Supported sulfonated polystyrene-divinylbenzene catalyst as well as preparation method and application thereof

Abstract

The invention relates to the technical field of catalysts, and provides a supported sulfonated polystyrene-divinylbenzene catalyst as well as a preparation method and application thereof. The preparation method of the catalyst comprises the following steps: carrying out hydrophobic modification on the surface of a carrier by adopting a silane coupling agent, then growing polystyrene-divinylbenzene on the modified carrier in situ, and carrying out sulfonation treatment to prepare the supported sulfonated polystyrene-divinylbenzene catalyst. The preparation method of the supported sulfonated polystyrene-divinylbenzene catalyst provided by the invention is simple, the utilization efficiency of resin can be improved, and the cost of the catalyst is reduced; the prepared catalyst is uniform in size, good in strength, not easy to crush, small in resistance and good in stability during liquid-phase flow catalytic continuous reaction, has good catalytic activity and high isosorbide yield when being used for catalyzing dehydration of sorbitol to prepare isosorbide, and can be recycled for multiple times.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and more specifically to a supported sulfonated polystyrene-divinylbenzene catalyst, a preparation method and application thereof. Background Art

[0002] As an important biomass raw material, isosorbide is widely used in medicine, liquid crystal materials, plasticizers, polymers and other fields. The industrial production process of isosorbide is to prepare glucose through starch and cellulose fermentation, prepare sorbitol through glucose hydrogenation, and prepare isosorbide through sorbitol catalytic dehydration, among which the dehydration of sorbitol to prepare isosorbide is the key step. Sorbitol can be dehydrated in the next step under acid catalysis to obtain 1,4-anhydrosorbitol and a small amount of 3,6-anhydrosorbitol, and further dehydrated to obtain isosorbide. At present, the research on sorbitol dehydration reaction mainly focuses on the development of high-efficiency solid acid catalysts, including metal salt solid acids, oxide solid acids, heteropoly acids (salts), polymer acid catalysts, ion exchange resins, zeolite molecular sieves, etc.

[0003] In the sorbitol dehydration reaction, strongly acidic cation exchange resin, such as sulfonated polystyrene-divinylbenzene resin, has relatively good sorbitol catalytic dehydration to prepare isosorbide performance.For example, CN110483678A discloses a catalyst and its preparation method and application for preparing isosorbide by sorbitol dehydration, and its catalyst is a super hydrophobic polymer-based solid acid catalyst, and the raw material composition of the catalyst is divinylbenzene, sodium p-styrene sulfonate, azobisisobutyronitrile, tetrahydrofuran.The super hydrophobic polymer solid acid catalyst of the present invention can achieve higher sorbitol conversion rate and isosorbide yield under the condition of being gentler and not adding any solvent.But the catalyst is powdery, and in the reaction process, resistance is large, and it is difficult to separate and recycle.CN109261202A discloses a catalyst for preparing isosorbide by sorbitol dehydration, and the catalyst is a polymer solid acid catalyst, which is divinylbenzene and sodium p-styrene sulfonate mixture, wherein the molar ratio of sodium p-styrene sulfonate and divinylbenzene is 0.085-10:1. The catalyst has the advantages of being mild, efficient, stable and regenerable, but it is also a powdered catalyst.

[0004] Strong acid cation exchange resin catalyst has high acid content and stable network structure, and has good catalytic effect on sorbitol dehydration. However, the existing resin catalyst generally uses suspension polymerization to prepare microspheres, and the microspheres are uneven and small in size. During the continuous flow reaction, the resistance is large, and the strength of the resin beads is poor and easy to be crushed. Therefore, it is necessary to develop a novel resin catalyst preparation method that can improve the utilization efficiency of the resin and reduce the catalyst cost. Summary of the invention

[0005] The object of the present invention is to provide a supported sulfonated polystyrene-divinylbenzene catalyst and a preparation method thereof, so as to solve the technical problems of uneven size and poor strength of strongly acidic cation exchange resin catalysts in the prior art.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a method for preparing a supported sulfonated polystyrene-divinylbenzene catalyst, comprising: hydrophobicizing the surface of a carrier using a silane coupling agent, then in-situ growing polystyrene-divinylbenzene on the modified carrier, and then sulfonating the carrier to obtain the supported sulfonated polystyrene-divinylbenzene catalyst.

[0008] It should be noted that the in-situ growth described in the present invention means that styrene first reacts chemically with the silanization agent on the surface of the carrier, is bonded to the carrier surface, and then undergoes surface polymerization. For example, when vinyltrimethoxysilane is used as a coupling agent, styrene first polymerizes with the double bonds in vinyltrimethoxysilane, and then further polymerizes and grows. This method is completely different from the common loading method that does not form surface chemical bonds.

[0009] Divinylbenzene (also called divinylbenzene) acts as a crosslinking agent in polystyrene-divinylbenzene polymers. It can generate a three-dimensional resin by copolymerization with polystyrene. Compared with linear resins, it has better thermal stability and a certain degree of improvement in mechanical strength. In addition, the three-dimensional resin can produce more pore structures, which is beneficial to the improvement of catalytic performance.

[0010] In the present invention, a silane coupling agent is used to hydrophobize the surface of the carrier. On the one hand, the hydrophilic surface of the carrier can be hydrophobized, the growth amount of polystyrene on the surface of the carrier can be increased, and the selectivity of the catalyst can be improved. If the surface of the carrier is not hydrophobized, polystyrene is difficult to grow on its surface and is more likely to polymerize in the solution. On the other hand, the hydrophobicity of the catalyst surface is increased, which is conducive to the desorption of water generated after the reaction from the surface and the stability of the catalyst is increased.

[0011] According to some embodiments of the present invention, the carrier is an inorganic carrier, preferably at least one selected from SiO2, Al2O3, TiO2, and molecular sieves.

[0012] In the present invention, various common types of molecular sieves can be used as carriers, such as H-Beta molecular sieve, ZSM-5 molecular sieve, and the like.

[0013] According to some embodiments of the present invention, the carrier is a spherical carrier.

[0014] According to some embodiments of the present invention, the particle size of the carrier is 1 to 5 mm.

[0015] According to some embodiments of the present invention, the silane coupling agent includes at least one of trimethoxypropylsilane (PTMS), trimethoxy-n-octylsilane (OTMS), and trimethoxyhexadecylsilane (HTMS).

[0016] According to some embodiments of the present invention, the hydrophobic modification comprises: dispersing the carrier in a first solvent, adding the silane coupling agent at 40 to 80° C., and stirring to react to obtain the modified carrier;

[0017] According to some embodiments of the present invention, the first solvent includes a mixed solvent of aqueous ammonia, anhydrous ethanol and water.

[0018] According to some embodiments of the present invention, the concentration of the aqueous ammonia is 10 to 25 wt %.

[0019] According to some embodiments of the present invention, the mass ratio of the aqueous ammonia, anhydrous ethanol and water is 1:(1-5):(1-5).

[0020] According to some embodiments of the present invention, the stirring reaction comprises stirring at a rotation speed of 100 to 1000 r / min for 24 to 72 hours.

[0021] According to some embodiments of the present invention, the mass ratio of the carrier to the silane coupling agent is 1:(0.025-1).

[0022] According to some embodiments of the present invention, the mass ratio of the carrier to the first solvent is 1:(1.5-8).

[0023] According to some embodiments of the present invention, the in situ growth of polystyrene-divinylbenzene on a modified support includes: adding a support, styrene, divinylbenzene, an initiator and a pore-forming agent into a second solvent, first stirring at 40 to 60° C. for 30 to 120 minutes, then heating to 70 to 80° C. and maintaining for 2 to 6 hours; then heating to 90 to 95° C. and reacting for 2 to 10 hours to obtain a modified support for in situ growth of polystyrene-divinylbenzene.

[0024] According to some embodiments of the present invention, a polymerization inhibitor is further added to the second solvent.

[0025] In the present invention, adding a polymerization inhibitor can effectively prevent styrene from polymerizing in an aqueous solution, thereby allowing more styrene to polymerize on the surface of the carrier.

[0026] According to some embodiments of the invention, the inhibitor comprises a methylene blue solution.

[0027] According to some embodiments of the invention, the second solvent comprises water.

[0028] According to some embodiments of the invention, the initiator comprises dibenzoyl peroxide (BPO).

[0029] According to some embodiments of the invention, the pore former comprises n-heptane and / or toluene.

[0030] In the present invention, the addition of pore-forming agent can make the polystyrene-divinylbenzene grown in situ on the carrier have a pore structure. The presence of the pore structure can significantly increase the surface area and the number of active sites of the catalyst, thereby increasing the rate of the catalytic reaction.

[0031] In the present invention, n-heptane and toluene are used together as pore-forming agents, and the pore-forming effect is better than that of n-heptane or toluene alone. The volume ratio of n-heptane to toluene is preferably within the range of 1: (0.8-1.2).

[0032] According to some embodiments of the present invention, the molar ratio of styrene to divinylbenzene is 10:(1-10), the mass ratio of the sum of the masses of styrene and divinylbenzene to the modified carrier is 1:(2-20), the mass ratio of the sum of the masses of styrene and divinylbenzene to n-heptane is 1:(1-5), and the mass ratio of the sum of the masses of styrene and divinylbenzene to dibenzoyl peroxide is 1:(0.05-0.20).

[0033] According to some embodiments of the present invention, the mass ratio of the sum of the masses of styrene and divinylbenzene to the mass of the second solvent is 1:(8-10).

[0034] According to some embodiments of the present invention, the sulfonation treatment comprises dispersing a modified carrier of in-situ grown polystyrene-divinylbenzene in a third solvent, adding a sulfonating reagent and stirring the reaction for 2 to 8 hours to obtain the supported sulfonated polystyrene-divinylbenzene catalyst.

[0035] According to some embodiments of the present invention, the third solvent includes at least one of ethylene dichloride, cyclohexane, n-heptane, and toluene.

[0036] According to some embodiments of the present invention, the sulfonation reagent includes at least one of chlorosulfonic acid, concentrated sulfuric acid, and sulfur trioxide.

[0037] According to some embodiments of the present invention, the mass ratio of the modified support for in-situ growth of polystyrene-divinylbenzene to the sulfonation reagent is (30-40): (1-10).

[0038] According to some embodiments of the present invention, the mass ratio of the modified support for in-situ growth of polystyrene-divinylbenzene to the third solvent is (30-40): (50-80).

[0039] In a second aspect, the present invention provides a supported sulfonated polystyrene-divinylbenzene catalyst prepared by the preparation method described in the first aspect.

[0040] In a third aspect, the present invention provides use of the supported sulfonated polystyrene-divinylbenzene catalyst described in the second aspect in catalyzing the dehydration of sorbitol to prepare isosorbide.

[0041] According to some embodiments of the present invention, the process conditions for preparing isosorbide by dehydration of sorbitol by the catalyst include: under normal pressure, the mass ratio of the catalyst to sorbitol is (0.01-0.2):1, under the condition of 30 mL / min N2 as protective gas and water vapor, the reaction temperature is 130-180°C, the stirring speed is 300-1500 r / min, and the reaction time is 1-4 h.

[0042] The beneficial effects of the present invention are at least:

[0043] The preparation method of the supported sulfonated polystyrene-divinylbenzene catalyst provided by the invention has simple steps, can improve the utilization efficiency of resin and reduce the catalyst cost; the prepared catalyst has uniform size, good strength and is not easy to be crushed; during the liquid phase flow catalytic continuous reaction, the resistance is small and the stability is good; the catalytic activity for catalyzing the dehydration of sorbitol to prepare isosorbide is good, the isosorbide yield is high and the catalyst can be recycled for multiple times. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a photograph of catalyst pellet A-4 prepared in Example 4.

[0045] Figure 2 This is a photograph of catalyst pellet D-2 prepared in Comparative Example 2. DETAILED DESCRIPTION

[0046] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this patent in detail and do not limit the scope of protection of the present invention in any way.

[0047] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the reagent amounts, unless otherwise specified, are the reagent amounts used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0048] Example 1

[0049] 80g of a mixed solvent of ammonia water (25wt%), anhydrous ethanol and double distilled water (mass ratio of 1:2:2) was added to a three-necked flask and stirred in a 40℃ constant temperature water bath for 10min. 10g of SiO2 round balls with a particle size of 1mm were weighed and slowly added to the three-necked flask and continued to stir for 5min. Then, 10g of trimethoxypropylsilane was added and continued to stir at 100r / min for 24h. After the reaction was completed, the solid balls obtained by filtration were washed with anhydrous ethanol and double distilled water and dried to obtain a modified carrier. Add the modified carrier to a three-necked flask, and then add styrene, divinylbenzene, n-heptane, distilled water, 3-5 drops of methylene blue solution, and dibenzoyl peroxide (BPO) initiator in proportion, wherein the mass ratio of (styrene + divinylbenzene) / modified carrier is 0.05:1, the molar ratio of styrene / divinylbenzene is 10:1, the mass ratio of n-heptane / (styrene + divinylbenzene) is 1:1, the mass ratio of distilled water / (styrene + divinylbenzene) is 8:1, and the mass ratio of dibenzoyl peroxide / (styrene + divinylbenzene) is 0.05:1. Stir in a 40°C constant temperature water bath for 30 minutes. Heat to 70°C under reflux conditions and keep for 2 hours, then heat to 90°C and react for 2 hours. After the reaction is completed, the solid pellets obtained by filtration are washed with anhydrous ethanol and double distilled water and dried to obtain a modified carrier of in-situ growth polystyrene-divinylbenzene. At room temperature, the modified support of in-situ grown polystyrene-divinylbenzene was added to a three-necked flask, the content of the modified support of in-situ grown polystyrene-divinylbenzene was 30%, the content of dichloroethane was 60%, and the content of chlorosulfonic acid was 10%, and the reaction was stirred for 4 hours. After the reaction was completed, the solid pellets obtained by filtration were washed with anhydrous ethanol and double distilled water until the filtrate was neutral, and then dried to obtain catalyst pellets A-1.

[0050] 50 g of sorbitol was weighed and added into a kettle reactor. After slowly heating up, 0.05 g of A-1 catalyst pellets were added after sorbitol was melted. 30 mL / min N2 was introduced as a protective gas and water vapor was removed. Under the conditions of 130°C and 300 r / min, the reaction was carried out for 1 h and then sampling and analysis were performed. The reaction results are shown in Table 1.

[0051] Example 2

[0052] 60g of a mixed solvent of ammonia water (25wt%), anhydrous ethanol and double distilled water (mass ratio of 1:2:2) was added to a three-necked flask and stirred in a 60℃ constant temperature water bath for 30min. 39g of SiO2 round balls with a particle size of 1mm were weighed and slowly added to the three-necked flask and continued to stir for 5min. Then, 1g of trimethoxypropylsilane was added and continued to stir at 500r / min for 48h. After the reaction was completed, the solid balls obtained by filtration were washed with anhydrous ethanol and double distilled water and dried to obtain a modified carrier. Add the modified carrier to a three-necked flask, and then add styrene, divinylbenzene, n-heptane, distilled water, 3-5 drops of methylene blue solution, and dibenzoyl peroxide (BPO) initiator in proportion, wherein the mass ratio of (styrene + divinylbenzene) / modified carrier is 0.1:1, the molar ratio of styrene / divinylbenzene is 2:1, the mass ratio of n-heptane / (styrene + divinylbenzene) is 3:1, the mass ratio of distilled water / (styrene + divinylbenzene) is 8:1, and the mass ratio of dibenzoyl peroxide / (styrene + divinylbenzene) is 0.1:1. Stir in a 60°C constant temperature water bath for 60 minutes. Heat to 70°C under reflux conditions and maintain for 4 hours, then heat to 90°C and react for 6 hours. After the reaction is completed, the solid pellets obtained by filtration are washed with anhydrous ethanol and double distilled water and dried to obtain a modified carrier of in-situ growth polystyrene-divinylbenzene. At room temperature, the modified support of in-situ grown polystyrene-divinylbenzene was added to a three-necked flask, the content of the modified support of in-situ grown polystyrene-divinylbenzene was 40%, the content of dichloroethane was 59%, and the content of chlorosulfonic acid was 1%, and the reaction was stirred for 4 hours. After the reaction was completed, the solid pellets obtained by filtration were washed with anhydrous ethanol and double distilled water until the filtrate was neutral, and then dried to obtain catalyst pellets A-2.

[0053] 50 g of sorbitol was weighed and added into a kettle reactor. After slowly heating up, 5 g of A-2 catalyst pellets were added after sorbitol was melted. 30 mL / min N2 was introduced as a protective gas and water vapor was removed. Under the conditions of 150°C and 1000 r / min, the reaction was carried out for 2 h and then sampling and analysis were performed. The reaction results are shown in Table 1.

[0054] Example 3

[0055] 70g of a mixed solvent of ammonia water (25wt%), anhydrous ethanol and double distilled water (mass ratio of 1:2:2) was added to a three-necked flask and stirred in a constant temperature water bath at 80℃ for 60min. 25g of SiO2 round balls with a particle size of 1mm were weighed and slowly added to the three-necked flask and continued to stir for 5min. Then, 5g of trimethoxyhexadecylsilane was added and continued to stir at 1000r / min for 72h. After the reaction was completed, the solid balls obtained by filtration were washed with anhydrous ethanol and double distilled water and dried to obtain a modified carrier. Add the modified carrier to a three-necked flask, and then add styrene, divinylbenzene, n-heptane, distilled water, 3-5 drops of methylene blue solution, and dibenzoyl peroxide (BPO) initiator in proportion, wherein the mass ratio of (styrene + divinylbenzene) / modified carrier is 0.5:1, the molar ratio of styrene / divinylbenzene is 1:1, the mass ratio of n-heptane / (styrene + divinylbenzene) is 5:1, the mass ratio of distilled water / (styrene + divinylbenzene) is 10:1, and the mass ratio of dibenzoyl peroxide / (styrene + divinylbenzene) is 0.2:1. Stir in a 60°C constant temperature water bath for 120 minutes. Heat to 70°C under reflux conditions and maintain for 6 hours, then heat to 90°C and react for 10 hours. After the reaction is completed, the solid pellets obtained by filtration are washed with anhydrous ethanol and double distilled water and dried to obtain a modified carrier of in-situ growth polystyrene-divinylbenzene. At room temperature, the modified support of in-situ grown polystyrene-divinylbenzene was added to a three-necked flask, the content of the modified support of in-situ grown polystyrene-divinylbenzene was 35%, the content of dichloroethane was 60%, and the content of chlorosulfonic acid was 5%, and the reaction was stirred for 4 hours. After the reaction was completed, the solid pellets obtained by filtration were washed with anhydrous ethanol and double distilled water until the filtrate was neutral, and then dried to obtain catalyst pellets A-3.

[0056] 50 g of sorbitol was weighed and added into a kettle reactor. After slowly heating, 10 g of A-3 catalyst pellets were added after sorbitol was melted. 30 mL / min N2 was introduced as a protective gas and water vapor was removed. Under the conditions of 180°C and 1500 r / min, the reaction was carried out for 4 h and then sampling and analysis were performed. The reaction results are shown in Table 1.

[0057] Example 4

[0058] 70g of a mixed solvent of ammonia water (25wt%), anhydrous ethanol and double distilled water (mass ratio of 1:2:2) was added to a three-necked flask and stirred in a 60℃ constant temperature water bath for 60min. 25g of Al2O3 round balls with a particle size of 3mm were weighed and slowly added to the three-necked flask and continued to stir for 5min. Then, 5g of trimethoxy-n-octylsilane was added and continued to stir at 500r / min for 72h. After the reaction was completed, the solid balls obtained by filtration were washed with anhydrous ethanol and double distilled water and dried to obtain a modified carrier. Add the modified carrier to a three-necked flask, and then add styrene, divinylbenzene, n-heptane, distilled water, 3-5 drops of methylene blue solution, and dibenzoyl peroxide (BPO) initiator in proportion, wherein the mass ratio of (styrene + divinylbenzene) / modified carrier is 0.1:1, the molar ratio of styrene / divinylbenzene is 2:1, the mass ratio of n-heptane / (styrene + divinylbenzene) is 3:1, the mass ratio of distilled water / (styrene + divinylbenzene) is 10:1, and the mass ratio of dibenzoyl peroxide / (styrene + divinylbenzene) is 0.1:1. Stir in a 60°C constant temperature water bath for 120 minutes. Heat to 70°C under reflux conditions and keep for 2 hours, then heat to 90°C and react for 2 hours. After the reaction is completed, the solid pellets obtained by filtration are washed with anhydrous ethanol and double distilled water and dried to obtain a modified carrier of in-situ growth polystyrene-divinylbenzene. At room temperature, the modified support of in-situ grown polystyrene-divinylbenzene was added to a three-necked flask, the content of the modified support of in-situ grown polystyrene-divinylbenzene was 35%, the content of dichloroethane was 60%, and the content of chlorosulfonic acid was 5%, and the reaction was stirred for 4 hours. After the reaction was completed, the solid pellets obtained by filtration were washed with anhydrous ethanol and double distilled water until the filtrate was neutral, and then dried to obtain catalyst pellets A-4. Figure 1 This is a photo of catalyst pellet A-4. Figure 1 It can be seen that the catalyst pellets A-4 are complete spherical particles with uniform size; they have good strength and are not easy to crush.

[0059] 50 g of sorbitol was weighed and added into a kettle reactor. After slowly heating up, 5 g of A-4 catalyst pellets were added after sorbitol was melted. 30 mL / min N2 was introduced as a protective gas and water vapor was removed. Under the conditions of 150°C and 1000 r / min, the reaction was carried out for 2 h and then sampling and analysis were performed. The reaction results are shown in Table 1.

[0060] Example 5

[0061] The preparation method of catalyst pellet A-5 refers to Example 4, except that 25 g of Al2O3 round pellets with a particle size of 3 mm are replaced by 25 g of SiO2 round pellets with a particle size of 3 mm.

[0062] The method for preparing isosorbide by catalytic dehydration of sorbitol using catalyst pellet A-5 is described in Example 4. The test results are shown in Table 1.

[0063] Example 6

[0064] The preparation method of catalyst pellet A-6 refers to Example 4, except that 25 g of Al2O3 round pellets with a particle size of 3 mm are replaced by 25 g of TiO2 round pellets with a particle size of 3 mm.

[0065] The method for using catalyst pellet A-6 to catalyze the dehydration of sorbitol to prepare isosorbide is referred to Example 4. The test results are shown in Table 1.

[0066] Example 7

[0067] The preparation method of catalyst pellet A-7 refers to Example 4, except that 25 g of Al2O3 round pellets with a particle size of 3 mm are replaced by 25 g of H-Beta round pellets with a particle size of 3 mm.

[0068] The method for using catalyst pellet A-7 to catalyze the dehydration of sorbitol to prepare isosorbide is referred to Example 4. The test results are shown in Table 1.

[0069] Example 8

[0070] The preparation method of catalyst pellet A-8 is similar to that of Example 4, except that n-heptane is replaced by a mixture of toluene and n-heptane of equal mass, wherein the mass ratio of toluene to n-heptane in the mixture is 1:1.

[0071] The method for preparing isosorbide by catalytic dehydration of sorbitol using catalyst pellet A-8 is described in Example 4. The test results are shown in Table 1.

[0072] Example 9

[0073] The preparation method of catalyst pellet A-9 is similar to that of Example 4, except that n-heptane is replaced with an equal mass of toluene.

[0074] The method for using catalyst pellet A-9 to catalyze the dehydration of sorbitol to prepare isosorbide is referred to Example 4. The test results are shown in Table 1.

[0075] Example 10

[0076] The preparation method of catalyst pellet A-10 is similar to that of Example 4, except that no methylene blue solution is added.

[0077] The method for using catalyst pellet A-10 to catalyze the dehydration of sorbitol to prepare isosorbide is referred to Example 4. The test results are shown in Table 1.

[0078] Comparative Example 1

[0079] Add Al2O3 spherical beads with a particle size of 3mm into a three-necked flask, and then add styrene, divinylbenzene, n-heptane, distilled water, 3-5 drops of methylene blue solution, and dibenzoyl peroxide (BPO) initiator in proportion, wherein the mass ratio of (styrene + divinylbenzene) / Al2O3 spherical beads is 0.1:1, the molar ratio of styrene / divinylbenzene is 2:1, the mass ratio of n-heptane / (styrene + divinylbenzene) is 3:1, the mass ratio of distilled water / (styrene + divinylbenzene) is 10:1, and the mass ratio of dibenzoyl peroxide / (styrene + divinylbenzene) is 0.1:1. Stir in a 60℃ constant temperature water bath for 120min. Heat to 70℃ under reflux conditions and keep for 2h, then heat to 90℃ and react for 2h. After the reaction is completed, the filtered solid beads are washed with anhydrous ethanol and double distilled water and dried to obtain Al2O3 spherical beads with surface growth resin. At room temperature, the Al2O3 spherical beads of the surface-grown resin were added into a three-necked flask, the content of the Al2O3 spherical beads of the surface-grown resin was 35%, the content of dichloroethane was 60%, and the content of chlorosulfonic acid was 5%, and the reaction was stirred for 4 hours. After the reaction was completed, the solid beads obtained by filtration were washed with anhydrous ethanol and double distilled water until the filtrate was neutral, and then dried to obtain catalyst beads D-1.

[0080] 50 g of sorbitol was weighed and added into a kettle reactor. After slowly heating up, 5 g of D-1 catalyst pellets were added after sorbitol was melted. 30 mL / min N2 was introduced as a protective gas and water vapor was removed. Under the conditions of 150°C and 1000 r / min, the reaction was carried out for 2 h and then sampling and analysis were performed. The reaction results are shown in Table 1.

[0081] Comparative Example 2

[0082] In a three-necked flask, add styrene, divinylbenzene, n-heptane, distilled water, 3-5 drops of methylene blue solution, and dibenzoyl peroxide (BPO) initiator in proportion, wherein the molar ratio of styrene / divinylbenzene is 2:1, the mass ratio of n-heptane / (styrene + divinylbenzene) is 3:1, the mass ratio of distilled water / (styrene + divinylbenzene) is 10:1, and the mass ratio of dibenzoyl peroxide / (styrene + divinylbenzene) is 0.1:1. Stir in a 60°C constant temperature water bath for 120 minutes. Raise the temperature to 70°C under reflux conditions and maintain for 2 hours, then raise the temperature to 90°C and react for 2 hours. After the reaction is completed, the solid pellets obtained by filtration are washed with anhydrous ethanol and double distilled water and dried to obtain polystyrene resin pellets.

[0083] At room temperature, polystyrene resin beads were added to a three-necked flask, the content of polystyrene resin beads was 15%, the content of dichloroethane was 70%, and the content of chlorosulfonic acid was 15%, and the reaction was stirred for 4 hours. After the reaction was completed, the solid beads obtained by filtration were washed with anhydrous ethanol and double distilled water until the filtrate was neutral, and then dried to obtain unsupported sulfonated polystyrene resin catalyst beads D-2. Figure 2 This is a photo of catalyst pellet D-2. Figure 2 It can be seen that the catalyst pellets D-2 have uneven particle sizes and various shapes, and have poor strength and are easily crushed.

[0084] 50 g of sorbitol was weighed and added into a kettle reactor. After slowly heating up, 5 g of D-2 catalyst pellets were added after sorbitol was melted. 30 mL / min N2 was introduced as a protective gas and water vapor was removed. Under the conditions of 150°C and 1000 r / min, the reaction was carried out for 2 h and then sampling and analysis were performed. The reaction results are shown in Table 1.

[0085] Table 1 Reaction results of different catalysts to generate isosorbide

[0086]

[0087] Evaluation of catalyst recycling results

[0088] After the reaction, the catalyst A-4 in Example 4 was filtered, washed with anhydrous ethanol and deionized water until the filtrate was neutral, and then dried and weighed. 50 g of sorbitol was weighed and added to the autoclave reactor. After slowly heating, the dried catalyst pellets were added after the sorbitol was melted, and 30 mL / min N2 was introduced as a protective gas to remove water vapor. At 150°C and 1000 r / min, the reaction was carried out for 2 hours and then sampled and analyzed. The reaction was repeated 5 times. The reaction results are shown in Table 2.

[0089] Table 2 Reaction results of catalyst A-4 to generate isosorbide at different cycle times

[0090]

[0091]

[0092] From the test results shown in Table 2, it can be seen that the supported sulfonated polystyrene-divinylbenzene catalyst provided by the present invention is used to catalyze the dehydration of sorbitol to prepare isosorbide. The catalyst loss after 5 cycles is very small, and the catalyst activity and selectivity do not show a significant decrease, so it is very suitable for recycling.

[0093] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A method for preparing a supported sulfonated polystyrene-divinylbenzene catalyst, characterized in that: include: The surface of the carrier is hydrophobically modified by using a silane coupling agent, and then polystyrene-divinylbenzene is in-situ grown on the modified carrier, and then subjected to a sulfonation treatment to obtain the supported sulfonated polystyrene-divinylbenzene catalyst.

2. The preparation method according to claim 1, characterized in that: The carrier is an inorganic carrier, preferably at least one selected from SiO2, Al2O3, TiO2, and molecular sieve; And / or, the carrier is a spherical carrier; And / or, the particle size of the carrier is 1 to 5 mm.

3. The preparation method according to claim 1 or 2, characterized in that: The silane coupling agent includes at least one of trimethoxypropylsilane, trimethoxy-n-octylsilane and trimethoxy-hexadecylsilane.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The hydrophobic modification comprises: dispersing the carrier in a first solvent, adding the silane coupling agent at 40-80° C., stirring and reacting to obtain the modified carrier; Preferably, The first solvent includes a mixed solvent of ammonia water, anhydrous ethanol and water; And / or, the stirring reaction includes stirring at a speed of 100 to 1000 r / min for 24 to 72 hours.

5. The preparation method according to claim 4, characterized in that: The mass ratio of the carrier to the silane coupling agent is 1:(0.025-1); And / or, the mass ratio of the carrier to the first solvent is 1:(1.5-8).

6. The preparation method according to any one of claims 1 to 5, characterized in that: The in-situ growth of polystyrene-divinylbenzene on the modified carrier comprises: adding the carrier, styrene, divinylbenzene, an initiator and a pore-forming agent into a second solvent, first stirring at 40-60° C. for 30-120 minutes, then heating to 70-80° C. and maintaining for 2-6 hours; then heating to 90-95° C. and reacting for 2-10 hours to obtain a modified carrier for in-situ growth of polystyrene-divinylbenzene.

7. The preparation method according to claim 6, characterized in that: A polymerization inhibitor is also added to the second solvent; preferably, the polymerization inhibitor comprises a methylene blue solution; and / or, the second solvent comprises water; and / or, the initiator comprises dibenzoyl peroxide; and / or, the pore-forming agent comprises n-heptane and / or toluene; And / or, the molar ratio of styrene to divinylbenzene is 10:(1-10), the mass ratio of the sum of the mass of styrene and divinylbenzene to the modified carrier is 1:(2-20), the mass ratio of the sum of the mass of styrene and divinylbenzene to n-heptane is 1:(1-5), and the mass ratio of the sum of the mass of styrene and divinylbenzene to dibenzoyl peroxide is 1:(0.05-0.20); And / or, the mass ratio of the sum of the masses of styrene and divinylbenzene to the mass of the second solvent is 1:(8-10).

8. The preparation method according to any one of claims 1 to 7, characterized in that: The sulfonation treatment comprises dispersing the modified carrier of in-situ grown polystyrene-divinylbenzene in a third solvent, adding a sulfonation reagent and stirring the reaction for 2 to 8 hours to obtain the supported sulfonated polystyrene-divinylbenzene catalyst; Preferably, The third solvent includes at least one of ethylene dichloride, cyclohexane, n-heptane, and toluene; And / or, the sulfonating agent includes at least one of chlorosulfonic acid, concentrated sulfuric acid, and sulfur trioxide; And / or, the mass ratio of the modified support of the in-situ grown polystyrene-divinylbenzene to the sulfonated reagent is (30-40): (1-10); And / or, the mass ratio of the modified carrier for in-situ growth of polystyrene-divinylbenzene to the third solvent is (30-40): (50-80).

9. A supported sulfonated polystyrene-divinylbenzene catalyst prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the supported sulfonated polystyrene-divinylbenzene catalyst according to claim 9 in catalyzing the dehydration of sorbitol to prepare isosorbide.

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