Hydrophobic SO4 < 2-> / MxOy solid acid catalyst as well as preparation method and application thereof

Abstract

The invention discloses a hydrophobic SO4 < 2-> / MxOy solid acid catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalysts for synthesizing methyl p-tert-butylbenzoate. According to the preparation method disclosed by the invention, the mesoporous oxide carrier is prepared by taking the mesoporous carbon material as the hard template agent, then the mesoporous oxide carrier is impregnated with the sulfate radical, and finally the hydrophobic SO4 < 2-> / MxOy solid acid is obtained by modifying with the organic amine, the hydrophobic modification is performed on the surface of the solid acid by adopting the organic amine, so that the damage of water to an acid active center in an esterification reaction is prevented; the mesoporous structure improves the specific surface area of the oxide carrier, so that not only can more sulfate radicals be loaded, but also the mass transfer efficiency of the catalyst is improved, and the reaction activity of the catalyst in a reaction for synthesizing methyl p-tert-butylbenzoate is enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of methyl p-tert-butylbenzoate synthesis catalysts, and specifically relates to a hydrophobic SO4 2- / M x O y Solid acid catalyst and its preparation method and application. Background Art

[0002] Methyl p-tert-butylbenzoate is an important pharmaceutical chemical intermediate and organic synthesis intermediate. It is mainly used to synthesize avobenzone, a new sunscreen agent. It is widely used in many industries such as medicine, cosmetics, flavors and fragrances, and chemical synthesis. The traditional production process of methyl p-tert-butylbenzoate is to obtain the target product through an esterification reaction of p-tert-butylbenzoic acid and methanol under the catalysis of concentrated sulfuric acid. In this process, the addition of sulfuric acid is excessive, and black waste sulfuric acid with a concentration of 50%-70% will be produced. Although the waste acid can be reused after treatment through extraction, decolorization, concentration and other steps, the purification process is complicated, the recovery efficiency is not high, and the environmental pollution is relatively large. At the same time, organic matter is prone to dehydration and carbonization, the post-reaction treatment is cumbersome, and the catalyst and product are difficult to separate. In addition, sulfuric acid will cause serious corrosion to the equipment, posing a great safety risk.

[0003] With the deepening of green chemistry concepts and the increasingly stringent national environmental protection supervision, the use of SO 4 2- / M x O y The use of solid acid to replace traditional sulfuric acid catalysts, maximize resource utilization, simplify process flow, and avoid equipment corrosion and environmental pollution has become a hot topic of research. 4 2- / M x O y The metal oxide carrier of the solid acid type has a small specific surface area, and the loaded sulfate ion is relatively small, resulting in low reaction efficiency. At the same time, the esterification reaction will produce water, and the metal oxide surface is hydrophilic, which will cause the sulfate ion to be lost during the reaction and have poor stability. Therefore, it is necessary to increase the specific surface area of ​​the metal oxide carrier while modifying its surface to make it hydrophobic in order to improve the catalytic activity and stability of the solid acid catalyst. Summary of the invention

[0004] The object of the present invention is to provide a hydrophobic SO4 2- / M x O y Solid acid catalyst and its preparation method and application to solve the traditional SO 4 2- / M x O y The solid acid catalyst has poor stability and low reaction efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The invention discloses a hydrophobic SO 4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Mesoporous oxide supports were prepared using mesoporous carbon materials as hard templates; The mesoporous oxide support was then impregnated with sulfate and subsequently modified with organic amines to obtain hydrophobic SO 4 2- / M x O y Solid acid catalyst.

[0006] Furthermore, the specific steps of preparing the mesoporous oxide support using the mesoporous carbon material as a hard template are: The inorganic salt or organic compound solution corresponding to the metal oxide is adsorbed on the surface of the mesoporous carbon material by an impregnation method, and then calcined to obtain a mesoporous oxide carrier; The mesoporous oxide support is Al 2 O 3 , Fe 2 O 3 、TiO 2 、CeO 2 、ZrO 2 , WO 3 and CuO 2 One or more of; The mesoporous carbon material is one or more of CMK-3, CMK-5 and FDU-15.

[0007] Furthermore, the calcination treatment is carried out at a temperature of 400-700°C and for a time of 1-6 hours.

[0008] Furthermore, the mass ratio of the inorganic salt or organic compound corresponding to the metal oxide to the mesoporous carbon material is (0.1~10):1.

[0009] Furthermore, the specific steps of impregnating the mesoporous oxide support with sulfate are: impregnating the mesoporous oxide support in a sulfuric acid solution; The concentration of the sulfuric acid solution is 0.1-5 mol / L.

[0010] Furthermore, the organic amine modification is to place the mesoporous oxide carrier impregnated with sulfate into an organic amine solution; The organic amine solution is obtained by mixing an organic amine and a solvent; the concentration of the organic amine solution is 0.1 mol / L to 10 mol / L; the mass ratio of the organic amine to the mesoporous oxide support impregnated with sulfate is (0.1 to 1): 1; The organic amine is C 6 -C 10 A type of fatty amine.

[0011] The present invention also discloses a hydrophobic SO prepared by the above preparation method. 4 2- / M x O y Solid acid catalyst.

[0012] The present invention also discloses the hydrophobic SO 4 2- / M x O y The application of a solid acid catalyst in the reaction of synthesizing methyl p-tert-butylbenzoate comprises the following steps: tert-butylbenzoic acid, methanol and hydrophobic SO 4 2- / M x O y After the solid acid catalyst is mixed, an esterification reaction is carried out to generate methyl p-tert-butylbenzoate.

[0013] Furthermore, the mass ratio of methanol to p-tert-butylbenzoic acid is 0.5-5; The hydrophobic SO 4 2- / M x O y The dosage of the solid acid catalyst is 0.1wt.%~10wt.% of p-tert-butylbenzoic acid.

[0014] Furthermore, the esterification reaction temperature is 50°C to 200°C, and the reaction time is 1 to 10 hours.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a hydrophobic SO4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: using a mesoporous carbon material as a hard template to prepare a mesoporous oxide carrier, then impregnating sulfate ions, and finally modifying the carrier with an organic amine to obtain a hydrophobic SO 4 2- / M x O ySolid acid, the method uses organic amine to modify the hydrophobicity of the solid acid surface, thereby preventing water from destroying the acid active center in the esterification reaction and improving the catalyst stability. In addition, since the mesoporous structure increases the specific surface area of ​​the oxide carrier, it can not only load more sulfate, but also improve the mass transfer efficiency of the catalyst, thereby enhancing the reaction activity of the catalyst in the synthesis of methyl p-tert-butylbenzoate.

[0016] Furthermore, the preparation method of the present invention is simple to prepare, has excellent catalytic performance, is easy to separate from the product, can be recycled, improves resource utilization, reduces the generation of three wastes in the production process, and improves the safety of the reaction process. It is a green and environmentally friendly process route. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0018] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0019] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0020] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0021] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0022] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0023] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0024] Example 1 A hydrophobic SO 4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Weigh 5 g of CMK-3 into a beaker and add 50 mL of 0.1 mol / L Ce(NO 3 ) 2 The ethanol solution was ultrasonicated for 30 min and stirred at room temperature for 12 h. The temperature was then raised to 60 °C to remove the ethanol. The obtained solid was placed in a muffle furnace and calcined at 600 °C for 3 h to obtain mesoporous CeO 2 Support (denoted as meso-CeO 2 ); Weigh 2 g of the prepared meso-CeO 2 The support was immersed in 10 mL of 0.5 mol / L sulfuric acid solution for 12 h, filtered, washed, and then dried at 120 °C for 12 h and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 2 ; 1g SO 4 2- / meso-CeO 2 Dispersed in 50 mL of ethanol, 0.2 g of n-hexylamine was added, ultrasonicated for 30 min, refluxed at 60 ° C for 3 h, filtered, washed, and dried at 120 ° C for 12 h to obtain a hydrophobic solid acid catalyst HA-SO 4 2- / meso-CeO 2 (Hydrophobic SO 4 2- / M x Oy solid acid catalyst).

[0025] Example 2 A hydrophobic SO 4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Weigh 5 g of CMK-3 into a beaker and add 50 mL of 0.1 mol / L Ce(NO 3 ) 2 The ethanol solution was ultrasonicated for 30 min and stirred at room temperature for 12 h, then heated to 60 °C to remove the ethanol. The obtained solid was placed in a muffle furnace and calcined at 600 °C for 3 h to obtain mesoporous CeO 2 Support (denoted as meso-CeO 2 ); Weigh 2 g of the prepared meso-CeO 2 The support was immersed in 10 mL 1 mol / L sulfuric acid solution for 12 h, filtered, washed, dried at 120 °C for 12 h, and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 2 ; 1g SO 4 2- / meso-CeO 2 Dispersed in 50 mL of ethanol, 0.2 g of n-hexylamine was added, ultrasonicated for 30 min, refluxed at 60 ° C for 3 h, filtered, washed, and dried at 120 ° C for 12 h to obtain a hydrophobic solid acid catalyst HA-SO 4 2- / meso-CeO 2 .

[0026] Example 3 A hydrophobic SO 4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Weigh 5 g of CMK-3 into a beaker and add 50 mL of 0.1 mol / L Ce(NO 3 ) 2 and 0.1mol / LCu(NO 3 ) 2 The ethanol solution was ultrasonicated for 30 min and stirred at room temperature for 12 h. The temperature was then raised to 60 °C to remove the ethanol. The obtained solid was placed in a muffle furnace and calcined at 600 °C for 3 h to obtain mesoporous CeO 2 Support (denoted as meso-CeO 2-CuO 2 ); Weigh 2 g of the prepared meso-CeO 2 -CuO 2 The support was immersed in 10 mL of 0.5 mol / L sulfuric acid solution for 12 h, filtered, washed, dried at 120 °C for 12 h, and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 2 -CuO 2 ; 1g SO 4 2- / meso-CeO 2 -CuO 2 Dispersed in 50 mL of ethanol, 0.2 g of n-hexylamine was added, ultrasonicated for 30 min, refluxed at 60 ° C for 3 h, filtered, washed, and dried at 120 ° C for 12 h to obtain a hydrophobic solid acid catalyst HA-SO 4 2- / meso-CeO 2 -CuO 2 .

[0027] Example 4 A hydrophobic SO 4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Weigh 5 g of CMK-3 into a beaker and add 50 mL of 0.1 mol / L Ce(NO 3 ) 2 The ethanol solution was ultrasonicated for 30 min and stirred at room temperature for 12 h. The temperature was then raised to 60 °C to remove the ethanol. The obtained solid was placed in a muffle furnace and calcined at 600 °C for 3 h to obtain mesoporous CeO 2 Support (denoted as meso-CeO 2 ); Weigh 2 g of the prepared meso-CeO 2 The support was immersed in 10 mL of 0.5 mol / L sulfuric acid solution for 12 h, filtered, washed, dried at 120 °C for 12 h, and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 2 ; 1g SO 4 2- / meso-CeO 2Dispersed in 50 mL of ethanol, 0.2 g of n-octylamine was added, ultrasonicated for 30 min, refluxed at 80 ° C for 3 h, filtered, washed, and dried at 120 ° C for 12 h to obtain a hydrophobic solid acid catalyst OA-SO 4 2- / meso-CeO 2 .

[0028] Example 5 A hydrophobic SO4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Weigh 5 g of CMK-3 into a beaker and add 50 mL of 0.1 mol / L Ce(NO 3 ) 2 The ethanol solution was ultrasonicated for 30 min and stirred at room temperature for 12 h. The temperature was then raised to 60 °C to remove the ethanol. The obtained solid was placed in a muffle furnace and calcined at 500 °C for 5 h to obtain mesoporous CeO 2 Support (denoted as meso-CeO 2 ); Weigh 2 g of the prepared meso-CeO 2 The support was immersed in 10 mL of 0.5 mol / L sulfuric acid solution for 12 h, filtered, washed, and then dried at 120 °C for 12 h and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 2 ; 1g SO 4 2- / meso-CeO 2 Dispersed in 50 mL of ethanol, 0.2 g of n-hexylamine was added, ultrasonicated for 30 min, refluxed at 60 ° C for 3 h, filtered, washed, and dried at 120 ° C for 12 h to obtain a hydrophobic solid acid catalyst HA-SO 4 2- / meso-CeO 2 .

[0029] Example 6 A hydrophobic SO4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Weigh 5 g of CMK-3 into a beaker and add 50 mL of 0.1 mol / L Ce(NO 3 ) 2The ethanol solution was ultrasonicated for 30 min and stirred at room temperature for 12 h. The temperature was then raised to 60 °C to remove the ethanol. The obtained solid was placed in a muffle furnace and calcined at 600 °C for 3 h to obtain mesoporous CeO 2 Support (denoted as meso-CeO 2 ); Weigh 2 g of the prepared meso-CeO 2 The support was immersed in 10 mL of 0.5 mol / L sulfuric acid solution for 12 h, filtered, washed, and then dried at 120 °C for 12 h and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 2 ; 1g SO 4 2- / meso-CeO 2 Dispersed in 50 mL of ethanol, 0.5 g of n-hexylamine was added, ultrasonicated for 30 min, refluxed at 60 ° C for 3 h, filtered, washed, and dried at 120 ° C for 12 h to obtain a hydrophobic solid acid catalyst HA-SO 4 2- / meso-CeO 2 .

[0030] Example 7 A hydrophobic SO4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Weigh 5g FDU-15 into a beaker and add 50mL 0.1mol / L Ce(NO 3 ) 2 The ethanol solution was ultrasonicated for 30 min and stirred at room temperature for 12 h. The temperature was then raised to 60 °C to remove the ethanol. The obtained solid was placed in a muffle furnace and calcined at 600 °C for 3 h to obtain mesoporous CeO 2 Support (denoted as meso-CeO 2 ); Weigh 2 g of the prepared meso-CeO 2 The support was immersed in 10 mL of 0.5 mol / L sulfuric acid solution for 12 h, filtered, washed, and then dried at 120 °C for 12 h and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 2 ; 1g SO 4 2- / meso-CeO 2Dispersed in 50 mL of ethanol, 0.2 g of n-hexylamine was added, ultrasonicated for 30 min, refluxed at 60 ° C for 3 h, filtered, washed, and dried at 120 ° C for 12 h to obtain a hydrophobic solid acid catalyst HA-SO 4 2- / meso-CeO 2 .

[0031] Example 8 A hydrophobic SO4 2- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Weigh 5 g of CMK-3 into a beaker and add 50 mL of 0.1 mol / L Ce(NO 3 ) 2 and 0.1 mol / L Al(NO 3 ) 3 The ethanol solution was ultrasonicated for 30 min and stirred at room temperature for 12 h. The temperature was then raised to 60 °C to remove the ethanol. The obtained solid was placed in a muffle furnace and calcined at 600 °C for 3 h to obtain mesoporous CeO 2 -Al 2 O 3 Support (denoted as meso-CeO 2 -Al 2 O 3 ); Weigh 2 g of the prepared meso-CeO 2 -Al 2 O 3 The support was immersed in 10 mL of 0.5 mol / L sulfuric acid solution for 12 h, filtered, washed, and then dried at 120 °C for 12 h and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 2 -Al 2 O 3 ; 1g SO 4 2- / meso-CeO 2 Dispersed in 50 mL of ethanol, 0.2 g of n-hexylamine was added, ultrasonicated for 30 min, refluxed at 60 ° C for 3 h, filtered, washed, and dried at 120 ° C for 12 h to obtain a hydrophobic solid acid catalyst HA-SO 4 2- / meso-CeO 2 -Al 2 O 3 .

[0032] Example 9 A hydrophobic SO42- / M x O y The preparation method of the solid acid catalyst comprises the following steps: Weigh 5g FDU-15 into a beaker and add 50mL 0.1mol / L Ce(NO 3 ) 2 and 0.1 mol / L Al(NO 3 ) 3 The ethanol solution was ultrasonicated for 30 min and stirred at room temperature for 12 h. The temperature was then raised to 60 °C to remove the ethanol. The obtained solid was placed in a muffle furnace and calcined at 400 °C for 6 h to obtain mesoporous CeO 2 -Al 2 O 3 Carrier; Weigh 2 g of the prepared mesoporous CeO 2 -Al 2 O 3 The support was immersed in 10 mL of 5 mol / L sulfuric acid solution for 12 h, filtered, washed, and then dried at 120 °C for 12 h and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 2 -Al 2 O 3 ; 1g SO 4 2- / meso-CeO 2 Dispersed in 50 mL of ethanol, 0.2 g of n-hexylamine was added, ultrasonicated for 30 min, refluxed at 60 ° C for 3 h, filtered, washed, and dried at 120 ° C for 12 h to obtain a hydrophobic solid acid catalyst HA-SO 4 2- / meso-CeO 2 -Al 2 O 3 .

[0033] Application Example 1 The catalyst prepared in Example 1, p-tert-butylbenzoic acid and methanol were added into the reactor in a mass ratio of 0.1:1:3.0. 2 After purging to remove the air, the reaction was stirred at 80°C and 500 r / min for 5 hours. After the reaction was completed, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. The results of liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 61%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 56%.

[0034] Application Example 2 The catalyst, p-tert-butylbenzoic acid and methanol in Example 1 were added into the reactor in a mass ratio of 0.5:1:3.0. 2 After purging to remove the air, the mixture was stirred at 80°C and 500 r / min for 5 hours. After the reaction, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. Liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 81%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 68%.

[0035] Application Example 3 The catalyst, p-tert-butylbenzoic acid and methanol in Example 1 were added into the reactor in a mass ratio of 0.1:1:3.0. 2 After purging to remove the air, the reaction was stirred at 120°C and 500 r / min for 5 hours. After the reaction was completed, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. The results of liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 86%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 72%.

[0036] Application Example 4 The catalyst, p-tert-butylbenzoic acid and methanol in Example 1 were added into the reactor in a mass ratio of 0.1:1:5.0. 2 After purging to remove the air, the reaction was stirred at 120°C and 500 r / min for 5 hours. After the reaction was completed, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. The results of liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 92%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 84%.

[0037] Application Example 5 The catalyst, p-tert-butylbenzoic acid and methanol in Example 1 were added into the reactor in a mass ratio of 0.1:1:3.0. 2 After purging to remove the air, the reaction was stirred at 80°C and 500 r / min for 8 hours. After the reaction was completed, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. The results of liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 64%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 58%.

[0038] Application Example 6 The catalyst prepared in Example 2, p-tert-butylbenzoic acid and methanol were added into the reactor in a mass ratio of 0.1:1:3.0. 2After purging to remove the air, the reaction was stirred at 80°C and 500 r / min for 5 hours. After the reaction was completed, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. The results of liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 78%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 69%.

[0039] Application Example 7 The catalyst prepared in Example 3, p-tert-butylbenzoic acid and methanol were added into the reactor in a mass ratio of 0.1:1:3.0. 2 After purging to remove the air, the reaction was stirred at 80°C and 500 r / min for 5 hours. After the reaction was completed, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. The results of liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 88%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 81%.

[0040] Application Example 8 The catalyst prepared in Example 4, p-tert-butylbenzoic acid and methanol were added into the reactor in a mass ratio of 0.1:1:3.0. 2 After purging to remove the air, the reaction was stirred at 80°C and 500 r / min for 5 hours. After the reaction was completed, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. The results of liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 84%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 76%.

[0041] Comparative Example 1 Compared with Example 1, the CeO prepared by precipitation method in this comparative example 2 As a carrier for the synthesis of HA-SO 4 2- / CeO 2 Catalyst for esterification reaction.

[0042] Weigh 3.26 g Ce(NO 3 ) 2 Dissolved in 100 mL of deionized water, slowly added 5 mol / L ammonia water under stirring, keeping the solution pH constant at 9, and aged for 5 h after the addition. The obtained precipitate was filtered, washed, dried at 120 ° C for 12 h, and calcined at 600 ° C for 3 h to obtain CeO 2 Carrier; weigh 2g of the prepared CeO 2 The support was immersed in 10 mL of 0.5 mol / L sulfuric acid solution for 12 h, filtered, washed, dried at 120 °C for 12 h, and calcined at 600 °C for 3 h to obtain SO 4 2- / meso-CeO 21 g was dispersed in 50 mL of ethanol, 0.2 g of n-octylamine was added, and the mixture was ultrasonicated for 30 min and refluxed at 80 °C for 3 h, filtered, washed, and dried at 120 °C for 12 h to obtain a hydrophobic solid acid catalyst OA-SO 4 2- / CeO 2 .

[0043] The catalyst prepared in this comparative example, p-tert-butylbenzoic acid and methanol were added into the reactor in a mass ratio of 0.1:1:3.0. 2 After purging to remove the air, the reaction was stirred at 80°C and 500 r / min for 5 hours. After the reaction was completed, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. The results of liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 46%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 38%.

[0044] Comparative Example 2 Compared with Example 1, this comparative example uses SO 4 2- / meso-CeO 2 As a catalyst, esterification reaction is carried out.

[0045] Will SO 4 2- / meso-CeO 2 , p-tert-butylbenzoic acid and methanol were added into the reactor in a mass ratio of 0.1:1:3.0, and N 2 After purging to remove the air, the reaction was stirred at 80°C and 500 r / min for 5 hours. After the reaction was completed, the catalyst was filtered out and distilled to obtain methyl p-tert-butylbenzoate. The results of liquid chromatography analysis showed that the conversion rate of p-tert-butylbenzoic acid was 51%, the selectivity of methyl p-tert-butylbenzoate was 99%, and the product yield was 43%.

[0046] In the present invention, hydrophobic SO 4 2- / M x O y The solid acid as a catalyst has high catalytic activity and catalyst stability and can be reused, which simplifies the production process of methyl tert-butylbenzoate and greatly reduces the generation of three wastes. It is an environmentally friendly green process route.

[0047] Compared with the catalyst prepared by the precipitation method, the catalyst obtained by the present invention has a higher specific surface area, can carry more acid centers, and has a higher catalytic activity; compared with the catalyst that has not been hydrophobically modified, the organic amine is conducive to the water generated in the esterification reaction to leave the catalyst surface faster, thereby greatly improving the activity and stability of the catalyst.

[0048] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A hydrophobic SO4 2- / M x O y The method for preparing a solid acid catalyst is characterized in that: The following steps are involved: Mesoporous oxide supports were prepared using mesoporous carbon materials as hard templates; The mesoporous oxide support is then impregnated with sulfate and subsequently modified with organic amines to obtain hydrophobic SO4 2- / M x O y Solid acid catalyst.

2. A hydrophobic SO4 according to claim 1 2- / M x O y The method for preparing a solid acid catalyst is characterized in that: The specific steps of preparing the mesoporous oxide support using the mesoporous carbon material as a hard template are: The inorganic salt or organic compound solution corresponding to the metal oxide is adsorbed on the surface of the mesoporous carbon material by an impregnation method, and then calcined to obtain a mesoporous oxide carrier; The mesoporous oxide carrier is one or more of Al2O3, Fe2O3, TiO2, CeO2, ZrO2, WO3 and CuO2; The mesoporous carbon material is one or more of CMK-3, CMK-5 and FDU-15.

3. A hydrophobic SO4 according to claim 2 2- / M x O y The method for preparing a solid acid catalyst is characterized in that: The calcination temperature is 400-700°C and the calcination time is 1-6 hours.

4. A hydrophobic SO4 according to claim 2 2- / M x O y The method for preparing a solid acid catalyst is characterized in that: The mass ratio of the inorganic salt or organic compound corresponding to the metal oxide to the mesoporous carbon material is (0.1~10):

1.

5. A hydrophobic SO4 according to claim 1 2- / M x O y The method for preparing a solid acid catalyst is characterized in that: The specific steps of impregnating the mesoporous oxide support with sulfate are: immersing the mesoporous oxide support in a sulfuric acid solution; The concentration of the sulfuric acid solution is 0.1-5 mol / L.

6. A hydrophobic SO4 according to claim 1 2- / M x O y The method for preparing a solid acid catalyst is characterized in that: The organic amine modification is to place the mesoporous oxide carrier impregnated with sulfate into an organic amine solution; The organic amine solution is obtained by mixing an organic amine and a solvent; the concentration of the organic amine solution is 0.1 mol / L to 10 mol / L; the mass ratio of the organic amine to the mesoporous oxide support impregnated with sulfate is (0.1 to 1): 1; The organic amine is C6-C 10 A type of fatty amine.

7. A hydrophobic SO4 2- / M x O y A solid acid catalyst, characterized in that The method is prepared by any one of claims 1 to 6.

8. The hydrophobic SO4 of claim 7 2- / M x O y The application of a solid acid catalyst in the synthesis of methyl p-tert-butylbenzoate is characterized in that: The following steps are involved: tert-butylbenzoic acid, methanol and hydrophobic SO4 2- / M x O y After the solid acid catalyst is mixed, an esterification reaction is carried out to generate methyl p-tert-butylbenzoate.

9. The hydrophobic SO4 according to claim 8 2- / M x O y The application of a solid acid catalyst in the synthesis of methyl p-tert-butylbenzoate is characterized in that: The mass ratio of methanol to p-tert-butylbenzoic acid is 0.5-5; The hydrophobic SO4 2- / M x O y The dosage of the solid acid catalyst is 0.1wt.%~10wt.% of p-tert-butylbenzoic acid.

10. The hydrophobic SO4 according to claim 8 2- / M x O y The application of a solid acid catalyst in the synthesis of methyl p-tert-butylbenzoate is characterized in that: The temperature of the esterification reaction is 50° C. to 200° C., and the reaction time is 1 to 10 hours.