Low-water-absorption Zn-MOFs, low-water-absorption Zn-MOFs composite molding body and preparation method and application of low-water-absorption Zn-MOFs composite molding body

Abstract

The invention provides low-water-absorption Zn-MOFs, a low-water-absorption Zn-MOFs composite molding body and a preparation method and application of the low-water-absorption Zn-MOFs composite molding body, and relates to the technical field of adsorption materials. Hydrophobic and nitrogen-rich organic ligands serve as a connecting agent of MOFs, and hydrophobic and carbon-philic columnar layered Zn-MOFs are obtained by changing synthesis conditions; an in-situ crystallization self-assembly technology is adopted, a precursor solution of MOFs is soaked in a macroporous polymer carrier, a solvothermal reaction is carried out, Zn-MOFs crystals grow in macropores of the carrier in situ, and a Zn-MOFs composite forming body is obtained. The preparation process disclosed by the invention has the remarkable advantages of simplicity and convenience in operation, strong parameter controllability, low raw material cost, stable supply, controllable safety risk and the like, is suitable for industrial amplified production, and solves the technical problems of water competitive adsorption and accumulation effect reduction of the MOFs adsorption material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of adsorption materials, in particular to a low-water-absorption Zn-MOF, a low-water-absorption Zn-MOF composite formed body and a preparation method and application thereof. BACKGROUND

[0002] With the increasing production scale of oil refining units and chemical units in oil refineries, the production of by-product dry gas and the emission of carbon dioxide (CO2) have also increased substantially. In order to realize the effective utilization of C2-C4 resources in refinery dry gas and reduce carbon emissions, it has become a top priority to develop high-efficiency and low-cost carbon capture technologies. Among many CO2 separation technologies, the pressure swing adsorption process is more convenient, cleaner and more efficient than the traditional low-temperature rectification or liquid amine absorption method; some classic and inexpensive adsorption materials, such as activated carbon and zeolite, have high CO2 adsorption performance. However, the CO2 adsorption capacity of activated carbon mainly depends on its high specific surface area, and usually exhibits excellent CO2 adsorption capacity at high pressure, but the CO2 adsorption capacity at normal pressure needs to be further improved; zeolite has high CO2 adsorption capacity and CO2 / N2 separation selectivity, but the desorption process usually requires high temperature (>200℃), which inevitably increases the regeneration cost; in addition, the difficulty of traditional zeolite in capturing CO2 in flue gas is the strong adsorption of H2O molecules, which will significantly affect the CO2 adsorption performance of zeolite in the presence of trace amounts of H2O. Therefore, the available CO2 pressure swing adsorption material must have the characteristics of carbon affinity, water resistance and low regeneration energy consumption.

[0003] Metal-Organic Frameworks (MOFs) materials have the advantages of high specific surface area, ordered pores and designable synthesis, providing a new way for the adsorption and separation of gases. In order to realize the efficient adsorption of CO2 molecules, introduction of unsaturated metal sites, functionalization, mixed linker / metal modification and other adjustment methods are used for the design and regulation of MOFs materials. However, due to the weak coordination bond between metal nodes and organic ligands, the stability and CO2 adsorption capacity of many MOFs are easily affected by water vapor. Therefore, in order to solve the problem of CO2 capture in high-water-content mixed gas, it is crucial to synthesize MOFs materials with high hydrophobicity and strong stability. From previous studies, it is known that the introduction of nitrogen-containing donors in carboxylic acid-based MOFs is conducive to the formation of strong ultramicroporous adsorption materials; in addition, in the actual application process, it is usually necessary to form MOF powder to overcome the problems of bed pressure drop, dust, blockage and mass loss, and the traditional extrusion molding and mechanical molding methods will inevitably cause the reduction of thermodynamic and kinetic properties of MOFs materials.

[0004] In view of this, the present application is proposed. SUMMARY

[0005] One of the purposes of the present application is to provide a low water absorption Zn-MOFs with low water absorption, low energy consumption, high CO2 adsorption capacity and high stability.

[0006] The second purpose of the present application is to provide a preparation method of the low water absorption Zn-MOFs, which is simple to operate, controllable, low in production cost, safe and controllable, and suitable for industrialized production.

[0007] The third purpose of the present application is to provide a low water absorption Zn-MOFs composite formed body, which has a multi-level pore coupling structure, improves the kinetic performance of the Zn-MOFs material while maintaining excellent thermodynamic performance, can exhibit excellent adsorption performance, and effectively solves the problem of stacking and efficiency reduction existing in the traditional forming method.

[0008] The fourth purpose of the present application is to provide a preparation method of the low water absorption Zn-MOFs composite formed body, which is simple to operate, controllable, low in production cost, safe and controllable, and suitable for industrialized production.

[0009] The fifth purpose of the present application is to provide an application of the low water absorption Zn-MOFs or the low water absorption Zn-MOFs composite formed body, which is beneficial to improve the effect of CO2 pressure swing adsorption.

[0010] In order to achieve the above-mentioned purposes of the present application, the following technical solutions are adopted: In a first aspect, a low water absorption Zn-MOFs is formed by a solvothermal reaction of a metal source and an organic ligand dissolved in a reaction solvent. The metal source includes at least one of zinc nitrate hexahydrate, zinc acetate, zinc chloride, zinc hydroxide, basic zinc carbonate, zinc oxide and oxides thereof. The organic ligand includes at least one of 1,2,4-triazole, 3-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 3-methyl-1,2,4-triazole, oxalic acid, isophthalic acid, terephthalic acid, 2,5-dihydroxyterephthalic acid, trimesic acid and fumaric acid.

[0011] In a second aspect, a preparation method of the low water absorption Zn-MOFs is provided, including the following steps: The metal source and the organic ligand are dissolved in the reaction solvent to perform a solvothermal reaction, so as to obtain the low water absorption Zn-MOFs.

[0012] Further, the reaction solvent includes at least one of N,N-dimethylformamide, water, methanol, ethanol and ethylene glycol. Preferably, the reaction temperature is 60-150℃, preferably 100-130℃. Preferably, the reaction time is 6h-72h, preferably 12h-48h.

[0013] In a third aspect, a low water absorption Zn-MOFs composite shaped body comprises a polymer carrier and Zn-MOFs crystals grown in the pores of the polymer carrier. The Zn-MOFs crystals are formed by in-situ crystallization self-assembly in the pores of the polymer carrier.

[0014] Further, the polymer carrier comprises a macroporous polymer carrier. Preferably, the macroporous polymer carrier comprises at least one of polyacrylate and polyacrylamide, preferably polyacrylate.

[0015] In a fourth aspect, a preparation method of the low water absorption Zn-MOFs composite shaped body is provided, comprising the following steps: The polymer carrier is immersed in a precursor solution of MOFs and then reacted to grow Zn-MOFs crystals in the pores of the polymer carrier, thereby obtaining the Zn-MOFs composite shaped body.

[0016] Further, the preparation method comprises the following steps: The oil phase of the macroporous polymer carrier is mixed with the water phase containing the precursor raw material in an aqueous system to perform a first reaction, and then the product obtained by the first reaction is dried and a solution containing the precursor raw material is added to perform a second reaction, thereby obtaining the Zn-MOFs composite shaped body.

[0017] Further, the oil phase comprises at least one of butyl acrylate, tert-butyl acrylate, tert-butyl methacrylate, trimethylolpropane triacrylate, glycidyl methacrylate, hexafluorobutyl acrylate, cyclohexane, toluene, xylene, carbon tetrachloride, and ethyl acetate. Preferably, the water phase comprises at least one of water, a metal source, an organic ligand, an oxidizing agent, and a dispersing agent. Preferably, the oxidizing agent comprises at least one of azobisisobutyronitrile, benzoyl peroxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide, and ammonium persulfate. Preferably, the dispersing agent comprises at least one of polyvinyl alcohol and polyvinylpyrrolidone.

[0018] Further, the temperature of the first reaction is 40℃-150℃, preferably 60℃-100℃. Preferably, the time of the first reaction is 0.5h-12h, preferably 1h-3h. Preferably, the temperature of the second reaction is 60℃-150℃, preferably 100℃-130℃. Preferably, the second reaction time is 6h-72h, preferably 12h-48h.

[0019] In a fifth aspect, the application provides a use of the low-water-absorption Zn-MOFs or the low-water-absorption Zn-MOFs composite formed body in CO2 pressure swing adsorption.

[0020] Compared with the prior art, the application has at least the following beneficial effects: The low-water-absorption Zn-MOFs provided by the application use a hydrophobic and nitrogen-rich organic ligand as a connecting agent of MOFs, and the Zn-MOFs powder is synthesized by regulating the crystal structure, and the Zn-MOFs are columnar and lamellar and hydrophobic and carbonophilic, and have low water absorption, low energy consumption, high CO2 adsorption capacity and high stability.

[0021] The preparation method of the low-water-absorption Zn-MOFs provided by the application is simple to operate, controllable, low in production cost, safe and controllable, and suitable for industrialized scale production.

[0022] The low-water-absorption Zn-MOFs composite formed body provided by the application has a multi-level pore coupling structure, improves the kinetic performance of the Zn-MOFs material while maintaining excellent thermodynamic performance, can exhibit excellent adsorption performance, and effectively solves the problem of stacking and performance reduction existing in the traditional forming method.

[0023] The preparation method of the low-water-absorption Zn-MOFs composite formed body provided by the application is simple to operate, controllable, low in production cost, safe and controllable, and suitable for industrialized scale production.

[0024] The application of the low-water-absorption Zn-MOFs or the low-water-absorption Zn-MOFs composite formed body provided by the application is conducive to improving the effect of CO2 pressure swing adsorption. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the specific embodiments or the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the application.

[0026] Figure 1 The scanning electron microscope image provided by one embodiment of the application. DETAILED DESCRIPTION

[0027] The technical solutions of the application will be described below in conjunction with the embodiments, and obviously, the described embodiments are some of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0028] According to a first aspect of the present application, a low water absorption Zn-MOFs is provided, which is formed by a solvothermal reaction of a metal source and an organic ligand in a reaction solvent; The metal source includes at least one of zinc nitrate hexahydrate, zinc acetate, zinc chloride, zinc hydroxide, basic zinc carbonate, zinc oxide and oxides thereof. The organic ligand includes at least one of 1,2,4-triazole, 3-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 3-methyl-1,2,4-triazole, oxalic acid, isophthalic acid, terephthalic acid, 2,5-dihydroxyterephthalic acid, trimesic acid and fumaric acid.

[0029] The present application uses hydrophobic and nitrogen-rich organic ligands as the connecting agent of MOFs, and synthesizes Zn-MOFs powder by controlling the crystal structure, which is a hydrophobic and carbon-loving columnar layered Zn-MOFs, and has low water absorption, low energy consumption, high CO2 adsorption capacity and high stability.

[0030] According to a second aspect of the present application, a preparation method of the low water absorption Zn-MOFs is provided, which comprises the following steps: The metal source and the organic ligand are dissolved in the reaction solvent to perform a solvothermal reaction, so as to obtain the low water absorption Zn-MOFs.

[0031] The preparation method of the present application is not only simple in operation, mild in reaction condition, but also has strong controllability, low production cost, safety and controllability, and is suitable for industrialized production.

[0032] The Zn metal source, the organic ligand and the reaction solvent are added into a beaker to mix uniformly to form a precursor solution, which is added into a reaction kettle with a polytetrafluoroethylene lining to perform a reaction, and the material after the reaction is centrifuged to obtain a white solid, which is washed with N,N-dimethylformamide and methanol, and the washed material is dried in a vacuum drying box to obtain the Zn-MOFs.

[0033] In a preferred embodiment, the metal source includes but is not limited to any one or more of zinc nitrate hexahydrate, zinc acetate, zinc chloride, zinc hydroxide, basic zinc carbonate, zinc oxide and oxides thereof.

[0034] In a preferred embodiment, the organic ligand includes but is not limited to any one or more of 1,2,4-triazole, 3-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 3-methyl-1,2,4-triazole, oxalic acid, isophthalic acid, terephthalic acid, 2,5-dihydroxyterephthalic acid, trimesic acid and fumaric acid.

[0035] In a preferred embodiment, the reaction solvent includes, but is not limited to, at least one of N,N-dimethylformamide, water, methanol, ethanol and ethylene glycol.

[0036] In a preferred embodiment, the temperature of the solvothermal reaction can be 60-150℃, and a typical but non-limiting temperature is, for example, 60℃, 80℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, and can be further preferred to be 100-130℃.

[0037] In a preferred embodiment, the time of the solvothermal reaction can be 6-72h, and a typical but non-limiting time is, for example, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 30h, 40h, 50h, 60h, 70h, and can be further preferred to be 12-48h.

[0038] According to a third aspect of the present application, a low-water-absorption Zn-MOFs composite shaped body is provided, including a polymer carrier and Zn-MOFs crystals grown in the pores of the polymer carrier. The Zn-MOFs crystals are formed by in-situ crystallization and self-assembly in the pores of the polymer carrier.

[0039] The low-water-absorption Zn-MOFs composite shaped body of the present application has a multi-level pore coupling structure, which improves the kinetic performance of Zn-MOFs materials while maintaining excellent thermodynamic performance, can exhibit excellent adsorption performance, and effectively solves the problem of stacking and performance reduction existing in traditional shaping methods.

[0040] In a preferred embodiment, the polymer carrier includes, but is not limited to, a macroporous polymer carrier; the macroporous polymer carrier includes, but is not limited to, at least one of polyacrylate and polyacrylamide, and can be further preferred to be polyacrylate.

[0041] According to a fourth aspect of the present application, a preparation method of the above-mentioned low-water-absorption Zn-MOFs composite shaped body is provided, including the following steps: After the polymer carrier is immersed in the precursor solution of MOFs, the polymer carrier is reacted to grow Zn-MOFs crystals in-situ in the pores of the polymer carrier, and a Zn-MOFs composite shaped body is obtained.

[0042] The precursor solution of MOFs is impregnated in a macroporous polymer carrier, and then a solvothermal reaction is carried out, so that the growth of Zn-MOFs crystals in the internal macropores of the carrier is realized, and the Zn-MOFs composite formed body is obtained; while realizing the powder structuring, the limited space and high surface energy provided by the macroporous polymer carrier are used to reduce the particle size of the Zn-MOFs crystals, and higher CO2 adsorption efficiency is provided; in addition, since the carrier is a multi-level pore interpenetrating network, the powder can maintain fast adsorption kinetics while realizing the molding, and the problem of efficiency reduction caused by stacking in the traditional molding method is effectively solved.

[0043] The preparation method is simple in operation, mild in reaction condition, strong in controllability, low in production cost, safe and controllable, and suitable for industrialized scale production.

[0044] The oil phase of the macroporous polymer carrier is mixed with the water phase containing the precursor raw material for compounding in an aqueous system, and a first reaction is carried out at a certain temperature; after the product obtained by the first reaction is dried, a mixed solution containing the remaining precursor raw material is added, and a second reaction is carried out at a certain temperature, so that the Zn-MOFs composite formed body is obtained.

[0045] In the present application, the oil phase can be any one or more of methyl acrylate, butyl acrylate, tert-butyl acrylate, tert-butyl methacrylate, trimethylolpropane triacrylate, glycidyl methacrylate, hexafluorobutyl acrylate, cyclohexane, toluene, xylene, carbon tetrachloride and ethyl acetate.

[0046] The precursor raw material can also include an organic ligand, which is dissolved in a solvent and participates in the reaction.

[0047] In the present application, the water phase can include any one or more of water, a metal source, an organic ligand, an oxidizing agent and a dispersing agent.

[0048] In a preferred embodiment, the oxidizing agent includes but is not limited to any one or more of azobisisobutyronitrile, benzoyl peroxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide and ammonium persulfate.

[0049] In a preferred embodiment, the dispersing agent includes but is not limited to any one or more of polyvinyl alcohol and polyvinylpyrrolidone.

[0050] In a preferred embodiment, the temperature of the first reaction can be 40-150℃, and a typical but non-limiting temperature thereof is, for example, 40℃, 60℃, 80℃, 100℃, 120℃, 140℃, 150℃, and it can be further preferred to be 60-100℃; the time of the first reaction can be 0.5-12h, and a typical but non-limiting time thereof is, for example, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 12h, and it can be further preferred to be 1-3h.

[0051] In a preferred embodiment, the temperature of the second reaction can be 60-150℃, and a typical but non-limiting temperature thereof is, for example, 60℃, 80℃, 100℃, 120℃, 140℃, 150℃, and it can be further preferred to be 100-130℃; the time of the second reaction can be 6-72h, and a typical but non-limiting time thereof is, for example, 6h, 8h, 10h, 12h, 14h, 16h, 20h, 30h, 40h, 50h, 60h, 72h, and it can be further preferred to be 12-48h.

[0052] In summary, the Zn-MOFs composite formed body is synthesized by in-situ crystallization self-assembly technology in the present application, and has a multi-level pore coupling structure, which optimizes the kinetic performance of the Zn-MOFs material while maintaining excellent thermodynamic performance; it is verified by experiments that the Zn-MOFs crystal in the composite formed body has more excellent adsorption performance than the Zn-MOFs powder obtained by the solvent method, and effectively solves the problem of stacking and reducing efficiency existing in the traditional forming method.

[0053] According to a fifth aspect of the present application, the application of the low-water-absorption Zn-MOFs or the low-water-absorption Zn-MOFs composite formed body described above in CO2 pressure swing adsorption is provided.

[0054] The Zn-MOFs and the composite formed body thereof in the present application can be used for CO2 pressure swing adsorption separation in a high-water-content scene, and are beneficial to improve the effect of CO2 pressure swing adsorption.

[0055] The present application will be further described by examples. Unless otherwise specified, the materials in the examples are prepared according to the existing method or directly purchased from the market.

[0056] Example 1 A preparation method of a Zn2(Atz)2(IPA) powder, comprising the following steps: ZnO (0.81 g), isophthalic acid (IPA) (0.82 g), 3-amino-1, 2, 4-triazole (Atz) (1.68 g) and a mixture of water (8 mL) and N, N-dimethylformamide (DMF) (2 mL) were sequentially poured into a 25 mL glass beaker and stirred for 30 min to mix uniformly; the mixture was poured into a 25 mL polytetrafluoroethylene liner, and the liner was placed in a high-pressure kettle and sealed for reaction in a 403 K oven for 24 h; after the reaction was completed, the white product was separated by a centrifuge, washed several times with DMF and methanol, and then dried in a vacuum oven at 353 K for 12 h to obtain Zn2(Atz)2(IPA) powder.

[0057] Example 2 A method for preparing Zn2(Datz)2(IPA) powder, comprising the following steps: A mixture of Zn(NO3)2·6(H2O) (2.97 g), IPA (0.82 g), Datz (1.68 g), water (1 mL), methanol (4 mL) and DMF (4 mL) was sequentially poured into a 25 mL glass beaker and stirred for 30 min to mix uniformly; the mixture was poured into a 25 mL polytetrafluoroethylene liner and the liner was placed in a high-pressure kettle and sealed for high-temperature reaction in a 383 K oven for 72 h; after the reaction was completed, the white product was separated by a centrifuge, washed several times with DMF and methanol, and then dried in a vacuum oven at 353 K for 12 h to obtain Zn2(Datz)2(IPA) powder, and a scanning electron microscope image thereof is shown in Figure 1 a.

[0058] Example 3 A method for preparing Zn2(Datz)2(IPA)@AFP-1 composite shaped body, comprising the following steps: 0.2 g of AFP carrier was weighed, and Zn(NO3)2·6(H2O) (4.45 g dissolved in 5 mL of water), IPA (1.23 g dissolved in 5 mL of DMF) and Datz (2.52 g dissolved in a mixed solution of 0.5 mL of water, 2 mL of methanol and 2 mL of DMF) were sequentially impregnated into the AFP balls under vacuum; the mixture was transferred to a high-pressure kettle containing a 10 mL polytetrafluoroethylene liner, and reacted in a 383 K oven for 72 h; the product was collected by filtration, washed with DMF and methanol, and then dried in a vacuum oven at 343 K for 12 h to obtain Zn2(Datz)2(IPA)@AFP-1 composite shaped body, and a scanning electron microscope image thereof is shown in Figure 1 f (internal structure diagram); The synthesis steps of the macroporous polyacrylate carrier, i.e. AFP carrier, are as follows: Oil phase: the reaction monomer glycidyl methacrylate (2.3 g), tert-butyl methacrylate (0.7 g), crosslinking agent trimethylolpropane triacrylate (2.0 g), emulsifier PEG-PPG-PEG (0.5 g) and oxidant benzoyl peroxide (0.2 g) were sequentially dissolved in 5 mL of toluene, and mixed under ultrasonic conditions for 10 min to form an oil phase; Water phase: 15 mL of deionized water was weighed as the water phase; Emulsion preparation: under continuous high-speed stirring, the above-mentioned dispersed phase was added dropwise into the oil phase to obtain a water-in-oil emulsion, and a reducing agent N,N-dimethylaniline (0.3 mL) of benzoyl peroxide was added during stirring at 8000 r·min -1 The reducing agent was uniformly dispersed in the emulsion by stirring at 8000 r·min Suspension polymerization: the obtained water-in-oil emulsion was slowly poured into the third phase containing deionized water (150 mL), polyvinyl alcohol (1 g) and ammonium persulfate (0.2 g); a reducing agent N,N,N',N'-tetramethyl ethylenediamine (0.5 mL) of ammonium persulfate was added to the third phase to initiate the redox reaction; the above reaction process was continuously reacted at a temperature of 333 K for 10 min, and the carrier obtained by the reaction was collected by filtration and dried in an oven at 343 K for 12 h for standby; Amine group functionalization: 2.0 g of the polyacrylate carrier was added to a mixed solution of tetraethylenepentamine (15 mL) and methanol (1 mL), and reacted at 383 K for 24 h; the above carrier was taken out, washed with deionized water until neutral, and dried in a vacuum oven at 343 K for 12 h to obtain an amine group functionalized polyacrylate carrier, i.e. AFP carrier, and the scanning electron microscope image thereof is shown in FIG. 2. Figure 1 b (morphology), c (surface pore structure), d (internal pore structure), e (internal pore structure).

[0059] Example 4 The Zn2(Datz)2(IPA)@AFP-1 composite formed body was immersed in water at 298 K, and after 24 h of immersion, it was taken out and dried to test the CO2 adsorption curve of the sample after water treatment, so as to characterize the change of the adsorption capacity of the crystal after the water stability experiment.

[0060] Example 5 The Zn2(Datz)2(IPA)@AFP-1 composite formed body was immersed in water at 298 K, and after 24 h of immersion, it was taken out and dried to test the CO2 adsorption curve of the sample after water treatment, so as to characterize the change of the adsorption capacity of the crystal after the water stability experiment.

[0061] Example 6 The Zn2(Datz)2(IPA)@AFP-1 composite shaped body was immersed in water with pH=2, and after 24h, the sample was taken out, dried and then the CO2 adsorption curve of the sample after water treatment was tested to characterize the change of the adsorption capacity of the crystal after the water stability experiment.

[0062] Example 7 The Zn2(Datz)2(IPA)@AFP-1 composite shaped body was immersed in water with pH=2, and after 24h, the sample was taken out, dried and then the CO2 adsorption curve of the sample after water treatment was tested to characterize the change of the adsorption capacity of the crystal after the water stability experiment.

[0063] Comparative Example 1 0.2g of AFP carrier was weighed, and Zn(NO3)2·6(H2O) (2.3g dissolved in 5mL water), IPA (0.62g dissolved in 5mL DMF), and Datz (1.2g dissolved in 0.5mL water, 2mL methanol and 2mL DMF mixed solution) were sequentially impregnated into the AFP balls under vacuum; the mixture was transferred to a high-pressure kettle containing 10mL of a polytetrafluoroethylene liner, and reacted in an oven at 383K for 72h; the product was collected by filtration, washed with DMF and methanol, and then placed in a vacuum oven at 343K for drying for 12h to obtain a composite shaped body.

[0064] Test Example The sample adsorption performance test results of Examples 1-7 and Comparative Example 1 are shown in Table 1.

[0065] Table 1: Sample adsorption performance test results

[0066] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A low water absorbing Zn-MOFs, characterized in that, is formed by a solvothermal reaction of a metal source and an organic ligand in a reaction solvent; the metal source includes at least one of zinc nitrate hexahydrate, zinc acetate, zinc chloride, zinc hydroxide, zinc carbonate basic, zinc oxide and oxides thereof; the organic ligand includes at least one of 1,2,4-triazole, 3-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 3-methyl-1,2,4-triazole, oxalic acid, isophthalic acid, terephthalic acid, 2,5-dihydroxyterephthalic acid, trimesic acid and fumaric acid.

2. A method of preparing the low water absorbing Zn-MOFs according to claim 1, characterized by, comprises the following steps: a solvothermal reaction of a metal source and an organic ligand in a reaction solvent to obtain the low-water-absorption Zn-MOFs.

3. The production method according to claim 2, characterized by, the reaction solvent includes at least one of N,N-dimethylformamide, water, methanol, ethanol and ethylene glycol; preferably, the reaction temperature is 60-150°C, preferably 100-130°C; preferably, the reaction time is 6-72h, preferably 12-48h.

4. A low water absorption Zn-MOFs composite molded body characterized by, comprises a polymer carrier and Zn-MOFs crystals grown in pores of the polymer carrier; the Zn-MOFs crystals are formed by in-situ crystallization and self-assembly in the pores of the polymer carrier.

5. The low-water-absorption Zn-MOFs composite molded body according to claim 4, characterized by the polymer carrier includes a macroporous polymer carrier; preferably, the macroporous polymer carrier includes at least one of polyacrylate and polyacrylamide, preferably polyacrylate.

6. A method for producing the low-water-absorption Zn-MOFs composite molded body according to claim 4 or 5, characterized by, comprises the following steps: immersing the polymer carrier in a precursor solution of MOFs and then performing a reaction to grow Zn-MOFs crystals in-situ in the pores of the polymer carrier to obtain the Zn-MOFs composite shaped body.

7. The production method according to claim 6, wherein the preparation method comprises the following steps: mixing an oil phase of the macroporous polymer carrier with an aqueous phase containing precursor raw materials in an aqueous system to perform a first reaction, drying the product obtained by the first reaction and then adding a solution containing precursor raw materials to perform a second reaction to obtain the Zn-MOFs composite shaped body.

8. The preparation method according to claim 7, characterized in that, the oil phase includes at least one of butyl acrylate, tert-butyl acrylate, tert-butyl methacrylate, trimethylolpropane triacrylate, glycidyl methacrylate, hexafluorobutyl acrylate, cyclohexane, toluene, xylene, carbon tetrachloride and ethyl acetate; preferably, the aqueous phase includes at least one of water, a metal source, an organic ligand, an oxidizing agent and a dispersant; preferably, the oxidizing agent includes at least one of azobisdimethylvaleronitrile, benzoyl peroxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide and ammonium persulfate; preferably, the dispersant includes at least one of polyvinyl alcohol and polyvinylpyrrolidone.

9. The preparation method according to claim 7, characterized in that, the temperature of the first reaction is 40-150°C, preferably 60-100°C; preferably, the time of the first reaction is 0.5-12h, preferably 1-3h; preferably, the temperature of the second reaction is 60-150°C, preferably 100-130°C; preferably, the time of the second reaction is 6-72h, preferably 12-48h.

10. Use of the low water absorbing Zn-MOFs according to claim 1 or the low water absorbing Zn-MOFs composite shaped body according to claim 4 or 5 in CO2 pressure swing adsorption.

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