Titanium sulfate supported catalyst, its preparation method and application in methyl methacrylate synthesis reaction

Abstract

The application relates to the fine chemical industry, and discloses a supported titanium sulfate catalyst, a preparation method thereof and application of the supported titanium sulfate catalyst in a methyl methacrylate synthesis reaction. The supported titanium sulfate catalyst is composed of illite mesoporous composite material and titanium sulfate loaded on the illite mesoporous composite material; the illite mesoporous composite material has a one-dimensional and two-dimensional hexagonal pore dual pore distribution structure, a first most probable pore diameter of 2-7 nm, a second most probable pore diameter of 20-40 nm, a specific surface area of 150-600 m 2 / g, and a pore volume of 0.7-1.6 cm 3 / g; and the content of the illite mesoporous composite material is 60-90% by weight, and the content of the titanium sulfate is 10-40% by weight, based on the total weight of the supported titanium sulfate catalyst. The supported titanium sulfate catalyst is used in a methacrylization reaction, and higher methacrylic acid conversion rate and methyl methacrylate selectivity can be obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fine chemical industry, in particular, to a supported titanium sulfate catalyst, a preparation method thereof and application of the catalyst in a methyl methacrylate synthesis reaction. BACKGROUND

[0002] As an important organic chemical product and raw material, the industrial production level and capacity of methyl methacrylate (MMA) have an important influence on the development of China's chemical industry. MMA is mainly used in the industries of organic glass (PMMA), paint, textile, adhesive, leather, papermaking, floor polishing, unsaturated resin modification, high-grade methyl methacrylate ester, wood preservative, printing and dyeing aid, and plastic plasticizer, etc. In recent years, the demand for MMA polymers, profiles, plates, coatings, emulsions, etc. at home and abroad is increasing, and the application field is continuously expanding, which promotes the rapid development of the MMA industry. At present, the production technology of methyl methacrylate in China is still in the initial stage. Developing methyl methacrylate esterification catalysts with independent intellectual property rights and supporting processes is the development demand of China's MMA production industry.

[0003] The esterification catalyst is the core technology of MMA production. For the esterification reaction of methacrylic acid and methanol, the traditional production process using inorganic acids such as sulfuric acid, phosphoric acid, and boric acid as catalysts is gradually eliminated, and the use of organic acids such as p-toluenesulfonic acid as catalyst also has the disadvantages of serious environmental pollution, low selectivity, and difficult product separation. Comparatively, the esterification catalyst for heterogeneous reaction is a relatively active research field at present. In the latest reports, researchers are constantly trying to use acidic resins, organic tin compounds, rare earth solid superacids, Lewis acids, and other catalysts for the synthesis of carboxylic acid esters, and have achieved meaningful experimental results. At present, acid cation exchange resins are generally used in the production of methyl methacrylate in industry. The cation exchange resin shows good stability, high selectivity, low cost, and easy separation in the esterification reaction. However, the cation exchange resin itself has poor heat resistance (generally not higher than 250℃ will decompose), small specific surface area and pore volume, and the cation exchange resin is easy to swell, which has poor reaction activity as an esterification catalyst and low ester yield. With the increasing demand for MMA, the synthesis of methyl methacrylate by using green and environmentally friendly process has broad prospects. At present, more and more attention is paid to the solid-supported esterification catalyst in the synthesis of methyl methacrylate. For researchers, developing esterification catalysts with excellent performance, improving reaction efficiency, and inhibiting the generation of by-products are important work directions in the future. SUMMARY

[0004] The application aims to overcome the problems of low conversion rate of methacrylic acid and low yield of methyl methacrylate in the current methyl methacrylate production process, and provides a supported titanium sulfate catalyst, a preparation method thereof and application thereof in a methyl methacrylate synthesis reaction. The supported titanium sulfate catalyst is used in a methacrylate esterification reaction, and higher conversion rate of methacrylic acid and selectivity of methyl methacrylate can be obtained.

[0005] To achieve the above-mentioned purpose, the first aspect of the application provides a supported titanium sulfate catalyst, wherein the supported titanium sulfate catalyst comprises an illite mesoporous composite material and titanium sulfate supported on the illite mesoporous composite material; wherein the illite mesoporous composite material has a one-dimensional and two-dimensional hexagonal pore dual pore distribution structure, a first most probable pore diameter of 2-7 nm, a second most probable pore diameter of 20-40 nm, a specific surface area of 150-600 m 2 / g, and a pore volume of 0.7-1.6 cm 3 / g; and the content of the illite mesoporous composite material is 60-90 wt% and the content of the titanium sulfate is 10-40 wt% based on the total weight of the supported titanium sulfate catalyst.

[0006] The second aspect of the application provides a preparation method of the aforementioned supported titanium sulfate catalyst, wherein the preparation method comprises:

[0007] contacting a titanium sulfate, an alcohol aqueous solution and an illite mesoporous composite material, and then drying the solid product after removing the solvent to obtain the supported titanium sulfate catalyst.

[0008] The third aspect of the application provides application of the aforementioned supported titanium sulfate catalyst in a methyl methacrylate synthesis reaction.

[0009] Through the above technical solution, the technical solution of the application has the following advantages:

[0010] 1. The supported titanium sulfate catalyst provided by the application has stable structure and does not deform or swell during the reaction. When used in the synthesis of methyl methacrylate, the conversion rate of methacrylic acid is high and the selectivity of methyl methacrylate is high.

[0011] 2. The supported titanium sulfate catalyst provided by the application has easily available raw materials, simple preparation method, easy-to-control conditions and good product repeatability.

[0012] 3. The catalyst provided by the application has mild process conditions and does not require a high reaction device when used in the synthesis of methyl methacrylate.

[0013] Other features and advantages of the application will be described in detail in the following specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is the XRD pattern of the illite mesoporous composite material A prepared in Example 1;

[0015] Figure 2 is the scanning electron microscope image of the illite mesoporous composite material A prepared in Example 1;

[0016] Figure 3 is the pore size distribution curve of the illite mesoporous composite material A prepared in Example 1. DETAILED DESCRIPTION

[0017] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. The exact numerical values of the endpoints of the ranges and any values are approximations which are now to be understood to have a value allowance to allow for these approximate values. For example, it is understood that the endpoints of the ranges and any values are approximations that can vary by a small amount. It is understood that the endpoints of the ranges and any values are approximations and are provided as a convenience. The endpoints of the ranges and any values have now been described and provided are understood and intended to be a part of the description of aspects of the application.

[0018] As described previously, the first aspect of the present application provides a supported titanium sulfate catalyst, wherein the supported titanium sulfate catalyst comprises an illite mesoporous composite material and titanium sulfate supported on the illite mesoporous composite material; wherein the illite mesoporous composite material has a one-dimensional and two-dimensional hexagonal pore dual pore structure, a first most probable pore diameter of 2-7 nm, a second most probable pore diameter of 20-40 nm, a specific surface area of 150-600 m 2 / g, and a pore volume of 0.7-1.6 cm 3 / g; and the content of the illite mesoporous composite material is 60-90 wt%, and the content of the titanium sulfate is 10-40 wt% based on the total weight of the supported titanium sulfate catalyst.

[0019] The inventors of the present application found that in the prior art, esterification catalysts for producing methyl methacrylate are classified into two categories, homogeneous and heterogeneous. Among them, the homogeneous catalysts mainly include inorganic acid solution and organic acid, and the heterogeneous catalysts mainly include solid acid and cation exchange resin. The homogeneous catalysts have the advantages of low price and good catalytic activity, but are gradually eliminated due to the defects of difficult separation of product and catalyst, more side reactions, and easy corrosion of equipment. The solid acid esterification catalyst solves the problems of difficult product separation and serious equipment corrosion, but is rarely applied to industrial production due to the disadvantages of poor catalytic activity, high reaction temperature, and low product selectivity. Compared with the above catalysts, the use of acidic cation exchange resin as an esterification catalyst to produce methyl methacrylate is the main process currently applied in industry. The resin catalyst has the advantages of high selectivity, low cost, and easy separation, but the yield of methyl methacrylate is low during the esterification reaction of methacrylic acid, and the high temperature resistance is also poor. Resin is an organic polymer material, which is easy to swell in organic solvents, and is easy to deform or even decompose in high temperature environment, which is the main reason for the poor temperature resistance of the resin catalyst. Developing a new type of solid catalyst system to compensate for the performance defects of the resin catalyst is a good way to solve the problem.

[0020] The present application provides a method for producing DOP by using a composite Lewis acid catalysis method, which selects a composite Lewis acid as a catalyst. The acid is a Lewis acid catalyst in the esterification process, which is highly active, highly selective, and has mild reaction conditions, and is therefore highly valued. However, ordinary Lewis acids are not stable in water and are easily deactivated by reaction with water. In addition, some Lewis acids are easily soluble in organic solvents, and during the esterification reaction, the dissolution of the Lewis acid catalyst in the reaction system will cause difficulty in separating the product. Titanium sulfate is a cheap and readily available inorganic compound, which belongs to Lewis acid salt and has excellent performance in catalyzing esterification reaction. Since no inorganic acid is involved in the reaction process, no difficult-to-handle waste liquid is generated, and the complex process such as neutralization, water washing, decolorization, and dehydration after the reaction is eliminated, greatly shortening the production cycle and greatly reducing the comprehensive production cost. In addition, titanium sulfate is not a dangerous chemical, which has environmental advantages. However, if titanium sulfate is directly used as a catalyst in the synthesis reaction of methyl methacrylate, the product may not be easily separated due to the partial dissolution of titanium sulfate in the reaction system. If a suitable carrier can be selected to disperse titanium sulfate well, the above problems can be solved, and an esterification catalyst with high efficiency can be obtained. If a high-performance supported titanium sulfate catalyst is to be obtained, a new material with excellent structural characteristics must be selected as the catalyst carrier first. The illite mesoporous composite material has a unique one-dimensional and two-dimensional hexagonal pore dual pore distribution mesoporous structure, and has the structural advantages of large pore size and large pore volume, which is beneficial to the diffusion of macromolecular reaction raw materials and products in the reaction, and may become a good carrier for the supported titanium sulfate catalyst.

[0021] The inventors of the present application found in the development of esterification catalysts that if titanium sulfate is loaded on an illite mesoporous composite material, the prepared supported catalyst will not dissolve, swell and deform in organic solvents. The catalyst can exhibit good catalytic activity and methyl methacrylate selectivity when used in the esterification reaction of methacrylic acid and methanol.

[0022] According to the present application, preferably, the content of the illite mesoporous composite material is 65-85% by weight and the content of the titanium sulfate is 15-35% by weight, based on the total weight of the supported titanium sulfate catalyst; more preferably, the content of the composite carrier is 70-80% by weight and the content of the titanium sulfate is 20-30% by weight, based on the total weight of the supported titanium sulfate catalyst. In the present application, the use of the specific content of the illite mesoporous composite material and the specific content of the titanium sulfate can make the prepared catalyst have better catalytic activity and ester selectivity when used in the esterification reaction of methacrylic acid.

[0023] According to the present application, preferably, the first most probable pore diameter of the illite mesoporous composite material is 2-5 nm, the second most probable pore diameter is 22-30 nm, the specific surface area is 250-450 m 2 / g, and the pore volume is 1.1-1.6 cm 3 / g; more preferably, the first most probable pore diameter of the illite mesoporous composite material is 3-4 nm, the second most probable pore diameter is 24-26 nm, the specific surface area is 301-349 m 2 / g, and the pore volume is 1.4-1.6 cm 3 / g. In the present application, the use of the illite mesoporous composite material with the foregoing specific parameters can make the prepared catalyst have better catalytic activity and ester selectivity when used in the esterification reaction of methacrylic acid.

[0024] According to the present application, the specific surface area of the supported titanium sulfate catalyst is 100-500 m 2 / g, and the pore volume is 0.5-1.5 cm 3 / g; preferably, the specific surface area of the supported titanium sulfate catalyst is 150-350 m 2 / g, and the pore volume is 0.7-1.4 cm 3 / g; more preferably, the specific surface area of the supported titanium sulfate catalyst is 207-285 m 2 / g, and the pore volume is 0.9-1.3 cm 3 / g. In the present application, the use of the supported titanium sulfate catalyst with the foregoing specific parameters can make the catalyst have better catalytic activity and ester selectivity when used in the esterification reaction of methacrylic acid.

[0025] According to the present application, the illite mesoporous composite material can be synthesized by the following method:

[0026] In the first step, tetramethoxysilane is contacted with an acid agent in the presence of a template agent, trimethylpentane and ethanol, and the mixture obtained after the contacting is crystallized and filtered to obtain a mesoporous molecular sieve material filter cake 1;

[0027] In the second step, tetraethyl orthosilicate (TEOS) is contacted with hydrochloric acid in the presence of a template agent, cetyltrimethylammonium bromide (CTAB), and the mixture obtained after the contacting is crystallized and filtered to obtain a mesoporous molecular sieve material filter cake 2;

[0028] In the third step, water glass is contacted with an inorganic acid, and the mixture obtained after the contacting is washed and suction filtered to obtain a silica gel filter cake;

[0029] In the fourth step, the mesoporous molecular sieve material filter cake 1, the mesoporous molecular sieve material filter cake 2, the silica gel filter cake and illite powder are ball milled together to obtain a solid powder;

[0030] In the fifth step, the solid powder obtained in the fourth step is prepared into a slurry in the presence of deionized water and then is spray dried;

[0031] In the sixth step, the product obtained in the fifth step is heated to remove the template agent to obtain an illite mesoporous composite material having a one-dimensional and two-dimensional pore dual pore distribution structure.

[0032] According to the present application, in the preparation method of the illite mesoporous composite material, the template agent in the first step can be various kinds of triblock copolymer polyoxyethylene-polyoxypropylene-polyoxyethylene template agents commonly used in the art, for example, can be the template agent with the trade name P123 and the molecular formula of EO 20 PO 70 EO 20 produced by Aldrich Company;

[0033] According to the present application, in the preparation method of the illite mesoporous composite material, the molar ratio of the template agent, ethanol, trimethylpentane and tetramethoxysilane in the first step is 1:100-500:200-500:50-200, preferably 1:200-400:250-400:70-150;

[0034] According to the present application, in the preparation method of the illite mesoporous composite material, the acid agent in the first step is one or several of an acetic acid / sodium acetate buffer solution with a pH value of 1-6 or a hydrochloric acid solution;

[0035] According to the present application, in the preparation method of the illite mesoporous composite material, preferably, the conditions for contacting the tetramethoxysilane with the acid agent in the first step include a temperature of 10-60℃, a time of 10-72 hours, and a pH value of 1-7.

[0036] According to the present application, in the preparation method of the illite mesoporous composite material, preferably, the conditions for crystallization in the first step include a temperature of 30-150℃, a time of 10-72 hours.

[0037] According to the present application, in the preparation method of the illite mesoporous composite material, the molar ratio of the template agent, tetraethyl orthosilicate, hydrochloric acid and water in the second step is 1:(0.1-2):(2-20):(50-200), preferably 1:(0.5-1.5):(5-10):(70-150).

[0038] According to the present application, in the preparation method of the illite mesoporous composite material, preferably, the conditions for contacting the tetraethyl orthosilicate with the hydrochloric acid in the second step include a temperature of 10-60℃, a time of 10-72 hours, and a pH value of 0-1.

[0039] According to the present application, in the preparation method of the illite mesoporous composite material, preferably, the conditions for crystallization in the second step include a temperature of 30-150℃, a time of 10-72 hours.

[0040] According to the present application, in the preparation method of the illite mesoporous composite material, preferably, the contacting temperature in the third step is 10-60℃, and the contacting time is 1-5 hours; the water glass and the inorganic acid are not specifically limited, the water glass is a solution of sodium silicate, the inorganic acid is one or more of sulfuric acid, nitric acid and hydrochloric acid, and the pH value of the mixed solution of the water glass and the inorganic acid is 2-4; the weight ratio of the water glass to the inorganic acid is 3-6:1.

[0041] According to the present application, in the preparation method of the illite mesoporous composite material, the suction filtration separation in the third step is a method for separating liquid and solid particles known to those skilled in the art, which is to separate liquid and solid particles or a mixture of liquid and liquid by using air pressure.

[0042] According to an embodiment of the present application, in the preparation method of the illite mesoporous composite material, the ball milling method in the fourth step comprises: adding the mesoporous molecular sieve material filter cake 1, the mesoporous molecular sieve material filter cake 2, the silica gel filter cake and the illite powder into a ball milling tank of a ball mill, lining the inner wall of the ball milling tank with polytetrafluoroethylene, and using a ball with a diameter of 2-3 mm and a rotating speed of 300-500 r / min. The solid powder is taken out after continuous grinding at a temperature of 15-100 ℃ for 0.1-100 hours. The number of the balls depends on the size of the ball milling tank, and for a ball milling tank with a size of 50-150 ml, one ball can be used. The material of the ball can be agate or polytetrafluoroethylene, and is preferably agate.

[0043] According to the present application, in the preparation method of the illite mesoporous composite material, the spray drying method in the fifth step comprises: mixing the solid powder after ball milling with deionized water to prepare a slurry at a temperature of 25-60 ℃, and rotating the slurry in an atomizer at a high speed with a rotating speed of 10,000-15,000 r / min, preferably 12,000 r / min.

[0044] According to the present application, in the preparation method of the illite mesoporous composite material, the conditions for removing the template agent in the sixth step are not particularly limited, for example, the temperature can be 400-600 ℃, and the time can be 10-80 hours.

[0045] The second aspect of the present application provides a preparation method of the supported titanium sulfate catalyst as described above, characterized in that the preparation method comprises:

[0046] contacting titanium sulfate, an aqueous alcohol solution and the illite mesoporous composite material, and then drying the solid product after removing the solvent to obtain the supported titanium sulfate catalyst.

[0047] According to the present application, the aqueous alcohol solution is a methanol-water mixed solution, an ethanol-water mixed solution or an isobutyl alcohol-water mixed solution.

[0048] According to the present application, the weight ratio of the alcohol to water in the aqueous alcohol solution is 1:(0.1-10), preferably 1:(0.2-5).

[0049] According to the present application, the weight ratio of the titanium sulfate, the aqueous alcohol solution and the illite mesoporous composite material is 1:(3-100):(1.5-9), preferably 1:(5-20):(1.8-6).

[0050] According to the present application, the contacting reaction conditions comprise: a temperature of 50-90 ℃, preferably 60-80 ℃; and a time of 0.5-12 h, preferably 1-8 h. Preferably, in order to achieve better mixing effect, rapid stirring or ultrasonic means can be used to improve the mixing efficiency during the contacting reaction.

[0051] According to the present application, the method for removing the solvent is not specially required and can be a method known in the art. For example, vacuum drying method, heating evaporation during stirring to remove the solvent or using a rotary evaporator to evaporate the solvent can be used.

[0052] According to the present application, the drying condition includes: temperature of 60-120℃, preferably 80-110℃; time of 1-30h, preferably 2-16h.

[0053] The third aspect of the present application provides an application of the supported titanium sulfate catalyst in the synthesis reaction of methyl methacrylate.

[0054] According to the present application, the application includes: simultaneously contacting methyl methacrylate and methanol with the supported titanium sulfate catalyst.

[0055] In the present application, the contacting condition of the methyl methacrylate and methanol with the catalyst includes: temperature of 40-150℃, preferably 60-120℃; pressure of 0.01-5MPa, preferably 0.1-3Mpa; mass space velocity of the methyl methacrylate of 0.01-30h -1 , preferably 0.1-10h -1 ; mass space velocity of the methanol of 0.01-50h -1 , preferably 0.1-30h -1 .

[0056] The present application will be described in detail through examples below.

[0057] In the following examples and comparative examples:

[0058] The small-angle XRD test of the sample was performed on a D8 ADVANCE high-power rotating target X-ray diffractometer of BRUKER AXS Company in Germany, and the scanning range was 0.5-10°.

[0059] The pore structure parameter analysis of the sample was performed on an ASAP2020-M+C adsorber purchased from Micromeritics Company in the United States. The sample was vacuum degassed at 40℃ for 4 hours before determination, the specific surface area of the sample was calculated by BET method, and the pore volume was calculated by BJH model.

[0060] The scanning electron microscope picture of the sample was obtained on an XL-30 field emission environmental scanning electron microscope produced by FEI Company in the United States.

[0061] The elemental analysis experiment of the sample was performed on an Eagle III energy dispersive X-ray fluorescence spectrometer produced by EDAX Company in the United States.

[0062] The rotary evaporator was produced by IKA, Germany, and the model was RV10 digital.

[0063] The drying oven was produced by Shanghai Yiheng Scientific Instrument Co., Ltd., and the model was DHG-9030A.

[0064] The muffle furnace was produced by CARBOLITE, and the model was CWF1100.

[0065] The polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer (P123) used in the examples and comparative examples was purchased from Sigma-Aldrich Chemistry Co.; other reagents used in the examples and comparative examples were purchased from National Pharmaceutical Group Chemical Reagent Co., Ltd., and the purity of the reagents was analytical pure.

[0066] Example 1

[0067] (1) Preparation of illite mesoporous composite material

[0068] 11.6 g (0.002 mol) of triblock copolymer surfactant P123 and 27.6 g (0.6 mol) of ethanol were added to 300 ml of pH 4 acetic acid and sodium acetate buffer, stirred at 30°C until the P123 was completely dissolved, then 60 g (0.52 mol) of trimethylpentane was added to the obtained solution, stirred at 30°C for 8 h, then 30.4 g (0.2 mol) of tetramethoxysilane was added, stirred at 30°C and pH 4.5 for 20 h, then the obtained solution was transferred to a polytetrafluoroethylene-lined reaction kettle, crystallized at 60°C for 24 h, then filtered and washed with deionized water for 4 times, and then suction filtered to obtain mesoporous molecular sieve material filter cake 1 with one-dimensional hexagonal pore channel single pore distribution structure;

[0069] 36.4 g (0.1 mol) of hexadecyltrimethylammonium bromide (CTAB) was added to 180 g of double-distilled water, stirred at 30°C for 2 h to obtain a homogeneous solution, the pH of the solution was adjusted to 0-1 with hydrochloric acid, and 20.8 g (0.1 mol) of tetraethyl orthosilicate (TEOS) was slowly added dropwise. After continuing to stir for 36 hours, the mixture was transferred to a polytetrafluoroethylene-lined kettle, and crystallized at 80°C for 40 h. Finally, the product was filtered and washed, and suction filtered to obtain mesoporous molecular sieve material filter cake 2 with two-dimensional hexagonal pore channel single pore distribution structure.

[0070] The water glass solution with a concentration of 15% by weight and the sulfuric acid solution with a concentration of 12% by weight were mixed in a weight ratio of 4:1 and contacted at 30°C for 2 hours, then the pH was adjusted to 3 with concentrated sulfuric acid with a concentration of 98% by weight, then the obtained reaction material was suction filtered and washed with distilled water until the sodium ion content was less than 0.02% by weight to obtain a silica gel filter cake.

[0071] The 5 g mesoporous molecular sieve material filter cake 1, 5 g mesoporous molecular sieve material filter cake 2, 10 g silica gel filter cake and 10 g illite prepared above were put into a 100 ml ball mill tank, wherein the material of the ball mill tank was polytetrafluoroethylene, the material of the grinding ball was agate, the diameter of the grinding ball was 3 mm, the number was 1, and the rotating speed was 400 r / min. The ball mill tank was closed, and the solid powder was obtained by ball milling at 60℃ for 1 hour in the ball mill tank. The solid powder was mixed with 30 g of deionized water, and spray dried at 200℃, with the rotating speed of the atomizer being 12000 r / min. The product obtained after spray drying was calcined in a muffle furnace at 500℃ for 30 hours to remove the template, and illite mesoporous composite material A was obtained.

[0072] The specific surface area of the illite mesoporous composite material A was 316 m 2 / g, and the pore volume was 1.5 ml / g.

[0073] Figure 1 Figure 1 is the XRD spectrum of the illite mesoporous composite material A prepared in Example 1. It can be seen from the small-angle spectrum peak appearing in the XRD spectrum that the illite mesoporous composite material A has a one-dimensional and two-dimensional hexagonal pore channel double pore distribution structure unique to mesoporous materials.

[0074] Figure 2 Figure 2 is the SEM scanning electron micrograph of the micro-morphology of the illite mesoporous composite material A prepared in Example 1. It can be seen from the figure that the micro-morphology of the illite mesoporous composite material A is spherical, and the particle diameter is between 30-60 μm.

[0075] Figure 3 Figure 3 is the pore size distribution curve of the illite mesoporous composite material A prepared in Example 1. It can be seen that the illite mesoporous composite material A has a clear double pore distribution structure, and the first most probable pore diameter is 3.5 nm, and the second most probable pore diameter is 25 nm.

[0076] (2) Preparation of supported titanium sulfate catalyst

[0077] In a round-bottom flask, 2.6 g of titanium sulfate, 15 g of ethanol and 15 g of water were mixed, heated to 60℃ in a water bath and stirred for 10 h to obtain a transparent aqueous solution. 7.4 g of illite mesoporous composite material A was added to the above transparent aqueous solution, heated to 70℃, and stirred for 3 hours. After the reaction, the solvent was removed by rotary evaporation, and the solid product was dried in air at 100℃ for 8 hours to obtain a supported titanium sulfate catalyst A.

[0078] The specific surface area of the supported titanium sulfate catalyst A was 241 m 2 / g, and the pore volume was 1.1 ml / g.

[0079] The content of the illite mesoporous composite material A is 74.6% by weight and the content of the titanium sulfate is 25.4% by weight based on the total weight of the supported titanium sulfate catalyst A.

[0080] (3) Catalyst reaction performance evaluation

[0081] The esterification reaction performance of the catalyst was evaluated on a fixed bed reaction device. 5 grams of the supported titanium sulfate catalyst A was loaded into a stainless steel fixed bed reactor with an inner diameter of 8 mm, the reaction temperature was 90°C, the reaction pressure was 0.5 MPa, the weight space velocity of methyl methacrylate was 1 h -1 , the weight space velocity of methanol was 2.7 h -1 , and the reaction time was 20 hours. After the product was cooled, it was analyzed by an Agilent 7890A gas chromatograph equipped with an FFAP capillary column and a hydrogen flame detector (FID), using programmed temperature and quantitative analysis with a correction factor. The conversion rate of methyl methacrylate was 96.8% and the selectivity of methyl methacrylate was 99.8%.

[0082] Example 2

[0083] (1) Preparation of illite mesoporous composite material

[0084] 11.6 g (0.002 mol) of triblock copolymer surfactant P123 and 18.4 g (0.4 mol) of ethanol were added to 200 ml of a pH 4 acetic acid and sodium acetate buffer solution, stirred at 10°C until the P123 was completely dissolved, then 57.6 g (0.5 mol) of trimethylpentane was added to the resulting solution, stirred at 10°C for 24 h, then 21.3 g (0.14 mol) of tetramethoxysilane was added, stirred at 10°C and pH 4.3 for 48 h, then the resulting solution was warmed to 30°C, crystallized under stirring conditions for 72 h, then filtered and washed with deionized water 8 times, and then suction filtered to obtain mesoporous molecular sieve material filter cake 1 with a one-dimensional hexagonal pore structure.

[0085] 36.4 g (0.1 mol) of cetyltrimethylammonium bromide (CTAB) was added to 126 g of double-distilled water, stirred at 10°C for 3 h to obtain a homogeneous solution, the pH of the solution was adjusted to 0-1 with hydrochloric acid, and 10.4 g (0.05 mol) of tetraethyl orthosilicate (TEOS) was slowly added dropwise. After continuing to stir for 66 hours, the mixture was warmed to 30°C, crystallized under stirring conditions for 72 h. Finally, the product was filtered and washed, and suction filtered to obtain mesoporous molecular sieve material filter cake 2 with a two-dimensional hexagonal pore structure.

[0086] A mixture of water glass with a concentration of 15 wt% and a sulfuric acid solution with a concentration of 12 wt% was mixed in a weight ratio of 3:1 and allowed to react at 10°C for 5 hours, followed by adjusting the pH to 2 using concentrated sulfuric acid with a concentration of 98 wt%, and then the obtained reaction material was suction filtered and washed with distilled water until the sodium ion content was less than 0.02 wt% to obtain a silica gel filter cake.

[0087] The 5 g of mesoporous molecular sieve material filter cake 1, 5 g of mesoporous molecular sieve material filter cake 2, 10 g of silica gel filter cake and 10 g of illite prepared above were placed in a 100 ml ball mill tank, wherein the material of the ball mill tank was polytetrafluoroethylene, the material of the grinding ball was agate, the diameter of the grinding ball was 3 mm, the number of the grinding ball was 1, and the rotation speed was 400 r / min. The ball mill tank was closed, and the ball milling was carried out at a temperature of 60°C in the ball mill tank for 1 hour to obtain a solid powder. The solid powder was mixed with 30 g of deionized water, and spray drying was carried out at 200°C, and the rotation speed of the atomizer was 12000 r / min. The product obtained after spray drying was calcined in a muffle furnace at 400°C for 80 hours to remove the template agent, and illite mesoporous composite material B was obtained.

[0088] The specific surface area of the illite mesoporous composite material B was 301 m 2 / g, the pore volume was 1.4 ml / g, the first most probable pore diameter was 3 nm, and the second most probable pore diameter was 24 nm.

[0089] (2) Preparation of supported titanium sulfate catalyst

[0090] In a round-bottom flask, 3 g of titanium sulfate, 5 g of methanol and 15 g of water were mixed, and the water bath was heated to 60°C and stirred for 10 h to obtain a transparent aqueous solution. 7 g of illite mesoporous composite material B was added to the above-mentioned transparent aqueous solution, and the temperature was raised to 80°C, and reflux stirring was carried out for 1 hour. After the reaction, the solvent was removed by a rotary evaporator, and the solid product was dried in air at 110°C for 2 hours to obtain a supported titanium sulfate catalyst B.

[0091] The specific surface area of the supported titanium sulfate catalyst B was 207 m 2 / g, and the pore volume was 0.9 ml / g.

[0092] Based on the total weight of the supported titanium sulfate catalyst B, the content of the illite mesoporous composite material B was 70 wt%, and the content of titanium sulfate was 30 wt%.

[0093] (3) Evaluation of the reaction performance of the catalyst

[0094] The esterification reaction performance test of the catalyst B was carried out according to the method of step (3) in Example 1. The conversion rate of methacrylic acid was 97%, and the selectivity of methyl methacrylate was 99.6%.

[0095] Example 3

[0096] (1) Preparation of illite mesoporous composite material

[0097] Into 450 ml of a buffer solution of acetic acid and sodium acetate with pH value of 4, 11.6 g (0.002 mol) of triblock copolymer surfactant P123 and 36.8 g (0.8 mol) of ethanol were added and stirred at 60°C until the P123 was completely dissolved, then 92.3 g (0.8 mol) of trimethylpentane was added to the obtained solution, stirred at 60°C for 2 h, then 45.6 g (0.3 mol) of tetramethoxysilane was added thereto, stirred at 60°C with pH value of 4.8 for 8 h, then the obtained solution was warmed to 150°C, crystallized under stirring for 10 h, then filtered and washed with deionized water for 6 times, then suction filtered to obtain mesoporous molecular sieve material filter cake 1 with one-dimensional hexagonal pore channel single pore distribution structure;

[0098] Into 270 g of double-distilled water, 36.4 g (0.1 mol) of cetyltrimethylammonium bromide (CTAB) was added, stirred at 60°C for 1 h to obtain a homogeneous solution, the pH value of the solution was adjusted to 0-1 with hydrochloric acid, and 31.2 g (0.15 mol) of tetraethyl orthosilicate (TEOS) was slowly added dropwise. After continuing to stir for 9 hours, the mixture was warmed to 150°C, and crystallized under stirring for 10 h. Finally, the product was filtered and washed, and suction filtered to obtain mesoporous molecular sieve material filter cake 2 with two-dimensional hexagonal pore channel single pore distribution structure.

[0099] The water glass with a concentration of 15% by weight and the sulfuric acid solution with a concentration of 12% by weight were mixed in a weight ratio of 6:1 and contacted at 60°C for 1 hour, then the pH value was adjusted to 4 with concentrated sulfuric acid with a concentration of 98% by weight, then the obtained reaction material was suction filtered and washed with distilled water until the sodium ion content was less than 0.02% by weight to obtain a silica gel filter cake.

[0100] The above-prepared 5 g of mesoporous molecular sieve material filter cake 1, 5 g of mesoporous molecular sieve material filter cake 2, 10 g of silica gel filter cake and 10 g of illite were placed in a 100 ml ball mill jar, wherein the material of the ball mill jar was polytetrafluoroethylene, the material of the grinding ball was agate, the diameter of the grinding ball was 3 mm, the number was 1, and the rotation speed was 500 r / min. The ball mill jar was closed, and the temperature in the ball mill jar was 40°C. Ball milling was carried out for 3 hours to obtain a solid powder. The above solid powder was mixed with 30 grams of deionized water, and spray drying was carried out at 200°C, with the rotation speed of the atomizer being 12000 r / min. The product obtained after spray drying was calcined in a muffle furnace at 600°C for 10 hours to remove the template agent, to obtain an illite mesoporous composite material C.

[0101] The specific surface area of the illite mesoporous composite material C was 349 m 2 / g, pore volume 1.6 ml / g, first most probable pore diameter 4 nm, second most probable pore diameter 26 nm.

[0102] (2) Preparation of supported titanium sulfate catalyst

[0103] In a round bottom flask, 2 g of titanium sulfate, 25 g of isobutyl alcohol and 5 g of water were mixed, heated to 60°C in a water bath and stirred for 10 h to obtain a transparent aqueous solution. 8 g of the illite mesoporous composite material C was added to the above transparent aqueous solution, and the temperature was kept at 60°C, and the reaction was stirred for 8 h under reflux. After the reaction, the solvent was removed by a rotary evaporator, and the solid product was dried in air at 80°C for 16 h to obtain the supported titanium sulfate catalyst C.

[0104] The specific surface area of the supported titanium sulfate catalyst C was 285 m 2 / g, and the pore volume was 1.3 ml / g.

[0105] The content of the illite mesoporous composite material C was 80 wt% and the content of titanium sulfate was 20 wt% based on the total weight of the supported titanium sulfate catalyst C.

[0106] (3) Evaluation of the reaction performance of the catalyst

[0107] The esterification reaction performance test of the catalyst C was carried out according to the method of step (3) in Example 1. The conversion rate of methacrylic acid was 96.7%, and the selectivity of methyl methacrylate was 99.7%.

[0108] Example 4

[0109] The supported titanium sulfate catalyst D was prepared according to the same method as in Example 1, except that the preparation conditions of the catalyst in step (2) in Example 1 were changed, specifically:

[0110] In a round bottom flask, 3.5 g of titanium sulfate, 20 g of ethanol and 15 g of water were mixed, heated to 60°C in a water bath and stirred for 10 h to obtain a transparent aqueous solution. 6.5 g of the illite mesoporous composite material A was added to the above transparent aqueous solution, and the temperature was raised to 70°C, and the reaction was stirred for 3 h under reflux. After the reaction, the solvent was removed by a rotary evaporator, and the solid product was dried in air at 100°C for 8 h to obtain the supported titanium sulfate catalyst D.

[0111] The specific surface area of the supported titanium sulfate catalyst D was 153 m 2 / g, and the pore volume was 0.7 ml / g.

[0112] The content of the illite mesoporous composite material A was 65 wt% and the content of titanium sulfate was 35 wt% based on the total weight of the supported titanium sulfate catalyst D.

[0113] The catalytic performance of catalyst D was tested according to the performance evaluation method of esterification reaction of step (3) in Example 1. The conversion rate of methacrylic acid was 95.4%, and the selectivity of methyl methacrylate was 99.2%.

[0114] Example 5

[0115] The supported titanium sulfate catalyst E was prepared according to the same method as in Example 3, except that the preparation conditions of the catalyst in step (2) in Example 3 were changed, specifically:

[0116] In a round-bottom flask, 1.5 g of titanium sulfate, 25 g of isobutyl alcohol, and 5 g of water were mixed, heated to 60°C in a water bath, and stirred for 10 h to obtain a transparent aqueous solution. 8.5 g of the illite mesoporous composite material C was added to the above transparent aqueous solution, and the temperature was kept at 60°C, and the reaction was stirred under reflux for 8 hours. After the reaction, the solvent was removed by a rotary evaporator, and the solid product was dried in air at 80°C for 16 hours to obtain the supported titanium sulfate catalyst E.

[0117] The specific surface area of the supported titanium sulfate catalyst E was 316 m 2 / g, and the pore volume was 1.4 ml / g.

[0118] The content of the illite mesoporous composite material C was 85% by weight, and the content of titanium sulfate was 15% by weight, based on the total weight of the supported titanium sulfate catalyst E.

[0119] The catalytic performance of catalyst E was tested according to the performance evaluation method of esterification reaction of step (3) in Example 1. The conversion rate of methacrylic acid was 95.2%, and the selectivity of methyl methacrylate was 99%.

[0120] Example 6

[0121] The supported titanium sulfate catalyst F was prepared according to the same method as in Example 1, except that the preparation conditions of the catalyst in step (2) in Example 1 were changed, specifically:

[0122] In a round-bottom flask, 4 g of titanium sulfate, 5 g of ethanol, and 15 g of water were mixed, heated to 60°C in a water bath, and stirred for 10 h to obtain a transparent aqueous solution. 6 g of the illite mesoporous composite material A was added to the above transparent aqueous solution, and the temperature was raised to 70°C, and the reaction was stirred under reflux for 3 hours. After the reaction, the solvent was removed by a rotary evaporator, and the solid product was dried in air at 100°C for 8 hours to obtain the supported titanium sulfate catalyst F.

[0123] The specific surface area of the supported titanium sulfate catalyst F was 124 m 2 / g, and the pore volume was 0.5 ml / g.

[0124] Based on the total weight of the supported titanium sulfate catalyst F, the illite mesoporous composite material A contains 60% by weight and the titanium sulfate content is 40% by weight.

[0125] The catalytic performance of catalyst F was tested according to the esterification reaction performance evaluation method in step (3) of Example 1. The conversion rate of methacrylic acid was 94.4%, and the selectivity of methyl methacrylate was 98.3%.

[0126] Example 7

[0127] The supported titanium sulfate catalyst G was prepared using the same method as in Example 3, except that the preparation conditions of the catalyst in step (2) of Example 3 were changed. Specifically:

[0128] In a round-bottom flask, 1 g of titanium sulfate, 15 g of isobutanol, and 5 g of water were mixed and heated in a water bath to 60 °C with stirring for 10 h to obtain a clear aqueous solution. 9 g of illite mesoporous composite material C was added to the above clear aqueous solution, and the mixture was refluxed and stirred at 60 °C for 8 h. After the reaction, the solvent was removed using a rotary evaporator, and the solid product was dried in air at 100 °C for 8 h to obtain the supported titanium sulfate catalyst G.

[0129] The specific surface area of ​​the supported titanium sulfate catalyst G is 329 m². 2 / g, pore volume is 1.5ml / g.

[0130] Based on the total weight of the supported titanium sulfate catalyst G, the illite mesoporous composite material C contains 90% by weight and the titanium sulfate content is 10% by weight.

[0131] The catalytic performance of catalyst G was tested according to the esterification reaction performance evaluation method in step (3) of Example 1. The conversion rate of methacrylic acid was 94.2%, and the selectivity of methyl methacrylate was 98.5%.

[0132] Comparative Example 1

[0133] The supported titanium sulfate catalyst D1 was prepared using the same method as in Example 1, except that the preparation conditions of the catalyst in step (2) of Example 1 were changed. Specifically:

[0134] In a round-bottom flask, 6 g of titanium sulfate, 5 g of ethanol, and 15 g of water were mixed and heated in a water bath to 60 °C with stirring for 10 h to obtain a transparent aqueous solution. 4 g of illite mesoporous composite material A was added to the above transparent aqueous solution, and the mixture was heated to 70 °C and refluxed with stirring for 3 h. After the reaction, the solvent was removed using a rotary evaporator, and the solid product was dried in air at 100 °C for 8 h to obtain the supported titanium sulfate catalyst D1.

[0135] The supported titanium sulfate catalyst D1 has a specific surface area of ​​92 m².2 / g, and the pore volume was 0.4 ml / g.

[0136] The content of the illite mesoporous composite A was 40% by weight, and the content of the titanium sulfate was 60% by weight, based on the total weight of the supported titanium sulfate catalyst D1.

[0137] The catalytic performance of the catalyst D1 was tested according to the esterification reaction performance evaluation method of step (3) in Example 1. The conversion rate of methacrylic acid was 81.4%, and the selectivity of methyl methacrylate was 94.8%.

[0138] Comparative Example 2

[0139] The supported titanium sulfate catalyst D2 was prepared according to the same method as in Example 3, except that the preparation conditions of the catalyst in step (2) in Example 3 were changed, specifically:

[0140] In a round-bottom flask, 0.5 g of titanium sulfate, 15 g of isobutyl alcohol, and 5 g of water were mixed, heated to 60°C in a water bath, and stirred for 10 h to obtain a transparent aqueous solution. 9.5 g of the illite mesoporous composite C was added to the above transparent aqueous solution, and the temperature was maintained at 60°C, and the reaction was stirred for 8 h under reflux. After the reaction, the solvent was removed by a rotary evaporator, and the solid product was dried in air at 100°C for 8 h to obtain the supported titanium sulfate catalyst D2.

[0141] The content of the illite mesoporous composite C was 95% by weight, and the content of the titanium sulfate was 5% by weight, based on the total weight of the supported titanium sulfate catalyst D2.

[0142] The catalytic performance of the catalyst D2 was tested according to the esterification reaction performance evaluation method of step (3) in Example 1. The conversion rate of methacrylic acid was 72.8%, and the selectivity of methyl methacrylate was 95.4%.

[0143] Comparative Example 3

[0144] Step (1) in Example 1 was cancelled, and the illite mesoporous composite A in step (2) in Example 1 was replaced by a commercially available silica (purchased from Qingdao Hailang Silica Gel Dryer Factory, with a specific surface area of 329 m 2 / g, and the pore volume was 0.6 cm 3 / g), to obtain the catalyst D3.

[0145] The content of the commercially available silica was 75% by weight, and the content of the titanium sulfate was 25% by weight, based on the total weight of the catalyst D3.

[0146] The catalytic performance of the catalyst D3 was tested according to the esterification reaction performance evaluation method of step (3) in Example 1. The conversion rate of methacrylic acid was 89.4%, and the selectivity of methyl methacrylate was 95.2%.

[0147] Comparative Example 4

[0148] The step (1) and step (2) in Example 1 were cancelled, and the catalytic performance of the resin catalyst was tested according to the esterification reaction performance evaluation method of step (3) in Example 1. The resin catalyst was purchased from Kerry Environmental Science and Technology Co., Ltd., and the model number was D009.

[0149] The conversion rate of methacrylic acid was 87.6%, and the selectivity of methyl methacrylate was 97.2%.

[0150] Comparative Example 5

[0151] The catalyst D5 was prepared according to the same method as in Example 1, except that in step (2), instead of loading titanium sulfate, sodium sulfate was loaded. The content of the illite mesoporous composite A was 75% by weight, and the content of sodium sulfate was 25% by weight, based on the total weight of the catalyst D5.

[0152] The catalytic performance of the catalyst D5 was tested according to the esterification reaction performance evaluation method of step (3) in Example 1. The conversion rate of methacrylic acid was 60.7%, and the selectivity of methyl methacrylate was 81.5%.

[0153] Comparative Example 6

[0154] The catalyst D6 was prepared according to the same method as in Example 1, except that the preparation of the illite mesoporous composite in step (1) was cancelled, and in step (2), “7.4g of illite mesoporous composite A” was replaced with “7.4g of all-silica silicalite-1 zeolite molecular sieve, and the specific surface area of the replaced carrier all-silica silicalite-1 zeolite molecular sieve was 384m 2 / g, the pore volume was 0.29ml / g, and the most probable pore diameter was 0.55nm”.

[0155] The catalytic performance of the catalyst D6 was tested according to the esterification reaction performance evaluation method of step (3) in Example 1. The conversion rate of methacrylic acid was 80.6%, and the selectivity of methyl methacrylate was 94.3%.

[0156] From the above results, it can be seen that the supported titanium sulfate catalyst provided by the present application can directly convert methacrylic acid and methanol to methyl methacrylate, and obtain a higher conversion rate of methacrylic acid and selectivity of methyl methacrylate.

[0157] In the comparative example 1, the content of the illite mesoporous composite material in the supported titanium sulfate catalyst is too low, and the content of the titanium sulfate is too high. Due to the uneven dispersion of the active component titanium sulfate on the carrier and the low utilization efficiency of the active sites in the reaction process, the conversion rate of methacrylic acid is low, and the selectivity of methyl methacrylate is low.

[0158] In the comparative example 2, the content of the illite mesoporous composite material in the supported titanium sulfate catalyst is too high, and the content of the active component titanium sulfate on the catalyst is too low. Due to the insufficient active sites in the reaction process, the conversion rate of methacrylic acid is low, and the selectivity of methyl methacrylate is low.

[0159] In the comparative example 3, the illite mesoporous composite material specified in the present application is not used, but a commercially available silica is used. Due to the irregular pore structure of the commercially available silica and the uneven dispersion of the active component on the surface of the carrier, the conversion rate of methacrylic acid is low, and the selectivity of methyl methacrylate is low.

[0160] In the comparative example 4, the supported titanium sulfate catalyst provided by the present application is not used, but a commercially available resin material is used for the synthesis reaction of methyl methacrylate. The conversion rate of methacrylic acid and the selectivity of methyl methacrylate of the resin catalyst are lower than those of the supported titanium sulfate catalyst provided by the present application.

[0161] In the comparative example 5, the active component in the supported esterification catalyst is not titanium sulfate but sodium sulfate. Due to the poor esterification catalytic performance of sodium sulfate, the conversion rate of methacrylic acid is low, and the selectivity of methyl methacrylate is low.

[0162] In the comparative example 6, the supported esterification catalyst has a full-silicon silicalite-1 zeolite molecular sieve carrier, which is a microporous material with a most probable pore diameter of only 0.55 nm, which is not conducive to the loading and dispersion of the active component. The conversion rate of methacrylic acid is low, and the selectivity of methyl methacrylate is low.

[0163] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. Use of a supported titanium sulfate catalyst in a methyl methacrylate synthesis reaction, the use comprising: The methacrylic acid and methanol are simultaneously contacted with a supported titanium sulfate catalyst; characterized in that the supported titanium sulfate catalyst comprises an illite mesoporous composite material and titanium sulfate supported on the illite mesoporous composite material; wherein the illite mesoporous composite material has a bimodal pore distribution structure of one-dimensional and two-dimensional hexagonal channels, a first most probable pore diameter of 2-7 nm, a second most probable pore diameter of 20-40 nm, a specific surface area of 150-600 m 2 / g, a pore volume of 0.7-1.6 cm 3 / g; and based on the total weight of the supported titanium sulfate catalyst, the content of the illite mesoporous composite material is 70-80% by weight, and the content of the titanium sulfate is 20-30% by weight.

2. The use according to claim 1, wherein, The first most probable pore diameter of the illite mesoporous composite material is 2-5 nm, the second most probable pore diameter is 22-30 nm, the specific surface area is 250-450 m 2 / g, and the pore volume is 1.1-1.6 cm 3 / g.

3. Use according to claim 2, wherein, The first most probable pore diameter of the illite mesoporous composite material is 3-4 nm, the second most probable pore diameter is 24-26 nm, the specific surface area is 301-349 m 2 / g, and the pore volume is 1.4-1.6 cm 3 / g.

4. The use according to claim 1, wherein, The specific surface area of the supported titanium sulfate catalyst is 100-500 m 2 / g, and the pore volume is 0.5-1.5 cm 3 / g.

5. Use according to claim 4, wherein, The specific surface area of the supported titanium sulfate catalyst is 150-350 m 2 / g, and the pore volume is 0.7-1.4 cm 3 / g.

6. Use according to claim 5, wherein, The specific surface area of the supported titanium sulfate catalyst is 207-285 m 2 / g, and the pore volume is 0.9-1.3 cm 3 / g.

7. The use according to any one of claims 1 to 6, wherein The preparation method of the supported titanium sulfate catalyst comprises the following steps: The titanium sulfate, the alcohol aqueous solution and the illite mesoporous composite material are subjected to a contact reaction, and then the solid product after removing the solvent is subjected to a drying treatment to obtain the supported titanium sulfate catalyst.

8. Use according to claim 7, wherein, The alcohol aqueous solution is a methanol-water mixed solution, an ethanol-water mixed solution or an isobutyl alcohol-water mixed solution.

9. Use according to claim 8, wherein, The weight ratio of methanol to water in the alcohol aqueous solution is 1: (0.1-10); Alternatively, the weight ratio of ethanol to water in the alcohol aqueous solution is 1: (0.1-10); Alternatively, the weight ratio of isobutyl alcohol to water in the alcohol aqueous solution is 1: (0.1-10).

10. Use according to claim 9, wherein, The weight ratio of methanol to water in the alcohol aqueous solution is 1: (0.2-5); Alternatively, the weight ratio of ethanol to water in the alcohol aqueous solution is 1: (0.2-5); Alternatively, the weight ratio of isobutyl alcohol to water in the alcohol aqueous solution is 1: (0.2-5).

11. Use according to claim 7, wherein, The weight ratio of the titanium sulfate, the alcohol aqueous solution and the illite mesoporous composite material is 1: (3-100): (1.5-9).

12. Use according to claim 11, wherein, The weight ratio of the titanium sulfate, the alcohol aqueous solution and the illite mesoporous composite material is 1: (5-20): (1.8-6).

13. The use according to claim 7, wherein, The contact reaction conditions comprise that the temperature is 50-90 ℃ and the time is 0.5-12 h.

14. The use according to claim 1, wherein, The conditions of the contact include: the temperature of the contact is 40-150℃, the pressure of the contact is 0.01-5MPa, the mass space velocity of the methacrylic acid is 0.01-30h -1 , the mass space velocity of the methanol is 0.01-50h -1 .

15. Use according to claim 14, wherein, The conditions of the contact include: the temperature of the contact is 60-120℃, the pressure of the contact is 0.1-3Mpa, the mass space velocity of the methacrylic acid is 0.1-10h -1 , the mass space velocity of the methanol is 0.1-30h -1 .

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