Novel polyacid-loaded metal organic framework material and application thereof

Abstract

The invention relates to a new polyacid-loaded metal organic framework material and application thereof, and belongs to the technical field of organic compound synthesis, 1-10 mmol of CuNO3. 3H2O, 2-20 mmol of H3BTC and 0.1-1 g of phosphomolybdic acid are weighed and dissolved in N, N-dimethylformamide, ultrasonic treatment and stirring are performed, the mixture is moved into a hydrothermal reaction kettle to be subjected to a hydrothermal reaction, cooling is performed to room temperature after the reaction is finished, and the polyacid-loaded metal organic framework material is obtained. And filtering and collecting a product, washing and drying to obtain the polyacid-loaded metal organic framework new material HPMoatCu-BTC. The invention also provides a method for catalytically synthesizing the dioctyl azelate by using the new polyacid-loaded metal organic framework material HPMoatCu-BTC. The polyacid-loaded metal organic framework new material has the advantages of simple synthesis, recoverability, reusability, no corrosion to equipment, high catalytic efficiency, light product color and luster and the like, and the synthesis method has the advantages of simple reaction operation, low reaction temperature and short reaction time, and is a new method for efficiently synthesizing isooctyl azelate.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic compound synthesis, and relates to a new metal-organic framework material loaded with polyoxometalate and its application, and more specifically to a method for synthesizing a new metal-organic framework material loaded with polyoxometalate for catalytic synthesis of dioctyl azelate and using the same to catalytically synthesize dioctyl azelate. Background Art

[0002] Dioctyl azelate (DOZ) belongs to the double-ester type synthetic lubricating base oil. Because of its good thermal stability, low volatility, good lubricity, and biodegradability, it is widely used in the industrial, automotive and aerospace fields. At the same time, it is also an excellent environmental-friendly plasticizer and can be used in the fields of polyvinyl chloride, polystyrene, etc. At present, the demand for dioctyl azelate in the domestic and international markets is very large. Its industrial production is esterified from azelaic acid and isooctanol under the catalysis of sulfuric acid. However, concentrated sulfuric acid is easy to corrode equipment, side reactions are likely to occur during the reaction process, the post-treatment process is complex, and a large amount of acidic wastewater is generated. Therefore, domestic and foreign researchers are exploring to replace sulfuric acid with better catalysts.

[0003] Among them, solid acid catalysts have the advantages of less corrosion to equipment, easy separation and recovery of products, easy recycling of catalysts, and less environmental pollution. Solid acid catalysts include metal oxides and composites, hydrotalcite, ion exchange resins, zeolites, heteropolyacids, ionic liquids, metal-organic framework materials, etc. Among them, metal-organic framework materials have the characteristics of high porosity, high specific surface area, clear and diverse structures and easy modification, and show more excellent activity in heterogeneous catalysis.

[0004] Therefore, it is of great significance to study the combination of polyoxometalate and metal-organic framework materials to develop new catalysts to solve the existing defects. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for synthesizing a new metal-organic framework material loaded with polyoxometalate for catalytic synthesis of dioctyl azelate and using the same to catalytically synthesize dioctyl azelate. This method uses a polyoxometalate solid catalyst loaded on a metal-organic framework material to replace the traditional sulfuric acid as a catalyst. This catalyst is simple to synthesize, has high catalytic efficiency, can be reused, and does not corrode equipment, thus opening up a new method for efficient synthesis of dioctyl azelate.

[0006] The technical solution adopted by the present invention to achieve its purpose:

[0007] A new metal-organic framework material loaded with polyoxometalate, and the new metal-organic framework material loaded with polyoxometalate is synthesized by a hydrothermal method: Weigh 1-10 mmol of CuNO 3 ·3H 2 O, 2-20 mmol of H 3BTC and 0.1 - 1 g of phosphomolybdic acid (H 3 PMo 12 O 40 ·nH 2 O, HPMo) were dissolved in 10 mL of N, N - dimethylformamide (DMF), ultrasonically treated for 15 - 30 min, stirred thoroughly and then transferred into a hydrothermal reaction kettle. The reaction was carried out at 120 °C for 24 - 48 h. After the reaction, it was cooled to room temperature, the product was collected by filtration, washed alternately with ethanol and water, and finally dried in an oven to obtain a new metal - organic framework material loaded with polyoxometalate, HPMo@Cu - BTC.

[0008] A synthesis process of dioctyl azelate is as follows:

[0009] S1. Esterification reaction: Azelaic acid and isooctanol were mixed at a mass ratio of 1:(2.0 - 3.0), added into a flask equipped with a stirrer, a thermometer and a condenser. After being stirred thoroughly to make them evenly mixed, a certain mass of the new metal - organic framework material loaded with polyoxometalate, HPMo@Cu - BTC, was added, and the reaction was carried out at a certain time and temperature to obtain a crude product of dioctyl isazelate.

[0010] S2. Refinement: The crude product of dioctyl azelate was filtered to remove the new metal - organic framework material loaded with polyoxometalate, HPMo@Cu - BTC; the filtrate was collected and distilled for purification, the unreacted isooctanol was distilled out, and dioctyl azelate was stored at 0 - 4 °C, crystallized and centrifuged to remove the unreacted azelaic acid, obtaining purified dioctyl azelate.

[0011] The beneficial effects of the present invention are as follows:

[0012] The present invention uses a new metal - organic framework material loaded with polyoxometalate synthesized by combining polyoxometalate with metal - organic framework material as a catalyst for synthesizing dioctyl azelate. Adsorption tests show that the specific surface area of this catalyst reaches 674 m 2 / g, and the pore size is concentrated at 0.6 nm. It has been successfully applied to the esterification reaction of synthesizing dioctyl azelate, achieving good catalytic effects. And this catalyst has a high recycling rate, and the product yield can still reach more than 96% after being reused 10 times.

[0013] The present invention combines polyoxometalate with metal - organic framework material to construct a solid catalyst of polyoxometalate supported on metal - organic framework material, and uses this material in the catalytic reaction of azelaic acid and isooctanol; it combines the advantages of polyoxometalate and metal - organic framework material, making up for the disadvantages of small specific surface area of polyoxometalate and being easily soluble in polar solvents and difficult to recycle and reuse.

[0014] A new material catalyst of metal-organic framework loaded with polyoxometalate was used to catalyze the esterification reaction of dioctyl azelate instead of sulfuric acid. This catalyst has the advantages of simple synthesis, reusability, non-corrosion of reaction vessels, high catalytic efficiency, etc. Moreover, the whole esterification reaction has simple operation and short reaction time. The synthesis method has simple reaction operation, low reaction temperature and short reaction time, and the product catalyzed is a light yellow transparent liquid, optimizing the product color. The catalyst is insoluble in the reaction system and easy to filter, and the post-treatment is very simple, thus opening up a new method for the efficient synthesis of dioctyl azelate. Brief Description of the Drawings

[0015] Figure 1 It is the nitrogen adsorption amount diagram of the new material HPMo@Cu-BTC of metal-organic framework loaded with polyoxometalate in Example 1.

[0016] Figure 2 It is the pore size distribution diagram of the new material HPMo@Cu-BTC of metal-organic framework loaded with polyoxometalate in Example 1.

[0017] Figure 3 It is the catalytic effect diagram of the new material HPMo@Cu-BTC catalyst of metal-organic framework loaded with polyoxometalate reused 10 times in Example 5. Detailed Embodiments

[0018] The present invention will be described in detail below with reference to the drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention. Where the present invention is not described in detail is the prior art. I. Specific Embodiments

[0020] Example 1

[0021] Weigh 1 mmol of CuNO 3 ·3H 2 O (0.24 g), 2 mmol of H 3 BTC (0.42 g) and 0.1 g of phosphomolybdic acid (H 3 PMo 12 O 40 ·nH 2 O, HPMo) and dissolve them in 10 mL of N,N-dimethylformamide (DMF). After ultrasonic treatment for 15 min and sufficient stirring and mixing, transfer them into a hydrothermal reaction kettle and react at 120 °C for 24 h. After the reaction, cool to room temperature, filter and collect the product, wash it alternately with ethanol and water, and finally dry it in an oven to obtain the new material HPMo@Cu-BTC of metal-organic framework loaded with polyoxometalate (hereinafter referred to as catalyst HPMo@Cu-BTC).

[0022] Example 2

[0023] Weigh 10 mmol of CuNO 3 ·3H 2 O (2.4 g), 20 mmol of H 3 BTC (4.2 g) and 1 g of phosphomolybdic acid (H 3 PMo 12 O 40 ·nH 2 O, HPMo) and dissolve them in 100 mL of N,N-dimethylformamide (DMF). After ultrasonic treatment for 15 min and thorough stirring, transfer the mixture into a hydrothermal reaction kettle and react at 120 °C for 24 h. After the reaction, cool it to room temperature, filter to collect the product, wash it alternately with ethanol and water, and finally dry it in an oven to obtain a new metal-organic framework material loaded with polyoxometalate, HPMo@Cu-BTC (hereinafter referred to as catalyst HPMo@Cu-BTC).

[0024] Example 3

[0025] Weigh 1 mmol of CuNO 3 ·3H 2 O (0.24 g), 2 mmol of H 3 BTC (0.42 g) and 0.1 g of phosphomolybdic acid (H 3 PMo 12 O 40 ·nH 2 O, HPMo) and dissolve them in 10 mL of N,N-dimethylformamide (DMF). After ultrasonic treatment for 30 min and thorough stirring, transfer the mixture into a hydrothermal reaction kettle and react at 120 °C for 24 h. After the reaction, cool it to room temperature, filter to collect the product, wash it alternately with ethanol and water, and finally dry it in an oven to obtain a new metal-organic framework material loaded with polyoxometalate, HPMo@Cu-BTC (hereinafter referred to as catalyst HPMo@Cu-BTC).

[0026] Example 4

[0027] Weigh 1 mmol of CuNO 3 ·3H 2 O (0.24 g), 2 mmol of H 3 BTC (0.42 g) and 0.1 g of phosphomolybdic acid (H 3 PMo 12 O 40 ·nH 2(O,HPMo) was dissolved in 10 mL of N,N-dimethylformamide (DMF), ultrasonicated for 15 min, and stirred thoroughly. After mixing evenly, it was transferred into a hydrothermal reactor and reacted at 120 °C for 48 h. After the reaction, it was cooled to room temperature, the product was collected by filtration, washed alternately with ethanol and water, and finally dried in an oven to obtain a new metal-organic framework material HPMo@Cu-BTC loaded with polyoxometalate (hereinafter referred to as catalyst HPMo@Cu-BTC).

[0028] Example 5

[0029] Weigh 18.8 g of azelaic acid and 32.5 g of isooctanol and add them to a flask equipped with a stirrer, a thermometer and a condenser. The molar ratio of acid to alcohol is 1:2.5. After stirring thoroughly to make them evenly mixed, add 1% of the catalyst HPMo@Cu-BTC (prepared in Example 1) based on the mass of azelaic acid, heat up to 190 °C, stir and react for 120 minutes, end the reaction, filter, separate and recover the catalyst HPMo@Cu-BTC, evaporate isooctanol under reduced pressure, store dioctyl azelate at 0-4 °C, crystallize and freeze-centrifuge to remove unreacted azelaic acid, and finally obtain the finished product of dioctyl azelate with a yield of 97.5%.

[0030] Example 6

[0031] The addition amounts of azelaic acid and isooctanol are the same as in Example 5. Add 0.5% of the catalyst HPMo@Cu-BTC (prepared in Example 1) based on the mass of azelaic acid, heat up to 190 °C, stir and react for 120 minutes, end the reaction, filter, separate and recover the catalyst HPMo@Cu-BTC, evaporate isooctanol under reduced pressure, store dioctyl azelate at 0-4 °C, crystallize and freeze-centrifuge to remove unreacted azelaic acid, and finally obtain the finished product of dioctyl azelate with a yield of 91.2%.

[0032] Example 7

[0033] The addition amounts of azelaic acid and isooctanol are the same as in Example 5. Add 2% of the catalyst HPMo@Cu-BTC (prepared in Example 1) based on the mass of azelaic acid, heat up to 190 °C, stir and react for 120 minutes, end the reaction, filter, separate and recover the catalyst HPMo@Cu-BTC, evaporate isooctanol under reduced pressure, store dioctyl azelate at 0-4 °C, crystallize and freeze-centrifuge to remove unreacted azelaic acid, and finally obtain the finished product of dioctyl azelate with a yield of 96.5%.

[0034] Example 8

[0035] The addition amounts of azelaic acid and isooctanol are the same as those in Example 5. Add 1% of the mass of azelaic acid of the catalyst HPMo@Cu-BTC (prepared in Example 1), heat up to 170 °C, stir and react for 120 minutes, end the reaction, filter, separate and recover the catalyst HPMo@Cu-BTC, evaporate isooctanol under reduced pressure, store dioctyl azelate at 0 - 4 °C, crystallize and freeze-centrifuge to remove the unreacted azelaic acid, and finally obtain the finished product of dioctyl azelate with a yield of 82.7%.

[0036] Example 9

[0037] The addition amounts of azelaic acid and isooctanol are the same as those in Example 5. Add 1% of the mass of azelaic acid of the catalyst HPMo@Cu-BTC (prepared in Example 1), heat up to 210 °C, stir and react for 120 minutes, end the reaction, filter, separate and recover the catalyst HPMo@Cu-BTC, evaporate isooctanol under reduced pressure, store dioctyl azelate at 0 - 4 °C, crystallize and freeze-centrifuge to remove the unreacted azelaic acid, and finally obtain the finished product of dioctyl azelate with a yield of 96.7%.

[0038] Example 10

[0039] The addition amounts of azelaic acid and isooctanol are the same as those in Example 5. Add 1% of the mass of azelaic acid of the catalyst HPMo@Cu-BTC (prepared in Example 1), heat up to 190 °C, stir and react for 60 minutes, end the reaction, filter, separate and recover the catalyst HPMo@Cu-BTC, evaporate isooctanol under reduced pressure, store dioctyl azelate at 0 - 4 °C, crystallize and freeze-centrifuge to remove the unreacted azelaic acid, and finally obtain the finished product of dioctyl azelate with a yield of 76.4%.

[0040] Example 11

[0041] The addition amounts of azelaic acid and isooctanol are the same as those in Example 5. Add 1% of the mass of azelaic acid of the catalyst HPMo@Cu-BTC (prepared in Example 1), heat up to 190 °C, stir and react for 90 minutes, end the reaction, filter, separate and recover the catalyst HPMo@Cu-BTC, evaporate isooctanol under reduced pressure, store dioctyl azelate at 0 - 4 °C, crystallize and freeze-centrifuge to remove the unreacted azelaic acid, and finally obtain the finished product of dioctyl azelate with a yield of 90.7%.

[0042] Example 12

[0043] The addition amounts of azelaic acid and isooctanol are the same as those in Example 5. Add the catalyst HPMo@Cu-BTC (prepared in Example 1) accounting for 1% of the mass of azelaic acid, heat up to 190 °C, stir and react for 150 minutes, end the reaction, filter, separate and recover the catalyst HPMo@Cu-BTC, evaporate isooctanol under reduced pressure, store dioctyl azelate at 0 - 4 °C, crystallize and centrifuge it frozen to remove unreacted azelaic acid, and finally obtain the finished product of dioctyl azelate with a yield of 97.5%.

[0044] Example 13

[0045] Since the esterification reaction effect in Example 5 is the best, the recovered catalyst HPMo@Cu-BTC separated in Example 5 was subjected to a recycling experiment, and the reaction effect after 10 uses is as Figure 3 shown. Thus, it can be seen that the recovered catalyst in the system of the method of the present invention has an excellent effect of recycling.

[0046] The results of the above examples are shown in Table 1.

[0047] Table 1

[0048]

[0049]

[0050] Using a new material catalyst of metal-organic framework loaded with polyoxometalate to replace sulfuric acid as the catalyst, the synthesis conditions of dioctyl azelate were optimized. The reaction temperature was optimized from 210 °C to 190 °C, and the reaction time was optimized from 3 hours to 2 hours. Moreover, the synthesized product has a higher purity and lighter color, and the used catalyst HPMo@Cu-BTC can also be recycled and reused 10 times. Compared with the reported sulfuric acid and solid acid catalysts (He Zuhui, Liu Yong, Cheng Xin, SO 4 2- / SnO 2 -TiO 2 -Al 2 O 3 Solid acid-catalyzed synthesis of dioctyl azelate, Applied Chemical Industry, 2013, 42, 650 - 653), the synthesis method of the present invention has simple reaction operation, low reaction temperature, short reaction time, the catalyst can be recycled and reused, and the product color is optimized, thus opening up a new method for the efficient synthesis of dioctyl azelate.

Claims

1. A new metal organic framework material loaded with polyacid, characterized in that: The preparation method is as follows: 1-10 mmol CuNO3·3H2O, 2-20 mmol H3BTC and 0.1-1 g phosphomolybdic acid are weighed and dissolved in N,N-dimethylformamide, and the mixture is ultrasonically treated and stirred to be fully mixed, and then transferred into a hydrothermal reactor for hydrothermal reaction. After the reaction is completed, the mixture is cooled to room temperature, and the product is filtered and collected, washed and dried to obtain a new metal organic framework material HPMo@Cu-BTC loaded with polyacid.

2. A polyacid-loaded metal organic framework new material according to claim 1, characterized in that: The amount of N,N-dimethylformamide used is 10 mL.

3. A polyacid-loaded metal organic framework new material according to claim 1, characterized in that: The frequency of ultrasound is 20kHz, and the time of ultrasound is 15 to 30 minutes.

4. A polyacid-loaded metal organic framework new material according to claim 1, characterized in that: The temperature of the hydrothermal reaction is 120°C and the reaction time is 24 to 48 hours.

5. The new metal organic framework material loaded with polyacid according to claim 1, characterized in that: Wash with ethanol and water three times respectively.

6. A method for catalyzing the synthesis of dioctyl azelate by a new metal organic framework material loaded with polyacid, characterized in that: The following steps are involved: S1. Esterification reaction: Azelaic acid and isooctyl alcohol are mixed and added into a flask equipped with a stirrer, a thermometer and a condenser. After being stirred thoroughly to make them uniformly mixed, HPMo@Cu-BTC, a new metal organic framework material loaded with polyacid, is added and the temperature is raised to react to obtain a crude product of diisooctyl azelate; S2. Refining: The crude product of dioctyl azelaic acid is filtered to remove the new metal organic framework material HPMo@Cu-BTC loaded with polyacid; the filtrate is collected and distilled to purify, and the unreacted isooctyl alcohol is evaporated, and the dioctyl azelaic acid is stored at 0-4°C, crystallized and freeze-centrifuged to remove the unreacted azelaic acid, thereby obtaining purified dioctyl azelaic acid.

7. The method for synthesizing dioctyl azelate catalyzed by a new metal organic framework material loaded with polyacid according to claim 6, characterized in that: In step S1, the molar ratio of azelaic acid to isooctyl alcohol is 1:(2.0-3.0).

8. The method for synthesizing dioctyl azelate catalyzed by a new metal organic framework material loaded with polyacid according to claim 6, characterized in that: In step S1, the amount of the new metal organic framework material HPMo@Cu-BTC loaded with polyacid is 0.5-2% of the mass of azelaic acid.

9. The method for synthesizing dioctyl azelate catalyzed by a new metal organic framework material loaded with polyacid according to claim 6, characterized in that: In step S1, the temperature of the temperature-raising reaction is 170-210° C., and the reaction time is 60-150 min.

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