An organic composite catalyst, a preparation method and application thereof

Abstract

The present application relates to organic catalysis, fine chemical catalyst technical field, especially to a kind of organic composite catalyst and its preparation method and application, the organic composite catalyst includes the following components: linear alkyl benzene sulfonic acid, p-toluenesulfonic acid, boron trifluoride and polar cosolvent.The present application compared with single organic acid, can catalyze the reaction of various phenolic mixture material and formaldehyde, the yield of target product is improved by 8%~22%, the reaction time is reduced by more than 10%, the corrosion of organic acid composite system is far lower than concentrated sulfuric acid and concentrated hydrochloric acid, the anticorrosion investment of equipment is reduced, raw material is cheap and easy to obtain, preparation condition is mild, high temperature and high pressure are not needed, suitable for continuous industrial production.

Description

Technical Field

[0001] This invention relates to the fields of organic catalysis and fine chemical catalysts, specifically to an organic composite catalyst, its preparation method, and its application. Background Technology

[0002] Currently, widely used organic acid catalytic systems in industry are mainly divided into two categories: liquid homogeneous organic acids and solid sulfonic acid resins. Liquid homogeneous organic acids include p-toluenesulfonic acid, oxalic acid, citric acid, and various alkyl acids. Although their catalytic activity meets the requirements of specific reactions to a certain extent, they have the following prominent problems in practical applications: generally low catalytic activity and large required quantities; because these organic acids are easily soluble in the reaction system, they are difficult to separate and recover from the products after the reaction, usually requiring neutralization treatment, which generates a large amount of saline wastewater, and equipment corrosion is also a significant problem. Solid sulfonic acid resins (such as sulfonated polystyrene-divinylbenzene resin) can achieve heterogeneous catalysis and are easy to separate, but their thermal stability is poor, and sulfonic acid groups are prone to detachment under high-temperature reaction conditions, leading to a decrease in activity; at the same time, their pore size distribution is difficult to precisely control, limiting the diffusion efficiency of the substrate inside the catalyst, and the catalyst life is generally short.

[0003] Besides the two common systems mentioned above, heteropoly acids (such as phosphotungstic acid and silicotungstic acid) exhibit high catalytic activity under homogeneous conditions, but they are easily soluble in the reaction medium, resulting in significant catalyst loss and high preparation costs, making them uneconomical. Traditional inorganic acids (sulfuric acid and hydrochloric acid), while possessing strong catalytic activity, are extremely corrosive, making waste acid treatment difficult and posing significant environmental pressures, thus gradually limiting their use in green chemical processes.

[0004] Existing patented technologies mostly focus on the application of single organic acids or the research on organic acids immobilized on single supports. For example, using p-toluenesulfonic acid or oxalic acid as a single catalytically active component, or loading a certain organic acid onto supports such as molecular sieves or silica. However, these technical solutions fail to effectively address the balance between catalytic activity and separation and recovery performance, especially lacking low-cost composite organic acid catalytic systems obtained through the modification of carboxylic acids and sulfonic acids. The synergistic catalytic effect between carboxylic acid and sulfonic acid components has not been systematically developed, and existing literature does not present technical solutions involving the specific ratio of the two components to achieve high-efficiency catalysis and easy separation without relying on complex supports. No solutions have yet been proposed to address these technical problems. Summary of the Invention

[0005] To address the problems in related technologies, this invention proposes an organic composite catalyst, its preparation method, and its application, in order to overcome the aforementioned technical problems existing in the prior art. The purpose of this invention is to catalyze the reaction of various phenolic mixtures with formaldehyde, compared with single organic acids, thereby increasing the yield of the target product by 8% to 22% and reducing the reaction time by more than 10%. The organic acid composite system is far less corrosive than concentrated sulfuric acid and concentrated hydrochloric acid, reducing equipment corrosion protection costs. The raw materials are inexpensive and readily available, and the preparation conditions are mild, requiring no high temperature or high pressure, making it suitable for continuous industrial production.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an organic composite catalyst, comprising the following components by mass fraction:

[0007] Straight-chain alkylbenzene sulfonic acid 20%–30%;

[0008] p-Toluenesulfonic acid 5%–15%;

[0009] Boron trifluoride 2%–10%;

[0010] Balance of polar cosolvent.

[0011] Preferably, the polar co-solvent is selected from one or more combinations of diethyl ether, silane oil, and naphthenic oil.

[0012] Preferably, the organic composite catalyst is a homogeneous liquid composite catalyst.

[0013] Preferably, the organic composite catalyst is immobilized and loaded onto a porous support to form an immobilized organic composite catalyst.

[0014] To achieve the above objectives, the present invention also provides the following technical solution:

[0015] A method for preparing an organic composite catalyst includes the following steps:

[0016] Step S1: Add at least a portion of the total amount of polar cosolvent as the first solvent into the reaction vessel and heat to 50-60°C;

[0017] Step S2: Under stirring conditions, add linear alkylbenzene sulfonic acid, p-toluene sulfonic acid and boron trifluoride in sequence;

[0018] Step S3: After mixing evenly, add the remaining polar co-solvent;

[0019] Step S4: Stir the reaction at 50-60℃ for 30-60 minutes, then cool to room temperature and discharge the material to obtain the organic composite catalyst.

[0020] Preferably, in step S1, the amount of polar co-solvent added is 50% to 80% of the total solvent volume.

[0021] To achieve the above objectives, the present invention also provides the following technical solution:

[0022] An organic composite catalyst prepared by a method is disclosed, and the application of the organic composite catalyst in acid-catalyzed reactions is disclosed, wherein the application is selected from at least one of the following reaction scenarios:

[0023] (1) Condensation reaction of phenol-ketone tar with formaldehyde;

[0024] (2) Condensation reaction of bisphenol A tar and formaldehyde;

[0025] (3) Condensation reaction of Posm oil with formaldehyde;

[0026] (4) The condensation reaction of lignin and formaldehyde;

[0027] (5) Phenolic polycondensation reaction;

[0028] (6) Acid-catalyzed conversion of agricultural and forestry biomass.

[0029] Preferably, the amount of the organic composite catalyst added to the reaction system is 0.1% to 5.0% of the total mass of the reaction substrate.

[0030] Preferably, the temperature of the catalytic reaction is 60–120°C, and the reaction time is 1–8 h.

[0031] Preferably, the organic composite catalyst is recovered and reused after the reaction is completed by filtration or centrifugation.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] (1) This invention is an organic composite catalyst and its preparation method and application. By combining linear alkylbenzene sulfonic acid, p-toluene sulfonic acid and boron trifluoride, the synergistic effect of sulfonic acid protonic acid and Lewis acid boron trifluoride is utilized to significantly improve the catalytic activity and selectivity of various acid catalytic reactions, the reaction conditions are milder and the reaction efficiency is high.

[0034] (2) This invention is an organic composite catalyst and its preparation method and application. As a homogeneous liquid composite catalyst, its components are uniform and active sites are dispersed, which can ensure the uniformity and stability of the reaction system. After being immobilized and loaded onto a porous support, it can form an immobilized organic composite catalyst, which is convenient for separation and recovery after the reaction and reduces the influence of catalyst residue on the product.

[0035] (3) This invention is an organic composite catalyst and its preparation method and application. By adopting stepwise feeding and controlling the temperature at 50-60℃, the reaction can be carried out for 30-60 minutes after uniform mixing. The process is simple and has good repeatability. The polar co-solvent is selected from one or more combinations of diethyl ether, silane oil and naphthenic oil, which can effectively dissolve and stabilize each active component to form a homogeneous liquid system and avoid phase separation.

[0036] (4) This invention is an organic composite catalyst and its preparation method and application. The organic composite catalyst can be effectively applied to the condensation reaction of phenol ketone tar, bisphenol A tar, Posm oil, lignin and formaldehyde, as well as various acid catalytic scenarios such as phenolic polycondensation and acid catalytic conversion of agricultural and forestry biomass, and has good versatility.

[0037] (5) This invention is an organic composite catalyst and its preparation method and application. The amount of catalyst added in the catalytic reaction is only 0.1% to 5.0% of the total mass of the reaction substrate. The amount is low and the catalytic efficiency is high. After the reaction, it can be easily recovered by filtration or centrifugation and reused, which significantly reduces the production cost and waste emissions and meets the requirements of green chemistry.

[0038] (6) This invention relates to an organic composite catalyst, its preparation method and application. Because the organic composite catalyst has strong acidity and multi-site synergistic effect, it can effectively promote the condensation conversion of formaldehyde with various tar, lignin or phenolic substrates, reduce side reactions and improve the yield and purity of the target product. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below.

[0040] This invention proposes a technical solution for an organic composite catalyst, its preparation method, and its application: an organic composite catalyst comprising the following components by mass fraction:

[0041] Straight-chain alkylbenzene sulfonic acid 20%–30%;

[0042] p-Toluenesulfonic acid 5%–15%;

[0043] Boron trifluoride 2%–10%;

[0044] Balance of polar cosolvent.

[0045] In this embodiment, the carbon chain length of the linear alkylbenzene sulfonic acid is C10 to C14, preferably C12, wherein the free sulfuric acid content is ≤1.5%; the p-toluenesulfonic acid is in monohydrate or anhydrous form with a purity ≥98%; the boron trifluoride is introduced in the form of gas, diethyl ether complex, or acetic acid complex, and its active ingredient is calculated as BF3; the polar cosolvent needs to be dried by molecular sieve before use, and the moisture content is ≤0.1%.

[0046] Furthermore, the polar co-solvent is selected from one or more combinations of diethyl ether, silane oil, and naphthenic oil.

[0047] In this embodiment, the silane oil is methylphenyl silicone oil or dimethyl silicone oil, with a viscosity of 50-500 cSt at 25°C; the naphthenic oil is hydrogenated naphthenic oil, with an aromatic hydrocarbon content of ≤5%; when combined, the mass ratio of diethyl ether to silane oil is preferably 1:0.5-1:2.

[0048] Furthermore, the organic composite catalyst is a homogeneous liquid composite catalyst.

[0049] In this embodiment, the homogeneous liquid composite catalyst is a transparent or slightly yellow liquid at 25°C, with no visible suspended particles, a viscosity range of 20–200 mPa·s, and a pH value (1% aqueous solution) ≤1.5.

[0050] Furthermore, the organic composite catalyst is immobilized and loaded onto a porous support to form an immobilized organic composite catalyst.

[0051] In this embodiment, the porous support is selected from at least one of activated carbon, molecular sieves (such as HZSM-5, MCM-41), diatomaceous earth, γ-alumina, or silica. The specific surface area of ​​the porous support is 200-1200 m² / g, and the average pore size is 2-50 nm. The immobilization treatment adopts the equal volume impregnation method or the excess impregnation method. The loading is 10%-40% of the total mass of the catalyst. After impregnation, it is vacuum dried at 80-120°C for 6-12 h.

[0052] A method for preparing an organic composite catalyst includes the following steps:

[0053] Step S1: Add at least a portion of the total amount of polar cosolvent as the first solvent into the reaction vessel and heat to 50-60°C;

[0054] Step S2: Under stirring conditions, add linear alkylbenzene sulfonic acid, p-toluene sulfonic acid and boron trifluoride in sequence;

[0055] Step S3: After mixing evenly, add the remaining polar co-solvent;

[0056] Step S4: Stir the reaction at 50-60℃ for 30-60 minutes, then cool to room temperature and discharge the material to obtain the organic composite catalyst.

[0057] In this embodiment, the stirring speed in step S2 is 200-600 rpm; when linear alkylbenzene sulfonic acid, p-toluene sulfonic acid and boron trifluoride are added sequentially, the interval between additions is 2-5 min; the criterion for judging uniform mixing in step S3 is that the solution is uniformly transparent or uniform without layering; in step S4, cooling is performed using jacketed circulating water cooling, and the cooling rate is controlled at 1-3℃ / min to avoid local overheating that could lead to component decomposition.

[0058] Furthermore, in step S1, the amount of polar co-solvent added is 50% to 80% of the total solvent volume.

[0059] In this embodiment, if the total solvent amount is defined as the total mass of polar cosolvent in the final product, then 50% to 80% of this total amount is added first in step S1, and the remaining 20% ​​to 50% is added in step S3. This stepwise addition method helps to control the viscosity and reaction rate in the early stage of the reaction and prevents boron trifluoride from being lost due to excessive local concentration.

[0060] An organic composite catalyst prepared by a method is disclosed, and the application of the organic composite catalyst in acid-catalyzed reactions is disclosed, wherein the application is selected from at least one of the following reaction scenarios:

[0061] (1) Condensation reaction of phenol-ketone tar with formaldehyde;

[0062] (2) Condensation reaction of bisphenol A tar and formaldehyde;

[0063] (3) Condensation reaction of Posm oil with formaldehyde;

[0064] (4) The condensation reaction of lignin and formaldehyde;

[0065] (5) Phenolic polycondensation reaction;

[0066] (6) Acid-catalyzed conversion of agricultural and forestry biomass.

[0067] In this embodiment, in the above application scenario, the reaction raw materials are pre-dehydrated to a moisture content of ≤2%; for the condensation reactions of (1) to (4), formaldehyde is added in the form of formaldehyde aqueous solution, paraformaldehyde or triformaldehyde, and the molar ratio of formaldehyde to phenolic hydroxyl groups in the substrate is 0.8:1 to 1.2:1; for (6) agricultural and forestry biomass, including corn cobs, rice husks, straw or wood chips, it needs to be crushed to 40 to 200 mesh before use.

[0068] Furthermore, the amount of the organic composite catalyst added to the reaction system is 0.1% to 5.0% of the total mass of the reaction substrate.

[0069] In this embodiment, the preferred addition amount is 0.5% to 2.0%. When the tar or lignin content in the reaction substrate is high (>60%), a higher addition amount (3.0% to 5.0%) is used; when the substrate is a pure phenolic monomer, a lower addition amount (0.1% to 1.0%) is used.

[0070] Furthermore, the temperature of the catalytic reaction is 60–120°C, and the reaction time is 1–8 h.

[0071] In this embodiment, the reaction temperature is preferably 80-100℃, the reaction time is preferably 2-5h, nitrogen or argon is used for protection during the reaction, and the pressure is atmospheric pressure or slightly positive pressure (0.1-0.3MPa). The reaction conversion rate can be tracked by sampling and measuring the acid value or hydroxymethyl content. When the acid value change rate is <1% / 30min or the hydroxymethyl content tends to stabilize, it is considered as the reaction endpoint.

[0072] Furthermore, the organic composite catalyst is recovered and reused after the reaction is completed by filtration or centrifugation.

[0073] In this embodiment, for homogeneous systems, after the reaction, equal volumes of organic solvent (such as toluene, ethyl acetate, or dichloromethane) and water are added for extraction and layering. The aqueous or organic phase containing the catalyst is separated and then subjected to vacuum distillation (vacuum degree -0.08 to -0.095 MPa) at 40–60 °C to remove the solvent and small molecule byproducts. The recovered catalyst can be recycled after replenishing lost components (usually requiring the addition of 5%–10% of the original amount of linear alkylbenzene sulfonic acid or boron trifluoride). For supported catalysts, filtration is performed using a 200–500 μm filter cloth or sieve. The filter cake is washed 2–3 times with the reaction solvent, dried under vacuum at 60 °C, and then directly reused. The catalyst can be reused 5–8 times with an activity decrease rate ≤15%.

[0074] Example 1

[0075] This invention proposes a technical solution for an organic composite catalyst, its preparation method, and its application: an organic composite catalyst comprising the following components by mass fraction:

[0076] 25% linear alkylbenzene sulfonic acid;

[0077] p-Toluenesulfonic acid 10%;

[0078] 3% boron trifluoride;

[0079] 3.5% diethyl ether;

[0080] 40% silane oil;

[0081] Naphthenic oil 1.5%.

[0082] A method for preparing an organic composite catalyst includes the following steps:

[0083] Step S1: Add at least a portion of the total amount of polar co-solvent as the first solvent to the reaction vessel and heat to 55°C; the amount of polar co-solvent added is 60% of the total solvent volume;

[0084] Step S2: Under stirring conditions, add linear alkylbenzene sulfonic acid, p-toluene sulfonic acid and boron trifluoride in sequence;

[0085] Step S3: After mixing evenly, add the remaining polar co-solvent;

[0086] Step S4: Maintain the temperature at 55℃ and stir the reaction for 45 minutes, then cool it down to room temperature and discharge the material to obtain the organic composite catalyst.

[0087] An organic composite catalyst prepared by a method is disclosed, and the application of the organic composite catalyst in acid-catalyzed reactions is disclosed, wherein the application is selected from at least one of the following reaction scenarios:

[0088] (1) Condensation reaction of phenol-ketone tar with formaldehyde;

[0089] (2) Condensation reaction of bisphenol A tar and formaldehyde;

[0090] (3) Condensation reaction of Posm oil with formaldehyde;

[0091] (4) The condensation reaction of lignin and formaldehyde;

[0092] (5) Phenolic polycondensation reaction;

[0093] (6) Acid-catalyzed conversion of agricultural and forestry biomass.

[0094] Furthermore, the amount of the organic composite catalyst added to the reaction system is 2.0% of the total mass of the reaction substrate.

[0095] Furthermore, the catalytic reaction is carried out at a temperature of 85°C for 4 hours.

[0096] Furthermore, the organic composite catalyst is recovered and reused after the reaction is completed by filtration or centrifugation.

[0097] It can be found that phenol tar, bisphenol A tar or Posm oil can be synthesized with formaldehyde with a conversion rate of 93.7%, and it has high catalytic activity for the reaction of various phenols and aldehydes.

[0098] Example 2

[0099] This invention proposes a technical solution for an organic composite catalyst, its preparation method, and its application: an organic composite catalyst comprising the following components by mass fraction:

[0100] Straight-chain alkylbenzene sulfonic acid 27%;

[0101] p-Toluenesulfonic acid 13%;

[0102] Boron trifluoride 6%;

[0103] Ether 4.1%;

[0104] Silane oil 42%;

[0105] Naphthenic oil 7.9%.

[0106] A method for preparing an organic composite catalyst includes the following steps:

[0107] Step S1: Add at least a portion of the total amount of polar co-solvent as the first solvent to the reaction vessel and heat to 56°C; the amount of polar co-solvent added is 70% of the total solvent volume;

[0108] Step S2: Under stirring conditions, add linear alkylbenzene sulfonic acid, p-toluene sulfonic acid and boron trifluoride in sequence;

[0109] Step S3: After mixing evenly, add the remaining polar co-solvent;

[0110] Step S4: Maintain the temperature at 57℃ and stir the reaction for 50 minutes, then cool it down to room temperature and discharge the material to obtain the organic composite catalyst.

[0111] An organic composite catalyst prepared by a method is disclosed, and the application of the organic composite catalyst in acid-catalyzed reactions is disclosed, wherein the application is selected from at least one of the following reaction scenarios:

[0112] (1) Condensation reaction of phenol-ketone tar with formaldehyde;

[0113] (2) Condensation reaction of bisphenol A tar and formaldehyde;

[0114] (3) Condensation reaction of Posm oil with formaldehyde;

[0115] (4) The condensation reaction of lignin and formaldehyde;

[0116] (5) Phenolic polycondensation reaction;

[0117] (6) Acid-catalyzed conversion of agricultural and forestry biomass.

[0118] Furthermore, the amount of the organic composite catalyst added to the reaction system is 3.0% of the total mass of the reaction substrate.

[0119] Furthermore, the catalytic reaction is carried out at a temperature of 102°C for 5 hours.

[0120] Furthermore, the organic composite catalyst is recovered and reused after the reaction is completed by filtration or centrifugation.

[0121] Example 3

[0122] This invention proposes a technical solution for an organic composite catalyst, its preparation method, and its application: an organic composite catalyst comprising the following components by mass fraction:

[0123] Straight-chain alkylbenzene sulfonic acid 30%;

[0124] p-Toluenesulfonic acid 15%;

[0125] 9% boron trifluoride;

[0126] 3.5% diethyl ether;

[0127] Silane oil 39%;

[0128] Naphthenic oil 3.5%.

[0129] A method for preparing an organic composite catalyst includes the following steps:

[0130] Step S1: Add at least a portion of the total amount of polar co-solvent as the first solvent to the reaction vessel and heat to 58°C; the amount of polar co-solvent added is 75% of the total solvent volume;

[0131] Step S2: Under stirring conditions, add linear alkylbenzene sulfonic acid, p-toluene sulfonic acid and boron trifluoride in sequence;

[0132] Step S3: After mixing evenly, add the remaining polar co-solvent;

[0133] Step S4: Maintain the temperature at 58℃ and stir the reaction for 55 minutes, then cool it down to room temperature and discharge the material to obtain the organic composite catalyst.

[0134] An organic composite catalyst prepared by a method is disclosed, and the application of the organic composite catalyst in acid-catalyzed reactions is disclosed, wherein the application is selected from at least one of the following reaction scenarios:

[0135] (1) Condensation reaction of phenol-ketone tar with formaldehyde;

[0136] (2) Condensation reaction of bisphenol A tar and formaldehyde;

[0137] (3) Condensation reaction of Posm oil with formaldehyde;

[0138] (4) The condensation reaction of lignin and formaldehyde;

[0139] (5) Phenolic polycondensation reaction;

[0140] (6) Acid-catalyzed conversion of agricultural and forestry biomass.

[0141] Furthermore, the amount of the organic composite catalyst added to the reaction system is 2.5% of the total mass of the reaction substrate.

[0142] Furthermore, the catalytic reaction is carried out at a temperature of 111°C for 2 hours.

[0143] Furthermore, the organic composite catalyst is recovered and reused after the reaction is completed by filtration or centrifugation.

[0144] Comparative Example 1 (pure p-toluenesulfonic acid as a single catalyst)

[0145] Under the same reaction conditions, the yield was 81.2%, and the mixed catalytic activity was low.

[0146] Comparative Example 2 (Commercial Strong Acid)

[0147] Under the same reaction conditions, the yield is 85.5%, but it is highly corrosive to equipment.

[0148] Therefore, it can be concluded that the organic composite catalyst of the present invention has higher catalytic activity (conversion rate up to 93.7%, significantly better than 81.2% and 85.5%), lower equipment corrosivity (avoiding direct use of strong acids), wider applicability (suitable for various phenol / aldehyde polycondensation and biomass conversion reactions), and can be recycled and reused (by filtration or centrifugation), showing good prospects for industrial application.

[0149] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An organic composite catalyst, characterized in that, Includes the following components by mass fraction: Straight-chain alkylbenzene sulfonic acid 20%–30%; p-Toluenesulfonic acid 5%–15%; Boron trifluoride 2%–10%; Balance of polar cosolvent.

2. The organic composite catalyst according to claim 1, characterized in that: The polar co-solvent is selected from one or more combinations of diethyl ether, silane oil, and naphthenic oil.

3. The organic composite catalyst according to claim 2, characterized in that: The organic composite catalyst is a homogeneous liquid composite catalyst.

4. The organic composite catalyst according to claim 2, characterized in that: The organic composite catalyst is immobilized and loaded onto a porous support to form an immobilized organic composite catalyst.

5. A method for preparing an organic composite catalyst as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Step S1: Add at least a portion of the total amount of polar cosolvent as the first solvent into the reaction vessel and heat to 50-60°C; Step S2: Under stirring conditions, add linear alkylbenzene sulfonic acid, p-toluene sulfonic acid and boron trifluoride in sequence; Step S3: After mixing evenly, add the remaining polar co-solvent; Step S4: Stir the reaction at 50-60℃ for 30-60 minutes, then cool to room temperature and discharge the material to obtain the organic composite catalyst.

6. The method for preparing an organic composite catalyst according to claim 1, characterized in that: In step S1, the amount of polar co-solvent added is 50% to 80% of the total solvent volume.

7. The application of the organic composite catalyst prepared by the method according to any one of claims 5-6 in acid-catalyzed reactions, characterized in that, The application is selected from at least one of the following reaction scenarios: (1) Condensation reaction of phenol-ketone tar with formaldehyde; (2) Condensation reaction of bisphenol A tar and formaldehyde; (3) Condensation reaction of Posm oil with formaldehyde; (4) The condensation reaction of lignin and formaldehyde; (5) Phenolic polycondensation reaction; (6) Acid-catalyzed conversion of agricultural and forestry biomass.

8. The application according to claim 7, characterized in that: The amount of the organic composite catalyst added to the reaction system is 0.1% to 5.0% of the total mass of the reaction substrate.

9. The application according to claim 7, characterized in that: The catalytic reaction is carried out at a temperature of 60–120°C for 1–8 hours.

10. The application according to claim 7, characterized in that: The organic composite catalyst is recovered and reused after the reaction is completed by filtration or centrifugation.