Three-dimensional rare earth sulfate supramolecular porous material as well as preparation method and application thereof
By constructing a rare earth ion-sulfate-amide organic amine mixed solvent system, the controllable synthesis of rare earth sulfate porous materials was achieved, solving the problems of high synthesis difficulty and low porosity of rare earth sulfate materials. Rare earth sulfate porous materials with high specific surface area and adjustable pore size were prepared and applied to gas adsorption, hydrogen energy storage and catalysis.
Patent Information
- Application Number
- CN202511379528.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-25
- Publication Date
- 2026-01-20
AI Technical Summary
Existing rare earth sulfate materials are difficult to synthesize and have unstable structures. Traditional methods produce materials with low porosity, making it difficult to achieve the controllable synthesis of high-porosity rare earth sulfate porous materials.
A mixed solvent system of rare earth ion solution-DMSO-PMDETA was used to achieve the directional assembly of rare earth sulfate frameworks under mild conditions. Amide organic amines were introduced to regulate the pore structure, and three-dimensional rare earth sulfate supramolecular porous materials were synthesized by solvothermal method.
A high specific surface area and adjustable pore size of rare earth sulfate porous materials have been achieved, making them suitable for applications such as gas adsorption, hydrogen storage, and catalysis.
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Figure CN121361824A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of rare earth porous materials, and particularly relates to a three-dimensional rare earth sulfate supramolecular porous material and a preparation method and application thereof. BACKGROUND
[0002] As a new inorganic-organic hybrid functional material, three-dimensional rare earth sulfate supramolecular porous materials have shown great application potential in the fields of energy storage, environmental governance, and biomedical engineering in recent years. This kind of material ingeniously combines the unique photoelectric and electromagnetic properties of rare earth elements with the high specific surface area and adjustable pore structure of porous materials, providing a new material basis for solving the major challenges in the current energy and environmental fields. With the growing global demand for clean energy and environmental protection, the development of high-performance porous materials has become a research hotspot in the field of materials science.
[0003] However, existing rare earth framework materials mostly rely on phosphoric acid, phosphorous acid, germanic acid, etc. as ligands, and there are few studies on rare earth framework coordinated with sulfate due to high synthesis difficulty and unstable structure. The reasons are as follows: 1) the coordination number of rare earth elements is high and the coordination geometry is variable, and the product is mostly dense phase or low-dimensional structure, which makes the structure of rare earth sulfate less controllable; 2) the solubility of sulfate is low, and when the concentration of sulfate is high in the system during crystal growth, rare earth ions and sulfate are easy to form precipitates, which is not conducive to crystal growth and structure regulation. In addition, the preparation of rare earth sulfates by traditional methods requires a strong acid environment or high-temperature sintering, resulting in low porosity of the product. Therefore, how to effectively regulate the growth process of rare earth sulfate crystals and controllably prepare rare earth sulfate porous materials with high porosity is a scientific problem to be solved in the field of rare earth materials. SUMMARY
[0004] In view of the deficiencies of the prior art, the present application realizes the directional assembly of rare earth sulfate framework and the controllable synthesis of three-dimensional rare earth sulfate supramolecular porous material under mild conditions by constructing a mixed solvent system of rare earth ion solution-DMSO-PMDETA. At the same time, by introducing amide organic amines in the synthesis system of rare earth sulfates, the dynamic adjustability of the pores is realized while maintaining the structural rigidity, and the crystal structure of rare earth sulfates is further regulated to controllably prepare rare earth sulfate porous materials with high porosity, which can be applied in gas adsorption and separation, hydrogen storage, and catalysis, etc.
[0005] To achieve the above purpose, the present application adopts the following technical solution: a preparation method of a three-dimensional rare earth sulfate supramolecular porous material, comprising the following steps:
[0006] S1, taking sulfuric acid solution, sulfate solution or dimethyl sulfoxide, and adding the amide organic amine into the rare earth ion solution to obtain a precursor solution; the concentration of the rare earth ion in the prepared precursor solution is 0.1-1.5 mol / L, the concentration of the amide organic amine is 10-100 mmol / L, the concentration of the sulfate radical is 0.2-2 mol / L or the concentration of the dimethyl sulfoxide is 0.2-2 mol / L;
[0007] S2, transferring the precursor solution to a reaction kettle with a polytetrafluoroethylene lining, and heat treating at 150-200℃ for 40-120h; after the reaction is completed, cooling to room temperature, and separating and washing the product to obtain the three-dimensional rare earth sulfate supermolecular porous material.
[0008] As a further improvement of the preparation method of the three-dimensional rare earth sulfate supermolecular porous material:
[0009] Preferably, the concentration of the rare earth ion in the rare earth ion solution in step S1 is 0.15-2 mol / L.
[0010] Preferably, the rare earth ion in the rare earth ion solution in step S1 is one or more of nitrate, triflate, tetrafluoroborate and halide of the rare earth ion.
[0011] Preferably, the solvent of the rare earth ion solution is one or more of water, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol and benzyl alcohol.
[0012] Preferably, the amide organic amine is one or more of N,N,N',N",N"-pentamethyldiethylenetriamine, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, 1,3-dimethylpropylene urea and 1,3-dimethyl-2-imidazolidinone.
[0013] Preferably, the concentration of the sulfuric acid solution in step S1 is 0.25-3 mol / L, and the concentration of the sulfate solution is 0.25-3 mol / L.
[0014] Preferably, the sulfate solution is one or more of ammonium sulfate, ammonium bisulfate, alkali metal sulfate and alkaline earth metal sulfate.
[0015] Preferably, the separated impurities are washed with methanol to remove black precipitate impurities in step S2.
[0016] The second object of the present application is to provide a three-dimensional rare earth sulfate supermolecular porous material prepared by the preparation method of the three-dimensional rare earth sulfate supermolecular porous material according to any one of the above.
[0017] The third object of the present application is to provide an application of the three-dimensional rare earth sulfate supermolecular porous material in gas adsorption, hydrogen energy storage and catalysis.
[0018] The present application has the following advantages over the prior art:
[0019] The present application belongs to the technical field of inorganic-organic hybrid materials, and combines the flexibility of organic components and the rigidity of inorganic components to synergistically optimize the mechanical properties of the material, and specifically relates to a long-range ordered framework with rare earth ions (for example, La 3+ , Ce 3+ / Ce 4+ , Pr 3+ , etc.) as nodes and sulfate (SO4 2- ) as ligands, and further introducing amide organic amines and rare earth sulfates for coordination to form more abundant pore structures. The material is controllably synthesized by a solvothermal method, has a high specific surface area and adjustable pore size, and is suitable for use in the fields of gas adsorption, hydrogen energy storage, catalysis and biomedicine.
[0020] The present application utilizes the slow decomposition of DMSO (dimethyl sulfoxide) at high temperature as a source of sulfate, or directly uses a sulfuric acid solution or a sulfate solution to control the crystallization process of rare earth sulfates, to realize the controllable synthesis of rare earth sulfate porous materials, and further introduces various amide organic amines in the synthesis system of rare earth sulfates to further control the crystal structure of rare earth sulfates, enriches the structure types of rare earth sulfate porous materials, and the prepared rare earth sulfate porous materials have a high specific surface area and adjustable pore size, and are suitable for use in the fields of gas adsorption, hydrogen energy storage and catalysis. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 is a crystal structure diagram of the three-dimensional rare earth sulfate supermolecular porous material prepared in examples 1, 2, 3, 4 and 5 of the present application;
[0022] Figure 2 is a crystal powder diffraction diagram of the three-dimensional rare earth sulfate supermolecular porous material prepared in examples 1, 2 and 3;
[0023] Figure 3 is a crystal thermogravimetric diagram of the three-dimensional rare earth sulfate supermolecular porous material prepared in examples 1, 2 and 3.
[0024] Figure 4 is a solid-state hydrogen absorption mass density diagram of the three-dimensional rare earth sulfate supermolecular porous material prepared in example 3;
[0025] Figure 5 is a solid-state hydrogen absorption mass density diagram of the three-dimensional rare earth sulfate supermolecular porous material prepared in example 4. DETAILED DESCRIPTION
[0026] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below with examples. All other examples obtained by those skilled in the art without creative labor based on the examples in the present application belong to the protection scope of the present application.
[0027] Example 1
[0028] The present example provides a preparation method of a three-dimensional rare earth sulfate supramolecular porous material, which specifically comprises the following steps:
[0029] S1, dissolve Ce(NO3)3·6H2O in a methanol and water (volume ratio of 2:1) solvent to obtain a rare earth ion solution, and the concentration of the rare earth ion is 0.3 mol / L;
[0030] Add dimethyl sulfoxide (DMSO) and N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA) to the above rare earth ion solution to obtain a precursor solution; the concentration of the rare earth ion in the prepared precursor solution is 0.3 mol / L, the concentration of the amide organic amine is 60 mmol / L, and the concentration of dimethyl sulfoxide is 0.6 mol / L;
[0031] S2, transfer the precursor solution to a reaction kettle with a polytetrafluoroethylene lining, heat treat at 170℃ for 72h, cool to room temperature after the reaction is completed, separate and purify the product, wash with methanol to remove impurities, and finally obtain a three-dimensional rare earth sulfate supramolecular porous material (NH4) Ce(SO4)2 crystal, and the crystal structure is as shown in Figure 1 .
[0032] Example 2
[0033] The present example provides a preparation method of a three-dimensional rare earth sulfate supramolecular porous material, which specifically comprises the following steps:
[0034] S1, dissolve Ce(NO3)3·6H2O in a methanol and water (volume ratio of 2:1) solvent to obtain a rare earth ion solution, and the concentration of the rare earth ion is 0.3 mol / L;
[0035] Add an ammonium sulfate solution (concentration of 0.25-3 mol / L) and N,N-dimethylformamide to the above rare earth ion solution to obtain a precursor solution; the concentration of the rare earth ion in the prepared precursor solution is 1.5 mol / L, the concentration of the amide organic amine is 100 mmol / L, and the concentration of the sulfate radical is 2 mol / L;
[0036] S2, the precursor solution is transferred to a reaction kettle with a polytetrafluoroethylene lining, and is heat treated at 170 DEG C for 72 h; after the reaction is completed, the product is cooled to room temperature, and is separated and purified; the product is washed with methanol to remove impurities, and finally, a three-dimensional rare earth sulfate supramolecular porous material (NH4) Ce(SO4)2 crystal is obtained; the crystal structure is as shown in Figure 1 .
[0037] Example 3
[0038] The embodiment provides a preparation method of a three-dimensional rare earth sulfate supramolecular porous material, and specifically comprises the following steps:
[0039] S1, Pr(NO3)3·6H2O is dissolved in a methanol and water (volume ratio 2:1) solvent to obtain a rare earth ion solution, and the concentration of the rare earth ion is 0.15 mol / L;
[0040] DMSO and PMDETA are added to the above rare earth ion solution to obtain a precursor solution; the concentration of the rare earth ion in the prepared precursor solution is 0.1 mol / L, the concentration of the amide organic amine is 10 mmol / L, and the concentration of the DMSO is 0.2 mol / L;
[0041] S2, the precursor solution is transferred to a reaction kettle with a polytetrafluoroethylene lining, and is heat treated at 170 DEG C for 72 h; after the reaction is completed, the product is cooled to room temperature, and is separated and purified; the product is washed with methanol to remove impurities, and finally, a three-dimensional rare earth sulfate supramolecular porous material (NH4) Ce(SO4)2 crystal is obtained; the crystal structure is as shown in Figure 1 .
[0042] The crystals obtained in Examples 1, 2 and 3 are verified for purity by using a powder X-ray diffraction analyzer (as shown in Figs. Figure 2 (a) and (b)). As can be seen from the figures, the positions of all diffraction peaks are consistent with the diffraction peak positions simulated by the single crystal data, and only the intensity is slightly different due to the different orientations of the crystals in the powder; the powder diffraction spectrum confirms the phase purity of the rare earth sulfate.
[0043] The rare earth sulfate porous materials (NH4) Ce(SO4)2 and (NH4) Pr(SO4)2 obtained in the embodiment are analyzed by thermogravimetry (as shown in Figs. Figure 3 (a) and (b)). Through the thermogravimetric analysis, it is found that the rare earth sulfate porous material is stable before 450 DEG C, and has very good thermal stability; the weight loss is 19.2% between 450 DEG C and 530 DEG C, which corresponds to the loss of 1 NH4 +and 1 SO3 molecule (theoretical weight loss 19.9%), and weight loss 31.5% between 710-830℃ corresponding to 1 SO3 molecule (theoretical weight loss 30.9%). The thermogravimetric analysis spectrum shows that the rare earth sulfate porous material prepared in the application has good thermal stability.
[0044] Example 4
[0045] The embodiment provides a preparation method of a three-dimensional rare earth sulfate supramolecular porous material, and specifically comprises the following steps:
[0046] S1, dissolving Eu(NO3)3·6H2O in a methanol and water (volume ratio 2:1) solvent to obtain a rare earth ion solution, wherein the concentration of the rare earth ion is 1 mol / L;
[0047] In the rare earth ion solution, an ammonium bisulfate solution (concentration 0.25-3 mol / L) and 1,3-dimethylpropylene urea are added to obtain a precursor solution; the concentration of the rare earth ion in the prepared precursor solution is 0.8 mol / L, the concentration of the amide organic amine is 40 mmol / L, and the concentration of the sulfate radical is 0.4 mol / L;
[0048] S2, transferring the precursor solution to a reaction kettle with a polytetrafluoroethylene lining, and performing heat treatment at 170℃ for 72h; after the reaction is completed, cooling to room temperature, and separating and purifying the product, washing with methanol to remove impurities, and finally obtaining a three-dimensional rare earth sulfate supramolecular porous material (NH4)Eu(SO4)2 crystal, and the crystal structure is as shown in Figure 1 .
[0049] Example 5
[0050] The embodiment provides a preparation method of a three-dimensional rare earth sulfate supramolecular porous material, and specifically comprises the following steps:
[0051] S1, dissolving La(NO3)3·6H2O in a methanol and water (volume ratio 2:1) solvent to obtain a rare earth ion solution, wherein the concentration of the rare earth ion is 1 mol / L;
[0052] In the rare earth ion solution, a dilute sulfuric acid solution (concentration 0.25-3 mol / L) and N,N-dimethylformamide are added to obtain a precursor solution; the concentration of the rare earth ion in the prepared precursor solution is 0.2 mol / L, the concentration of the amide organic amine is 40 mmol / L, and the concentration of the sulfate radical is 0.4 mol / L;
[0053] S2. The precursor solution was transferred to a reaction vessel lined with polytetrafluoroethylene and heat-treated at 170°C for 72 hours. After the reaction, it was cooled to room temperature, and the product was separated and purified. Impurities were removed by washing with methanol, and finally, three-dimensional rare earth sulfate supramolecular porous material (NH4)La(SO4)2 crystal was obtained. The crystal structure is as follows: Figure 1 As shown.
[0054] In summary, this invention achieves the directional assembly of rare earth sulfate frameworks under mild conditions by constructing a rare earth ion-sulfate solution-amide organic amine mixed solvent system, thus realizing the controllable synthesis of rare earth sulfate porous materials. The prepared rare earth sulfate porous materials have high specific surface area and adjustable pore size, and are suitable for gas adsorption, hydrogen energy storage and catalysis.
[0055] The room temperature hydrogen storage mass density curves of (NH4)Pr(SO4)2 and (NH4)Eu(SO4)2 crystals in Examples 3 and 4 above are shown below. Figure 4 , 5 As shown, both exhibit room temperature hydrogen storage performance of 2.5 wt% and 3.5 wt%, respectively, demonstrating excellent application prospects in the field of solid-state hydrogen storage.
[0056] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments. It should be noted that many modifications and improvements can be made by those skilled in the art, and all modifications or improvements not exceeding the scope of the claims should be considered within the protection scope of the present invention.
Claims
1. A method for preparing a three-dimensional rare earth sulfate supramolecular porous material, characterized in that, Includes the following steps: S1. Take sulfuric acid solution, sulfate solution or dimethyl sulfoxide, and add it together with amide organic amine into rare earth ion solution to obtain precursor solution; The precursor solution contains rare earth ions at a concentration of 0.1-1.5 mol / L, amide organic amines at a concentration of 10-100 mmol / L, and sulfate at a concentration of 0.2-2 mol / L or dimethyl sulfoxide at a concentration of 0.2-2 mol / L. S2. The precursor solution is transferred to a reaction vessel with a polytetrafluoroethylene liner and heat-treated at 150-200℃ for 40-120h. After the reaction is completed, the mixture is cooled to room temperature, and the product is separated and washed to finally obtain a three-dimensional rare earth sulfate supramolecular porous material.
2. The method for preparing a three-dimensional rare earth sulfate supramolecular porous material according to claim 1, characterized in that, In step S1, the concentration of rare earth ions in the rare earth ion solution is 0.15-2 mol / L.
3. The method for preparing a three-dimensional rare earth sulfate supramolecular porous material according to claim 1 or 2, characterized in that, The rare earth ions in the rare earth ion solution of step S1 are one or more of the following: rare earth ions: nitrate, trifluoromethanesulfonate, tetrafluoroborate, and halide.
4. The method for preparing a three-dimensional rare earth sulfate supramolecular porous material according to claim 1 or 2, characterized in that, The solvent for the rare earth ion solution is one or more of the following: water, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, and benzyl alcohol.
5. The method for preparing a three-dimensional rare earth sulfate supramolecular porous material according to claim 1, characterized in that, The amide organic amine is one or more of N,N,N',N”,N”-pentamethyldiethylenetriamine, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, 1,3-dimethylpropylene urea, and 1,3-dimethyl-2-imidazolinone.
6. The method for preparing a three-dimensional rare earth sulfate supramolecular porous material according to claim 1, characterized in that, In step S1, the concentration of the sulfuric acid solution is 0.25-3 mol / L, and the concentration of the sulfate solution is 0.25-3 mol / L.
7. The method for preparing a three-dimensional rare earth sulfate supramolecular porous material according to claim 1 or 6, characterized in that, The sulfate solution is one or more of ammonium sulfate, ammonium bisulfate, alkali metal sulfate, and alkaline earth metal sulfate.
8. The method for preparing a three-dimensional rare earth sulfate supramolecular porous material according to claim 1, characterized in that, In step S2, the separated impurities are washed with methanol to remove the black precipitate impurities.
9. A three-dimensional rare earth sulfate supramolecular porous material prepared by the preparation method of any one of claims 1-8.
10. The application of the three-dimensional rare earth sulfate supramolecular porous material of claim 9 in gas adsorption, hydrogen energy storage and catalysis.