A membrane catalytic material for efficient catalysis of aldol condensation reaction at room temperature

Abstract

The present invention provides a membrane catalytic material for efficiently catalyzing aldol condensation reaction at room temperature. The present invention modifies sulfonic acid organic amine molecules on the surface of graphene oxide so that the surface of graphene oxide has both acid and base active sites, and then uses a vacuum filtration method to prepare a graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups. Using the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups, in a continuous mobile phase reaction mode, the reaction raw materials pass through and react in the interlayer confined channel of the membrane catalytic material, and the obtained product flows out with the mobile phase, realizing a rapid aldol condensation reaction at room temperature, and the reactant conversion rate can reach 100%, the selectivity can reach 100%, and the product does not need to be separated and purified.

Description

Technical Field

[0001] The invention relates to the technical field of membrane catalyst materials, and in particular to a graphene oxide membrane catalyst material containing sulfonic acid groups and amino groups, a preparation method thereof, and an application thereof in catalyzing aldol condensation reactions quickly, with high conversion rate and high selectivity at room temperature. Background Art

[0002] The aldol condensation reaction is a very important reaction in organic synthesis. It usually refers to the reaction in which an aldehyde or ketone with α-H undergoes a nucleophilic addition reaction with a carbonyl compound under the action of a catalyst to obtain a β-hydroxyaldehyde or ketone intermediate, which is then dehydrated to form an α,β-unsaturated aldehyde or ketone.

[0003] The aldol condensation reaction can realize the formation of carbon-carbon bonds in molecules and increase the carbon number of carbon chains. Therefore, the aldol condensation reaction plays an important role in organic synthesis. In traditional aldol condensation reactions, strongly alkaline and strongly acidic solutions are often used as homogeneous catalysts, but these catalysts are used in large amounts, which will seriously pollute the environment. At the same time, there are also problems such as difficulty in separating the product and the catalyst. Therefore, heterogeneous catalysts have become a hot topic for researchers. Their main advantages are: no pollution to the environment, recyclable and reusable, easy to separate from the product, etc.

[0004] At present, the common catalysts in the aldol condensation reaction include solid base catalysts (such as MgO-Al 2 O 3 ), solid acid catalysts (such as zeolites) and acid-base bifunctional catalysts. However, most heterogeneous catalysts still have disadvantages such as the need for heating (50-100°C), long reaction time (>12 hours), low reaction selectivity (50-90%), and low reaction conversion rate (60-90%) at room temperature. In addition, after the homogeneous catalytic reaction, it is necessary to separate and purify by silica gel column chromatography or preparative liquid chromatography, while heterogeneous catalysis requires centrifugal separation to obtain the product, which consumes a lot of reagents and time, and also pollutes the environment, which is not in line with the concept of green chemistry. Summary of the invention

[0005] In order to improve the shortcomings of the existing heterogeneous catalytic aldol condensation reaction, such as high reaction temperature, long reaction time, low reactant conversion rate, low product selectivity and the need for separation and purification of products, the present invention provides a membrane catalytic material for efficiently catalyzing aldol condensation reaction at room temperature. The present invention first modifies the surface of graphene oxide with catalytically active sulfonic acid organic amine molecules to obtain a graphene oxide dispersion containing sulfonic acid groups and amino groups; then obtains the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups by a vacuum filtration method; under the driving force of pressure difference, the reaction raw materials pass through the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups in a continuous mobile phase reaction mode, the reaction raw materials pass through the interlayer channels of the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups and react efficiently, the products flow out with the mobile phase and leave the system, and finally a rapid (<2 minutes) aldol condensation reaction is achieved at room temperature, and the reactant conversion rate can reach 100%, the selectivity can reach 100%, and the product does not need to be separated and purified.

[0006] The object of the present invention is achieved through the following technical solutions:

[0007] A method for preparing a graphene oxide film catalytic material containing sulfonic acid groups and amino groups, the method comprising the following steps:

[0008] 1) dispersing graphene oxide in an organic solvent, then adding an activator for activation, adding a sulfonic acid organic amine molecule for reaction after the activation, and centrifuging, dialysis and ultrasonically treating the reaction system after the reaction to obtain a graphene oxide dispersion containing sulfonic acid groups and amino groups;

[0009] 2) vacuum filtering the graphene oxide dispersion containing sulfonic acid groups and amino groups in step 1) to form a membrane, and drying the obtained membrane to obtain the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups.

[0010] According to an embodiment of the present invention, in step 1), the graphene oxide is a single-layer graphene oxide nanosheet, and the sheet diameter of the single-layer graphene oxide nanosheet is greater than 500 nm.

[0011] According to an embodiment of the present invention, in step 1), the organic solvent is selected from at least one of N,N-dimethylformamide and N,N-dimethylpropionamide.

[0012] According to an embodiment of the present invention, in step 1), the activator is selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide.

[0013] According to an embodiment of the present invention, in step 1), the sulfonic acid organic amine molecule is selected from p-aminobenzenesulfonic acid and / or p-aminobiphenylsulfonic acid.

[0014] According to an embodiment of the present invention, in step 1), the mass volume ratio of graphene oxide to organic solvent is 0.5-2 mg / mL, such as 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL or 2 mg / mL.

[0015] According to an embodiment of the present invention, in step 1), the mass ratio of the graphene oxide to the activator is 1:8-1:15, for example, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14 or 1:15.

[0016] According to an embodiment of the present invention, in step 1), the mass ratio of the graphene oxide to the sulfonic acid organic amine molecules is 1:10-1:50, for example, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45 or 1:50.

[0017] According to an embodiment of the present invention, in step 1), the reaction temperature is 20-40° C., and the reaction time is 12-36 hours, such as 24 hours.

[0018] According to an embodiment of the present invention, in step 1), the activation temperature is 20-40° C., and the activation time is 12-36 hours, such as 24 hours.

[0019] According to an embodiment of the present invention, in step 1), the centrifugation is to centrifuge the reaction system after the reaction to collect the solid component. Exemplarily, the centrifugation condition is to centrifuge the reaction system after the reaction at 10,000 revolutions per minute for 30 minutes. The centrifugation can collect the graphene oxide modified with the sulfonic acid organic amine molecule, and is convenient for subsequent dialysis and ultrasonic treatment.

[0020] According to an embodiment of the present invention, in step 1), the dialysis is to disperse the solid components collected after centrifugation in deionized water to obtain a dispersion, and then pour the dispersion into a dialysis bag (dialysis bag molecular weight cutoff 4500-20000g / mol), and use deionized water for dialysis treatment for more than 5 days. The dialysis can remove small molecular impurities in the solid components to obtain a pure sulfonic acid organic amine molecule-modified graphene oxide dispersion.

[0021] According to an embodiment of the present invention, in step 1), the ultrasonic treatment time is 5 min-15 min, and the ultrasonic treatment power is 50-200 W, for example, 100 W ultrasonic treatment for 10 min. The ultrasonic treatment can further disperse the graphene oxide modified with the sulfonic acid organic amine molecules.

[0022] According to an embodiment of the present invention, in step 1), the concentration of the graphene oxide dispersion containing sulfonic acid groups and amino groups is 0.5-3 mg / mL, for example, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL or 3 mg / mL.

[0023] According to an embodiment of the present invention, in step 1), the graphene oxide dispersion containing sulfonic acid groups and amino groups includes graphene oxide nanosheets containing sulfonic acid groups and amino groups and deionized water.

[0024] According to an embodiment of the present invention, in step 2), a membrane formed by stacking a plurality of graphene oxide nanosheets containing sulfonic acid groups and amino groups and having a certain thickness is prepared on a porous substrate by a vacuum filtration method.

[0025] According to an embodiment of the present invention, the porous substrate may be made of an organic filter membrane such as nylon 66, polyvinylidene fluoride, polytetrafluoroethylene, etc. The pore size of the porous substrate is 0.1-0.3 μm, for example, 0.22 μm.

[0026] According to an embodiment of the present invention, in step 2), the drying is carried out at room temperature or under heating conditions, and the heating temperature is 40-100°C, for example, 40°C, 60°C, 80°C or 100°C; the drying time is 3-24 hours, for example, 6 hours, 8 hours, 10 hours, 12 hours, 15 hours or 18 hours.

[0027] According to an embodiment of the present invention, in step 2), the graphene oxide dispersion containing sulfonic acid groups and amino groups is added to a filter cup of a vacuum filtration device, and the vacuum pump is started to perform vacuum filtration with a vacuum degree of 1-5 Pa; as the filtration proceeds, the graphene oxide nanosheets containing sulfonic acid groups and amino groups in the graphene oxide dispersion containing sulfonic acid groups and amino groups are assembled into a layered structure under the action of water flow, and after the filtration is completed, a graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups is obtained.

[0028] The present invention also provides a graphene oxide film catalytic material containing sulfonic acid groups and amino groups prepared by the above method.

[0029] According to an embodiment of the present invention, the graphene oxide film catalytic material containing sulfonic acid groups and amino groups is a layered structure formed by stacking graphene oxide nanosheets containing sulfonic acid groups and amino groups; preferably, a layered structure formed by stacking multiple graphene oxide nanosheets containing sulfonic acid groups and amino groups. The diameter of the graphene oxide nanosheets containing sulfonic acid groups and amino groups is greater than 500 nm.

[0030] According to an embodiment of the present invention, the interlayer spacing of the graphene oxide film catalyst material containing sulfonic acid groups and amino groups is 1.0-2.0nm, for example, 1.0nm, 1.1nm, 1.2nm, 1.3nm, 1.4nm, 1.5nm, 1.6nm, 1.7nm, 1.8nm, 1.9nm or 2.0nm. The interlayer spacing of the graphene oxide film catalyst material containing sulfonic acid groups and amino groups is regulated by regulating the size of the sulfonic acid organic amine molecules or by removing the bound water between the interlayers of the graphene oxide film catalyst material containing sulfonic acid groups and amino groups by heating. For example, the higher the drying temperature, the smaller the interlayer spacing of the graphene oxide film catalyst material containing sulfonic acid groups and amino groups is obtained.

[0031] According to an embodiment of the present invention, the thickness of the graphene oxide film catalytic material containing sulfonic acid groups and amino groups is 0.5-10 μm, for example, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.8 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm μm, 9.5μm or 10μm; the thickness of the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups can be adjusted by adjusting the concentration of the graphene oxide dispersion containing sulfonic acid groups and amino groups or the volume of the dispersion filtration. The greater the concentration of the graphene oxide dispersion containing sulfonic acid groups and amino groups or the larger the volume of the dispersion filtration, the thicker the thickness of the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups; the smaller the concentration of the graphene oxide dispersion containing sulfonic acid groups and amino groups or the smaller the volume of the dispersion filtration, the thinner the thickness of the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups. Too thin membrane catalytic materials will easily crack in the subsequent reaction process, and the reaction raw materials will separate from the membrane catalytic materials before they have time to react, resulting in a decrease in conversion rate; while too thick membrane catalytic materials require a long vacuum filtration time, and are prone to introduce too many defects during the preparation process, reducing the orderliness of the two-dimensional confined space provided for the reaction molecules.

[0032] According to an embodiment of the present invention, the graphene oxide film catalytic material containing sulfonic acid groups and amino groups is used for aldol condensation reaction.

[0033] According to an embodiment of the present invention, the graphene oxide film catalytic material containing sulfonic acid groups and amino groups is used to catalyze the aldol condensation reaction of benzaldehyde substances and acetone.

[0034] According to an embodiment of the present invention, the benzaldehyde substance includes at least one of benzaldehyde, p-nitrobenzaldehyde, p-tolualdehyde, p-methoxybenzaldehyde, p-chlorobenzaldehyde and p-fluorobenzaldehyde.

[0035] The present invention also provides use of the graphene oxide film catalytic material containing sulfonic acid groups and amino groups in an aldol condensation reaction.

[0036] According to an embodiment of the present invention, the graphene oxide film catalytic material containing sulfonic acid groups and amino groups is used to catalyze the aldol condensation reaction of benzaldehyde substances and acetone.

[0037] The present invention also provides a method for aldol condensation reaction, which comprises the following steps:

[0038] a) mixing benzaldehyde substance and acetone to obtain a reaction solution;

[0039] b) driving the reaction solution through the above-mentioned graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups by pressure difference to carry out aldol condensation reaction.

[0040] According to an embodiment of the present invention, in step a), the benzaldehyde substance includes at least one of benzaldehyde, p-nitrobenzaldehyde, p-tolualdehyde, p-methoxybenzaldehyde, p-chlorobenzaldehyde and p-fluorobenzaldehyde.

[0041] According to an embodiment of the present invention, in step a), the acetone serves as both a reactant and a solvent.

[0042] According to an embodiment of the present invention, in step a), the molar volume (mol / L) ratio of the benzaldehyde substance to acetone is 1:20-100, for example, 1:20, 1:40, 1:60, 1:80 or 1:100.

[0043] According to an embodiment of the present invention, in step b), the aldol condensation reaction is carried out in a continuous mobile phase reaction driven by pressure difference, and the benzaldehyde substance and acetone react efficiently in the interlayer confined channel of the membrane catalytic material, and the product flows out with the mobile phase and leaves the system.

[0044] According to an embodiment of the present invention, in step b), the temperature of the aldol condensation reaction is room temperature, and the room temperature refers to a temperature range of 20-30°C, for example, 23°C.

[0045] According to an embodiment of the present invention, in step b), the aldol condensation reaction time is 10-120s.

[0046] According to an embodiment of the present invention, in step b), the pressure difference is greater than or equal to 1 atm.

[0047] Beneficial effects of the present invention:

[0048] The present invention provides a membrane catalytic material for efficiently catalyzing aldol condensation reaction at room temperature. The present invention modifies sulfonic acid organic amine molecules on the surface of graphene oxide so that the surface of graphene oxide has acid and base active sites (sulfonic acid group and amino group) at the same time, and then uses a vacuum filtration method to prepare a graphene oxide membrane catalytic material containing sulfonic acid group and amino group. Using the graphene oxide membrane catalytic material containing sulfonic acid group and amino group, in a continuous mobile phase reaction mode, the reaction raw materials pass through and react in the interlayer confined channel of the membrane catalytic material, and the obtained product flows out with the mobile phase, realizing a rapid aldol condensation reaction at room temperature, and the reactant conversion rate can reach 100%, the selectivity can reach 100%, and the product does not need to be separated and purified. Further, by adjusting the size of the sulfonic acid organic amine molecules modified on the surface of graphene oxide and the temperature of the drying treatment to control the interlayer spacing of the membrane catalytic material, it can be suitable for aldol condensation reactions of different reaction activities and different sizes of reaction molecules. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The graphs are the characterization test graphs of the p-aminobenzenesulfonic acid modified graphene oxide and p-aminobiphenylsulfonic acid modified graphene oxide of Example 3 and the graphene oxide of Comparative Example 4, wherein Figure 1 a in the figure is a schematic diagram of the structure of graphene oxide of Comparative Example 4; Figure 1 b is a schematic diagram of the structure of p-aminobenzenesulfonic acid modified graphene oxide and p-aminobiphenylsulfonic acid modified graphene oxide of Example 3; Figure 1 c in the figure is the infrared spectra of the graphene oxide modified with p-aminobenzenesulfonic acid and the graphene oxide modified with p-aminobiphenylsulfonic acid in Example 3.

[0050] Figure 2 This is a schematic diagram of a membrane extraction device and a membrane reaction device according to a preferred embodiment of the present invention.

[0051] Figure 3 It is a schematic diagram of the reaction of substituted benzaldehyde substances and acetone catalyzed by the graphene oxide film catalytic material containing sulfonic acid groups and amino groups of the present invention, as well as the X-ray diffraction pattern of the reaction of p-nitrobenzaldehyde and acetone catalyzed by the graphene oxide film catalytic material containing sulfonic acid groups and amino groups of Example 3 and the graphene oxide film of Comparative Example 4. DETAILED DESCRIPTION

[0052] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions 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 included in the scope that the present invention is intended to protect.

[0053] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the reagents, materials, etc. used in the following examples, unless otherwise specified, can be obtained from commercial channels.

[0054] The calculation method of the reaction conversion mentioned in the following examples and comparative examples is as follows:

[0055] The collected liquid through the membrane was quantitatively analyzed by nuclear magnetic resonance hydrogen spectrum, and the reaction conversion rate was calculated, which specifically included the following steps: after the reaction was completed, acetone was added to the filter bottle to dissolve the product and obtain the product collected liquid, part of the collected liquid was taken into a 10mL flask, and the acetone solvent was removed by rotary evaporation at 30°C, and deuterated dimethyl sulfoxide (C2D6SO) was used to prepare the nuclear magnetic sample. There are characteristic hydrogen in the molecules of the reactants and products. There is a corresponding relationship between the characteristic hydrogen and the number of molecules. The integral area of ​​the single peaks at different chemical shifts was compared by single peak fitting calculation, and the corresponding molecular number ratio was calculated, and then the reaction conversion rate was calculated.

[0056] The conversion rate of the reaction in the following examples and comparative examples can be calculated by the following formula:

[0057]

[0058] The selectivity of the reaction in the following examples and comparative examples can be calculated by the following formula:

[0059]

[0060] Wherein, n(aldol product) is the peak area of ​​the aldol product in the H NMR spectrum, n(enol product) is the peak area of ​​the enol product in the H NMR spectrum, and n(unreacted aldehyde) is the peak area of ​​the unreacted aldehyde in the H NMR spectrum.

[0061] The mass of the membrane catalytic material involved in the reaction in the following examples can be calculated by the following formula:

[0062]

[0063] Among them, C is the concentration of the graphene oxide dispersion containing sulfonic acid groups and amino groups (in mg / mL); V is the volume of the graphene oxide dispersion containing sulfonic acid groups and amino groups (in mL); D is the diameter of the modified membrane, which is 40 mm; d is the diameter of the actual reaction liquid passing through the membrane, which is 15 mm. Substituting the two into the above formula, we can get m≈0.1406×C×V.

[0064] Comparative Example 1

[0065] 100 mg of graphene oxide (GO) was dispersed in 100 ml of N,N-dimethylformamide, 1400 μL of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added, and the mixture was stirred for 24 hours. 1 g of p-aminobenzenesulfonic acid was added and stirred for 24 hours. After centrifugation to remove the solvent, the obtained solid sample was dispersed in 100 ml of water and dialyzed for 5 days to remove small molecules. After the dialysate was taken out, it was ultrasonically treated at 150 W for 10 min. After ultrasonic dispersion, the dispersion was transferred to a reagent bottle and stored in a sealed container at room temperature (the concentration was about 1.8 mg / mL). The dispersion was marked as modified sample 1.

[0066] 100 mg of graphene oxide (GO) was dispersed in 100 ml of N,N-dimethylformamide, 1400 μL of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added, and the mixture was stirred for 24 hours. 2 g of p-aminobiphenylsulfonic acid was added and stirred for 24 hours. After centrifugation to remove the solvent, the obtained solid sample was dispersed in 100 ml of water and dialyzed for 5 days to remove small molecules. After the dialysate was taken out, it was ultrasonically treated at 150 W for 10 min. After ultrasonic dispersion, the dispersion was transferred to a reagent bottle and stored in a sealed container at room temperature (the concentration was about 1.8 mg / mL). The dispersion was marked as modified sample 2.

[0067] Take an appropriate amount of modified sample 1 and perform vacuum freeze drying to obtain a powder of modified sample 1, which is named modified powder 1. Take an appropriate amount of modified sample 2 and perform vacuum freeze drying to obtain a powder of modified sample 2, which is named modified powder 2.

[0068] The dried modified powder was used for bulk reaction, i.e., catalyzing the condensation reaction of p-nitrobenzaldehyde and acetone. The specific operation was as follows: p-nitrobenzaldehyde (0.5 mmol, about 76 mg) was weighed and added to 10 mL of acetone, and mechanically stirred for 5 min to obtain a reaction solution; 30 mg of modified powder 1 or modified powder 2 was weighed and added to the above reaction solution, and mechanical stirring was maintained. The reaction temperature was controlled to 25°C by an oil bath constant temperature magnetic stirrer; after reacting for 24 h, 2.0 mL of the above reaction solution was sampled, the solvent was removed by rotary evaporation, the concentrate was dissolved with deuterated dimethyl sulfoxide, and then 1 The components were analyzed by HNMR spectroscopy and the conversion and selectivity were determined.

[0069] The catalytic results of modified powder 1 are: the reaction temperature is 25°C, the reaction time is 24 hours, the conversion rate and selectivity are 22% and 94% respectively. The catalytic results of modified powder 2 are: the reaction temperature is 25°C, the reaction time is 24 hours, the conversion rate and selectivity are 23% and 95% respectively.

[0070] Comparative Example 2

[0071] The other operations are the same as those in Comparative Example 1, except that:

[0072] The temperature of the condensation reaction of p-nitrobenzaldehyde and acetone was controlled to be 50°C.

[0073] The catalytic results of modified powder 1 are: the reaction temperature is 50°C, the reaction time is 24 hours, the conversion rate and selectivity are 35% and 78% respectively. The catalytic results of modified powder 2 are: the reaction temperature is 50°C, the reaction time is 24 hours, the conversion rate and selectivity are 45% and 70% respectively.

[0074] Comparative Example 3

[0075] The other operations are the same as those in Comparative Example 1, except that:

[0076] The temperature of the condensation reaction of p-nitrobenzaldehyde and acetone was controlled to be 75°C.

[0077] The catalytic results of modified powder 1 are: the reaction temperature is 75°C, the reaction time is 24 hours, the conversion rate and selectivity are 68% and 38% respectively. The catalytic results of modified powder 2 are: the reaction temperature is 75°C, the reaction time is 24 hours, the conversion rate and selectivity are 88% and 37% respectively.

[0078] Comparative Example 4

[0079] Take 10 ml of graphene oxide (concentration is about 2.0 mg / mL) dispersion, and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named graphene oxide membrane.

[0080] Substituting V=10mL and C=2.0mg / mL into the mass calculation formula of the membrane participating in the reaction yields m≈2.8mg, that is, the mass of the membrane catalytic material actually participating in the reaction is approximately 2.8mg.

[0081] The dried graphene oxide membrane was used for membrane catalytic reaction to catalyze the aldol condensation reaction of p-nitrobenzaldehyde and acetone. The specific operation was as follows: the membrane was fixed and sealed in a micro-filtration device. Then, 10 mL of acetone reaction solution containing p-nitrobenzaldehyde (0.5 mmol, about 76 mg) was added to the measuring cylinder above the filtration device. Driven by the pressure difference (1 atm), the reaction solution passed through the two-dimensional channel between the layers of the membrane, the reactants reacted between the layers, and the products flowed out with the solvent. The solvent was removed by rotary evaporation, and the concentrate was dissolved with deuterated dimethyl sulfoxide and then 1 The composition was analyzed by HNMR spectrum and the conversion rate was determined. The catalytic results of the graphene oxide membrane were: the reaction temperature was 23°C, the reaction time was less than 2 minutes, the conversion rate and selectivity were 0% and 0% respectively.

[0082] Example 1

[0083] 100 mg of graphene oxide (GO) was dispersed in 100 ml of N,N-dimethylformamide, 1400 μL of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added, and the mixture was stirred for 24 hours. 1 g of p-aminobenzenesulfonic acid was added and stirred for 24 hours. After centrifugation to remove the solvent, the obtained solid sample was dispersed in 100 ml of water and dialyzed for 5 days to remove small molecules. After the dialysate was taken out, it was ultrasonically treated at 150 W for 10 min. After ultrasonic dispersion, the dispersion was transferred to a reagent bottle and stored in a sealed container at room temperature (the concentration was about 1.8 mg / mL). The dispersion was marked as modified sample 1.

[0084] 100 mg of graphene oxide (GO) was dispersed in 100 ml of N,N-dimethylformamide, 1400 μL of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide was added, and the mixture was stirred for 24 hours. 2 g of p-aminobiphenylsulfonic acid was added and stirred for 24 hours. After centrifugation to remove the solvent, the obtained solid sample was dispersed in 100 ml of water and dialyzed for 5 days to remove small molecules. After the dialysate was taken out, it was ultrasonically treated at 150 W for 10 min. After ultrasonic dispersion, the dispersion was transferred to a reagent bottle and stored in a sealed container at room temperature (the concentration was about 1.8 mg / mL). The dispersion was marked as modified sample 2.

[0085] Take 8 mL of modified sample 1 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 1 (membrane thickness is about 4.14 μm).

[0086] Take 8 mL of modified sample 2 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 2 (membrane thickness is about 4.54 μm).

[0087] Substituting V=8mL and C=1.8mg / mL into the mass calculation formula of the membrane participating in the reaction yields m≈2mg, that is, the mass of the membrane catalytic material actually participating in the reaction is approximately 2.0 mg.

[0088] The dried modified membrane 1 and modified membrane 2 were used for membrane catalytic reaction to catalyze the aldol condensation reaction of p-nitrobenzaldehyde and acetone. The specific operation was as follows: the membrane was fixed and sealed in a micro-filtration device. Then, 10 mL of acetone reaction solution containing p-nitrobenzaldehyde (0.5 mmol, about 76 mg) was added to the measuring cylinder above the filtration device. Driven by the pressure difference (1 atm), the reaction solution passed through the two-dimensional channel between the layers of the membrane, the reactants reacted between the layers, and the products flowed out with the solvent. The solvent was removed by rotary evaporation, and the concentrate was dissolved with deuterated dimethyl sulfoxide and then 1 The components were analyzed by HNMR spectroscopy and the conversion and selectivity were determined.

[0089] The catalytic results of modified membrane 1 are: the reaction temperature is 23°C, the reaction time is less than 1 minute, the conversion rate and selectivity are 64% and 100% respectively. The catalytic results of modified membrane 2 are: the reaction temperature is 23°C, the reaction time is less than 1 minute, the conversion rate and selectivity are 53% and 100% respectively.

[0090] Example 2

[0091] Other operations are the same as those in Example 1, except that:

[0092] Take 10 mL of modified sample 1 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 1 (membrane thickness is about 4.9 μm).

[0093] Take 10 mL of modified sample 2 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 2 (membrane thickness is about 5.49 μm).

[0094] Substituting V=10mL and C=1.8mg / mL into the mass calculation formula of the membrane participating in the reaction yields m≈2.5mg, that is, the mass of the membrane catalytic material actually participating in the reaction is approximately 2.5mg.

[0095] The catalytic results of modified membrane 1 are: the reaction temperature is 23°C, the reaction time is less than 1 minute, the conversion rate and selectivity are 88% and 100% respectively. The catalytic results of modified membrane 2 are: the reaction temperature is 23°C, the reaction time is less than 1 minute, the conversion rate and selectivity are 75% and 100% respectively.

[0096] Example 3

[0097] Other operations are the same as those in Example 1, except that:

[0098] Take 12 mL of modified sample 1 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 1 (membrane thickness is about 5.78 μm).

[0099] Take 12 mL of modified sample 2 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 2 (membrane thickness is about 6.65 μm).

[0100] Substituting V=12mL and C=1.8mg / mL into the mass calculation formula of the membrane participating in the reaction yields m≈3.0mg, that is, the mass of the membrane catalytic material actually participating in the reaction is approximately 3.0mg.

[0101] The catalytic results of modified membrane 1 are: the reaction temperature is 23°C, the reaction time is less than 1 minute, the conversion rate and selectivity are both 100%. The catalytic results of modified membrane 2 are: the reaction temperature is 23°C, the reaction time is less than 1 minute, the conversion rate and selectivity are 87% and 99% respectively.

[0102] Example 4

[0103] Other operations are the same as those in Example 1, except that:

[0104] Take 14 mL of modified sample 1 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 1 (membrane thickness is about 6.99 μm).

[0105] Take 14 mL of modified sample 2 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 2 (membrane thickness is about 8.18 μm).

[0106] Substituting V=14mL and C=1.8mg / mL into the mass calculation formula of the membrane participating in the reaction yields m≈3.5mg, that is, the mass of the membrane catalytic material actually participating in the reaction is approximately 3.5mg.

[0107] The catalytic results of modified membrane 1 are: the reaction temperature is 23°C, the reaction time is less than 2 minutes, and the conversion rate and selectivity are both 100%. The catalytic results of modified membrane 2 are: the reaction temperature is 23°C, the reaction time is less than 2 minutes, and the conversion rate and selectivity are 96% and 100% respectively.

[0108] Example 5

[0109] Other operations are the same as those in Example 1, except that:

[0110] Take 16 mL of modified sample 1 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 1 (membrane thickness is about 8.2 μm).

[0111] Take 16 mL of modified sample 2 and prepare a membrane by vacuum filtration (vacuum degree 1 atm). After the water above the membrane is drained, remove the membrane from the filtration device and place it in a watch glass to dry at room temperature for 12 hours. It is named modified membrane 2 (membrane thickness is about 9.7 μm).

[0112] Substituting V=16mL and C=1.8mg / mL into the mass calculation formula of the membrane participating in the reaction yields m≈4.0mg, that is, the mass of the membrane catalytic material actually participating in the reaction is approximately 4.0mg.

[0113] The catalytic results of modified membrane 1 are: the reaction temperature is 23°C, the reaction time is less than 2 minutes, and the conversion rate and selectivity are both 100%. The catalytic results of modified membrane 2 are: the reaction temperature is 23°C, the reaction time is less than 2 minutes, and the conversion rate and selectivity are both 100%.

[0114] Example 6

[0115] Other operations are the same as those in Example 5, except that:

[0116] The dried modified membrane 1 and modified membrane 2 were used for membrane catalytic reaction to catalyze the aldol condensation reaction of benzaldehyde and acetone. The specific operation was as follows: the membrane was fixed and sealed in a micro-filtration device. Then, 10 mL of acetone reaction solution containing benzaldehyde (0.5 mmol, about 53 mg) was added to the measuring cylinder above the filtration device. Driven by the pressure difference (1 atm), the reaction solution passed through the two-dimensional channel between the layers of the membrane, the reactants reacted between the layers, and the products flowed out with the solvent. The solvent was removed by rotary evaporation, and the concentrate was dissolved with deuterated dimethyl sulfoxide and then 1 The components were analyzed by HNMR spectroscopy and the conversion rate was determined.

[0117] The reaction results are as follows: the catalytic results of modified membrane 1 are: the reaction temperature is 23°C, the reaction time is less than 2 minutes, and the conversion rate and selectivity are both 100%. The catalytic results of modified membrane 2 are: the reaction temperature is 23°C, the reaction time is less than 2 minutes, and the conversion rate and selectivity are both 100%.

[0118] Example 7

[0119] Other operations are the same as those in Example 5, except that:

[0120] The dried modified membrane 1 and modified membrane 2 were used for membrane catalytic reaction to catalyze the aldol condensation reaction of p-methylbenzaldehyde and acetone. The specific operation was as follows: the membrane was fixed and sealed in a micro-filtration device. Then, 10 mL of acetone reaction solution containing p-methylbenzaldehyde (0.5 mmol, about 60 mg) was added to the measuring cylinder above the filtration device. Driven by the pressure difference (1 atm), the reaction solution passed through the two-dimensional channel between the layers of the membrane, the reactants reacted between the layers, and the products flowed out with the solvent. The solvent was removed by rotary evaporation, and the concentrate was dissolved with deuterated dimethyl sulfoxide and then 1 The components were analyzed by HNMR spectroscopy and the conversion rate was determined.

[0121] The reaction results are as follows: the catalytic results of modified membrane 1 are: the reaction temperature is 23°C, the reaction time is less than 2 minutes, and the conversion rate and selectivity are both 100%. The catalytic results of modified membrane 2 are: the reaction temperature is 23°C, the reaction time is less than 2 minutes, and the conversion rate and selectivity are both 100%.

[0122] Figure 1 a in FIG. 4 is a schematic diagram of the structure of graphene oxide in Comparative Example 4, Figure 1 b in the figure is a schematic diagram of the structure of p-aminobenzenesulfonic acid modified graphene oxide and p-aminobiphenylsulfonic acid modified graphene oxide in Example 3. Figure 1 a and Figure 1 As can be seen in b, there are abundant epoxy and carboxyl groups on the surface of graphene oxide. By utilizing the reaction between amino groups and these two groups, p-aminobenzenesulfonic acid and p-aminobiphenylsulfonic acid molecules can be modified onto the surface of graphene oxide respectively.

[0123] Figure 1 c in FIG. 3 is an infrared spectrum of the graphene oxide modified with p-aminobenzenesulfonic acid and the graphene oxide modified with p-aminobiphenylsulfonic acid in Example 3. Figure 1 As can be seen from the figure c, the infrared spectra of the two molecular modified samples have a wavelength of 1730 cm -1 The absorption peak (stretching vibration of the carbonyl group in the carboxyl group) disappears, 1630 cm -1 The absorption peaks of carbonyl stretching vibration in amide group are enhanced at 705 and 620 cm -1 The appearance of the absorption peak (vibration of the sulfonic acid group) indicates that the p-aminobenzenesulfonic acid and p-aminobiphenylsulfonic acid molecules have been successfully modified onto the surface of GO.

[0124] Figure 2 This is a schematic diagram of a membrane extraction device and a membrane reaction device according to a preferred embodiment of the present invention. Figure 2 It can be seen that the membrane extraction device and the membrane reaction device of the present invention are both sand core filtration devices. The difference is that the inner diameter of the membrane extraction device is slightly larger than that of the membrane reaction device. This is mainly to ensure the sealing so that the reaction liquid can effectively pass through the membrane reaction.

[0125] Figure 3 a in the figure is a schematic diagram of the reaction of the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups of the present invention catalyzing the substituted benzaldehyde substances and acetone, wherein the Aldol product is the target product and the enol product is the dehydration by-product.

[0126] Figure 3b in the figure is the X-ray diffraction pattern of the graphene oxide film catalytic material containing sulfonic acid groups and amino groups in Example 3 and the graphene oxide film in Comparative Example 4 during the reaction of p-nitrobenzaldehyde and acetone, specifically the X-ray diffraction pattern of the graphene oxide film after catalyzing the reaction of p-nitrobenzaldehyde and acetone for 10 hours. Figure 3 As can be seen from b, the interlayer channel size of the graphene oxide film is 0.80nm, while the interlayer channel sizes of the membrane catalytic materials of graphene oxide after two different molecular modifications are 1.15nm and 1.46nm, respectively.

[0127] Table 1 is a comparison chart of the reaction temperature, reaction time and yield of the membrane catalytic material of the present invention and the catalyst reported in the literature. As shown in Table 1, the current reports in the literature usually require a higher reaction temperature (30-90°C) and a long reaction time (>4 hours), but high temperature usually leads to side reactions and reduces selectivity. In contrast, the membrane catalytic material of the present invention can greatly improve the reaction efficiency and optimize the reaction temperature (23°C) and reaction time (<60s).

[0128]

[0129] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A graphene oxide film catalytic material containing sulfonic acid groups and amino groups for aldol condensation reaction, wherein: The graphene oxide film catalytic material containing sulfonic acid groups and amino groups is a layered structure formed by stacking graphene oxide nanosheets containing sulfonic acid groups and amino groups; The interlayer spacing of the graphene oxide film catalytic material containing sulfonic acid groups and amino groups is 1.0-2.0 nm.

2. The graphene oxide film catalytic material containing sulfonic acid groups and amino groups for aldol condensation reaction according to claim 1, wherein: The thickness of the graphene oxide film catalytic material containing sulfonic acid groups and amino groups is 0.5-10 μm.

3. The graphene oxide film catalytic material containing sulfonic acid groups and amino groups for aldol condensation reaction according to claim 1 or 2, wherein: The graphene oxide film catalytic material containing sulfonic acid groups and amino groups is used for catalyzing the aldol condensation reaction of benzaldehyde substances and acetone.

4. The method for preparing the graphene oxide film catalytic material containing sulfonic acid groups and amino groups for aldol condensation reaction according to any one of claims 1 to 3, comprising the following steps: 1) dispersing graphene oxide in an organic solvent, then adding an activator for activation, adding a sulfonic acid organic amine molecule for reaction after the activation, and centrifuging, dialysis and ultrasonically treating the reaction system after the reaction to obtain a graphene oxide dispersion containing sulfonic acid groups and amino groups; 2) vacuum filtering the graphene oxide dispersion containing sulfonic acid groups and amino groups in step 1) to form a membrane, and drying the obtained membrane to obtain the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups.

5. The preparation method according to claim 4, wherein In step 1), the activator is selected from 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide; and / or the sulfonic acid organic amine molecule is selected from p-aminobenzenesulfonic acid and / or p-aminobiphenylsulfonic acid.

6. The preparation method according to claim 4, wherein In step 1), the mass volume ratio of the graphene oxide to the organic solvent is 0.5-2 mg / mL; and / or the mass ratio of the graphene oxide to the activator is 1:8-1:15; and / or the mass ratio of the graphene oxide to the sulfonic acid organic amine molecule is 1:10-1:

50.

7. The preparation method according to claim 4, wherein In step 1), the concentration of the graphene oxide dispersion containing sulfonic acid groups and amino groups is 0.5-3 mg / mL.

8. The preparation method according to claim 4, wherein In step 1), the graphene oxide dispersion containing sulfonic acid groups and amino groups includes graphene oxide nanosheets containing sulfonic acid groups and amino groups and deionized water.

9. The preparation method according to claim 4, wherein: In step 2), a membrane formed by stacking a plurality of graphene oxide nanosheets containing sulfonic acid groups and amino groups with a certain thickness is prepared on a porous substrate by a vacuum filtration method.

10. The preparation method according to claim 4, wherein: In step 2), the drying is carried out at room temperature or under heating conditions, the heating temperature is 40-100° C., and the drying time is 3-24 hours.

11. A method for an aldol condensation reaction, comprising the steps of: a) mixing benzaldehyde substance and acetone to obtain a reaction solution; b) driving the reaction solution through the graphene oxide membrane catalytic material containing sulfonic acid groups and amino groups according to any one of claims 1 to 3 by pressure difference to carry out aldol condensation reaction.

12. The method for aldol condensation reaction according to claim 11, wherein In step a), the benzaldehyde substance includes at least one of benzaldehyde, p-nitrobenzaldehyde, p-tolualdehyde, p-methoxybenzaldehyde, p-chlorobenzaldehyde and p-fluorobenzaldehyde; And / or, in step a), the molar volume ratio of the benzaldehyde substance to acetone is 1:20-100.

13. The method for aldol condensation reaction according to claim 11, wherein In step b), the temperature of the aldol condensation reaction is room temperature; And / or, in step b), the aldol condensation reaction time is 10-120s; And / or, in step b), the pressure difference is greater than or equal to 1 atm.

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