Porous liquid material based on MIL-100 (Fe) base, preparation of porous liquid material and application of porous liquid material in extraction coupling oxidative desulfurization

Abstract

The invention relates to the technical field of material science, in particular to a porous liquid material based on an MIL-100 (Fe) base, preparation of the porous liquid material and application of the porous liquid material in extraction coupling oxidative desulfurization. The porous liquid material based on the MIL-100 (Fe) base is successfully prepared by compounding the MIL-100 (Fe) metal organic framework and the ionic liquid. The material not only retains the high specific surface area and excellent pore structure characteristics of MOF, but also shows liquid characteristics, the fluidity and adaptability of the material in the extraction process are remarkably improved, and the material is especially suitable for the continuous multi-stage extraction process in the industry; and the material can realize high-efficiency sulfide molecular adsorption and oxidative desulfurization reaction under wider operation conditions. Compared with a traditional solid MOF material, the material has remarkable advantages in the desulfurization process, including higher desulfurization rate (more than 90%), higher reaction speed and excellent cycle stability.

Description

Technical Field

[0001] The present invention relates to the field of material science and technology, in particular to a porous liquid material based on MIL-100 (Fe), a preparation method thereof, and an application thereof in extraction-coupled oxidation desulfurization. Background Art

[0002] With increasingly stringent environmental regulations, the removal of sulfur compounds from fuels has become an urgent environmental issue. Residual sulfur compounds in fuels release large amounts of sulfur oxides (SOx) during combustion, causing severe atmospheric pollution and posing a threat to human health. Traditional desulfurization technologies primarily include hydrodesulfurization (HDS) and oxidative desulfurization (ODS). HDS is widely used in petroleum refining, but its removal efficiency for aromatic sulfides (such as dibenzothiophene, DBT) is poor, primarily due to their stable conjugated structure and lack of sufficient hydrogenation activity. This technology also requires high temperatures and pressures, resulting in high energy consumption. In contrast, oxidative desulfurization uses oxidants (such as hydrogen peroxide or ozone) to convert sulfides into soluble oxidation products (such as diphenylsulfide) under mild conditions, which are then removed by solvent extraction or adsorption. This method is highly effective in removing aromatic sulfides, does not require high temperatures or pressures, and is simple to operate, thus attracting widespread attention. However, oxidative desulfurization still faces several challenges, particularly in catalyst selection and reaction system optimization. Traditional oxidative desulfurization catalysts, such as metal oxides and transition metal salts, have limited catalytic activity and are easily contaminated in complex systems, resulting in low catalytic efficiency and selectivity.

[0003] Therefore, the development of new and efficient catalytic materials, especially catalysts with high specific surface area, adjustable active sites and good cycle performance, has become an important research direction in the current field of oxidative desulfurization. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a porous liquid material based on MIL-100 (Fe) and its preparation and application in extractive coupled oxidative desulfurization.

[0005] The present invention combines MOFs with ionic liquids to form a new type of composite material: porous liquid (PILs) material, which has a highly adjustable pore structure and catalytic performance. Due to their low vapor pressure, good thermal stability and solubility, ionic liquids show unique advantages in chemical processes such as adsorption and extraction separation. After the ionic liquid is combined with MOFs, it can not only further enhance the dispersibility and catalytic activity of the catalyst, but also improve the contact efficiency between the reactants and the catalyst, thereby enhancing the catalytic effect. This characteristic of the PILs material gives it great application potential in oxidative desulfurization reactions, especially in the removal of aromatic sulfides.

[0006] The object of the present invention can be achieved by the following technical solutions:

[0007] The first object of the present invention is to provide a preparation method of a porous liquid material based on MIL-100(Fe), comprising the following steps:

[0008] Mix the MIL-100(Fe) metal-organic framework material with an ionic solution to obtain a porous liquid material based on MIL-100(Fe);

[0009] The ionic liquid is selected from one or more of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium hexafluorophosphate, or 1-butyl-3-methylimidazolium bis(fluorosulfonyl)imide.

[0010] In one embodiment of the present invention, in the porous liquid material, the loading amount of the MIL-100(Fe) metal-organic framework material is 2 wt% to 10 wt%.

[0011] The second object of the present invention is to provide a porous liquid material based on MIL-100(Fe), which is prepared by the above method.

[0012] The third object of the present invention is to provide an application of a porous liquid material based on MIL-100(Fe) in extraction-coupled oxidative desulfurization.

[0013] In one embodiment of the present invention, the porous liquid material based on MIL-100(Fe) can not only efficiently remove sulfides in fuels, improve the quality and environmental protection performance of fuels, but also effectively recover oxidation products through the extraction effect of ionic liquids, and has good operation stability.

[0014] In one embodiment of the present invention, the porous liquid material based on MIL-100(Fe) is used for desulfurization of sulfur-containing oil solutions.

[0015] The fourth object of the present invention is to provide a desulfurization method of a porous liquid material based on MIL-100(Fe), comprising the following steps:

[0016] Mix the sulfur-containing oil solution with the porous liquid material based on MIL-100(Fe), then add an oxidant to carry out an oxidation reaction (sulfides are converted into oxidation products (dibenzothiophene sulfone) with stronger polarity and easier to be extracted), and after the oxidation reaction is completed, stand for phase separation (utilize the solubility and extraction effect of the ionic liquid to separate the oxidation products from the oil phase) to obtain desulfurized oil and a porous liquid containing oxidation products.

[0017] In one embodiment of the present invention, the oxidant is selected from one or more of hydrogen peroxide, ozone, peracetic acid or potassium permanganate;

[0018] The mass ratio of the sulfur-containing oil solution to the MIL-100(Fe)-based porous liquid material is 1:1 to 5;

[0019] The molar ratio of S in the sulfur-containing oil solution to O in the oxidant is 1:3 to 7.

[0020] In one embodiment of the present invention, during the oxidation reaction process, the temperature is 30°C to 70°C and the time is 30 min to 240 min.

[0021] In one embodiment of the present invention, an anti-extraction agent is added to the porous liquid containing the oxidation product. After mixing evenly, it is allowed to stand for phase separation to obtain the anti-extraction agent containing the oxidation product and the MIL-100(Fe)-based porous liquid material,

[0022] Or, the porous liquid containing the oxidation product is subjected to a drying treatment to obtain the MIL-100(Fe)-based porous liquid material.

[0023] In one embodiment of the present invention, after the desulfurization reaction is completed, the upper-layer simulated oil solution is removed, and the reaction vessel is placed in a 70°C forced-air drying oven to remove the residual oil product. Then, a new simulated oil solution and an oxidant are added for the next round of experiments;

[0024] Or, after the reaction is completed, the catalyst phase is separated, an anti-extraction agent is added to the porous liquid containing the oxidation product, mixed evenly and allowed to stand for phase separation to separate the anti-extraction agent containing the oxidation product and the MIL-100(Fe)-based porous liquid material. After drying, it is re-introduced into the reaction for subsequent recycling to improve the recycling performance.

[0025] In one embodiment of the present invention, the anti-extraction agent is selected from one or more of diethyl ether, dibutyl ether or ethyl acetate; the volume ratio of the anti-extraction agent to the porous liquid containing the oxidation product is 1 to 10:1 (preferably, the volume ratio of the anti-extraction agent to the porous liquid containing the oxidation product is 1:1); during the mixing process, the temperature is 5°C to 30°C and the time is 5 min to 30 min;

[0026] During the drying treatment process, the temperature is 60 to 80°C and the time is 0.5 to 1.5 h.

[0027] An efficient desulfurization mechanism of the porous liquid material based on MIL-100(Fe) material proposed by the present invention involves the synergistic effect of ionic liquid and MIL-100(Fe)-based MOF. First, DBT molecules in the oil phase are extracted into the ionic liquid phase through C-H…π interaction to reach extraction equilibrium. With the assistance of MIL-100(Fe)-based MOF in the ionic liquid phase, hydrogen peroxide (H2O2) is converted into hydroxyl radicals (·OH) under the action of the catalytic sites of the MOF. During this process, the positively charged Fe atoms on the surface of the MOF have electrostatic interaction with the ·OH radicals, activating the ·OH radicals, thereby promoting their oxidation reaction with DBT. During the oxidation process, the ·OH radicals convert DBT into more polar oxidation products DBTO and DBTO2. Since these oxidation products have higher polarity than DBT, they are more easily extracted into the ionic liquid phase, thus effectively removing sulfides from the oil phase until the sulfur content in the oil is reduced to an ultra-low level. At the same time, under the action of hydrogen peroxide, the generation of ·OH radicals starts the reaction cycle, realizing a continuous desulfurization process.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) By compounding the MIL-100(Fe) metal-organic framework with the ionic liquid, the present invention successfully prepares a porous liquid material based on MIL-100(Fe). This material not only retains the high specific surface area and excellent pore structure characteristics of the MOF, but also exhibits liquid characteristics, significantly improving its fluidity and adaptability in the extraction process, especially suitable for continuous multi-stage extraction processes in industry. Moreover, this material can achieve efficient adsorption and oxidative desulfurization reactions of sulfide molecules under a wider range of operating conditions. Compared with traditional solid MOF materials, this material has significant advantages in the desulfurization process, including higher desulfurization rate (exceeding 90%), faster reaction speed, and excellent cycle stability. Experimental results show that the extraction-coupled oxidative desulfurization method of the present invention can not only achieve deep desulfurization, but also maintain excellent performance in multiple cycles.

[0030] (2) Compared with traditional oxidative desulfurization technologies, the porous liquid material used in the method of the present invention can provide more catalytic active sites, and the ionic liquid as a solvent can effectively enhance the dispersion and stability of the catalyst, thereby improving the desulfurization efficiency; by combining different types of ionic liquids with MIL-100(Fe) materials, the catalytic performance and desulfurization efficiency can be adjusted according to the reaction requirements, thereby optimizing the desulfurization process; this method is easy to operate, the catalyst is stable, and the desulfurization efficiency is high, which can effectively remove sulfides in fuels and avoid the harsh conditions of high temperature and high pressure in traditional desulfurization methods. Description of the Drawings

[0031] Figure 1 Characterization and analysis of MIL-100(Fe) in Example 1: (a) XRD pattern, (b) scanning electron microscopy image, and (c) particle statistical analysis of MIL-100(Fe);

[0032] Figure 2 BET analysis diagram of MIL-100(Fe) in Example 1;

[0033] Figure 3 Characterization and analysis of MIL-100(Fe)-based porous liquid prepared in Example 1: (a) Fourier transform infrared spectroscopy diagram and (b) transmission electron microscopy image;

[0034] Figure 4 Comparison diagram of catalytic oxidation desulfurization performance of individual components in Example 1;

[0035] Figure 5 Comparison diagram of the influence of hydrogen peroxide dosage on the desulfurization rate during extraction oxidation desulfurization in Examples 2, 3, 4, 5, and 6;

[0036] Figure 6 Comparison diagram of the influence of experimental temperature on the extraction desulfurization experimental effect during extraction oxidation desulfurization in Examples 7, 8, 5, 9, and 10;

[0037] Figure 7 Comparison diagram of the influence of the loading amount of MIL-100(Fe) on the extraction desulfurization experimental effect during extraction oxidation desulfurization in Examples 11, 12, 13, 14, 15, 5, and 16;

[0038] Figure 8 Diagram of the cyclic performance test of MIL-100(Fe)-based porous liquid in Example 19(a) and Example 20(b);

[0039] Figure 9 Diagram of the test results of the generation of free radicals in the reaction system of porous liquid by ESR. Detailed implementation manners

[0040] The present invention will be described in detail below with reference to the accompanying drawings and specific examples.

[0041] In the following examples, the conditions for analyzing the concentration of dibenzothiophene using an ultraviolet spectrophotometer are as follows: The ultraviolet spectrophotometer used is a UV-Vis 1800 type, with a wavelength range of 200 nm to 400 nm. The absorbance of dibenzothiophene is measured, and its maximum absorption wavelength (at approximately 235 nm) is selected. To ensure that the absorbance is within the measurement range of the ultraviolet spectrophotometer, the simulated oil solution is appropriately diluted before testing to keep its absorbance value within 1.0. By comparing the absorbance changes before and after the reaction, the removal rate of sulfide is obtained. For each sample to be measured, at least three parallel analyses are performed, and the measurement deviation is 1%.

[0042] Unless otherwise specified, all reagents used are commercially available reagents, and all detection means and methods used are conventional detection means and methods in the art.

[0043] Example 1

[0044] This example provides a preparation method for a porous liquid material based on MIL-100(Fe) material, which specifically includes the following steps:

[0045] In a glass bottle, 0.35 g of MIL-100(Fe) (characterization tests are as Figure 1 , Figure 2 shown) is dissolved in 4 g of ionic liquid [BMIM][NTf2] and ultrasonicated for 20 min. The ultrasonicated mixture is transferred to room temperature and stirred continuously for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2] (Fourier transform infrared spectroscopy and transmission electron microscopy images are as Figure 3 shown).

[0046] Through Figure 1 and Figure 2 it can be found that the simulated XRD pattern of MIL-100(Fe) has diffraction peak characteristics that highly match the crystallographic data reported in the literature; the particle size of MIL-100(Fe) particles is mainly distributed in the range of 180 - 220 nm, and the average particle size is 200 ± 15 nm, which conforms to the typical growth law of octahedral crystals; BET analysis confirms that the material has a microporous structure.

[0047] Through Figure 3It can be found that the transmission electron microscope image shows that MIL-100(Fe) particles are uniformly distributed in the [BMIM][NTf2] matrix. The octahedral morphology of MIL-100(Fe) is completely retained in the liquid phase, with a particle size of about 200 nm, which is consistent with the scanning electron microscope statistics results, proving that [BMIM][NTf2] does not destroy the crystal structure. Moreover, the characteristic spectral bands of MIL-100(Fe)@[BMIM][NTf2] and [BMIM][NTf2] are almost completely the same, and the characteristic peaks of MIL-100(Fe) are not significant in the porous liquid, presumably because the mass fraction of MIL-100(Fe) in the system is relatively small. Based on the above analysis, it can be known that MIL-100(Fe) has been successfully dispersed in the ionic liquid and does not destroy the original structure of [BMIM][NTf2], which further confirms the successful construction of Type III PL.

[0048] The MIL-100(Fe)@[BMIM][NTf2], [BMIM][NTf2] and MIL-100(Fe) of this example are respectively used for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0049] Weigh 0.1149 g of dibenzothiophene, dissolve it in n-heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and place it in 3 small glass bottles respectively. Then add 4 g of [BMIM][NTf2], 0.35 g of MIL-100(Fe) and 4 g of MIL-100(Fe)@[BMIM][NTf2] to them respectively. Add 7.7 μL of H2O2 (O / S molar ratio is 3:1), stir for 2 h in a 50 °C water bath, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase, measure the absorbance at this time with an ultraviolet spectrophotometer, and calculate to find that the removal rate of sulfide is 49.3% for [BMIM][NTf2], 22.8% for MIL-100(Fe), and 95.4% for MIL-100(Fe)@[BMIM][NTf2] (as Figure 4 shown). Through Figure 4It can be found that the desulfurization efficiency of the [BMIM][NTf2] system remains basically unchanged, indicating that it is inert to the action of H2O2 and only has extraction ability, and the maximum desulfurization rate is only 49.3%. Similarly, the extraction effect of single MIL-100(Fe) has no obvious improvement, which may be due to the lack of a stable dispersion medium. MIL-100(Fe) agglomerates in neutral oil, and the active sites on its structure cannot fully contact with H2O2, thus limiting the improvement of its extraction effect. It is worth noting that the MIL-100(Fe)@[BMIM][NTf2] system performs excellently, with a desulfurization rate as high as 95.4%. Its excellent desulfurization performance stems from the synergistic effect of MIL-100(Fe)@[BMIM][NTf2], that is, [BMIM][NTf2] provides efficient extraction ability, while MIL-100(Fe) is responsible for the catalytic oxidation process. The two complement each other to achieve deep desulfurization.

[0050] Example 2

[0051] Weigh 0.1149 g of dibenzothiophene, dissolve it in n-heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL-100(Fe)@[BMIM][NTf2] to it. Add 7.7 μL of H2O2 (O / S molar ratio is 3:1), stir at 50 °C for 2 h, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase, measure the absorbance at this time using an ultraviolet spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 70.3% (as Figure 5 shown).

[0052] Example 3

[0053] This example provides a preparation method of a porous liquid material based on MIL-100(Fe) material, which specifically includes the following steps:

[0054] Weigh 0.35 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue to stir for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0055] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for the desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0056] Weigh 0.1149 g of dibenzothiophene, dissolve it in n-heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL-100(Fe)@[BMIM][NTf2] to it. Add 10.3 μL of H2O2 (O / S molar ratio is 4:1), stir at 50 °C for 2 h, let it stand for 30 min, and the porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase, measure the absorbance at this time using an ultraviolet spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 75.2% (as Figure 5 shown).

[0057] Example 4

[0058] This example provides a preparation method of a porous liquid material based on MIL-100(Fe) material, which specifically includes the following steps:

[0059] Weigh 0.35 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue stirring for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0060] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0061] Weigh 0.1149 g of dibenzothiophene, dissolve it in n-heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL-100(Fe)@[BMIM][NTf2] to it. Add 12.9 μL of H2O2 (O / S molar ratio is 5:1), stir at 50 °C for 2 h, let it stand for 30 min, and the porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase, measure the absorbance at this time using an ultraviolet spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 79.5% (as Figure 5 shown).

[0062] Example 5

[0063] This example provides a preparation method of a porous liquid material based on MIL-100(Fe) material, which specifically includes the following steps:

[0064] Weigh 0.35 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle, and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue stirring for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0065] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0066] Weigh 0.1149 g of dibenzothiophene, dissolve it in n-heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use a UV spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution, add 4 g of MIL-100(Fe)@[BMIM][NTf2] to it, add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 50 °C for 2 h, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase, and measure the absorbance at this time using a UV spectrophotometer. After calculation, it is found that the removal rate of sulfide is 94.6% (as Figure 5 、 6 、shown in Figure 7).

[0067] Example 6

[0068] This example provides a preparation method of a porous liquid material based on MIL-100(Fe) material, which specifically includes the following steps:

[0069] Weigh 0.35 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle, and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue stirring for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0070] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0071] Weigh 0.1149 g of dibenzothiophene and dissolve it in n - heptane solution in a beaker. Then, prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 - mL volumetric flask, and use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL - 100(Fe)@[BMIM][NTf2] to it. Add 18.0 μL of H2O2 (the molar ratio of O / S is 7:1), stir at 50 °C for 2 h, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper - layer oil phase, measure the absorbance at this time using an ultraviolet spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 88.7% (as Figure 5 shown).

[0072] It can be found through Figure 5 that in the extraction stage within the first 30 min, the extraction rate is stable at about 50%, indicating that this stage mainly relies on the extraction effect, and the amount of H2O2 used has little effect on the desulfurization effect. After 30 min, it enters the oxidation stage, and the influence of the amount of H2O2 used on the sulfur removal rate gradually appears. When O / S = 3:1, due to insufficient oxidant, the desulfurization rate only reaches 70%. When O / S = 4:1, the desulfurization rate slightly increases to 75%, but the improvement is limited. When O / S = 5:1, the desulfurization rate significantly rises to 90%, indicating that the amount of oxidant used is appropriate and can effectively promote oxidative desulfurization. When O / S = 6:1, the desulfurization rate further increases to 95%, indicating that increasing the amount of hydrogen peroxide can significantly enhance the oxidation reaction. When O / S = 7:1, the desulfurization rate is similar to that when O / S = 6:1, indicating that when the amount of H2O2 used reaches a certain level (O / S ≥ 6:1), continuing to increase the amount has no significant improvement on the desulfurization effect, which may be limited by factors such as the active sites of the catalyst.

[0073] Example 7

[0074] This example provides a preparation method of a porous liquid material based on MIL - 100(Fe) material, which specifically includes the following steps:

[0075] Weigh 0.35 g of MIL - 100(Fe) and dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle, and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue to stir for 12 h to prepare a porous liquid material based on MIL - 100(Fe) material: MIL - 100(Fe)@[BMIM][NTf2].

[0076] Use the MIL - 100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur - containing oil solution, which specifically includes the following steps:

[0077] Weigh 0.1149 g of dibenzothiophene, dissolve it in n - heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 - mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL - 100(Fe)@[BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 30 °C for 2 h, let it stand for 30 min, and the porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper - layer oil phase, measure the absorbance at this time using an ultraviolet spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 48.9% (as Figure 6 shown).

[0078] Example 8

[0079] This example provides a preparation method of a porous liquid material based on MIL - 100(Fe) material, which specifically includes the following steps:

[0080] Weigh 0.35 g of MIL - 100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue to stir for 12 h to prepare a porous liquid material based on MIL - 100(Fe) material: MIL - 100(Fe)@[BMIM][NTf2].

[0081] Use the MIL - 100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur - containing oil solution, which specifically includes the following steps:

[0082] Weigh 0.1149 g of dibenzothiophene, dissolve it in n - heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 - mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL - 100(Fe)@[BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 40 °C for 2 h, let it stand for 30 min, and the porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper - layer oil phase, measure the absorbance at this time using an ultraviolet spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 75.1% (as Figure 6 shown).

[0083] Example 9

[0084] This example provides a preparation method of a porous liquid material based on MIL - 100(Fe) material, which specifically includes the following steps:

[0085] Weigh 0.35 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle, and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue stirring for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0086] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0087] Weigh 0.1149 g of dibenzothiophene, dissolve it in n-heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL-100(Fe)@[BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 60 °C for 2 h, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase and measure the absorbance at this time with an ultraviolet spectrophotometer. After calculation, it is found that the removal rate of sulfide is 94.8% (as Figure 6 shown).

[0088] Example 10

[0089] This example provides a preparation method of a porous liquid material based on MIL-100(Fe) material, which specifically includes the following steps:

[0090] Weigh 0.35 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle, and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue stirring for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0091] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0092] Weigh 0.1149 g of dibenzothiophene, dissolve it in n - heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use a UV - visible spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL - 100(Fe)@[BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 70 °C for 2 h, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase, and measure the absorbance at this time using a UV - visible spectrophotometer. After calculation, it is found that the removal rate of sulfide is 84.2% (as Figure 6 shown).

[0093] It can be found through Figure 6 that within the first 30 min, the DBT removal rate under each temperature condition is close to 50%, indicating that this stage mainly relies on extraction and the temperature has little effect. After 30 min, it enters the oxidation stage, and the influence of temperature on the desulfurization efficiency gradually appears. At 30 °C, the sulfur removal rate basically remains at about 50%, indicating that low temperature limits the activity of the oxidant and the catalytic effect of MIL - 100(Fe) on it, resulting in the hindrance of the oxidative desulfurization reaction. At 40 °C, the DBT removal rate gradually increases and finally reaches about 75%, indicating that the increase in temperature promotes the activation of the oxidant, thereby improving the desulfurization efficiency. At 50 °C, the sulfur removal rate significantly increases to about 90%, indicating that the oxidant can be fully activated by the catalyst at this temperature, enabling the efficient progress of oxidative desulfurization. Under the condition of 60 °C, the sulfur removal rate further increases, approaching 95%, but the increase amplitude compared to 50 °C is limited, indicating that although higher temperature promotes the oxidation reaction, the effect tends to be stable. At 70 °C, the sulfur removal rate drops to 83% instead, probably because H2O2 decomposes by itself at high temperature, reducing its effective utilization rate. Considering the industrial cost and the effective utilization of the oxidant, 50 °C is more valuable for practical application as the optimal temperature of the experiment.

[0094] Example 11

[0095] This example provides a desulfurization method for sulfur - containing oil solution, which specifically includes the following steps:

[0096] Weigh 0.1149 g of dibenzothiophene, dissolve it in n - heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use a UV - visible spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of [BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 50 °C for 2 h, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase, and measure the absorbance at this time using a UV - visible spectrophotometer. After calculation, it is found that the removal rate of sulfide is 49.2% (asFigure 7 as shown

[0097] Example 12

[0098] This example provides a method for preparing a porous liquid material based on MIL-100(Fe) material, which specifically includes the following steps:

[0099] Weigh 0.04 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle, and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue stirring for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0100] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0101] Weigh 0.1149 g of dibenzothiophene, dissolve it in n-heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL-100(Fe)@[BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 50 °C for 2 h, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase and measure the absorbance at this time with an ultraviolet spectrophotometer. After calculation, it is found that the removal rate of sulfide is 53.1% (as Figure 7 as shown

[0102] Example 13

[0103] This example provides a method for preparing a porous liquid material based on MIL-100(Fe) material, which specifically includes the following steps:

[0104] Weigh 0.08 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle, and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue stirring for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0105] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0106] Weigh 0.1149 g of dibenzothiophene, dissolve it in n - heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 - mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL - 100(Fe)@[BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 50 °C for 2 h, let it stand for 30 min, and the porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper - layer oil phase, measure the absorbance at this time using an ultraviolet spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 61.4% (as Figure 7 shown).

[0107] Example 14

[0108] This example provides a preparation method of a porous liquid material based on MIL - 100(Fe) material, which specifically includes the following steps:

[0109] Weigh 0.12 g of MIL - 100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue to stir for 12 h to prepare a porous liquid material based on MIL - 100(Fe) material: MIL - 100(Fe)@[BMIM][NTf2].

[0110] Use the MIL - 100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur - containing oil solution, which specifically includes the following steps:

[0111] Weigh 0.1149 g of dibenzothiophene, dissolve it in n - heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 - mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL - 100(Fe)@[BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 50 °C for 2 h, let it stand for 30 min, and the porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper - layer oil phase, measure the absorbance at this time using an ultraviolet spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 70.4% (as Figure 7 shown).

[0112] Example 15

[0113] This example provides a preparation method of a porous liquid material based on MIL - 100(Fe) material, which specifically includes the following steps:

[0114] Weigh 0.21 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle, and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue stirring for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0115] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0116] Weigh 0.1149 g of dibenzothiophene, dissolve it in n-heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL-100(Fe)@[BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 50 °C for 2 h, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase and measure the absorbance at this time with an ultraviolet spectrophotometer. After calculation, it is found that the removal rate of sulfide is 90.2%.

[0117] Example 16

[0118] This example provides a preparation method of a porous liquid material based on MIL-100(Fe) material, which specifically includes the following steps:

[0119] Weigh 0.44 g of MIL-100(Fe), dissolve it in 4 g of ionic liquid [BMIM][NTf2] in a glass bottle, and ultrasonically treat it for 20 min. Transfer the ultrasonically treated mixture to room temperature and continue stirring for 12 h to prepare a porous liquid material based on MIL-100(Fe) material: MIL-100(Fe)@[BMIM][NTf2].

[0120] Use the MIL-100(Fe)@[BMIM][NTf2] prepared in this example for desulfurization of sulfur-containing oil solution, which specifically includes the following steps:

[0121] Weigh 0.1149 g of dibenzothiophene, dissolve it in n-heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 mL volumetric flask. Use an ultraviolet spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL-100(Fe)@[BMIM][NTf2] to it. Add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 50 °C for 2 h, and let it stand for 30 min. The porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper oil phase and measure the absorbance at this time with an ultraviolet spectrophotometer. After calculation, it is found that the removal rate of sulfide is 96.1% (as Figure 7 shown).

[0122] It can be found through Figure 7 that as the mass fraction of MIL-100(Fe) gradually increases from 0 wt% to 10 wt%, the sulfur removal rate shows a significant upward trend. When the mass fraction of MIL-100(Fe) is 0 wt%, the system relies on the extraction of [BMIM][NTf2] to achieve a DBT removal rate of 49%; when the mass fraction rises to 1 wt%, the sulfur removal rate reaches 53%, and when it is 2 wt%, it is 61%, indicating that a small amount of MIL-100(Fe) can have a positive impact. When the mass fraction is 5 wt%, it jumps significantly to 86%, indicating that MIL-100(Fe) has a significant promoting effect on desulfurization within this range. When the mass fraction is 8 wt%, the sulfur removal rate reaches 95%, and when it is 10 wt%, it is 96%. At this time, the desulfurization effect tends to be stable, and further increasing the dosage has limited improvement. This is because the porous structure of MIL-100(Fe) and the Fe metal sites can promote the adsorption, diffusion of sulfides, and the activation of oxidants, synergistically improving the desulfurization efficiency. However, too much MIL-100(Fe) may cause the active sites to not fully utilize the oxidant or reduce the effective active area due to agglomeration.

[0123] Example 17

[0124] This example provides MIL-100(Fe)@[BMIM][NTf2] (prepared in Example 5) for the cyclic desulfurization of sulfur-containing oil solutions, which specifically includes the following steps:

[0125] Weigh 0.1149 g of dibenzothiophene, dissolve it in n - heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 - mL volumetric flask. Use a UV - visible spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL - 100(Fe)@[BMIM][NTf2] to it, add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 50 °C for 2 h, let it stand for 30 min, and the porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper - layer oil phase, measure the absorbance at this time with a UV - visible spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 94.6%.

[0126] Separate MIL - 100(Fe)@[BMIM][NTf2] from the oil phase. After evaporating the residual oil phase in a blast drying oven at 70 °C, add 15.5 μL of H2O2 and 4 g of the simulated oil solution for the next - round reaction. Recycle 4 times, and the extraction rates are 92.34%, 89.27%, 89.65%, and 80.21% respectively (as Figure 8 (a) shown).

[0127] Example 18

[0128] This example provides the use of MIL - 100(Fe)@[BMIM][NTf2] (prepared in Example 5) for the cyclic desulfurization of sulfur - containing oil solutions, specifically including the following steps:

[0129] Weigh 0.1149 g of dibenzothiophene, dissolve it in n - heptane solution in a beaker, and then prepare a simulated oil solution with an initial sulfur content of 200 ppm in a 100 - mL volumetric flask. Use a UV - visible spectrophotometer to measure the absorbance of the simulated oil. Take 4 g of the simulated sulfur solution and add 4 g of MIL - 100(Fe)@[BMIM][NTf2] to it, add 15.5 μL of H2O2 (O / S molar ratio is 6:1), stir at 50 °C for 2 h, let it stand for 30 min, and the porous liquid phase and the oil phase are separated. Use a pipette to take 100 μL of the upper - layer oil phase, measure the absorbance at this time with a UV - visible spectrophotometer, and after calculation, it is found that the removal rate of sulfide is 94.6%.

[0130] Separate MIL-100(Fe)@[BMIM][NTf2] from the oil phase, and add 10 g of carbon tetrachloride (CCl4) to perform back-extraction on MIL-100(Fe)@[BMIM][NTf2]. After two back-extractions, place MIL-100(Fe)@[BMIM][NTf2] in a forced-air drying oven for drying. After evaporating the residual oil phase at 70 °C in the forced-air oven, supplement 15.5 μL of H2O2 and 4 g of the simulated oil solution for the next round of reaction. Reuse it 4 times, and the extraction rates are 92.34%, 91.67%, 90.22%, and 89.41% respectively (as Figure 8 (shown in (b)).

[0131] It can be found through Figure 8 that during the recycling process of the catalyst, the sulfur removal rate gradually decreases, dropping to 80.21% at the 4th time, indicating that its activity has declined somewhat. This may be because the generated reaction products cover the surface of the catalyst, hindering the interaction between the active sites and the oxidant and the substrate.

[0132] To improve the recycling stability of the catalyst, CCl4 extraction is used to remove the residual products after each cycle. Figure 8 The results show that after regeneration with CCl4, the performance decline of the catalyst is significantly slowed down. The sulfur removal rates in the 2nd, 3rd, and 4th cycles are 91.67%, 90.22%, and 89.41% respectively, indicating that the regeneration treatment effectively restores the activity of the catalyst and improves the recycling stability.

[0133] Figure 9 Figure for the test results of the generation of free radicals in the reaction system by porous liquid through ESR. It can be found through Figure 9 that the ESR spectra at reaction times of 3 min and 10 min are given respectively. At the initial stage of the reaction, the signal peak intensity is weak and the peak shape is relatively flat. This may be because there are not enough reactive oxygen species generated in the system at this time, or the number of generated reactive oxygen species is small and they are relatively dispersed. As the reaction time extends to 10 min, the signal peak intensity in the spectrum significantly increases and the peak shape becomes sharper, indicating that a large number of reactive oxygen species are generated in the system at this time.

[0134] It can be inferred from this that during the oxidative desulfurization process involving MIL-100(Fe)@BN, the hydroxyl radical (·OH) generated by the decomposition of H2O2 is very likely the main reactive oxygen species. During the reaction process, as time goes by, the system gradually generates and accumulates a sufficient amount of ·OH. These ·OH, as key reactive species, participate in the oxidation process of sulfur-containing compounds, thus achieving the purpose of desulfurization.

[0135] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the interpretation of the present invention should be within the protection scope of the present invention.

Claims

1. A preparation method of a porous liquid material based on MIL-100(Fe), characterized in that, It includes the following steps: Mix the MIL-100(Fe) metal-organic framework material with an ionic solution to obtain a porous liquid material based on MIL-100(Fe). The ionic liquid is selected from one or more of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium hexafluorophosphate, or 1-butyl-3-methylimidazolium bis(fluorosulfonyl)imide.

2. The preparation method of a porous liquid material based on MIL-100(Fe), according to claim 1, is characterized in that, In the porous liquid material, the loading amount of the MIL-100(Fe) metal-organic framework material is 2wt% - 10wt%.

3. A MIL-100(Fe)-based porous liquid material, characterized in that, It is prepared by the method according to any one of claims 1 - 2.

4. Application of a porous liquid material based on MIL-100(Fe) as described in claim 3 in extraction-coupled oxidative desulfurization.

5. The application according to claim 4, wherein The porous liquid material based on MIL-100(Fe) is used for desulfurization of sulfur-containing oil solutions.

6. A desulfurization method of the MIL-100(Fe)-based porous liquid material as described in claim 3, characterized in that, It includes the following steps: Mix the sulfur-containing oil solution with the porous liquid material based on MIL-100(Fe), then add an oxidant to carry out an oxidation reaction. After the oxidation reaction ends, stand for phase separation to obtain desulfurized oil and a porous liquid containing oxidation products.

7. The desulfurization method of a porous liquid material based on MIL-100(Fe), according to claim 6, is characterized in that, The oxidant is selected from one or more of hydrogen peroxide, ozone, peracetic acid, or potassium permanganate; The mass ratio of the sulfur-containing oil solution to the porous liquid material based on MIL-100(Fe) is 1:1 - 5; The molar ratio of S in the sulfur-containing oil solution to O in the oxidant is 1:3 - 7.

8. The desulfurization method of a porous liquid material based on MIL-100(Fe), according to claim 6, is characterized in that During the oxidation reaction, the temperature is 30°C - 70°C and the time is 30 min - 240 min.

9. The cyclic regeneration desulfurization method of a MIL-100(Fe)-based porous liquid material according to claim 6, characterized in that, Add an anti-solvent to the porous liquid containing oxidation products, mix well and then stand for phase separation to obtain an anti-solvent containing oxidation products and a porous liquid material based on MIL-100(Fe), or, dry the porous liquid containing oxidation products to obtain a porous liquid material based on MIL-100(Fe).

10. A cyclic regeneration desulfurization method of a MIL-100(Fe)-based porous liquid material according to claim 9, characterized in that, The anti-solvent is selected from one or more of carbon tetrachloride, diethyl ether, dibutyl ether, or ethyl acetate; the volume ratio of the anti-solvent to the porous liquid containing oxidation products is 1 - 10:1; during the mixing process, the temperature is 5°C - 30°C and the time is 5 min - 30 min; During the drying process, the temperature is 60 - 80°C and the time is 0.5 - 1.5 h.

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