Use of a metal ion-doped graphene oxide membrane catalytic material in catalyzing sulfide oxidation reaction to synthesize sulfone

Abstract

The present invention relates to a kind of metal ion doped graphene oxide film catalyst material at room temperature and efficiently and quickly catalyzes the purposes of sulfide oxidation synthesis sulfone.By adding metal ions in the dispersion of graphene oxide, so that graphene oxide interacts with metal ions and performs the doping of metal ions, then the dispersion of graphene oxide doped with metal ions is prepared as metal ion doped graphene oxide film catalyst material by vacuum filtration method, and the content of metal ions in metal ion doped graphene oxide film catalyst material is continuously adjustable.Compared with traditional catalytic method, the present invention is in the mode of continuous mobile phase reaction, and sulfide substrate and oxidant react in the two-dimensional interlayer confined channel of metal ion doped graphene oxide film catalyst material, and product flows out with mobile phase, and the catalytic method can realize the high conversion rate (90‑100%) of sulfide oxidation reaction at room temperature, high selectivity (60‑100%), fast (1‑60s) purpose of carrying out.

Description

Technical Field

[0001] The invention relates to use of a metal ion-doped graphene oxide membrane catalyst material in catalyzing a sulfide oxidation reaction to synthesize sulfone, and belongs to the technical field of membrane materials and catalytic applications. Background Art

[0002] Thioether oxidation plays an important role in organic synthesis, pharmaceutical synthesis, and environmental governance. This is partly because thioether oxidation is a simple synthetic pathway for preparing sulfones. Sulfones are highly useful pharmaceutical reagents in organic and medicinal chemistry, such as amisulpride, commonly used in the treatment of schizophrenia, and vimodegib, used to treat advanced basal cell carcinoma of the skin. Furthermore, thioether oxidation is considered one of the most promising methods for deep fuel desulfurization due to its mild operating conditions, high desulfurization efficiency, low equipment cost, and simple operation. For example, by oxidizing aromatic sulfides into highly polar sulfones, followed by extraction with a suitable polar solvent, deep desulfurization can be achieved, thereby reducing environmental pollution caused by gases such as SO2 produced by sulfur-containing substances during fuel use.

[0003] Currently, common catalysts for catalyzing the oxidation of sulfides to sulfones include metal catalysts such as polyoxometalates, metal oxides, zeolites, and metal-organic frameworks; non-metallic catalysts such as graphene oxide and carbon nanotubes are also available. While most currently studied catalysts can achieve complete conversion of sulfides and highly selectively produce sulfones, these oxidation reactions generally require relatively high reaction temperatures and times. Therefore, there is a clear need for a method for rapidly catalyzing the oxidation of sulfides to sulfones at room temperature. Summary of the Invention

[0004] Although many catalysts currently studied can catalyze sulfide oxidation reactions and obtain high conversion rates and selectivity of sulfones, there are problems such as high reaction temperature, long reaction time, and large amount of oxidant. In order to solve the defects of the above-mentioned prior art, the present invention provides a metal ion-doped graphene oxide film catalytic material for use in catalyzing sulfide oxidation reactions to synthesize sulfones. The metal ion-doped graphene oxide film catalytic material provides a two-dimensional interlayer channel with a confined effect on the basis of retaining acid catalytic sites, and efficiently catalyzes the occurrence of sulfide oxidation reactions through the action of acid catalytic sites and two-dimensional interlayer confined channels. At the same time, the doping of metal ions can provide metal active centers. By utilizing the combined catalytic effect of metal active centers and inherent acid catalytic sites, the conversion rate of sulfide oxidation reactions and the selectivity of sulfones can be improved, and rapid and efficient catalytic sulfide oxidation to synthesize sulfones at room temperature can be achieved.

[0005] The object of the present invention is achieved through the following technical solutions:

[0006] A metal ion-doped graphene oxide membrane catalytic material is used in catalyzing sulfide oxidation reaction to synthesize sulfone.

[0007] According to an embodiment of the present invention, the metal ion-doped graphene oxide membrane catalytic material is used to rapidly catalyze the sulfide oxidation reaction to synthesize sulfone at room temperature.

[0008] According to an embodiment of the present invention, the metal ion-doped graphene oxide film catalytic material is used to quickly and efficiently catalyze the sulfide oxidation reaction to synthesize sulfone at room temperature.

[0009] According to an embodiment of the present invention, the room temperature refers to a temperature range of 20-30°C.

[0010] According to an embodiment of the present invention, the rapid reaction time refers to a reaction time of 1-60s.

[0011] According to an embodiment of the present invention, the high efficiency refers to a sulfide conversion rate of 90-100% and / or a sulfone selectivity of 60-100%.

[0012] According to an embodiment of the present invention, the thickness of the metal ion-doped graphene oxide membrane catalytic material is 0.1-5μm, for example, 0.1μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm or 5μm; by regulating the membrane thickness, the retention time of the reaction molecules in the two-dimensional interlayer confined channel of the metal ion-doped graphene oxide membrane catalytic material can be regulated, thereby optimizing its catalytic performance. The study found that the retention time of reactants in metal ion-doped graphene oxide membrane catalytic materials that are too thin (thickness less than 0.1μm) is too short, and high conversion rate and selectivity cannot be achieved; metal ion-doped graphene oxide membrane catalytic materials that are too thick (thickness greater than 5μm) will greatly reduce the flow rate of the reaction liquid and increase the preparation cost of the membrane catalytic material, significantly reducing the efficiency of the catalytic sulfide reaction.

[0013] According to an embodiment of the present invention, the interlayer spacing of the metal ion-doped graphene oxide film catalytic material is For example, or

[0014] According to an embodiment of the present invention, the mass of the metal ions in the metal ion-doped graphene oxide membrane catalytic material accounts for 0.01-15wt% of the total mass of the membrane catalytic material, for example, 0.01wt%, 0.02wt%, 0.05wt%, 0.08wt%, 0.1wt%, 0.2wt%, 0.5wt%, 0.6wt%, 0.8wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt% or 15wt%. When the mass of metal ions in the metal ion-doped graphene oxide membrane catalytic material accounts for less than 0.01wt% of the total mass of the membrane catalytic material, the content of metal active centers in the membrane catalytic material will be relatively low, and the catalytic effect on the sulfide oxidation reaction will not be obvious enough; when the mass of metal ions in the metal ion-doped graphene oxide membrane catalytic material accounts for more than 15wt% of the total mass of the membrane catalytic material, the interaction between the graphene oxide nanosheets and the metal ions will be enhanced, affecting the uniformity and structural stability of the metal ion-doped graphene oxide membrane catalytic material.

[0015] According to an embodiment of the present invention, the metal ions in the metal ion-doped graphene oxide film catalytic material are selected from at least one of the main metal ions and transition metal ions; illustratively, the metal ions are selected from Li + 、Na + , K + Mg 2+ , Ca 2+ 、Al 3+ 、Mn 2+ 、Fe 3+ 、Co 2+ 、Ni 2+ 、Cu 2+ and Zn 2+ At least one of, preferably Fe 3+ .

[0016] According to an embodiment of the present invention, in the metal ion-doped graphene oxide film catalytic material, the atomic ratio of oxygen to carbon is 0.8-1, for example, 0.8, 0.85, 0.9, 0.95 or 1.

[0017] According to an embodiment of the present invention, the metal ion-doped graphene oxide film catalytic material is a layered structure formed by stacking metal ion-doped graphene oxide, preferably a layered structure formed by stacking metal ion-doped graphene oxide nanosheets.

[0018] According to an embodiment of the present invention, the metal ion-doped graphene oxide film catalytic material includes metal ion-doped graphene oxide, preferably includes metal ion-doped graphene oxide nanosheets.

[0019] According to an embodiment of the present invention, the metal ion-doped graphene oxide includes graphene oxide and metal ions, and the metal ions are doped onto the graphene oxide.

[0020] According to an embodiment of the present invention, the metal ion-doped graphene oxide film catalytic material is prepared by the following method:

[0021] (1) adding a metal salt to a dispersion of graphene oxide and mixing by ultrasonication to obtain a mixed solution;

[0022] (2) The mixed solution of step (1) is assembled into a metal ion-doped graphene oxide membrane by vacuum filtration, and then subjected to a constant temperature and humidity static treatment to prepare the metal ion-doped graphene oxide membrane catalytic material.

[0023] According to an embodiment of the present invention, in step (1), by changing the concentration of the graphene oxide dispersion and the mass ratio of the graphene oxide dispersion and the metal salt, the mass proportion of the metal ions in the metal ion-doped graphene oxide membrane catalytic material can be regulated, thereby regulating the catalytic performance of the metal ion-doped graphene oxide membrane catalytic material.

[0024] According to an embodiment of the present invention, in step (1), by adding a metal salt to the dispersion of graphene oxide, and then performing ultrasonic mixing treatment, the graphene oxide and the metal ions are allowed to fully react, thereby achieving metal ion doping on the graphene oxide, and at the same time, a more uniformly dispersed metal ion-doped graphene oxide can be obtained.

[0025] According to an embodiment of the present invention, in step (1), the graphene oxide is preferably a graphene oxide nanosheet, the graphene oxide nanosheet is a single-layer graphene oxide nanosheet, and the sheet diameter of the graphene oxide nanosheet is greater than 500 nm.

[0026] According to an embodiment of the present invention, in step (1), the concentration of the graphene oxide dispersion is 0.01-0.25 mg / mL, that is, 1 mL of the graphene oxide dispersion contains 0.01-0.25 mg of graphene oxide; illustratively, the concentration of the graphene oxide dispersion is 0.01 mg / mL, 0.02 mg / mL, 0.05 mg / mL, 0.06 mg / mL, 0.08 mg / mL, 0.1 mg / mL, 0.12 mg / mL, 0.15 mg / mL, 0.16 mg / mL, 0.18 mg / mL, 0.2 mg / mL, 0.22 mg / mL, 0.24 mg / mL or 0.25 mg / mL.

[0027] According to an embodiment of the present invention, in step (1), the metal salt is selected from at least one of a family metal salt and a transition metal salt; illustratively, the metal salt is selected from at least one of LiCl, NaCl, KCl, MgCl2, CaCl2, AlCl3, MnCl2, FeCl3, CoCl2, NiCl2, CuCl2 and ZnCl2, preferably FeCl3.

[0028] According to an embodiment of the present invention, in step (1), the molar volume ratio of the metal salt and the graphene oxide dispersion is 1-20 μmol / 40 mL, that is, 1-20 μmol of metal salt is added to every 40 mL of graphene oxide dispersion; illustratively, the molar volume ratio of the metal salt and the graphene oxide dispersion is 1 μmol / 40 mL, 2 μmol / 40 mL, 3 μmol / 40 mL, 4 μmol / 40 mL, 5 μmol / 40 mL, 6 μmol / 40 mL, 7 μmol / 40 mL, 8 μmol / 40 mL, 9 μmol / 40 mL, 10 μmol / 40 mL, 12 μmol / 40 mL, 15 μmol / 40 mL, 18 μmol / 40 mL or 20 μmol / 40 mL. Adding too much metal salt will lead to an enhanced interaction between graphene oxide and metal ions, making it impossible to disperse it evenly in water through ultrasound. It may also cause coagulation, affecting the uniformity and structural stability of the metal ion-doped graphene oxide membrane catalytic material prepared subsequently.

[0029] According to an embodiment of the present invention, in step (1), the ultrasonic mixing time is 5-15 minutes, for example, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes or 15 minutes; the ultrasonic mixing power is 100-500 W, for example, 100 W, 150 W, 200 W, 250 W, 300 W, 350 W, 400 W, 450 W or 500 W. Under these conditions, ultrasonic mixing treatment can achieve uniform dispersion of metal ion-doped graphene oxide in water without destroying the structure of metal ion-doped graphene oxide.

[0030] According to an embodiment of the present invention, step (2) specifically includes the following steps:

[0031] 21) Laying a porous substrate in the filter cup of a vacuum filtration device;

[0032] 22) adding the mixed solution of step (1) into a filter cup of a vacuum filtration device, starting a vacuum pump, and performing vacuum filtration with a vacuum degree of 1-5 Pa; utilizing the vacuum pressure difference to assemble the metal ion-doped graphene oxide layer by layer on the porous substrate to obtain a metal ion-doped graphene oxide membrane catalytic material.

[0033] According to an embodiment of the present invention, the material of the porous substrate may be an organic filter membrane such as nylon 66, polyvinylidene fluoride, or polytetrafluoroethylene.

[0034] According to an embodiment of the present invention, the pore size of the porous substrate is 0.1-0.3 μm, for example, 0.22 μm.

[0035] According to an embodiment of the present invention, a membrane formed by stacking multiple single-layer metal ion-doped graphene oxide (preferably metal ion-doped graphene oxide nanosheets) of a certain thickness is prepared on a porous substrate by vacuum filtration.

[0036] According to an embodiment of the present invention, as the filtration proceeds, the metal ion-doped graphene oxide in the mixed solution is assembled into a layered structure under the action of water flow, and when the filtration is completed, the metal ion-doped graphene oxide membrane catalytic material is obtained.

[0037] According to an embodiment of the present invention, in step (2), the constant temperature and humidity static treatment is, for example, a static treatment for a period of time under constant temperature and constant humidity conditions; illustratively, the constant temperature and humidity static treatment is performed in a constant temperature and humidity chamber. Exemplarily, the constant temperature and humidity static treatment is performed at 20-30°C and 10-20% RH for 12-24 hours. The constant temperature and humidity static treatment can remove free water from the metal ion-doped graphene oxide membrane catalytic material after filtration.

[0038] According to an embodiment of the present invention, the method for synthesizing sulfone by catalytic sulfide oxidation reaction comprises the following steps:

[0039] a) dissolving a thioether substrate and an oxidant in an organic solvent to obtain a reaction solution;

[0040] b) driving the reaction solution of step a) through the metal ion-doped graphene oxide membrane catalytic material at room temperature by pressure difference to perform sulfide oxidation reaction to prepare sulfone.

[0041] The present invention also provides a method for synthesizing sulfone by catalyzing the oxidation reaction of sulfide, the method comprising the following steps:

[0042] a) dissolving a thioether substrate and an oxidant in an organic solvent to obtain a reaction solution;

[0043] b) driving the reaction solution of step a) through the metal ion-doped graphene oxide membrane catalytic material at room temperature by pressure difference to perform sulfide oxidation reaction to prepare sulfone.

[0044] According to an embodiment of the present invention, driven by pressure difference, the sulfide substrate and the oxidant react in a continuous mobile phase reaction within the two-dimensional interlayer confined channel of the metal ion-doped graphene oxide membrane catalytic material, and the sulfide oxidation product obtained by the reaction flows out with the organic solvent and leaves the catalytic system.

[0045] According to an embodiment of the present invention, in step a), the molar ratio of the thioether substrate to the oxidant is 1:1-10, for example, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.

[0046] According to an embodiment of the present invention, in step a), the oxidant is selected from at least one of hydrogen peroxide, tert-butyl hydroperoxide, and the like.

[0047] According to an embodiment of the present invention, in step a), the thioether substrate includes at least one of methyl phenyl sulfide (CAS No.: 100-68-5), p-methyl phenyl sulfide (CAS No.: 623-13-2), phenyl ethyl sulfide (CAS No.: 622-38-8), cyclopropyl phenyl sulfide (CAS No.: 14633-54-6), allyl benzene sulfide (CAS No.: 5296-64-0), ethyl sulfide (CAS No.: 352-93-2), dipropyl sulfide (CAS No.: 111-47-7), diphenyl sulfide (CAS No.: 139-66-2), 4-nitrophenyl phenyl sulfide (CAS No.: 952-97-6), albendazole (CAS No.: 54965-21-8), etc.

[0048] According to an embodiment of the present invention, in step a), the organic solvent is selected from at least one of acetonitrile, ethanol, methanol and acetic acid.

[0049] According to an embodiment of the present invention, in step a), the concentration of the thioether substrate is 0.01-1 mol / L.

[0050] According to an embodiment of the present invention, in step b), the reaction time is 1-60s, for example, 1s, 2s, 5s, 6s, 8s, 10s, 12s, 15s, 16s, 18s, 20s, 22s, 25s, 26s, 28s, 30s, 32s, 35s, 38s, 40s, 42s, 45s, 48s, 50s, 52s, 55s, 58s or 60s.

[0051] According to an embodiment of the present invention, in step b), the room temperature refers to a temperature range of 20-30°C.

[0052] According to an embodiment of the present invention, in step b), the method for generating the pressure difference is not particularly limited. For example, negative pressure can be generated on the lower surface of the metal ion-doped graphene oxide membrane catalytic material by vacuum filtration, and / or positive pressure can be generated on the upper surface of the metal ion-doped graphene oxide membrane catalytic material by applying external pressure.

[0053] Exemplarily, the pressure difference is achieved by vacuum filtration, for example, adding the reaction solution to a vacuum filtration device provided with a metal ion-doped graphene oxide membrane catalytic material, starting the vacuum pump, and performing vacuum filtration to generate a pressure difference between the upper surface and the lower surface of the metal ion-doped graphene oxide membrane catalytic material.

[0054] According to an embodiment of the present invention, in step b), the pressure difference is greater than or equal to 0.9 atm, for example, 0.9-8 atm, such as 0.9-4 atm, and illustratively is 0.9 atm, 1 atm, 1.2 atm, 1.5 atm, 1.8 atm, 2 atm, 2.2 atm, 2.5 atm, 2.8 atm, 3 atm, 3.2 atm, 3.5 atm, 3.8 atm or 4 atm.

[0055] According to an embodiment of the present invention, in step b), the conversion rate of the reaction is 90-100%, for example, 90%, 95%, 98% or 100%.

[0056] According to an embodiment of the present invention, in step b), the selectivity of the sulfone is 60-100%, for example, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100%.

[0057] The present invention also provides a method for preparing a metal ion-doped graphene oxide film catalytic material, the method comprising the following steps:

[0058] (1) adding a metal salt to a dispersion of graphene oxide and mixing by ultrasonication to obtain a mixed solution;

[0059] (2) The mixed solution of step (1) is assembled into a metal ion-doped graphene oxide membrane by vacuum filtration, and then subjected to a constant temperature and humidity static treatment to prepare the metal ion-doped graphene oxide membrane catalytic material.

[0060] The present invention also provides a metal ion-doped graphene oxide film catalytic material prepared by the above method.

[0061] The present invention also provides a catalytic system, which contains the above-mentioned metal ion-doped graphene oxide film catalytic material.

[0062] The present invention relates to the use of a metal ion-doped graphene oxide membrane catalyst material for efficiently and rapidly catalyzing the oxidation of sulfides to synthesize sulfones at room temperature. Metal ions are added to a dispersion of graphene oxide, causing interaction between the graphene oxide and the metal ions and metal ion doping. The dispersion of the metal ion-doped graphene oxide is then prepared into a metal ion-doped graphene oxide membrane catalyst material (GO-M membrane) using a vacuum filtration method. The metal ion content in the metal ion-doped graphene oxide membrane catalyst material is continuously adjustable.

[0063] Compared with traditional catalytic methods, the present invention adopts a continuous mobile phase reaction mode, in which the sulfide substrate and the oxidant react in the two-dimensional interlayer confined channel of the metal ion-doped graphene oxide membrane catalytic material, and the product flows out with the mobile phase. The catalytic method can achieve a high conversion rate (90-100%), high selectivity (60-100%), and fast (1-60s) of the sulfide oxidation reaction under room temperature conditions.

[0064] Beneficial effects of the present invention:

[0065] (1) The GO-M membrane provides a two-dimensional interlayer confined channel, which optimizes the interaction between the sulfide substrate and the oxidant through the confined space effect, thereby reducing the reaction activation energy and achieving efficient catalytic oxidation of sulfide to sulfone at room temperature.

[0066] (2) The GO-M membrane provides active metal centers. Under the synergistic effect of the active metal centers and the Lewis acid centers on graphene oxide, the interaction between the sulfide substrate and the oxidant is further enhanced. By changing the reaction mechanism, the activation energy of the reaction is reduced, and the oxidizing ability of the oxidant is improved, thereby achieving efficient catalytic oxidation of sulfide to sulfone at room temperature.

[0067] (3) By changing the molar amount of metal salt added during the preparation process, the content of metal active centers in the GO-M membrane can be regulated, thereby improving the catalytic effect.

[0068] (4) The GO-M membrane prepared by the present invention exhibits strong catalytic performance at room temperature. While maintaining a high sulfide conversion rate (90-100%), it significantly shortens the time required for the reaction (residence time 1-60s), effectively avoiding high temperature conditions and high energy consumption caused by long-term reactions. The GO-M membrane prepared by the present invention also has high sulfone selectivity (60-100%). This room temperature membrane confined flow catalytic system can not only improve the oxidation performance of the oxidant, thereby significantly improving the conversion rate and selectivity of the reaction, but also avoid the energy consumption of long-term and high-temperature reactions, providing a new solution for the efficient and green application of sulfide oxidation to sulfone. The present invention utilizes two-dimensional nano-confined channels provided by a metal ion-doped graphene oxide membrane catalytic material with a layered structure. Driven by a pressure difference, a reaction liquid passes through the two-dimensional interlayer confined channels and an efficient catalytic reaction occurs under the combined catalysis of acidic sites and metal active centers. Ultimately, efficient catalytic oxidation of sulfide to produce sulfone is achieved at room temperature. The conversion rate of the reactants can reach up to 100%, and the selectivity of sulfone can reach up to 100%. The oxidant is hydrogen peroxide or tert-butyl hydroperoxide, which is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 : Schematic diagram of the preparation of metal ion-doped graphene oxide film by vacuum filtration method.

[0070] Figure 2 : Schematic diagram of the synthesis of sulfone by oxidation of sulfide using confined flow catalysis on metal ion-doped graphite oxide film.

[0071] Figure 3 : H NMR spectra and HPLC chromatograms of sulfide substrate, sulfoxide and sulfone products.

[0072] Figure 4 : Comparison of the conversion rate and sulfone selectivity of the sulfide oxidation reaction catalyzed by the GO powder of Comparative Example 5, the GO-Fe powder of Comparative Example 6, the GOM membrane sample of Comparative Example 4, and the GOM-5μmolFe membrane sample of Example 2, as well as the reaction time. DETAILED DESCRIPTION

[0073] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0074] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the reagents, materials, etc. used in the following examples are all commercially available unless otherwise specified.

[0075] In the following examples and comparative examples, unless otherwise specified, “GO” refers to “graphene oxide”, “GO dispersion” refers to “graphene oxide dispersion”, and “GO film” refers to “graphene oxide film”.

[0076] In the following examples and comparative examples, unless otherwise specified, “GO-M” refers to “metal ion-doped graphene oxide”, “GO-M dispersion” refers to “metal ion-doped graphene oxide dispersion”, and “GO-M film” refers to “metal ion-doped graphene oxide film”.

[0077] The collected liquid through the membrane is quantitatively analyzed by nuclear magnetic resonance hydrogen spectrum or high performance liquid chromatography, and the conversion rate of the reaction and the selectivity of the product are calculated based on this, which specifically includes the following steps:

[0078] For H NMR spectroscopy, a portion of the collected solution is removed by rotary evaporation to remove excess solvent. The sample is then dissolved in a deuterated reagent (DMSO-d6) to prepare the NMR sample. Both the substrate and product molecules exhibit characteristic hydrogen peaks, and the area of ​​these peaks correlates with the number of molecules. Single-peak fitting is used to calculate the integrated area of ​​each characteristic peak, which is then used to calculate the number ratio of the corresponding molecules, thereby calculating the reaction conversion and selectivity.

[0079] For HPLC testing, a portion of the liquid collected after the membrane is diluted with acetonitrile to prepare the liquid test sample. The substrate and product separate due to their different polarities, resulting in different peak retention times. Single peak fitting is used to compare the peak areas at different peak retention times to obtain the number ratio of the corresponding molecules, thereby calculating the reaction conversion and selectivity.

[0080] Example 1

[0081] (1) Prepare 0.125 mg / mL GO-M dispersion: Take 5 mg of GO and dissolve it in 40 mL of deionized water. Then add 5 μmol FeCl3 to the GO aqueous solution. After mixing evenly, disperse it under ultrasound (400 W) for 10 min to obtain a dark brown transparent solution.

[0082] (2) The GO-M dispersion prepared above was prepared into a GO-M membrane on a nylon substrate by vacuum filtration. After the water on the membrane was drained, the membrane was removed from the filtration device and placed in a constant temperature and humidity environment (25.0°C, 21% RH) for air drying for 12 hours before being taken out for use. It was named GOM-5μmolFe. The environmental scanning electron microscopy (ESEM) and X-ray diffraction (XRD) data showed that the membrane thickness of GOM-5μmolFe was about 1.84μm, and the dry interlayer spacing was about

[0083] (3) GOM-5μmolFe was used as a catalyst to catalyze the sulfide oxidation reaction. The specific operation steps were as follows: a flat and smooth part on the GOM-5μmolFe was selected and cut into a regular octagon (side length 10 mm), and then fixed on the surface of the sand core filter head of the micro-filtration device and the filter head and filter cup were clamped with a clamp to ensure sealing; then the reaction solution was prepared: 4mmol methylphenyl sulfide and 8mmol H2O2 (30% aqueous solution) were dissolved in acetonitrile to prepare 40mL of reaction solution, which was prepared immediately; 17.5mL of the above-prepared reaction solution was taken and added to the filter cup of the micro-filtration device, and the reaction solution was driven through the two-dimensional interlayer confined channel in the GOM-5μmolFe by the pressure difference (~0.9atm) provided by the circulating vacuum water pump. At room temperature, the reactants reacted in the confined channel and then flowed out with the solvent acetonitrile; 1 The components were analyzed by HNMR or HPLC spectroscopy, and the reaction conversion and selectivity were calculated. The test results showed that the reaction temperature was 20-30°C, the residence time of the reactants was approximately 20.3 seconds, the conversion of the sulfide was 98.8±0.4%, and the selectivity of the sulfone was 64.7±6.0%.

[0084] Comparative Example 1

[0085] (1) Preparation of 0.125 mg / mL GO dispersion: 5 mg of GO was added to 40 mL of deionized water and dispersed by ultrasonication (160 W) for 5 min to obtain a brown transparent solution.

[0086] (2) The GO dispersion prepared above was prepared into a GO membrane on a nylon substrate by vacuum filtration. After the water on the membrane was drained, the membrane was removed from the filtration device and placed in a constant temperature and humidity environment (25.0°C, 21% RH) for air drying for 12 hours before being taken out for use. It was named GOM. The environmental scanning electron microscopy (ESEM) and X-ray diffraction (XRD) data showed that the membrane thickness of GOM was about 1.64 μm and the dry interlayer spacing was about

[0087] (3) GOM is used as a catalyst to catalyze the sulfide oxidation reaction. The specific operation steps are as follows: select a flat and smooth part on the GOM, cut it into a regular octagon (side length 10 mm), and then fix it on the surface of the sand core filter head of the micro filtration device and clamp the filter head and filter cup with a clamp to ensure sealing; then prepare the reaction solution: 4 mmol methyl phenyl sulfide and 8 mmol H2O2 (30% aqueous solution) are dissolved in acetonitrile to prepare 40 mL of reaction solution, which is prepared as needed; 17.5 mL of the above-prepared reaction solution is taken and added to the filter cup of the micro filtration device, and the reaction solution is driven through the two-dimensional interlayer confined channel in the GOM by the pressure difference (~0.9 atm) provided by the circulating vacuum water pump. At room temperature, the reactants react in the confined channel and then flow out with the solvent acetonitrile; use 1 The components were analyzed by HNMR or HPLC spectroscopy, and the reaction conversion and selectivity were calculated. The test results showed that the reaction temperature was 20-30°C, the residence time of the reactants was approximately 15.3 seconds, the conversion of the sulfide was 94.8±5.4%, and the selectivity of the sulfone was 23.4±5.8%.

[0088] Comparative Example 2

[0089] 0.4mmol methylphenyl sulfide and 0.8mmol H2O2 (30% aqueous solution) were dissolved in acetonitrile to prepare a 4mL reaction solution; 2.5mg GO powder (catalyst is GO powder) was added to the reaction solution and mechanical stirring was maintained. 1mL of the reaction solution was sampled 24h after the start of the reaction and prepared as a test sample. 1 The sample components were analyzed by HNMR or HPLC, and the reaction conversion rate and selectivity were calculated. The test results showed that the reaction temperature was 20-30°C, the residence time of the reactants was about 24 hours, the conversion rate of sulfide was 65.5%, and the selectivity of sulfone was 0.8%.

[0090] Comparative Example 3

[0091] 0.4 mmol of methyl phenyl sulfide and 0.8 mmol of H2O2 (30% aqueous solution) were dissolved in acetonitrile to prepare a 4 mL reaction solution. 2.5 mg of GO powder and 2.5 μmol of FeCl3 (the catalyst was GO-Fe powder) were added to the reaction solution and mechanical stirring was maintained. 1 mL of the reaction solution was sampled 24 h after the start of the reaction and prepared as a test sample. 1 The sample components were analyzed by HNMR or HPLC, and the reaction conversion rate and selectivity were calculated. The test results showed that the reaction temperature was 20-30°C, the residence time of the reactants was about 24 hours, the conversion rate of sulfide was 87.9%, and the selectivity of sulfone was 2.2%.

[0092] Example 2

[0093] The other operations were the same as in Example 1, except that the reaction solution contained 4 mmol of methylphenyl sulfide and 40 mmol of H₂O₂ (30% aqueous solution). Test results showed that the reaction temperature was 20-30° C., the residence time of the reactants was approximately 8.6 s, the conversion of the sulfide was 100%, and the selectivity of the sulfone was 92.5±4.9%.

[0094] Comparative Example 4

[0095] The other operations were the same as those in Comparative Example 1, except that the reaction solution contained 4 mmol of methylphenyl sulfide and 40 mmol of H₂O₂ (30% aqueous solution). Test results showed that the reaction temperature was 20-30° C., the residence time of the reactants was approximately 10.5 s, the conversion of the sulfide was 100%, and the selectivity for sulfone was 42.7±5.3%.

[0096] Comparative Example 5

[0097] 0.4mmol methylphenyl sulfide and 4mmol H2O2 (30% aqueous solution) were dissolved in acetonitrile to prepare 4mL of reaction solution; 2.5mg GO powder (catalyst is GO powder) was added to the reaction solution and mechanical stirring was maintained. 1mL of the reaction solution was sampled 24h after the start of the reaction and prepared as a test sample. 1 The sample components were analyzed by HNMR or HPLC, and the reaction conversion rate and selectivity were calculated. The conversion rate of sulfide was 90.1%, and the selectivity of sulfone was 0.8%.

[0098] Comparative Example 6

[0099] 0.4mmol methylphenyl sulfide and 4mmol H2O2 (30% aqueous solution) were dissolved in acetonitrile to prepare 4mL of reaction solution; 2.5mg GO powder and 2.5μmol FeCl3 (catalyst is GO-Fe powder) were added to the reaction solution and mechanical stirring was maintained. 1mL of the reaction solution was sampled 24h after the start of the reaction and prepared as a test sample. 1 The sample components were analyzed by HNMR or HPLC, and the reaction conversion rate and selectivity were calculated. The conversion rate of sulfide was 100%, and the selectivity of sulfone was 30.1%.

[0100] Example 3

[0101] (1) Prepare 0.125 mg / mL GO-M dispersion: Take 5 mg of GO and dissolve it in 40 mL of deionized water. Then add 10 μmol FeCl3 to the GO aqueous solution. After mixing evenly, disperse it under ultrasound (400 W) for 10 min to obtain a dark brown transparent solution.

[0102] (2) The GO-M dispersion prepared above was prepared into a GO-M membrane on a nylon substrate by vacuum filtration. After the water on the membrane was drained, the membrane was removed from the filtration device and placed in a constant temperature and humidity environment (25.0°C, 21% RH) to air-dry for 12 hours before being taken out for use. It was named GOM-10μmolFe.

[0103] (3) GOM-10μmolFe was used as a catalyst to catalyze the sulfide oxidation reaction. The specific operation steps were as follows: a flat and smooth part on the GOM-10μmolFe was selected and cut into a regular octagon (side length 10mm), and then fixed on the surface of the sand core filter head of the micro-filtration device and the filter head and filter cup were clamped with a clamp to ensure sealing; then the reaction solution was prepared: 4mmol methylphenyl sulfide and 40mmol H2O2 (30% aqueous solution) were dissolved in acetonitrile to prepare 40mL of reaction solution, which was prepared immediately; 17.5mL of the above-prepared reaction solution was taken and added to the filter cup of the micro-filtration device, and the reaction solution was driven through the two-dimensional interlayer confined channel in the GOM-10μmolFe by the pressure difference (~0.9atm) provided by the circulating vacuum water pump. At room temperature, the reactants reacted in the confined channel and then flowed out with the solvent acetonitrile; 1 The components were analyzed by HNMR or HPLC spectroscopy, and the reaction conversion and selectivity were calculated. The test results showed that the reaction temperature was 20-30°C, the residence time of the reactants was approximately 8.2 seconds, the sulfide conversion was 100%, and the sulfone selectivity was 97.6±1.1%.

[0104] Example 4

[0105] The other operations were the same as in Example 1, except that the reaction solution contained 4 mmol of p-methylphenyl sulfide and 40 mmol of H2O2 (30% aqueous solution). The test results showed that the reaction temperature was 20-30°C, the residence time of the reactants was about 4.3 seconds, the conversion of the sulfide was 100%, and the selectivity of the sulfone was 100%.

[0106] Example 5

[0107] The other operations were the same as in Example 1, except that the reaction solution contained 4 mmol of cyclopropylphenyl sulfide and 40 mmol of H2O2 (30% aqueous solution). Test results showed that the reaction temperature was 20-30°C, the residence time of the reactants was about 7.7 seconds, the conversion of the sulfide was 100%, and the selectivity of the sulfone was 100%.

[0108] Example 6

[0109] The other operations were the same as in Example 1, except that the reaction solution contained 4 mmol of albendazole and 40 mmol of H2O2 (30% aqueous solution). Test results showed that the reaction temperature was 20-30°C, the residence time of the reactants was about 37.6 s, the conversion of the sulfide was 100%, and the selectivity of the sulfone was 86.1±9.1%.

[0110] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. Use of a metal ion-doped graphene oxide film catalyst material in catalyzing the oxidation reaction of sulfide to synthesize sulfone; The mass of the metal ions in the metal ion-doped graphene oxide membrane catalytic material accounts for 0.01-15wt% of the total mass of the membrane catalytic material; the metal ions are selected from Fe 3+ ; The metal ion-doped graphene oxide film catalytic material is a layered structure formed by metal ion-doped graphene oxide stacked together.

2. The use according to claim 1, wherein The thickness of the metal ion-doped graphene oxide film catalytic material is 0.1-5 μm.

3. The use according to claim 1, wherein The metal ion-doped graphene oxide film catalytic material is a layered structure formed by stacking metal ion-doped graphene oxide nanosheets.

4. The use according to claim 1, wherein The metal ion-doped graphene oxide film catalytic material is prepared by the following method: (1) adding metal salt to the graphene oxide dispersion and ultrasonically mixing to obtain a mixed solution; (2) The mixed solution of step (1) is assembled into a metal ion-doped graphene oxide membrane by a vacuum filtration method, and then the mixed solution is placed in a constant temperature and humidity environment to prepare the metal ion-doped graphene oxide membrane catalytic material.

5. The use according to claim 4, wherein In step (1), the concentration of the graphene oxide dispersion is 0.01-0.25 mg / mL; And / or, in step (1), the metal salt is selected from FeCl3; and / or, in step (1), the molar volume ratio of the dispersion of the metal salt and graphene oxide is 1-20 µmol / 40 mL; And / or, in step (1), the ultrasonic mixing time is 5-15 minutes; the ultrasonic mixing power is 100-500W.

6. The use according to any one of claims 1 to 5, wherein The method for synthesizing sulfone by catalytic sulfide oxidation reaction comprises the following steps: a) dissolving a thioether substrate and an oxidant in an organic solvent to obtain a reaction solution; b) driving the reaction solution of step a) through the metal ion-doped graphene oxide membrane catalytic material under pressure difference at room temperature to perform sulfide oxidation reaction to prepare sulfone.

7. The use according to claim 6, wherein In step a), the molar ratio of the thioether substrate to the oxidant is 1:1-10; and / or, in step a), the oxidant is selected from at least one of hydrogen peroxide and tert-butyl hydroperoxide; and / or, in step a), the thioether substrate includes at least one of methyl phenyl sulfide, p-methyl phenyl sulfide, phenylethyl sulfide, cyclopropyl phenyl sulfide, allyl phenyl sulfide, ethyl sulfide, dipropyl sulfide, diphenyl sulfide, 4-nitrophenyl phenyl sulfide, and albendazole; and / or, in step a), the concentration of the thioether substrate is 0.01-1 mol / L; and / or, in step b), the reaction time is 1-60 s; and / or, in step b), the pressure difference is greater than or equal to 0.9 atm.

8. A method for synthesizing sulfone by catalyzing the oxidation reaction of sulfide, the method comprising the following steps: a) dissolving a thioether substrate and an oxidant in an organic solvent to obtain a reaction solution; b) driving the reaction solution of step a) through a metal ion-doped graphene oxide membrane catalytic material at room temperature by pressure difference to carry out sulfide oxidation reaction to prepare sulfone; the mass of the metal ion in the metal ion-doped graphene oxide membrane catalytic material accounts for 0.01-15wt% of the total mass of the membrane catalytic material; the metal ion is selected from Fe 3+ ; The metal ion-doped graphene oxide film catalytic material is a layered structure formed by metal ion-doped graphene oxide stacked together.

9. The method according to claim 8, wherein The thickness of the metal ion-doped graphene oxide film catalytic material is 0.1-5 μm.

10. The method according to claim 9, wherein: The metal ion-doped graphene oxide film catalytic material is a layered structure formed by stacking metal ion-doped graphene oxide nanosheets.

11. The method according to claim 8, wherein In step a), the molar ratio of the thioether substrate to the oxidant is 1:1-10; and / or, in step a), the oxidant is selected from at least one of hydrogen peroxide and tert-butyl hydroperoxide; and / or, in step a), the thioether substrate includes at least one of methyl phenyl sulfide, p-methyl phenyl sulfide, phenylethyl sulfide, cyclopropyl phenyl sulfide, allyl phenyl sulfide, ethyl sulfide, dipropyl sulfide, diphenyl sulfide, 4-nitrophenyl phenyl sulfide, and albendazole; and / or, in step a), the concentration of the thioether substrate is 0.01-1 mol / L; and / or, in step b), the reaction time is 1-60 s; and / or, in step b), the pressure difference is greater than or equal to 0.9 atm.

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