Mof-nh-so3h composite material and preparation method thereof, cation adsorption resin and preparation method and application thereof

Abstract

The application relates to the field of metal ion recovery, and discloses a MOF-NH-SO3H composite material and a preparation method thereof, a cation adsorption resin and a preparation method and application thereof. The method comprises the following steps: (1) mixing reaction I of a metal salt and 2-amino terephthalic acid in the presence of an alcohol substance to obtain an NH2-MOF material; the metal element in the metal salt is selected from at least one of a copper element, a zinc element and a zirconium element; (2) mixing reaction II of the NH2-MOF material and a sulfonating agent in the presence of an organic solvent to obtain a MOF-NH-SO3H composite material. The MOF-NH-SO3H composite material prepared by the method for preparing the MOF-NH-SO3H composite material has high metal lithium ion adsorption capacity and can selectively adsorb metal lithium ions.

Description

Technical Field

[0001] This invention relates to the field of lithium ion recovery, specifically to a MOF-NH-SO3H composite material and its preparation method, a cation adsorption resin and its preparation method and application. Background Technology

[0002] The booming development of the new energy industry has led to a significant increase in global lithium consumption. Precipitation, membrane separation, solvent extraction, and adsorption are important methods for lithium extraction from salt lakes. Among these, adsorption is widely used due to its advantages of simple process, high lithium recovery rate, and relatively low cost. However, the diagonal relationship between lithium and magnesium in the periodic table gives them similar chemical properties, and they have similar affinities for functional groups. Research and analysis have revealed that existing lithium-ion selective adsorption materials possess both adsorption site and size sieving functions. Therefore, based on... and Designing and constructing lithium-ion selective adsorbents based on differences in hydration diameter is an effective approach.

[0003] Metal-organic frameworks (MOFs) possess well-defined pore structures at the sub-nanometer scale and large specific surface areas, making them ideal media for constructing ion-selective adsorption materials. However, due to the flexibility and adaptability of MOF frameworks, and the similar properties of lithium and magnesium ions, MOFs are rarely used for the separation of monovalent and divalent ions.

[0004] For example, CN115888667A discloses a method for preparing a photosensitive regenerated lithium adsorbent. This method involves heating a metal-organic framework (MOF) and a spiropyran (SP) with an initiator to produce a photosensitive regenerated lithium ion adsorbent PSP-MOF with high selectivity for lithium and magnesium. The adsorbed material is desorbed and regenerated by sunlight, showing excellent stability. However, this adsorbent has the disadvantages of being expensive and having a complex preparation process.

[0005] Therefore, in view of the problems of existing lithium-ion adsorption materials that require acid / alkali / salt regeneration, have poor stability, or have low adsorption capacity, there is an urgent need to prepare a material with high selectivity for lithium ions, large adsorption capacity, easy regeneration, good cycle performance, and stable structure for the extraction of lithium ions from salt lakes. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing lithium-ion adsorption materials, such as low adsorption capacity and inability to selectively adsorb lithium and magnesium.

[0007] To achieve the above objectives, a first aspect of the present invention provides a method for preparing MOF-NH-SO3H composite materials, the method comprising:

[0008] (1) In the presence of alcohols, a metal salt and 2-aminoterephthalic acid are mixed and reacted to obtain NH2-MOF material; the metal element in the metal salt is selected from at least one of copper, zinc and zirconium.

[0009] (2) In the presence of an organic solvent, the NH2-MOF material is mixed with a sulfonating agent to obtain a MOF-NH-SO3H composite material.

[0010] The molar ratio of the metal salt, the 2-aminoterephthalic acid, and the sulfonating agent is 1:0.8-1.2:0.8-1.2.

[0011] In a preferred embodiment, in step (1), the metal salt is selected from at least one of the nitrates, hydrochlorides, and acetates of a metal element.

[0012] Preferably, the alcohol is selected from at least one of methanol, ethanol and ethylene glycol.

[0013] Preferably, in step (2), the sulfonating agent is 1,3-propanesulfonate lactone and / or 1,4-butanesulfonate lactone.

[0014] In a preferred embodiment, in step (2), the mixing reaction ⅠⅠ takes 20-28 hours.

[0015] A second aspect of the present invention provides a MOF-NH-SO3H composite material prepared by the method described in the first aspect.

[0016] A third aspect of the present invention provides a cation adsorption resin containing a MOF-NH-SO3H composite material and an organic binder, wherein the mass ratio of the MOF-NH-SO3H composite material to the organic binder is 18-20:1.

[0017] The MOF-NH-SO3H composite material is the MOF-NH-SO3H composite material described in the second aspect.

[0018] Preferably, the organic binder is a polymer, and the weight-average molecular weight of the polymer is 4000-6000.

[0019] Preferably, the polymer is polyvinyl chloride and / or polysulfone.

[0020] A fourth aspect of the present invention provides a method for preparing the cation adsorption resin described in the third aspect, the method comprising: performing a coagulation treatment on an intermediate material obtained by mixing a MOF-NH-SO3H composite material and a casting solution containing an organic binder to obtain the cation adsorption resin.

[0021] The fifth aspect of the present invention provides the application of the cation adsorption resin described in the third aspect in the adsorption of metallic lithium ions.

[0022] Through the above technical solution, the present invention has at least the following advantages:

[0023] (1) The preparation method of MOF-NH-SO3H composite material provided by the present invention increases the adsorption active sites of MOF-based adsorbent and enhances the metal ion absorption capacity.

[0024] (2) The preparation method of MOF-NH-SO3H composite material provided by the present invention is simple to operate and easy to implement, and has great application prospects in the field of lithium metal ion recovery.

[0025] (3) The MOF-NH-SO3H composite material provided by the present invention has a high adsorption capacity for lithium metal ions, can selectively adsorb lithium metal ions, and has the advantages of being recyclable, having good stability, and having a low loss rate.

[0026] (4) The cationic adsorption resin provided by the present invention is easy to recover, which solves the problem of difficult recovery of MOF-based powder adsorbent. Detailed Implementation

[0027] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0028] As previously stated, a first aspect of the present invention provides a method for preparing MOF-NH-SO3H composite materials, the method comprising:

[0029] (1) In the presence of alcohols, a metal salt and 2-aminoterephthalic acid are mixed and reacted to obtain NH2-MOF material; the metal element in the metal salt is selected from at least one of copper, zinc and zirconium.

[0030] (2) In the presence of an organic solvent, the NH2-MOF material is mixed with a sulfonating agent to obtain a MOF-NH-SO3H composite material.

[0031] The molar ratio of the metal salt, the 2-aminoterephthalic acid, and the sulfonating agent is 1:0.8-1.2:0.8-1.2.

[0032] According to a preferred embodiment, step (1) includes the following specific operations:

[0033] S1: Dissolve 2-aminoterephthalic acid in a portion of the alcohol to obtain solution A; and dissolve the metal salt in another portion of the alcohol to obtain solution B;

[0034] S2: Add solution B dropwise to solution A to carry out the mixing reaction I, and obtain the NH2-MOF material.

[0035] The present invention does not impose any particular limitation on the amount of alcohol added in step S1, as long as it can completely dissolve 2-aminoterephthalic acid and the metal salt; the present invention also does not impose any particular limitation on the dropping rate of solution B in step S2.

[0036] Preferably, the conditions for the mixed reaction I include: a temperature of 50-70°C and a time of 8-12 hours.

[0037] It should be noted that the time for the mixed reaction I described in this invention includes the time of dropwise addition.

[0038] In a preferred embodiment, in step (1), the metal salt is selected from at least one of the nitrates, hydrochlorides, and acetates of a metal element.

[0039] More preferably, the metal salt is selected from at least one of copper nitrate, zinc acetate, and zirconium chloride.

[0040] Preferably, in step (1), the alcohol is selected from at least one of methanol, ethanol and ethylene glycol.

[0041] Preferably, the method for preparing MOF-NH-SO3H composite material further includes: washing and drying the NH2-MOF material sequentially before step (2).

[0042] Preferably, in step (2), the sulfonating agent is 1,3-propanesulfonate lactone and / or 1,4-butanesulfonate lactone.

[0043] Preferably, in step (2), the organic solvent is at least one of chloroform, dichloromethane, and 1,2-dichloroethane.

[0044] In a preferred embodiment, in step (2), the mixing reaction ⅠⅠ takes 20-28 hours.

[0045] Preferably, in step (2), the method further includes: washing and drying the product obtained from the mixing reaction ⅠⅠ in sequence to obtain the MOF-NH-SO3H composite material.

[0046] As previously stated, a second aspect of the present invention provides a MOF-NH-SO3H composite material prepared by the method described in the first aspect.

[0047] As mentioned above, a third aspect of the present invention provides a cation adsorption resin containing a MOF-NH-SO3H composite material and an organic binder, wherein the mass ratio of the MOF-NH-SO3H composite material to the organic binder is 18-20:1.

[0048] The MOF-NH-SO3H composite material is the MOF-NH-SO3H composite material described in the second aspect.

[0049] Preferably, the organic binder is a polymer, and the weight-average molecular weight of the polymer is 4000-6000.

[0050] Preferably, the polymer is polyvinyl chloride and / or polysulfone.

[0051] As previously stated, a fourth aspect of the present invention provides a method for preparing the cation adsorption resin described in the third aspect, the method comprising: performing a coagulation treatment on an intermediate material obtained by mixing a MOF-NH-SO3H composite material and a casting solution containing an organic binder to obtain the cation adsorption resin.

[0052] According to a preferred embodiment, the specific operation of the coagulation treatment includes: adding the intermediate material dropwise into a water coagulation bath system for coagulation treatment.

[0053] The water coagulation bath system described in this invention refers to a coagulation bath system that uses water as the coagulation liquid. Using this system, the intermediate material can be transformed from a liquid state to a solid state.

[0054] Preferably, the dropping rate of the intermediate material is 5-10 mL / min.

[0055] Preferably, the temperature of the water coagulation bath system is 25-35℃.

[0056] In a preferred embodiment, the solidification process takes 9-11 hours.

[0057] Preferably, the solvent in the casting solution is N,N-dimethylformamide and / or N,N-dimethylacetamide.

[0058] As previously described, the fifth aspect of the present invention provides the application of the cation adsorption resin described in the third aspect in the adsorption of metallic lithium ions.

[0059] Preferably, the lithium metal ion adsorption capacity is ≥22 mg / g, more preferably ≥24 mg / g, and even more preferably ≥25 mg / g.

[0060] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, the raw materials and equipment used are commercially available products.

[0061] Polyvinyl chloride (PVC): Purchased from Aladdin Company, with a weight-average molecular weight of 5000.

[0062] Polysulfone (PS): Purchased from Aladdin Company, with a weight-average molecular weight of 5000.

[0063] In the following examples, room temperature refers to a temperature of 23±2℃.

[0064] The following preparation examples illustrate the preparation method of the MOF-NH-SO3H composite material of the present invention.

[0065] Preparation Example 1

[0066] (1) At 60℃, 2-aminoterephthalic acid was dissolved in methanol to obtain solution A. 0.1 mol of the metal salt copper nitrate was dissolved in another part of methanol to obtain solution B. Then, solution B was added dropwise to solution A to carry out the reaction. The reaction time was 10 h. After the reaction was complete, the solution was centrifuged, washed, and dried to obtain NH2-MOF.

[0067] (2) The NH2-MOF obtained in step (1) is uniformly dispersed in 100 mL of chloroform, and then sulfonating agent 1,3-propanesulfonic acid lactone is added. The reaction is carried out at room temperature for 24 hours. After the reaction is complete, the mixture is centrifuged, washed, and dried to obtain MOF-NH-SO3H composite material (abbreviated as MOFs-1).

[0068] The molar ratio of the metal salt, 2-aminoterephthalic acid, and sulfonating agent is 1:1:1.

[0069] Preparation Example 2

[0070] The preparation was carried out using a method similar to that of Example 1, except that an equimolar amount of zinc acetate was used instead of copper nitrate.

[0071] Everything else is the same, resulting in the MOF-NH-SO3H composite material (MOFs-2 for short).

[0072] Preparation Example 3

[0073] The preparation was carried out using a method similar to that of Example 1, except that an equimolar amount of zirconium chloride was used instead of copper nitrate.

[0074] Everything else is the same, resulting in the MOF-NH-SO3H composite material (MOFs-3 for short).

[0075] Comparative Preparation Example 1

[0076] The preparation was carried out using a method similar to that of Preparation Example 1. The difference was that, in this comparative preparation example, the amount of metal salt was kept constant, and the molar ratio of metal salt, 2-aminoterephthalic acid and sulfonating agent was adjusted to 1:2:2.

[0077] Everything else is the same, resulting in the MOF-NH-SO3H composite material (abbreviated as MOFs-D1).

[0078] The following examples illustrate the preparation method of the cation adsorption resin of the present invention.

[0079] Example 1

[0080] The organic binder polyvinyl chloride was dissolved in 100g of N,N-dimethylformamide to form a casting solution. 95g of MOFs-1 was added to the casting solution. After the intermediate material was stirred and dispersed evenly, it was added dropwise to a 30℃ water coagulation bath system at a rate of 5mL / min using an injection pump for coagulation treatment (i.e., phase inversion) for 10h to obtain a cationic adsorption resin (referred to as resin-1).

[0081] The mass ratio of MOFs-1 to organic binder is 19:1.

[0082] Example 2

[0083] The procedure was carried out in a similar manner to that in Example 1, except that MOFs-1 were replaced with MOFs-2 of equal weight.

[0084] Everything else is the same, resulting in a cation adsorption resin (referred to as resin-2).

[0085] Example 3

[0086] The procedure was carried out using a method similar to that in Example 1, except that MOFs-1 was replaced with an equal weight of MOFs-3, and polysulfone was replaced with an equal weight of polyvinyl chloride.

[0087] Everything else is the same, resulting in a cation adsorption resin (referred to as resin-3).

[0088] Comparative Example 1

[0089] The procedure was carried out in a similar manner to that in Example 1, except that MOFs-1 was replaced with MOFs-D1 of equal weight.

[0090] Everything else is the same, resulting in a cation adsorption resin (referred to as resin-D1).

[0091] Application examples

[0092] Weigh 0.25 g of the cation adsorption resin prepared in the example and add it to 25 mL of lithium-containing solution (lithium ion concentration of 0.1 g / L and magnesium ion concentration of 0.1 g / L). Shake vigorously for 5 h, centrifuge to separate the layers, and obtain the extract phase and raffinate phase. Determine the concentration of residual metal ions in the raffinate phase using atomic absorption spectrometry to obtain the metal ion concentration in the extract phase. Then calculate the metal ion adsorption capacity using the following formula:

[0093] Adsorption capacity (mg / g) = (Metal ion concentration before adsorption - Metal ion concentration after adsorption) × Volume of lithium-containing solution / Mass of cation adsorption resin Equation (1)

[0094] In formula (1), the unit of metal ion concentration is mg / L, the unit of lithium-containing solution volume is L, and the unit of cation adsorption resin mass is g.

[0095] The calculation results are shown in Table 1.

[0096] Table 1

[0097] Cationic adsorption resin Lithium ion adsorption capacity (mg / g) Magnesium ion adsorption capacity (mg / g) Example 1 <![CDATA[Cu-MOF-NH-SO3H / PVC]]> 26.68 3.66 Example 2 <![CDATA[Zn-MOF-NH-SO3H / PVC]]> 22.73 5.73 Example 3 <![CDATA[Zr-MOF-NH-SO3H / PS]]> 24.17 4.48 Comparative Example 1 <![CDATA[Cu-MOF-NH-SO3H / PVC]]> 10.4 2.31

[0098] As can be seen from the results in Table 1, the MOF-NH-SO3H composite material prepared by the method provided in this invention has a high adsorption capacity for lithium ions and can selectively adsorb lithium ions, showing significantly better performance compared to existing technologies.

[0099] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. The application of a cation adsorption resin in the selective adsorption of metallic lithium ions, characterized in that, The cation adsorption resin has an ion adsorption capacity of ≥22 mg / g for lithium metal ions; the cation adsorption resin contains MOF-NH-SO3H composite material and organic binder, and the mass ratio of the content of MOF-NH-SO3H composite material to the content of organic binder is 18-20:1; The MOF-NH-SO3H composite material is prepared by a method comprising the following steps: (1) In the presence of alcohols, a metal salt and 2-aminoterephthalic acid are mixed and reacted to obtain NH2-MOF material; the metal element in the metal salt is selected from at least one of copper, zinc and zirconium. (2) In the presence of an organic solvent, the NH2-MOF material is mixed with a sulfonating agent to obtain a MOF-NH-SO3H composite material. The molar ratio of the metal salt, the 2-aminoterephthalic acid, and the sulfonating agent is 1:0.8-1.2:0.8-1.

2.

2. The application according to claim 1, characterized in that, In step (1), the metal salt is selected from at least one of the nitrates, hydrochlorides and acetates of a metal element; And / or, the alcohol is selected from at least one of methanol, ethanol and ethylene glycol.

3. The application according to claim 1, characterized in that, In step (2), the sulfonating agent is 1,3-propanesulfonate lactone and / or 1,4-butanesulfonate lactone.

4. The application according to any one of claims 1-3, characterized in that, In step (2), the mixing reaction ⅠⅠ takes 20-28 hours.

5. The application according to claim 1, characterized in that, The organic binder is a high molecular weight polymer, and the weight-average molecular weight of the high molecular weight polymer is 4000-6000.

6. The application according to claim 5, characterized in that, The polymer is polyvinyl chloride and / or polysulfone.

7. The application according to any one of claims 1-3, characterized in that, The preparation method of the cation adsorption resin includes: mixing an intermediate material obtained by mixing a MOF-NH-SO3H composite material and a casting solution containing an organic binder, and then performing a coagulation treatment to obtain the cation adsorption resin.