Catalyst for addition esterification of olefins and carboxylic acids and preparation method and application thereof

Abstract

The present invention provides a catalyst for addition esterification of olefins and carboxylic acids, a preparation method and application thereof, and relates to the field of catalytic technology. The catalyst comprises modified coke powder and a calixarene compound chemically modified on the surface of the modified coke powder, and the surface of the modified coke powder and the calixarene compound are modified with sulfonic acid groups. The catalyst can be used for direct esterification of olefins and carboxylic acids to generate corresponding carboxylic acid esters, and has the characteristics of good activity, long life, easy separation, etc.

Description

Technical Field

[0001] The present invention relates to the field of catalytic technology, and in particular to a catalyst for addition esterification of olefins and carboxylic acids, and a preparation method and application thereof. Background Art

[0002] Organic carboxylates are important intermediates for the preparation of medicines, pesticides, material monomers, etc. They are also commonly used in the fields of flavors, fragrances, organic solvents, etc. In industry, the common preparation methods of organic carboxylates include alcohol-carboxylic acid condensation, ester-ester exchange, and olefin-carboxylic acid addition esterification. Among them, olefin-carboxylic acid addition esterification is the most important, and its advantages include: 1. Direct use of olefins as raw materials, without the need for alcohol as an intermediate, reducing production costs; 2. No by-products are generated in the process, reducing the discharge of three wastes, and meeting the atomic economy. At present, in industrial and laboratory research, a variety of catalyst types have been reported for olefin-acid addition esterification reactions. The paper "Research Progress on Catalysts for Olefin Acid Addition Esterification Reaction", Yu Fengping et al., Industrial Catalysis, 2019, 27(6), 16-25. Various common catalyst systems for olefin-acid addition esterification processes, such as acid catalysts, ion exchange resin catalysts, heteropolyacid compound catalysts, ionic liquid catalysts, zeolite molecular sieve catalysts and transition metal catalysts, are reviewed, and the advantages and disadvantages of different catalyst systems are compared.

[0003] Obviously, heterogeneous catalysis has the advantages of continuous production and simple separation in the esterification reaction. Therefore, the research hotspot is mainly to develop heterogeneous catalysts with better performance. For example, patents CN113398992A and CN1483717A introduce the use of resin catalysts, silica gel-supported heteropoly acid catalysts, silica gel-supported phosphoric acid catalysts and superacid catalysts for olefin-acid addition esterification; for another example, patent CN 101863763A uses activated carbon supported by tin tetrachloride as a catalyst, which can effectively catalyze the direct esterification of α-pinene and methacrylic acid; for another example, the paper "Preparation of sulfonated graphene and its catalytic performance research", Chen Liangyong et al., Guangzhou Chemical Industry, 2016, 44 (05), 110-113. Sulfonated graphene is used as a solid acid catalyst for the preparation of biodiesel, etc. However, the above-mentioned catalytic systems all have obvious disadvantages, which are mainly reflected in the following aspects: 1. The loss of active components. Whether it is resin or activated carbon, the active center of the supported catalyst is easily lost during the reaction process; 2. The stability of the resin catalyst is poor. It is easy to swell at high temperature and in an organic system, resulting in uneven distribution of the catalyst and the material, affecting the conversion rate of the reaction, and even causing the catalyst to break and pulverize, blocking the reactor; 3. Although the properties of activated carbon-based catalysts are relatively stable, the specific surface area of ​​activated carbon is large and the adsorption capacity is strong. The reaction products are easily adsorbed on the catalyst surface, resulting in a decrease in product yield and causing clogging and deactivation of the catalyst active sites; 4. The preparation cost of graphene-based catalysts is high, and the preparation method has strict requirements, making it difficult to achieve large-scale industrial production; 5. For heteropoly acids, changes in appearance and disintegration often occur during the reaction, which not only makes subsequent centrifugation and filtration difficult, but also easily introduces a large amount of heavy metal ions into the reactants, affecting product quality.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art and technical needs, a solid catalyst system of modified coke powder bonded to sulfonated calixarene has been developed. The catalyst is suitable for catalyzing olefin-acid addition esterification reactions. The catalyst is less affected by mechanical, temperature, pressure, solvent, etc., and the catalytic activity is maintained for a long time, thus solving the problem of easy pulverization and deactivation of solid catalysts in the prior art.

[0006] One of the objects of the present invention is to provide a catalyst for the addition esterification of olefins and carboxylic acids.

[0007] The second object of the present invention is to provide a method for preparing a catalyst for addition esterification of olefins and carboxylic acids.

[0008] The third object of the present invention is to provide a catalyst for addition esterification of olefins and carboxylic acids for use in the preparation of carboxylic acid ester compounds.

[0009] In one aspect, the present invention provides a catalyst for addition esterification of olefins and carboxylic acids, the catalyst comprising modified coke powder and a calixarene compound chemically modified on the surface of the modified coke powder, wherein the surface of the modified coke powder and the calixarene compound are modified with sulfonic acid groups;

[0010] The modified coke powder is prepared by a method comprising the following steps: calcining the coke powder, introducing a small amount of water vapor to activate it during the calcination process, cooling it, washing it, and drying it to obtain surface-activated coke powder; soaking the surface-activated coke powder with an oxidant to obtain oxidized coke powder; filtering the oxidized coke powder, washing it, and drying it to constant weight to obtain modified coke powder.

[0011] Modified coke powder:

[0012] Coke powder refers to the by-product produced during the coking process of coking enterprises. Compared with coke, it has a smaller particle size and limited application scenarios, resulting in an extremely low selling price and limited uses of coke powder. However, since the volatile matter of coke powder has been completely removed by the coke oven, the carbon content is about 80-90%, and it is mainly composed of graphitized carbon structure, which has the advantages of high structural strength and stable properties. After modification, it has certain advantages as a catalyst carrier.

[0013] Modified coke powder refers to coke powder obtained after pretreatment (surface activation and surface oxidation). Water vapor is used for surface activation (pore expansion and cleaning of coke powder surface), and oxidant is used for oxidation. After oxidation, the surface of the modified coke powder has hydroxyl, epoxy, carboxyl and other groups.

[0014] In some embodiments, calcination includes at least two stages. During the first stage, the temperature in the tube furnace is increased from room temperature to 300-800°C, preferably 500-600°C, with a temperature increase gradient of 1-10°C / min, preferably 2-3°C / min, and the holding time is 1-24 hours, preferably 2-3 hours;

[0015] In the second stage, the temperature is further increased to 700-1100°C, preferably 800-900°C, with a temperature increase gradient of 1-10°C / min, preferably 2-3°C / min, and the holding time is 1-24 hours, preferably 2-3 hours;

[0016] Preferably, water vapor is introduced for activation immediately after the second stage is heated to the highest point or during the insulation process, and the amount of water vapor introduced is 10-200% of the mass of the coke powder, preferably 20-50%, such as 30-50%, and is introduced all at once.

[0017] In some embodiments, the oxidant is one or two selected from hydrogen peroxide and concentrated sulfuric acid;

[0018] Preferably, the amount of hydrogen peroxide used is 1-6% of the mass of the surface-activated coke powder, such as 1-5% or 2-3%; the mass concentration of hydrogen peroxide is 10-60%, preferably 30-50%;

[0019] Preferably, the amount of concentrated sulfuric acid used is 1-10% of the mass of the surface-activated coke powder, such as 4-6% or 5-10%;

[0020] Preferably, the soaking time is 1-24 hours, preferably 2-4 hours, and the soaking temperature is 20-80°C, preferably 25-45°C.

[0021] Calixarene compounds:

[0022] The calixarene compounds have a delocalized large π system, including calixarene and its derivatives, such as calix[4]arene and its derivatives, calix[5]arene and its derivatives, calix[6]arene and its derivatives, calix[8]arene and its derivatives, etc. The calixarene derivatives are preferably calixarene modified with a substituent at the lower edge. Considering the use effect, preparation difficulty and production cost, alkoxy-substituted calixarene is preferred, and alkoxy-substituted calix[4]arene is more preferred, especially alkoxy-substituted calix[4]arene represented by formula (I) or formula (II).

[0023]

[0024] Sulfonic acid group:

[0025] The surface of the modified coke powder and the calixarene compounds are provided with sulfonic acid groups through the sulfonation reaction, and the calixarene compounds are modified with the sulfonic acid groups to become sulfonated calixarene.

[0026] In some embodiments, based on the mass of the modified coke powder, the content of the calixarene compound is 0.1-5 wt %, such as 0.1-1.5 wt % or 0.4-1 wt %.

[0027] In some embodiments, the content of the sulfonic acid group is 0.5-1.5 wt % based on the total mass of the modified coke powder and the calixarene compound.

[0028] Another aspect of the present invention also provides a method for preparing the above-mentioned catalyst for addition esterification of olefins and carboxylic acids, comprising the following steps:

[0029] (1) crushing and screening the coke powder;

[0030] (2) calcining the screened coke powder, introducing water vapor to activate the powder during the calcination process, cooling the powder, washing the powder, and drying the powder to obtain surface-activated coke powder;

[0031] (3) soaking the surface activated coke powder obtained in step (2) with an oxidant to obtain oxidized coke powder;

[0032] (4) filtering and washing the oxidized coke powder obtained in step (3), and then drying to a constant weight to obtain modified coke powder;

[0033] (5) modifying the calixarene compound on the surface of the modified coke powder through a chemical reaction to obtain the calixarene compound-modified coke powder;

[0034] (6) The coke powder modified with the calixarene compound is subjected to a sulfonation reaction, so that the surface of the modified coke powder and the calixarene compound are modified with sulfonic acid groups, thereby obtaining a catalyst for the addition esterification of olefins and carboxylic acids.

[0035] In some embodiments, in step (1), the coke powder is sieved after being crushed, and after sieving, the particle size distribution is 1-5 mm, preferably, the particle size distribution is 2-3 mm.

[0036] In some embodiments, in step (2), the calcination includes at least two stages. During the first stage, the temperature in the tube furnace is increased from room temperature to 300-800°C, preferably 500-600°C, the temperature increase gradient is 1-10°C / min, preferably 2-3°C / min, and the holding time is 1-24 hours, preferably 2-3 hours;

[0037] In the second stage, the temperature is further increased to 700-1100°C, preferably 800-900°C, with a temperature increase gradient of 1-10°C / min, preferably 2-3°C / min, and a holding time of 1-24 hours, preferably 2-3 hours;

[0038] Preferably, in step (2), water vapor is introduced for activation immediately after the second stage is heated to the highest point or during the insulation process, and the amount of water vapor introduced is 10-200% of the mass of the coke powder, preferably 20-50%, such as 30-50%, and is introduced all at once.

[0039] Preferably, in step (2), cooling is natural cooling.

[0040] Preferably, in step (2), the calcined and cooled coke powder is soaked in 5% dilute hydrochloric acid for preferably 30-60 minutes.

[0041] Preferably, in step (2), the calcined, cooled, and preferably diluted hydrochloric acid-soaked coke powder is washed with desalted water until the pH of the filtrate is 5-6.

[0042] Preferably, in step (2), drying is carried out at 80° C. until the coke powder reaches a constant weight.

[0043] In some embodiments, in step (3), the oxidant is one or two selected from hydrogen peroxide and concentrated sulfuric acid;

[0044] Preferably, the amount of hydrogen peroxide used is 1-6% of the mass of the surface-activated coke powder, such as 1-5% or 2-3%; the mass concentration of hydrogen peroxide is 10-60%, preferably 30-50%;

[0045] Preferably, the amount of concentrated sulfuric acid used is 1-10% of the mass of the surface-activated coke powder, such as 4-6% or 5-10%;

[0046] Preferably, in step (3), the soaking time is 1-24 hours, preferably 2-4 hours, and the soaking temperature is 20-80°C, preferably 25-45°C.

[0047] In some embodiments, in step (4), washing with desalted water to a water pH of 4-6;

[0048] Preferably, in step (4), the drying temperature is 60-120°C, preferably 80-90°C;

[0049] In step (5), the calixarene compound and the surface of the modified coke powder (active groups in the calixarene compound and hydroxyl groups on the surface of the modified coke powder) can be covalently linked by any known chemical reaction.

[0050] Calixarene compounds include calixarene and its derivatives, such as calix[4]arene and its derivatives, calix[5]arene and its derivatives, calix[6]arene and its derivatives, calix[8]arene and its derivatives, etc. The calixarene derivatives are preferably calixarene modified with substituents at the lower edge. Considering the use effect, preparation difficulty and production cost, alkoxy-substituted calixarene is preferred, especially alkoxy-substituted calix[4]arene.

[0051] In some embodiments, step (5) comprises the following steps:

[0052] Mixing the alkoxy-substituted calix[4]arene, the modified coke powder obtained in step (4), and an organic solvent, adding a condensation reagent to react, filtering, washing with an organic solvent to remove by-products generated by the reaction, and drying to obtain alkoxy-substituted calix[4]arene-modified coke powder;

[0053] Preferably, the alkoxy-substituted calix[4]arene is a structure represented by formula (I) or formula (II),

[0054]

[0055] The preparation method thereof can be found in Angew.Chem.Inter.1 Edition, 2010, 49(40), 7222-7224 and Tetrahedron Letters, 2003, 44, 4681.

[0056] Preferably, the amount of alkoxy-substituted calix[4]arene added is 0.1-10% by mass of the modified coke powder, such as 0.1-2.0% or 0.5-1%;

[0057] Preferably, the condensation reagent is an azodicarbonate diester and a phosphine compound; the azodicarbonate diester is, for example, diethyl azodicarbonate (DEAD) or diisopropyl azodicarbonate (DIAD), and the phosphine compound is, for example, triphenylphosphine (TPP), tributylphosphine, and the like. Preferably, the molar ratio of the azodicarbonate diester to the alkoxy-substituted calix[4]arene is 1:1-2:1, for example, 1:1 or 2:1, and the molar ratio of the phosphine compound to the alkoxy-substituted calix[4]arene is 1:1-2:1, for example, 1:1 or 2:1.

[0058] Preferably, the organic solvent is selected from tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether, dichloromethane, chloroform, benzene, toluene, xylene, ethyl acetate, acetonitrile, dimethyl sulfoxide, petroleum ether, etc., preferably, it is selected from tetrahydrofuran, methyltetrahydrofuran and methyl tert-butyl ether, etc.; the amount of the organic solvent added is 10-200% of the mass of the modified coke powder, preferably 50-100%.

[0059] In some embodiments, step (6) includes the following steps: reacting the char powder modified with the calixarene compound obtained in step (5) with chlorosulfonic acid, and then filtering, washing, and drying the reactants to constant weight to obtain a catalyst for addition esterification of olefins and carboxylic acids.

[0060] Preferably, the amount of chlorosulfonic acid added is 10-200% of the mass of the calixarene compound-modified coke powder, preferably 100-150%, such as 120-150%.

[0061] Preferably, the reaction is carried out in an organic solvent such as dichloromethane;

[0062] Preferably, the reaction system is cooled to 0°C;

[0063] Preferably, chlorosulfonic acid is slowly added dropwise during the reaction, and stirring is continued after the addition is completed;

[0064] Preferably, washing with desalted water;

[0065] Preferably, drying is carried out at 80°C to constant weight.

[0066] In another aspect, the present invention provides an application of the above catalyst in preparing carboxylic acid ester compounds by addition esterification of olefins and carboxylic acids.

[0067] Illustrative olefins include propylene, 1-butene, 2-butene, 2-pentene, cyclohexene, styrene, cyclododecene, 1,5,9-cyclododecatriene, 1,5-cyclooctadiene, oleic acid, linolenic acid, linoleic acid, etc., but are not limited thereto.

[0068] Examples of carboxylic acids include acetic acid, propionic acid, butyric acid, benzoic acid, etc., but are not limited thereto.

[0069] In some embodiments, the application includes: in the presence of a catalyst, an olefin and a carboxylic acid undergo an addition esterification reaction to obtain a corresponding carboxylic acid ester compound.

[0070] In some embodiments, the addition esterification reaction conditions are: using a batch or autoclave reaction, the reaction temperature is 40-200° C., preferably 100-120° C.; and / or

[0071] The reaction time is 2-120 hours, preferably 6-12 hours; and / or

[0072] The reaction pressure is 0.1-5.0 MPa, preferably normal pressure or self-pressurization during the reaction in a closed reactor; and / or

[0073] The mass ratio of carboxylic acid to olefin is 1-10:1.0, preferably 1.5-2.0:1.0; and / or

[0074] The mass ratio of the catalyst mass to the olefin mass is 0.5-5.0:1, preferably 0.8-1.2:1.

[0075] In the present invention, the catalytic effect of the catalyst is the synergistic effect of the sulfonic acid groups (active centers) on the calixarene located on the surface of the activated coke powder, the sulfonic acid groups on the surface of the coke powder, and the interaction with the coke powder surface on olefins, thereby promoting the contact and reaction between the carboxylic acid on the catalyst surface and the olefins.

[0076] Compared with the disadvantages of sulfonic acid macroporous resins that they are not resistant to high temperatures and have low mechanical strength, the coke powder has a higher mechanical strength because it undergoes a coking process at 900-1000°C in the coke oven (the M25 value of coke can be referred to, and the M25 value of the coke powder used in the present invention is much greater than 92%). Especially in a kettle reactor, the catalyst is in contact and collision with the agitator blades and the reactor wall for a long time, showing good structural stability.

[0077] Coke powder itself has the stability and chemical inertness of activated carbon and graphene, and also has strength characteristics that ion exchange resin does not have. At the same time, coke powder is inexpensive, only a few tenths of the cost of activated carbon and graphene. Compared with activated carbon, coke powder is calcined in a coke oven and has an extremely low surface porosity, and will not adsorb the product during use.

[0078] Compared with the prior art, the catalyst of the present invention is used to catalyze the esterification reaction of carboxylic acid and olefin, and its beneficial effects are embodied in the following aspects:

[0079] 1. The present invention uses sulfonated calixarene compounds to modify coke powder. On the one hand, the characteristics of the polysulfonic acid groups of the sulfonated calixarene compounds themselves enhance the acidity, making the addition esterification process of olefins easier to carry out; on the other hand, the calixarene compounds enhance the interaction between the catalyst and the olefin on the surface of the coke powder, thereby improving the catalytic activity and efficiency. At the same time, the sulfonic acid groups on the surface of the coke powder also play a synergistic role, further enhancing the reaction activity of the catalyst and promoting the reaction of the olefin on the catalyst surface;

[0080] 2. The present invention uses sulfonic acid-modified calixarene to bond with coke powder, which effectively increases the density of B acid active sites in the carboxylic acid-olefin addition esterification reaction, thereby improving the reaction activity of the catalyst;

[0081] 3. Calixarene is bonded to the surface of coke powder by covalent bonds, which is more stable than ionic liquids, inorganic heteropolyacids and macroporous resins, reducing the loss of catalyst during the reaction and ensuring the catalyst has a good service life and stability for multiple cycles;

[0082] 4. During the use of this catalyst, compared with other types of catalysts, the selectivity of this catalyst for olefin-carboxylic acid addition esterification is improved, and it is found that it has an inhibitory effect on common side reactions such as olefin polymerization.

[0083] The present invention has been described in detail above, but the above embodiments are only illustrative in nature and are not intended to limit the present invention. In addition, this article is not limited by any theory described in the above prior art or invention content or the following examples.

[0084] Unless otherwise expressly stated, the numerical ranges throughout the application documents include any subranges therein and any numerical values ​​incremented by the smallest subunit of a given value therein. Unless otherwise expressly stated, the numerical values ​​throughout the application documents represent approximate measurements or limitations of the range of embodiments including slight deviations from the given values ​​and having approximately the values ​​mentioned and having the exact values ​​mentioned. Except for the working examples provided at the end of the detailed description, all numerical values ​​of parameters (e.g., quantities or conditions) in this application document (including the appended claims) should be understood in all cases as modified by the term "approximately", regardless of whether "approximately" actually appears before the numerical value. "Approximately" means that the numerical value described allows for slight imprecision (some close to precision in the value; approximately or reasonably close to the value; approximately). If the imprecision provided by "approximately" is not understood in this ordinary sense in the art, the "approximately" used herein at least represents the variation that can be produced by ordinary methods of measuring and using these parameters. For example, "approximately" can include a variation of less than or equal to 10%, less than or equal to 5%, less than or equal to 4%, less than or equal to 3%, less than or equal to 2%, less than or equal to 1% or less than or equal to 0.5%. DETAILED DESCRIPTION

[0085] The present invention is further described below in conjunction with examples. It should be noted that the following examples are provided for illustrative purposes only and do not constitute a limitation on the scope of protection claimed for the present invention.

[0086] Unless otherwise specified, the raw materials, reagents, methods, etc. used in the examples are conventional raw materials, reagents, methods in the art.

[0087] raw material:

[0088] Coke powder: comes from Hebei Xuyang New Energy Co., Ltd. of Xuyang Group.

[0089] Test method:

[0090] Specific surface area determination: adopt the method of GB / T 7702.20 "Test method for pore volume and specific surface area of ​​coal-based granular activated carbon".

[0091] Determination and calculation of ash, volatile matter and carbon content of coke powder: adopt the method in national standard GB / T 2001-2013 "Analysis and determination method for coke industry";

[0092] Determination of the bulk density of coke powder: Take a certain amount of coke powder particles with a particle size of 2-3 mm, put them into a 0.5L cylindrical container, vibrate and smooth the upper part, weigh them, and calculate the bulk density of the coke powder based on the ratio of weight to volume.

[0093] Example

[0094] Preparation Example 1 Preparation of alkoxy-substituted calix[4]arene (I):

[0095]

[0096] Preparation of intermediate 2: In a 2000 mL round-bottom flask, a stirrer was added and a reflux condenser was set up. Then, calix[4]arene 1 (34.0 g, 80 mmol), finely ground anhydrous potassium carbonate (13.8 g, 100 mmol) and methyl toluenesulfonate (29.8 g, 160 mmol) and 800 mL of acetonitrile were added, and nitrogen was replaced three times. Under nitrogen protection, reflux was performed for 24 hours. The end point of the reaction was determined by TLC. After the reaction was completed, acetonitrile was removed by rotary evaporation, and 500 mL of deionized water was added to the residual solid mixture. After sufficient dissolution, the pH was adjusted to 3.0-4.0 with 1 mol / L dilute hydrochloric acid, and then extracted three times with 300 mL of dichloromethane. The extracts were combined and washed three times with saturated brine and deionized water in turn. The organic phase was dried over powdered anhydrous magnesium sulfate, the desiccant was filtered, the solvent was removed by rotary evaporation, and the crude product was recrystallized from chloroform / methanol to obtain white crystals 2 (35.2 g, 97.2%). 1 H-NMR (400MHz, CDCl 3 )δ:7.75(s,2H),7.09(d,4H),6.87(d,4H),6.73(t,2H),6.69(t,2H,),4.31(d,4H),3.99(s,6H),3.40(d,4H).

[0097] Preparation of intermediate 3: In a 500 mL round-bottom flask, add a stirring magnet and a reflux condenser, and mix intermediate 2 (4.52 g, 10.0 mmol), Cs 2 CO 3 (13.0 g, 40 mmol), methyl bromoacetate (6.13 g, 40 mmol) and 250 mL of anhydrous acetonitrile were added into the reaction flask at one time, and the atmosphere was replaced with nitrogen three times. The flask was then heated to reflux under nitrogen protection and reacted for 72 hours. The reaction progress was monitored by TLC. After the reaction, the acetonitrile was removed by rotary evaporation. Then, 250 mL of deionized water was added to the residue, and the pH was adjusted to 3.0-4.0 with 10% hydrochloric acid. An organic solvent, dichloromethane, was added and extracted three times with 150 mL each time. The organic phases were combined, dried with powdered magnesium sulfate, filtered, and the filtrate was rotary evaporated to remove the solvent. The crude product was recrystallized with chloroform-methanol to obtain compound 3 as a white solid powder with a yield of 3.70 g (62%). 1 H-NMR (400MHz, CDCl 3 )δ: 7.20(d,4H),7.03(t,2H),6.87-6.45(m,6H),4.71(s,4H),4.31(d,4H),3.85(s,6H),3.77(s,6H),3.38(d,4H).

[0098] Preparation of alkoxy-substituted calix[4]arene (I): In a 100 mL three-necked round-bottom flask, add a magnetic bar, then add intermediate 3 (2.39 g, 4.0 mmol) and a solution in anhydrous tetrahydrofuran (40 mL) to the flask and stir until completely dissolved. Use an ice bath to lower the system temperature to <5°C, then slowly add LiAlH 4 (0.759 g, 20 mmol). After the addition, the temperature was raised to room temperature and stirred for 3-5 hours. The extent of the reduction reaction was monitored by TLC. A small amount of LiAlH 4 After the reaction is complete, 50 mL of 1.0 mol / L hydrochloric acid solution is slowly added to the system, the mixture is stirred for 30 minutes, and then extracted with dichloromethane 3 times, 40 mL each time. The organic layers are combined, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness under reduced pressure. The crude product is recrystallized from chloroform-methanol to obtain 1.83 g of a white powdery product with a yield of 84.3%. 1 H-NMR (400MHz, CDCl 3 )δ: 7.20(m,4H),7.07-6.45(m,8H),5.20–4.90(b,2H),4.37(d,4H),4.01(m,8H),3.75(s,6H),3.38(d,4H).

[0099] Preparation Example 2 Preparation of alkoxy-substituted calix[4]arene (II):

[0100]

[0101] In a round-bottom flask, add the intermediate 2 (4.52 g, 10 mmol) in Preparation Example 1, acetonitrile (50 mL), diethyl azodicarboxylate (3.48 g, 20 mmol) and triphenylphosphine (5.24 g, 20 mmol) in sequence, stir at room temperature for 30 min, then add diethylene glycol (3.2 g, 30 mmol), the reaction mixture continues to react at room temperature overnight, remove the solvent, add dichloromethane (100 mL) to the residue, and wash with dilute hydrochloric acid (1.0 mol / L, 25 mL×2) and deionized water (50 mL×2) in sequence. The organic phase is dried over anhydrous sodium sulfate, filtered, concentrated, and the crude product is purified by silica gel chromatography (eluent petroleum ether: ethyl acetate = 5:1, v / v). 4.78 g of product II is obtained, with a yield of 76%. 1 H-NMR (400MHz, CDCl 3)δ: 7.21(m,4H),7.07-6.45(m,8H),5.20–4.90(b,2H),4.37(d,4H),4.05(m,4H),3.96–3.82(m,12H),3.75(s,6H),3.37(d,4H).

[0102] Preparation Example 3 Preparation of 2,6-dimethylphenol derivative (III):

[0103]

[0104] In a round-bottom flask, 2,6-dimethylphenol (12.2 g, 0.1 mol), acetonitrile (150 mL), ethyl bromoacetate (36.7 g, 0.24 mol) and powdered potassium carbonate (33.1 g, 0.24 mol) were added in sequence, heated, refluxed for 12 h, filtered to remove the salt generated by the reaction and excess potassium carbonate, and distilled under reduced pressure to remove the solvent and residual unreacted methyl bromoacetate. The remaining oil was added with anhydrous tetrahydrofuran (100 mL) to fully dissolve, and LiAlH was slowly added at 0 °C. 4 (19.0g, 0.5mol), after the addition was completed, the system was warmed to room temperature and stirred for 1 hour. The solvent in the system was removed under reduced pressure, and dichloromethane (100mL) was added to the residue to dissolve it, and it was washed with dilute hydrochloric acid (1.0mol / L, 100mL×3) and deionized water (50mL×3) in sequence. The organic phase was dried with anhydrous sodium sulfate, filtered, and the solvent was removed. The residue was separated and purified by silica gel chromatography (eluent dichloromethane: ethyl acetate = 3:1, v / v). 14.6g of light yellow oily liquid was obtained, with a yield of 88%. 1 H-NMR (400MHz, DMSO-D6 / D 2 O)δ: 7.10 (t, 1H), 7.05 (d, 2H), 4.20 (t, 2H), 3.90 (t, 2H), 2.20 (s, 6H). Example 1 Preparation of Catalyst I

[0105] S1. Crush the coke powder, screen it with 10 mesh and 5 mesh sieves, and select coke powder particles with a particle size of 2-3 mm. Weigh 100g of the screened coke powder, place it in a tube furnace, replace it with nitrogen, and heat it up as follows: heat it up from 25℃ to 500℃ at a rate of 2℃ / min, keep it warm for 2 hours, then heat it up from 500℃ to 900℃ at a rate of 2℃ / min. When the temperature reaches 900℃, introduce 30g of water vapor into the tube furnace at one time, keep it warm for 2 hours, and cool it naturally to room temperature after the holding time is reached.

[0106] Open the tube furnace and take out the coke powder. At this time, the coke powder is partially agglomerated and some parts of the surface are white. The weight is about 80-85g.

[0107] The mixture was crushed and sieved to retain the coke powder particles with a particle size of 2-3 mm, suspended in 100 mL of 5% dilute hydrochloric acid and soaked for 30 min, filtered, and the filter cake was washed with desalted water until the pH of the filtrate was 5-6. Subsequently, the filter cake was dried at 80° C. to a constant weight, and 50-60 g of coke powder for further preparation was obtained;

[0108] S2. In a shaking flask, add 50 g of the coke powder prepared in S1 and 1.5 g of 30% hydrogen peroxide. After shaking for 2 minutes, add 2.5 g of concentrated sulfuric acid and shake thoroughly for 120 minutes. It can be observed that the temperature of the sample rises from about 25°C to 28-30°C, and a small amount of black flocculent or filamentous adhesions are observed on the wall of the shaking flask.

[0109] After the reaction is completed, 100 mL of desalted water is added to the system and soaked for 2-3 hours. At this time, a small amount of black floccules or flakes can be observed floating on the liquid surface. The floating objects are decanted together, and the remaining solids are repeatedly washed with desalted water to pH 5-6. The solids are dried at 80°C to constant weight. About 50 g of oxidized coke powder (modified coke powder) can be obtained;

[0110] The coke powder parameters before and after modification in this example are shown in Table 1-1 below.

[0111] Table 1-1

[0112] project <![CDATA[Specific surface area (m 2 / g)]]> Carbon content (%) Ash content (%) Volatile matter (%) Bulk density (g / L) Modified coke powder 1.54 90.0 9.6 0.1 ～500 Modified coke powder 9.89 86.3 11.0 - ～450

[0113] S3, in a three-necked flask, set up a mechanical stirring device, then add 20g of the oxidized coke powder prepared in S2, add 20-25mL of anhydrous tetrahydrofuran, then add 100mg of alkoxy-substituted calix[4]arene (I) (0.185mmol, 0.5% of the mass of the coke powder), 32mg of DEAD (0.185mmol), and slowly add 48.5mg of TPP solid (0.185mmol) under sufficient stirring, and continue stirring for 2 hours. After the reaction is completed, filter to remove the solvent, and then wash once with 20mL of anhydrous tetrahydrofuran to fully remove the generated triphenylphosphine, and then the product is dried at 60°C to constant weight to obtain a calixarene-coke powder condensation product.

[0114] S4. Add 10g of the above-mentioned S3 product to a round-bottom flask, add 10mL of dichloromethane, cool the system to 0°C, and slowly drip 10g of chlorosulfonic acid under stirring (note: control heat release and avoid water absorption during the reaction). After the addition is completed, stir for 30 minutes, carefully add water to quench the reaction (violent heat release with water), filter, wash the catalyst three times with deionized water, and dry at 80°C to constant weight to obtain the target catalyst product, and about 11g of catalyst can be obtained.

[0115] The analysis and characterization of the catalyst properties obtained from S4 are detailed in Table 1.

[0116] Example 2 Preparation of Catalyst II

[0117] The operation method is the same as that of Example 1, except that in step S1, the mass of water vapor introduced into the tube furnace is increased to 50 g; the subsequent steps are the same as those of Example 1, and about 11 g of catalyst II is obtained.

[0118] The analysis and characterization of the catalyst properties are shown in Table 1.

[0119] Example 3 Preparation of Catalyst III

[0120] The operation method is the same as that of Example 1, except that in step S2, 3.0 g of 30% hydrogen peroxide is added, shaken for 2 minutes, and then 2.5 g of concentrated sulfuric acid is added and shaken for 120 minutes; the subsequent steps are the same as those of Example 1, and about 12 g of catalyst III is obtained.

[0121] The analysis and characterization of the catalyst properties are shown in Table 1.

[0122] Example 4 Preparation of Catalyst IV

[0123] The operation method is the same as that of Example 1, except that in step S2, 1.5 g of 30% hydrogen peroxide is added, shaken for 2 minutes, and then 5.0 g of concentrated sulfuric acid is added and shaken for 120 minutes; the subsequent steps are the same as those of Example 1 to obtain about 10 g of catalyst IV.

[0124] The analysis and characterization of the catalyst properties are shown in Table 1.

[0125] Example 5 Preparation of Catalyst V

[0126] The operation method is the same as that of Example 1, except that in step S2, 3.0 g of 30% hydrogen peroxide is added, shaken for 2 minutes, and then 5.0 g of concentrated sulfuric acid is added and shaken for 120 minutes; the subsequent steps are the same as those of Example 1, and about 10 g of catalyst V is obtained.

[0127] The analysis and characterization of the catalyst properties are shown in Table 1.

[0128] Example 6 Preparation of Catalyst VI

[0129] The operation method is the same as that of Example 1, except that in step S3, 100 mg of alkoxy-substituted calix[4]arene (II) is added, and other conditions remain unchanged; the subsequent steps are the same as those of Example 1, and about 10 g of catalyst VI is obtained.

[0130] The analysis and characterization of the catalyst properties are shown in Table 1.

[0131] Example 7 Catalyst I is used to catalyze the addition esterification of cyclododecene and acetic acid

[0132] The experiment was carried out in a 50 mL high pressure reactor. The reactor was made of 316L stainless steel and lined with polytetrafluoroethylene. The reactor was equipped with a thermocouple, a pressure gauge, an air inlet and an air outlet. The stirring method was magnetic stirring and the heating method was external oil bath heating. 16.6 g of acetic acid, 8.3 g (50 mmol) of cyclododecene and 8.0 g of catalyst I were added to the reactor. The reactor was closed and heated with N 2 Gas replacement, stirring is turned on, the speed is 600 rpm, the oil bath is heated to 115-120°C, the reaction is kept warm for 12 hours, cooled to room temperature, the reactor is opened, the reaction liquid is poured out, and the catalyst reactor can be used. The reaction liquid is analyzed by gas chromatography to determine the residual cyclododecene of the raw material and the conversion rate is calculated, the ratio of the monoester and diester of the product is analyzed, and the selectivity of the reaction process is calculated. The excess acetic acid in the reaction liquid can be collected by vacuum distillation and then used. The results of conversion rate, selectivity and product distribution are listed in Table 2.

[0133] Example 8 Catalyst I is used to catalyze the addition esterification of 1,5,9-cyclododecatriene with acetic acid

[0134] The operation method is the same as that of Example 7, and the target product is cyclododecadienyl acetate.

[0135] The conversion, selectivity and product distribution results are listed in Table 2.

[0136] Example 9 Catalyst I is used to catalyze the addition esterification of 1,5-cyclooctadiene with acetic acid

[0137] The operation method is the same as that of Example 7, and the target product is cyclooctenyl acetate.

[0138] The conversion, selectivity and product distribution results are listed in Table 2.

[0139] Example 10 Catalyst II is used to catalyze the addition esterification of cyclododecene and acetic acid

[0140] The operation method is the same as Example 7.

[0141] The conversion, selectivity and product distribution results are listed in Table 2.

[0142] Example 11 Catalyst III is used to catalyze the addition esterification of cyclododecene and acetic acid

[0143] The operation method is the same as Example 7.

[0144] The conversion, selectivity and product distribution results are listed in Table 2.

[0145] Example 12 Catalyst IV is used to catalyze the addition esterification of cyclododecene and acetic acid

[0146] The operation method is the same as Example 7.

[0147] The conversion, selectivity and product distribution results are listed in Table 2.

[0148] Example 13 Catalyst V is used to catalyze the addition esterification of cyclododecene and acetic acid

[0149] The operation method is the same as Example 7.

[0150] The conversion, selectivity and product distribution results are listed in Table 2.

[0151] Example 14 Catalyst VI is used to catalyze the addition esterification of cyclododecene and acetic acid

[0152] The operation method is the same as Example 7.

[0153] The conversion, selectivity and product distribution results are listed in Table 2.

[0154] Example 15 Catalyst I is used for catalytic addition esterification of cyclododecene and acetic acid. Catalyst recycling experiment

[0155] The recycled catalyst comes from Example 7. The process of the application experiment is the same as that of Example 7. After the reaction is completed, the reaction liquid is carefully poured out, and the catalyst remains at the bottom of the reactor. New acetic acid and cyclododecene are added, and the reaction is carried out under the same conditions. The application experiment is repeated 6 times.

[0156] The results of the loop application are listed in Table 3.

[0157] Comparative Example 1 Preparation of Comparative Catalyst I

[0158] The operation method is the same as that of Example 1, except that step S3 is skipped, alkoxy-substituted calix[4]arene (I) is not added to modify the structure of the coke powder surface, and the coke powder surface is directly sulfonated after oxidation, while other conditions remain unchanged; subsequent steps are the same as those of Example 1, and about 12 g of comparative catalyst I is obtained.

[0159] The properties analysis and characterization of the comparative catalysts are detailed in Table 1.

[0160] Comparative Example 2 Preparation of Comparative Catalyst II

[0161] The operation method is the same as that of Example 1, except that in step S3, a 2,6-dimethylphenol derivative (III) is added to modify the structure of the coke powder surface, and other conditions remain unchanged; the subsequent steps are the same as those of Example 1, and about 12 g of comparative catalyst II is obtained.

[0162] The properties analysis and characterization of the comparative catalysts are detailed in Table 1.

[0163] Comparative Example 3 Comparative Catalyst I is used to catalyze the addition esterification of cyclododecene and acetic acid

[0164] The operation method and catalyst addition ratio are the same as those in Example 7.

[0165] The conversion, selectivity and product distribution results are listed in Table 2.

[0166] Comparative Example 4 Comparative Catalyst II is used to catalyze the addition esterification of cyclododecene and acetic acid

[0167] The operation method and catalyst addition ratio are the same as those in Example 7.

[0168] The conversion, selectivity and product distribution results are listed in Table 2.

[0169] Comparative Example 5: Sulfonated Calixarene is used to catalyze the addition esterification of cyclododecene and acetic acid

[0170] Sulfonated calixarene (4-sulfonylcalix[4]arene hydrate, CAS: 112269-92-8, Aladdin) was used as a catalyst. The operation method was the same as that in Example 7. The amount of sulfonated calixarene added was 0.18 g (0.25 mmol).

[0171] The conversion, selectivity and product distribution results are listed in Table 2.

[0172] Table 1

[0173]

[0174] Table 2

[0175]

[0176] Table 3

[0177]

[0178] Combining Table 1 and Table 2, it can be seen that due to the hard surface of the coke powder, the volatile matter has been completely lost during the coking process. Therefore, the conventional means of pore expansion of coal-based activated carbon, such as water vapor, has limited effect on the increase of the specific surface area of ​​the coke powder, and only part of the carbon element is lost due to the water-gas reaction. This can also be seen in conjunction with Table 2. Under the condition that other conditions remain unchanged, simply adding water vapor to increase the surface activity of the coke powder, such as Catalyst II, has little effect on the reaction effect. On the contrary, increasing the oxidation depth, such as increasing the amount of hydrogen peroxide and concentrated sulfuric acid, has a significant effect on improving the conversion rate and selectivity, such as Catalyst V in Table 2.

[0179] As can be seen from Table 2, through the above examples and comparative examples, it is shown that the catalyst prepared by the present invention has good selectivity and conversion rate for the addition esterification reaction of olefins, and can obtain single-site addition products with high selectivity and conversion rate, providing an important raw material basis for subsequent applications. In addition, compared with the comparative examples, it is fully demonstrated that the introduction of calixarene significantly improves the efficiency and selectivity of the catalyst.

[0180] It can be seen from Table 3 that, compared with the traditional preparation method, the catalyst recycling effect of the present invention is good, and the activity of the catalyst does not change significantly after being reused six times.

[0181] In addition, after the coke powder itself is sulfonated, it also has a certain catalytic effect, but due to the small number of active sites (such as hydroxyl groups, etc.) on the surface of the coke powder, the catalytic effect per unit mass of coke powder is poor; after the sulfonated calixarene is introduced in the present application, each molecule of sulfonated calixarene itself carries at least 4 sulfonate groups, which is equivalent to increasing the number and density of active sites of the catalyst; after the sulfonated calixarene and the coke powder are bonded, the active sites are no longer limited to the two-dimensional surface of the coke powder, but extend to the three-dimensional space through the sulfonated calixarene, thereby increasing the probability of contact between the catalyst and the substrate and improving the catalytic effect; since the sulfonated calixarene can be dissolved in polar solvents, the use of sulfonated calixarene alone as a catalyst has an effect similar to that of methanesulfonic acid and benzenesulfonic acid, and is easy to be lost during the reaction. The sulfonated calixarene in the present application is not loaded on the surface of the coke powder, but is firmly bonded to the surface of the coke powder through chemical bonds, which completely solves the problem of loss of active components and realizes multiple and stable cycles of the catalyst system.

[0182] In summary, in the olefin-esterification addition catalyst solution provided by the present invention, the sulfonated calixarene improves the catalytic activity of the sulfonated coke powder, and the coke powder fixes the sulfonated calixarene through chemical bonds, so that the catalytic system achieves a synergistic effect.

[0183] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst for addition esterification of olefins and carboxylic acids, characterized in that: The catalyst comprises modified coke powder and a calixarene compound chemically modified on the surface of the modified coke powder, and the surface of the modified coke powder and the calixarene compound are modified with sulfonic acid groups; The modified coke powder is prepared by a method comprising the following steps: calcining the coke powder, introducing water vapor to activate the coke powder during the calcination process, cooling, washing, and drying to obtain surface-activated coke powder; soaking the surface-activated coke powder with an oxidant to obtain oxidized coke powder; filtering, washing, and drying the oxidized coke powder to obtain modified coke powder. The calixarene compound is an alkoxy-substituted calix[4]arene represented by formula (I) or formula (II), 。 2. The catalyst according to claim 1, characterized in that The calcination includes at least two stages. In the first stage, the temperature in the tube furnace is increased from room temperature to 300-800°C, the temperature increase gradient is 1-10°C / min, and the holding time is 1-24 hours. In the second stage, the temperature is further increased to 700-1100 °C, the temperature gradient is 1-10 °C / min, and the holding time is 1-24 hours; The amount of water vapor introduced is 10-200% of the mass of the coke powder.

3. The catalyst according to claim 1, characterized in that The oxidant is one or two selected from hydrogen peroxide and concentrated sulfuric acid; The soaking time is 1-24 hours and the soaking temperature is 20-80 ℃.

4. The catalyst according to claim 3, characterized in that The amount of hydrogen peroxide used is 1-6% of the mass of the surface activated coke powder; the mass concentration of hydrogen peroxide is 10-60%; The amount of concentrated sulfuric acid used is 1-10% of the mass of the surface activated coke powder.

5. A method for preparing a catalyst for addition esterification of olefins and carboxylic acids according to claim 1, characterized in that: The following steps are involved: (1) Crushing and screening the coke powder; (2) calcining the screened coke powder, introducing water vapor to activate the powder during the calcination process, and washing and drying the powder after cooling to obtain surface-activated coke powder; (3) soaking the surface activated coke powder obtained in step (2) with an oxidant to obtain oxidized coke powder; (4) filtering, washing, and drying the oxidized coke powder obtained in step (3) to a constant weight to obtain modified coke powder; (5) modifying the surface of the modified coke powder with a calixarene compound by chemical reaction to obtain coke powder modified with the calixarene compound; (6) The coke powder modified with the calixarene compound is subjected to a sulfonation reaction, so that the surface of the modified coke powder and the calixarene compound are modified with sulfonic acid groups, thereby obtaining a catalyst for the addition esterification of olefins and carboxylic acids.

6. The preparation method according to claim 5, characterized in that The calcination includes at least two stages. In the first stage, the temperature in the tube furnace is increased from room temperature to 300-800°C, the temperature increase gradient is 1-10°C / min, and the holding time is 1-24 hours. In the second stage, the temperature is further increased to 700-1100 °C, the temperature gradient is 1-10 °C / min, and the holding time is 1-24 hours; The amount of water vapor introduced is 10-200% of the mass of the coke powder.

7. The preparation method according to claim 5, characterized in that: The oxidant is one or two selected from hydrogen peroxide and concentrated sulfuric acid; The soaking time is 1-24 hours and the soaking temperature is 20-80 ℃.

8. The preparation method according to claim 7, characterized in that: The amount of hydrogen peroxide used is 1-6% of the mass of the surface activated coke powder; the mass concentration of hydrogen peroxide is 10-60%; The amount of concentrated sulfuric acid used is 1-10% of the mass of the surface activated coke powder.

9. The preparation method according to claim 5, characterized in that: Step (5) comprises the following steps: mixing the calixarene compound, the modified coke powder obtained in step (4), and an organic solvent, adding a condensation reagent to react, filtering, washing with an organic solvent to remove by-products generated by the reaction, and drying to obtain coke powder modified with the calixarene compound.

10. The preparation method according to claim 5, characterized in that: The amount of calixarene compounds added is 0.1-10% of the mass of the modified coke powder; The condensation reagents are azodicarbonate diester and a phosphine compound; the molar ratio of the azodicarbonate diester to the calixarene compound is 1:1-2:1, and the molar ratio of the phosphine compound to the calixarene compound is 1:1-2:1; The organic solvent is one or more selected from tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether, dichloromethane, chloroform, benzene, toluene, xylene, ethyl acetate, acetonitrile, dimethyl sulfoxide, and petroleum ether; the amount of the organic solvent added is 10-200% of the mass of the modified coke powder.

11. The preparation method according to claim 5, characterized in that: Step (6) comprises the following steps: reacting the char powder modified with the calixarene compound obtained in step (5) with chlorosulfonic acid, and then filtering, washing and drying the reactants in sequence to constant weight to obtain a catalyst for addition esterification of olefins and carboxylic acids.

12. The preparation method according to claim 11, characterized in that The amount of chlorosulfonic acid added is 10-200% of the mass of the char powder modified with the calixarene compound.

13. Use of the catalyst for addition esterification of olefins and carboxylic acids according to any one of claims 1 to 4 in the preparation of carboxylic acid ester compounds by addition esterification of olefins and carboxylic acids.

14. The use according to claim 13, characterized in that The application includes: in the presence of a catalyst, an olefin and a carboxylic acid undergo an addition esterification reaction to obtain a corresponding carboxylic acid ester compound; The reaction temperature of the addition esterification is 40-200°C; and / or The reaction time is 2-120 hours; and / or The reaction pressure is 0.1-5.0 Mpa; and / or The mass ratio of carboxylic acid to olefin is 1-10:1.0; and / or The mass ratio of the catalyst mass to the olefin mass is 0.5-5.0:1.

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