improve the reactivity, it can also be set to 20°C or higher. The upper limit of the reaction temperature can be appropriately set, and it can also be set to 60°C or lower, for example.

[0092] The reaction time in the step of preparing the metal-organic structure is not particularly limited, and it is preferably 0.05 hours to 72 hours, more preferably 0.1 hours to 24 hours, and particularly preferably 0.2 hours to 12 hours.

[0093] The method for manufacturing the metal-organic structure of the present application may also include other steps other than the foregoing.

[0094] As other steps, known steps can be cited. Specifically, for example, a step of separating the obtained metal-organic structure; a step of washing the obtained metal-organic structure; a step of drying the obtained metal-organic structure, etc.

[0095] In the step of drying the obtained metal-organic structure, heating drying or reduced-pressure drying can be performed. In the case of performing heating drying, the drying temperature is preferably 200°C or lower, more preferably 150°C or lower, and further preferably 130°C or lower.

[0096] In addition, from the viewpoint of suppressing coloring when kneaded into a resin, the content of nitrogen atoms in the obtained metal-organic structure is preferably 5% by mass or less, more preferably 2% by mass or less, particularly preferably 0.5% by mass or less, and most preferably 0.1% by mass or less. It should be noted that the lower limit is 0% by mass. The content of nitrogen atoms can be measured by the Dumas method using MICRO CORDER JM11 manufactured by J-SCIENCELAB CO., Ltd.

[0097] From the viewpoint of adsorption, the specific surface area of the obtained metal-organic structure is preferably 500 m 2 / g or more, more preferably 700 m 2 / g or more, particularly preferably 900 m 2 / g or more, and may also be 1000 m 2 / g or more.

[0098] The half-value width (peak width at a height of 1 / 2 of the peak height) of the main peak in the spectrum obtained by measuring the obtained metal-organic structure by powder X-ray diffraction (PXRD) is preferably 0.4° or less, more preferably 0.35° or less, and particularly preferably 0.3° or less.

[0099] Examples

[0100] The present invention will be specifically described below based on examples. It should be noted that the present invention is not limited to these examples. In addition, unless otherwise specified, "parts" and "%" hereinafter refer to "parts by mass" and "% by mass", respectively.

[0101] <Reagents>

[0102] The reagents used in the examples are as described below.

[0103] ･Zirconium oxychloride octahydrate (ZrOCl2･8H2O, manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0104] ･Acetic acid (manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0105] ･Sodium carbonate (manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0106] ･Terephthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0107] ･ Sodium hydroxide (manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0108] ･ Ethanol (manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0109] ･ Methanol (manufactured by FUJIFILM Wako Pure Chemical Corporation)

[0110] (Example 1: Synthesis of Metal-Organic Framework (UiO-66))

[0111] <Preparation of Aqueous Zirconium Complex Solution>

[0112] 3.22 g (10 mmol) of ZrOCl2･8H2O and 13.1 g of acetic acid were added to 30 g of pure water, and the mixture was stirred at 50 °C for 24 hours. Then, 1.48 g of sodium carbonate was added to the solution and stirred to adjust the pH (25 °C) to 5.0, thereby preparing an aqueous zirconium complex solution.

[0113] <Preparation of Organic Ligand Solution>

[0114] 1.66 g (10 mmol) of terephthalic acid and 0.8 g (20 mmol) of sodium hydroxide were added to 50 g of pure water, and the mixture was stirred at 80 °C for 30 minutes, thereby preparing an organic ligand solution.

[0115] <Synthesis of Metal-Organic Framework>

[0116] At room temperature (25 °C, the same below), 12.0 g of the organic ligand solution was added dropwise to 9.0 g of the aqueous zirconium complex solution while stirring. Then, 42 g of ethanol was added, and the mixture was stirred at 40 °C for 1 hour. After solid-liquid separation by centrifugation, the solid was recovered, washed three times with 50 mL of water, and then dried by heating overnight at 80 °C, thereby obtaining the product of Example 1 (metal-organic framework UiO-66 ([Zr6(OH)4O4(bdc)6]), white, granular, yield 95%). It should be noted that bdc represents terephthalic acid dianion. In addition, the molar ratio of zirconium atoms to the organic ligand is zirconium atoms: organic ligand = 1:1.18. Further, the content of the compound having a nitrogen atom in the product of Example 1 is 0%.

[0117] (Example 2: Synthesis of Metal-Organic Framework (UiO-66))

[0118] <Preparation of Aqueous Zirconium Complex Solution>

[0119] Prepare an aqueous solution of zirconium complex in the same manner as in Example 1.

[0120] <Synthesis of Metal-Organic Structure>

[0121] At room temperature (25 °C, the same hereinafter), while stirring, 12.0 g of the organic ligand solution was added dropwise to 9.0 g of the aqueous solution of zirconium complex. Thereafter, 10.5 g of ethanol was added, and the mixture was stirred at 40 °C for 1 hour. After solid-liquid separation by centrifugation, the solid was recovered, washed three times with 50 mL of water, and then dried by heating overnight at 80 °C, whereby the product of Example 2 (metal-organic structure UiO-66 ([Zr6(OH)4O4(bdc)6]), white, granular, yield 92%) was obtained. It should be noted that bdc represents terephthalate dianion. In addition, the molar ratio of zirconium atom to organic ligand is zirconium atom:organic ligand = 1:1.18. Further, the content of the compound having a nitrogen atom in the product of Example 2 is 0%.

[0122] (Comparative Example 1)

[0123] The product of Comparative Example 1 (metal-organic structure UiO-66) was obtained by the same method as in Non-Patent Document 1. Specifically, as follows.

[0124] In a polytetrafluoroethylene container, 1.288 g (4 mmol) of ZrOCl2･8H2O and 3 mL of acetic acid were added to 12 mL of pure water, and the mixture was heated at 70 °C for 2 hours, and then slowly cooled to room temperature to prepare an aqueous solution of zirconium complex.

[0125] 0.6640 g (4 mmol) of terephthalic acid and 0.32 g (8 mmol) of sodium hydroxide were added to 20 mL of pure water, mixed, and dissolved to prepare an organic ligand solution.

[0126] 10 mL of the organic ligand solution was added to a 50 mL centrifuge tube, and 20 M (= 20 mol / L) aqueous sodium hydroxide solution, 37 mass% hydrochloric acid, and pure water were used to prepare 13.5 mL of the organic ligand solution adjusted to pH 4.9.

[0127] 10 mL of the aqueous solution of zirconium complex was quickly added to the organic ligand solution with a pipette, and then centrifuged at 12000 rpm (revolutions per minute) for 5 minutes.

[0128] The obtained precipitate was dried in an oven at 70 °C for 8 hours. The obtained deposit was washed in the order of 0.01 M hydrochloric acid, 0.001 M aqueous sodium hydroxide solution, dimethyl sulfoxide, and methanol, and methanol was added for solvent replacement overnight. After centrifugation again, it was dried at 70 °C to obtain the product of Comparative Example 1 (metal-organic framework UiO-66, Zr6(OH)4O4(bdc)6), white, granular, yield 74%).

[0129] <Evaluation>

[0130] Each of the obtained products was evaluated by the following method, and the evaluation results are shown in Table 1.

[0131] - Crystallinity evaluation: Analysis method of powder X-ray diffraction (PXRD) pattern

[0132] Using D8 ADVANCE manufactured by Bruker Corporation, the PXRD pattern was analyzed. The measurement angle was 3° to 50°.

[0133] Using the software "DIFFRAC.EVA" manufactured by Bruker Corporation, the half-value width of the main peak of the obtained metal-organic framework pattern was calculated. The narrower the half-value width, the more excellent the crystallinity.

[0134] The PXRD (powder X-ray diffraction) patterns obtained by analyzing the metal-organic frameworks (UiO-66) manufactured in Example 1, Example 2, and Comparative Example 1 are shown in Figures 1 to 3 . Figure 1 is the pattern of the metal-organic framework obtained in Example 1, Figure 2 is the pattern of the metal-organic framework obtained in Example 2, Figure 3 is the pattern of the metal-organic framework obtained in Comparative Example 1. Respectively, the vertical axis of the figure represents the diffracted X-ray intensity (Counts, counts), and the horizontal axis represents the diffraction angle (2θ (°)).

[0135] - Measurement of specific surface area

[0136] Using "AUTOSORB-1" manufactured by Anton Paar GmbH, the nitrogen adsorption amount at the boiling point of liquid nitrogen (-195.8 °C) was measured at 5 points in the relative pressure range of 0.1 to 0.3, an adsorption isotherm was made, and the BET specific surface area per unit mass (m 2 / g) was determined.

[0137] [Table 1]

[0138]

[0139] As shown in Table 1 above, the metal-organic structure obtained by the manufacturing method of the metal-organic structure of the example has excellent crystallinity compared to the metal-organic structure obtained by the manufacturing method of the metal-organic structure of the comparative example.

[0140] In addition, as shown in Table 1 above, the manufacturing method of the metal-organic structure of the example can obtain a metal-organic structure with a large specific surface area, and the yield is also excellent.

[0141] The disclosure of Japanese Patent Application No. 2022-212323 filed on December 28, 2022 is incorporated herein by reference in its entirety.

[0142] All documents, patent applications, and technical standards described in this specification are incorporated into this specification by reference to the same extent as if each individual document, patent application, and technical standard were specifically and separately incorporated by reference.

Claims

1. A method for manufacturing a metal-organic structure, comprising: a step of preparing an aqueous zirconium complex solution containing a zirconium complex; and a step of obtaining a metal-organic structure by mixing the aqueous zirconium complex solution, an organic ligand, and an alcohol sequentially or simultaneously.

2. The manufacturing method of the metal-organic structure according to claim 1, wherein, The liquid temperature during mixing in the step of obtaining the metal-organic structure is 80 °C or lower.

3. The manufacturing method of the metal-organic structure according to claim 1, wherein, Before the step of obtaining the metal-organic structure, it further includes a step of adjusting the pH of the aqueous zirconium complex solution to 2 to 9.

4. The manufacturing method of the metal-organic structure according to claim 1, wherein, The organic ligand is a polycarboxylic acid or its salt.

5. The manufacturing method of the metal-organic structure according to claim 1, wherein, The organic ligand is a polycarboxylic acid having a benzene skeleton or its salt.

6. The manufacturing method of the metal-organic structure according to claim 1, wherein, The molar ratio of the zirconium atom to the organic ligand is zirconium atom:organic ligand = 1:0.1 to 1:

3.

7. The manufacturing method of the metal-organic structure according to claim 1, wherein, In the step of obtaining the metal-organic structure, the mass ratio of water to alcohol in the solvent after mixing the alcohol is water:alcohol = 1:0.1 to 1:

3.

8. The manufacturing method of the metal-organic structure according to claim 1, wherein, In the step of obtaining the metal-organic structure, the content of the compound having a nitrogen atom in the solvent after mixing the aqueous zirconium complex solution, the organic ligand, and the alcohol is 1% by mass or less.

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