Porous liquid based on supramolecular deep-eutectic solvent as well as preparation method and application of porous liquid

Abstract

The invention provides a porous liquid based on a supramolecular deep-eutectic solvent and a preparation method and application thereof, the preparation method comprises the following steps: mixing methylated beta-cyclodextrin and levulinic acid, and then carrying out stirring reaction to obtain the supramolecular deep-eutectic solvent; the preparation method comprises the following steps: adding H2O2 into a phosphotungstic acid aqueous solution, stirring for reaction, adding a tetrabutylammonium chloride aqueous solution, and washing and drying an obtained solid to prepare peroxyphosphotungstic acid; the preparation method comprises the following steps: dissolving peroxy phosphotungstic acid and Zn (NO3) 2.6 H2O in methanol, adding a methanol solution containing 2-methylimidazole, stirring at room temperature to react, washing an obtained white solid, and drying to obtain peroxy phosphotungstic acid packaged ZIF-8; and mixing the ZIF-8 packaged with peroxy phosphotungstic acid with the supramolecular deep eutectic solvent, and uniformly dispersing through stirring and ultrasonic treatment to obtain the porous liquid.

Description

Technical Field

[0001] The invention relates to a porous liquid based on a supramolecular low eutectic solvent and a preparation method and application thereof, belonging to the technical field of fuel oil desulfurization. Background Art

[0002] Porous liquid refers to liquid materials with permanent pore structures. Professor Stuart L. James of Queen's University Belfast and his collaborators first proposed the concept of porous liquid in 2007, and divided porous liquids into three types according to the different causes of permanent pores: Type I is pure liquid porous liquid, that is, liquid composed of a single rigid molecule or component with a pore or cavity structure inside; Type II is a molecular porous liquid, that is, a liquid formed by a rigid main molecule with a cavity structure dissolved in a steric solvent; Type III is a porous solid material porous liquid, which mainly refers to a liquid formed by porous solid materials (such as MOF, molecular sieves, porous organic polymers, etc.) uniformly and stably dispersed in a steric solvent. Among them, Type III porous liquids prepared with porous solid materials as cavity main molecules and ionic liquids as steric solvents have many application examples in the field of fuel oil extraction / oxidative desulfurization. For example, Yang et al. used ZIF-8 loaded with phosphomolybdic acid as the cavity main molecule and ionic liquid [Emim][NTf2] as the hindered solvent to prepare type III porous liquid for extraction / oxidative desulfurization of fuel oil. After reacting for 2 hours at room temperature, the desulfurization rate of dibenzothiophene in the simulated fuel oil reached 100%. Yin and Li et al. used UiO-66 as the cavity main molecule and ionic liquid [P 6,6,6,14Two types of porous liquids with ][NTF2] and [Omim][NTF2] as hindered solvents were prepared for the extraction / oxidative desulfurization of fuel oil. Type III porous liquids based on porous solid materials / ionic liquids can improve the desulfurization rate when used for the extraction / oxidative desulfurization of fuel oil. However, ionic liquids are expensive and are not economically feasible for practical application. Moreover, ionic liquids have problems such as complex synthesis process and difficult purification. In particular, some ionic liquids, such as imidazole and pyridine ionic liquids, are difficult to biodegrade and have biological toxicity. These problems have led to great controversy in the feasibility of ionic liquids in actual industrial processes. Low eutectic solvents are low eutectic mixtures composed of hydrogen bond acceptors and hydrogen bond donors in a certain stoichiometric ratio, and their freezing point is significantly lower than the melting point of the pure substances of each component. As a new type of ionic liquid, low eutectic solvents not only have the characteristics of conventional ionic liquids, such as being liquid at room temperature or near room temperature, not volatile, high thermal stability and chemical stability, but also have characteristics superior to conventional ionic liquids, such as abundant and low-cost raw material sources, simple preparation process, low or no biological toxicity. Conventional low eutectic solvents have a small molecular volume and are easy to enter the main molecular cavity and block its pore structure, making it impossible to obtain porous liquids. Supramolecular low eutectic solvents are a new type of low eutectic solvents synthesized using supramolecular macrocyclic compounds (such as α-, β-, γ-cyclodextrin and its derivatives) as hydrogen bond receptors. Cyclodextrin has a diameter of The macrocyclic structure is larger than the pore opening diameter of many microporous solid materials. Therefore, it is completely feasible to construct porous liquids with microporous solid materials as cavity host molecules if supramolecular low eutectic solvents are used as steric hindered solvents. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a porous liquid based on a supramolecular deep eutectic solvent and a preparation method and application thereof.

[0004] The present invention provides a method for preparing a porous liquid based on a supramolecular deep eutectic solvent, comprising:

[0005] The methylated β-cyclodextrin and levulinic acid are mixed, and then stirred for reaction to obtain a supramolecular deep eutectic solvent;

[0006] Add H2O2 to the phosphotungstic acid aqueous solution, stir to react, add tetrabutylammonium chloride aqueous solution, wash and dry the obtained solid to prepare peroxyphosphotungstic acid;

[0007] Peroxyphosphotungstic acid and Zn(NO3)2·6H2O were dissolved in methanol, and a methanol solution containing 2-methylimidazole was added. After stirring at room temperature, the obtained white solid was washed and dried to obtain ZIF-8 encapsulating peroxyphosphotungstic acid.

[0008] The ZIF-8 encapsulating peroxyphosphotungstic acid is mixed with a supramolecular low eutectic solvent, and is uniformly dispersed by stirring and ultrasound to obtain a porous liquid.

[0009] Furthermore, the present invention provides a porous liquid based on a supramolecular deep eutectic solvent prepared by the above method.

[0010] Furthermore, the present invention provides an application of the above-mentioned porous liquid based on supramolecular low eutectic solvent in fuel oil extraction / oxidative desulfurization.

[0011] The advantages and beneficial effects of the present invention over the prior art are as follows:

[0012] 1. The present invention uses a low eutectic solvent instead of an ionic liquid as a hindered solvent to prepare a porous liquid, which can avoid the problems of high price of ionic liquids, complex synthesis process, difficult purification, difficulty in biodegradation, and biological toxicity. Using a supramolecular low eutectic solvent as a hindered solvent to construct a porous liquid can solve the problem that conventional low eutectic solvents are small in molecular volume and easily enter the cavity of the main molecule to block its pore structure. Moreover, the porous liquid is used for fuel oil extraction-oxidative desulfurization. Under the conditions of a solvent-oil mass ratio of 1:8 and a H2O2 / S molar ratio of 5:1, the desulfurization rate can reach 100%, which has great application prospects in the field of fuel oil desulfurization.

[0013] 2. The present invention uses a low eutectic solvent instead of an ionic liquid as a hindered solvent to prepare a porous liquid, thereby avoiding the problems of high price, complex synthesis process, difficult purification, difficulty in biodegradation, and biological toxicity of ionic liquids. Using a supramolecular low eutectic solvent instead of a conventional low eutectic solvent as a hindered solvent to construct a porous liquid can solve the problem that conventional low eutectic solvents are small in molecular volume and easily enter the cavity of the main molecule to block its pore structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 This is the preparation process of the porous liquid of the present invention.

[0016] Figure 2 The FTIR spectra of the peroxyphosphotungstic acid, ZIF-8 and ZIF-8 encapsulating different amounts of peroxyphosphotungstic acid of the present invention are shown.

[0017] Figure 3The XRD patterns of the peroxyphosphotungstic acid, ZIF-8 and ZIF-8 encapsulating different amounts of peroxyphosphotungstic acid in the present invention are shown. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] An embodiment of the present invention provides a method for preparing a porous liquid based on a supramolecular deep eutectic solvent, and the specific steps are as follows:

[0020] S1. Mixing methylated β-cyclodextrin and levulinic acid, stirring and reacting the mixture to obtain a supramolecular low eutectic solvent.

[0021] Permanent pores are a prerequisite for porous liquids. Conventional deep eutectic solvents are small in molecular size and easily enter the main molecular cavity, resulting in the disappearance of permanent pores. Supramolecular deep eutectic solvents are a new type of deep eutectic solvents synthesized with supramolecular macrocyclic compounds as hydrogen bond acceptors. Their large molecular volume makes it difficult to enter the main molecular cavity, thus maintaining the permanent pore structure of porous liquids.

[0022] S2, adding H2O2 to the phosphotungstic acid aqueous solution, stirring for reaction, adding tetrabutylammonium chloride aqueous solution, washing and drying the obtained solid to prepare peroxyphosphotungstic acid;

[0023] S3. Dissolve peroxyphosphotungstic acid and Zn(NO3)2·6H2O in methanol, add a methanol solution containing 2-methylimidazole, stir at room temperature for reaction, wash and dry the obtained white solid to obtain ZIF-8 encapsulating peroxyphosphotungstic acid.

[0024] The surface pore opening diameter of ZIF-8 is approximately It can prevent the supramolecular low eutectic solvent from entering the cavity and blocking its pore structure; at the same time, its inner cavity diameter is about It can just accommodate one phosphotungstic acid peroxide molecule. Moreover, the small H2O2 molecule can enter the inner cavity through the pore opening on the surface of ZIF-8 and react with phosphotungstic acid peroxide to achieve catalytic oxidative desulfurization.

[0025] S4. The ZIF-8 encapsulating peroxyphosphotungstic acid is mixed with a supramolecular low eutectic solvent, and is uniformly dispersed by stirring and ultrasound to obtain a porous liquid.

[0026] Porous liquids can act as both extractants and catalysts during the desulfurization process. ZIF-8 encapsulating peroxyphosphotungstic acid can catalyze oxidative desulfurization, and supramolecular low eutectic solvents can act as extractive desulfurization. Moreover, the porous liquid quasi-homogeneous system helps to improve the catalytic performance of the catalyst, thereby increasing the extraction / oxidative desulfurization rate.

[0027] In some specific embodiments, methylated β-cyclodextrin and levulinic acid are mixed in a molar ratio of 1:9-45.

[0028] In some specific embodiments, the methylated β-cyclodextrin and levulinic acid are mixed and reacted with stirring at 40° C.-100° C. for 0.5-3 hours.

[0029] In some specific embodiments, 7 ml of 30% by mass H2O2 aqueous solution is added to 2.1 ml of an aqueous solution containing 1.01 g of phosphotungstic acid, and the reaction is stirred for 60 min. Then, 2.1 ml of an aqueous solution containing 0.32 g of tetrabutylammonium chloride is added, and the obtained solid is washed and dried to obtain peroxyphosphotungstic acid.

[0030] In some specific embodiments, 80-400 mg of peroxyphosphotungstic acid and 1-3 mmol of Zn(NO3)2·6H2O are dissolved in 10-40 mL of methanol, 10-40 mL of a methanol solution containing 10-30 mmol of 2-methylimidazole is added, and the mixture is stirred at room temperature for 1-3 hours.

[0031] In some specific embodiments, the mass percentage of ZIF-8 encapsulating peroxyphosphotungstic acid in the porous liquid is 0.5-5%.

[0032] The ZIF-8 encapsulated with peroxyphosphotungstic acid plays a role in catalytic oxidation desulfurization in the desulfurization process. If its concentration is too low, the catalytic oxidation efficiency is low, and thus the desulfurization rate is low; conversely, if its concentration is too high, it is difficult to disperse evenly in the supramolecular low eutectic solvent, which affects the catalytic oxidation efficiency and also leads to a low desulfurization rate.

[0033] An embodiment of the present invention provides a porous liquid based on a supramolecular deep eutectic solvent prepared by the above method.

[0034] An embodiment of the present invention provides an application of the above-mentioned porous liquid based on supramolecular deep eutectic solvent in fuel oil extraction / oxidative desulfurization.

[0035] In some specific embodiments, a porous liquid based on a supramolecular low eutectic solvent is mixed and stirred with a simulated fuel oil at a mass ratio of 1:1-10; H2O2 is added after stirring, and the molar ratio of H2O2 to S in the simulated fuel oil is 1-10:1; the mixture is stirred and reacted at a temperature of 20-80°C for 1-3 hours. After the reaction is completed, the mixture is allowed to stand, and the upper oil phase is taken to determine the sulfur content, and the desulfurization rate is calculated.

[0036] In some specific embodiments, the simulated fuel is prepared by dissolving sulfide in n-dodecane or n-octane, with a sulfur content of 500 ppm; the sulfide includes various aliphatic sulfides and aromatic sulfides. Aromatic sulfides include thiophene, benzothiophene or dibenzothiophene and their derivatives. Aliphatic sulfides include mercaptans, thioethers, etc.

[0037] The present invention has been tested for many times, and some test results are now cited as references to further describe the invention in detail, and the following is a detailed description in conjunction with specific embodiments.

[0038] Example 1

[0039] Step (1), methylated β-cyclodextrin and levulinic acid are mixed in a molar ratio of 1:27, and stirred at 60° C. to react until a uniform and stable liquid is formed, thereby preparing a supramolecular low eutectic solvent.

[0040] Step (2), add 7 ml of 30% H2O2 aqueous solution to 2.1 ml of 1.01 g of phosphotungstic acid aqueous solution, stir and react for 60 min, then add 2.1 ml of 0.32 g of tetrabutylammonium chloride aqueous solution, and wash and dry the obtained solid to obtain peroxyphosphotungstic acid PPT.

[0041] Step (3), 243 mg of peroxyphosphotungstic acid and 2 mmol Zn(NO3)2·6H2O were dissolved in 25 mL methanol, 25 mL of methanol solution containing 20 mmol 2-methylimidazole was added, and the mixture was stirred at room temperature for 3 hours. The obtained white solid was washed and dried to obtain PPT@ZIF-8Ⅲ.

[0042] Step (4), dispersing 1% PPT@ZIF-8Ⅲ by mass in a supramolecular low eutectic solvent to prepare a porous liquid; mixing the porous liquid and simulated fuel (the simulated fuel is prepared by dissolving dibenzothiophene in n-octane, and the sulfur content is 500ppm) at a mass ratio of 1:8; after stirring, adding a 30% H2O2 aqueous solution by mass fraction, the molar ratio of H2O2 to S in the simulated fuel is 5:1, and then stirring and reacting at 70°C for 2.5 hours. After the reaction is completed, let it stand, take the upper oil phase to determine the sulfur content, and calculate the desulfurization rate. The desulfurization rate of this embodiment reaches 100%.

[0043] Figure 2 The FTIR spectra of ZIF-8, PPT, and PPT@ZIF-8 are shown. 1085cm -1 and 1058cm -1 is the stretching vibration absorption peak of PO. These two absorption peaks can also be found in all PPT@ZIF-8. This shows that PPT is successfully encapsulated in ZIF-8. Figure 3 It can be seen that 2θ=7.3, 10.3, 12.6, 14.6, 16.4, 17.9, 24.3 and 26.5° are the characteristic diffraction peaks of ZIF-8. These 8 characteristic peaks can be found in all PPT@ZIF-8, indicating that the crystal structure of ZIF-8 remains unchanged after encapsulating PPT. The porous liquid based on the supramolecular low eutectic solvent synthesized in the present invention can simultaneously play the dual role of extractant and catalyst in the desulfurization process. ZIF-8 encapsulating peroxyphosphotungstic acid can play a catalytic oxidative desulfurization role, and the supramolecular low eutectic solvent can play an extractive desulfurization role. Moreover, the porous liquid quasi-homogeneous system helps to improve the catalytic performance of the catalyst, thereby improving the extraction / oxidative desulfurization rate.

[0044] Example 2

[0045] Step (1) and step (2) are the same as in Example 1.

[0046] Step (3), 162 mg of peroxyphosphotungstic acid and 2 mmol of Zn(NO3)2·6H2O were dissolved in 25 mL of methanol, 25 mL of a methanol solution containing 20 mmol of 2-methylimidazole was added, and the mixture was stirred at room temperature for 3 hours. The obtained white solid was washed and dried to obtain PPT@ZIF-8Ⅱ.

[0047] Step (4), dispersing 3% PPT@ZIF-8Ⅱ in a supramolecular low eutectic solvent to prepare a porous liquid; mixing the porous liquid and simulated fuel at a mass ratio of 1:8; adding a 30% H2O2 aqueous solution after stirring, the molar ratio of H2O2 to S in the simulated fuel is 5:1, and then stirring and reacting at 70°C for 2.5 hours. After the reaction is completed, let it stand, take the upper oil phase to determine the sulfur content, and calculate the desulfurization rate. The desulfurization rate of this embodiment reaches 97.8%.

[0048] Example 3

[0049] Step (1) and step (2) are the same as in Example 1.

[0050] Step (3), 81 mg of peroxyphosphotungstic acid and 2 mmol Zn(NO3)2·6H2O were dissolved in 25 mL methanol, 25 mL of methanol solution containing 20 mmol 2-methylimidazole was added, and the mixture was stirred at room temperature for 3 hours. The obtained white solid was washed and dried to obtain PPT@ZIF-8Ⅰ.

[0051] Step (4), dispersing 3% PPT@ZIF-8Ⅰ by mass in a supramolecular low eutectic solvent to prepare a porous liquid; mixing the porous liquid and simulated fuel at a mass ratio of 1:8; adding a 30% H2O2 aqueous solution after stirring, the molar ratio of H2O2 to S in the simulated fuel is 5:1, and then stirring and reacting at 70°C for 2.5 hours. After the reaction is completed, let it stand, take the upper oil phase to determine the sulfur content, and calculate the desulfurization rate. The desulfurization rate of this embodiment reaches 85.5%.

[0052] Example 4

[0053] Step (1) and step (2) are the same as in Example 1.

[0054] Step (3), 324 mg of peroxyphosphotungstic acid and 2 mmol of Zn(NO3)2·6H2O were dissolved in 25 mL of methanol, 25 mL of a methanol solution containing 20 mmol of 2-methylimidazole was added, and the mixture was stirred at room temperature for 3 hours. The obtained white solid was washed and dried to obtain PPT@ZIF-8Ⅳ.

[0055] Step (4), dispersing 1% PPT@ZIF-8Ⅳ by mass in a supramolecular low eutectic solvent to prepare a porous liquid; mixing the porous liquid and simulated fuel at a mass ratio of 1:8; adding a 30% H2O2 aqueous solution after stirring, the molar ratio of H2O2 to S in the simulated fuel is 5:1, and then stirring and reacting at 70°C for 2.5 hours. After the reaction is completed, let it stand, take the upper oil phase to determine the sulfur content, and calculate the desulfurization rate. The desulfurization rate of this embodiment reaches 100%.

[0056] Example 5

[0057] Step (1) and step (2) are the same as in Example 1.

[0058] Step (3), 243 mg of peroxyphosphotungstic acid and 2 mmol Zn(NO3)2·6H2O were dissolved in 25 mL methanol, 25 mL of methanol solution containing 20 mmol 2-methylimidazole was added, and the mixture was stirred at room temperature for 3 hours. The obtained white solid was washed and dried to obtain PPT@ZIF-8Ⅲ.

[0059] Step (4), dispersing 1% PPT@ZIF-8Ⅲ by mass in a supramolecular low eutectic solvent to prepare a porous liquid; mixing the porous liquid and simulated fuel at a mass ratio of 1:8; adding a 30% H2O2 aqueous solution after stirring, wherein the molar ratio of H2O2 to S in the simulated fuel is 5:1, and then stirring and reacting at 70°C for 2 hours. After the reaction is completed, the mixture is allowed to stand, and the upper oil phase is taken to determine the sulfur content, and the desulfurization rate is calculated. The desulfurization rate of this embodiment reaches 97.6%.

[0060] Example 6

[0061] Step (1) and step (2) are the same as in Example 1.

[0062] Step (3), 243 mg of peroxyphosphotungstic acid and 2 mmol Zn(NO3)2·6H2O were dissolved in 25 mL methanol, 25 mL of methanol solution containing 20 mmol 2-methylimidazole was added, and the mixture was stirred at room temperature for 3 hours. The obtained white solid was washed and dried to obtain PPT@ZIF-8Ⅲ.

[0063] Step (4), dispersing 1% PPT@ZIF-8Ⅲ by mass in a supramolecular low eutectic solvent to prepare a porous liquid; mixing the porous liquid and simulated fuel at a mass ratio of 1:8; adding a 30% H2O2 aqueous solution after stirring, wherein the molar ratio of H2O2 to S in the simulated fuel is 5:1, and then stirring and reacting at 60°C for 2.5 hours. After the reaction is completed, the mixture is allowed to stand, and the upper oil phase is taken to determine the sulfur content, and the desulfurization rate is calculated. The desulfurization rate of this embodiment reaches 79%.

[0064] Example 7

[0065] Step (1) and step (2) are the same as in Example 1.

[0066] Step (3), 243 mg of peroxyphosphotungstic acid and 2 mmol Zn(NO3)2·6H2O were dissolved in 25 mL methanol, 25 mL of methanol solution containing 20 mmol 2-methylimidazole was added, and the mixture was stirred at room temperature for 3 hours. The obtained white solid was washed and dried to obtain PPT@ZIF-8Ⅲ.

[0067] Step (4), dispersing 1% PPT@ZIF-8Ⅲ by mass in a supramolecular low eutectic solvent to prepare a porous liquid; mixing the porous liquid and simulated fuel at a mass ratio of 1:8; adding a 30% H2O2 aqueous solution after stirring, wherein the molar ratio of H2O2 to S in the simulated fuel is 3:1, and then stirring and reacting at 70°C for 2.5 hours. After the reaction is completed, the mixture is allowed to stand, and the upper oil phase is taken to determine the sulfur content, and the desulfurization rate is calculated. The desulfurization rate of this embodiment reaches 94.9%.

[0068] Example 8

[0069] Step (1) and step (2) are the same as in Example 1.

[0070] Step (3), 243 mg of peroxyphosphotungstic acid and 2 mmol Zn(NO3)2·6H2O were dissolved in 25 mL methanol, 25 mL of methanol solution containing 20 mmol 2-methylimidazole was added, and the mixture was stirred at room temperature for 3 hours. The obtained white solid was washed and dried to obtain PPT@ZIF-8Ⅲ.

[0071] Step (4), dispersing 1% PPT@ZIF-8Ⅲ by mass in a supramolecular low eutectic solvent to prepare a porous liquid; mixing the porous liquid and simulated fuel at a mass ratio of 1:9; adding a 30% H2O2 aqueous solution after stirring, wherein the molar ratio of H2O2 to S in the simulated fuel is 5:1, and then stirring and reacting at 70°C for 2.5 hours. After the reaction is completed, the mixture is allowed to stand, and the upper oil phase is taken to determine the sulfur content, and the desulfurization rate is calculated. The desulfurization rate in this embodiment reaches 98%.

[0072] Comparative Example 1

[0073] A porous liquid was prepared by dispersing 3% UIO66 in the ionic liquid [Omim][NTF2]; 0.5 g of the porous liquid was mixed with 5 ml of simulated fuel oil for stirring; after stirring, a 30% H2O2 aqueous solution was added, and the O / S molar ratio was 5:1, and then stirred at 50°C for 4.5 hours. After the reaction was completed, the mixture was allowed to stand, and the upper oil phase was taken to determine the sulfur content and the desulfurization rate was calculated. The desulfurization rate of this embodiment reached 90.0%.

[0074] Comparative Example 2

[0075] Disperse 7% UIO66 in ionic liquid [P 6,6,6,14 ][NTF2] to prepare a porous liquid; 0.5g of the porous liquid was mixed with 5ml of simulated fuel oil for stirring; after stirring, a 30% by mass H2O2 aqueous solution was added, and the O / S molar ratio was 5:1, and then stirred at 50°C for 4 hours. After the reaction was completed, the mixture was allowed to stand, and the sulfur content of the upper oil phase was determined. The desulfurization rate was calculated. The desulfurization rate of this embodiment reached 95.3%.

[0076] Compared with the comparative example, the porous liquid based on the supramolecular deep eutectic solvent of the present invention is used for fuel oil extraction / oxidative desulfurization, and a higher desulfurization rate (100%) can be obtained in a shorter desulfurization reaction time (2.5 hours). Compared with ionic liquids, deep eutectic solvents are easier to synthesize and have lower costs, which has very obvious advantages.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a porous liquid based on a supramolecular deep eutectic solvent, characterized in that: include: The methylated β-cyclodextrin and levulinic acid are mixed, and then stirred for reaction to obtain a supramolecular deep eutectic solvent; Add H2O2 to the phosphotungstic acid aqueous solution, stir to react, add tetrabutylammonium chloride aqueous solution, wash and dry the obtained solid to prepare peroxyphosphotungstic acid; Peroxyphosphotungstic acid and Zn(NO3)2·6H2O were dissolved in methanol, and a methanol solution containing 2-methylimidazole was added. After stirring at room temperature, the obtained white solid was washed and dried to obtain ZIF-8 encapsulating peroxyphosphotungstic acid. The ZIF-8 encapsulating peroxyphosphotungstic acid is mixed with a supramolecular low eutectic solvent, and is uniformly dispersed by stirring and ultrasound to obtain a porous liquid.

2. The method for preparing a porous liquid based on a supramolecular deep eutectic solvent according to claim 1, characterized in that: The methylated β-cyclodextrin and levulinic acid are mixed at a molar ratio of 1:9-45.

3. The method for preparing a porous liquid based on a supramolecular deep eutectic solvent according to claim 1, characterized in that: The methylated β-cyclodextrin and levulinic acid are mixed and reacted at 40° C.-100° C. with stirring for 0.5-3 hours.

4. The method for preparing a porous liquid based on a supramolecular deep eutectic solvent according to claim 1, characterized in that: 7 ml of 30% H2O2 aqueous solution was added to 2.1 ml of 1.01 g of phosphotungstic acid aqueous solution, and the mixture was stirred for 60 min. Then 2.1 ml of 0.32 g of tetrabutylammonium chloride aqueous solution was added. The obtained solid was washed and dried to obtain peroxyphosphotungstic acid.

5. The method for preparing a porous liquid based on a supramolecular deep eutectic solvent according to claim 1, characterized in that: Dissolve 80-400 mg of peroxyphosphotungstic acid and 1-3 mmol of Zn(NO3)2·6H2O in 10-40 mL of methanol, add 10-40 mL of a methanol solution containing 10-30 mmol of 2-methylimidazole, and stir at room temperature for 1-3 hours.

6. The method for preparing a porous liquid based on a supramolecular deep eutectic solvent according to claim 1, characterized in that: The mass percentage of ZIF-8 encapsulating peroxyphosphotungstic acid in the porous liquid is 0.5-5%.

7. A porous liquid based on a supramolecular deep eutectic solvent prepared by the method according to any one of claims 1 to 6.

8. Use of the porous liquid based on supramolecular deep eutectic solvent according to claim 7 in fuel oil extraction / oxidative desulfurization.

9. The use according to claim 8, characterized in that: The porous liquid based on the supramolecular low eutectic solvent and the simulated fuel are mixed and stirred at a mass ratio of 1:1-10; H2O2 is added after stirring, and the molar ratio of H2O2 to S in the simulated fuel is 1-10:1, and then the reaction is stirred at a temperature of 20-80°C for 1-3 hours. After the reaction is completed, the mixture is allowed to stand, and the upper oil phase is taken to determine the sulfur content and calculate the desulfurization rate.

10. The use according to claim 9, characterized in that: The simulated fuel is prepared by dissolving sulfides in n-dodecane or n-octane; the sulfides include various aliphatic sulfides and aromatic sulfides.

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