A heterogeneous catalyst for olefin epoxidation reaction and its preparation method and application

Abstract

The present invention relates to the technical field of catalysts for olefin epoxidation, and particularly to a heterogeneous catalyst for olefin epoxidation reaction, its preparation method and application. The catalyst composition of the present invention includes δ-MnO2, MoO3, WO3 and an AlPO4 support; the mass ratio of δ-MnO2, MoO3, WO3 and AlPO4 is (25-50):(1-10):(1-10):100. The catalyst of the present invention combines the advantages of each component, can improve the interaction between active components, has a high dispersion degree and a large number of active sites, can promote the improvement of catalyst performance, significantly improves various performances of the catalyst, has a good pore structure and good thermal conductivity, can strengthen the diffusion of products in the pores and the transfer of reaction heat, can effectively prevent the catalyst from carbon deposition and overheating, and finally realizes a high yield and selectivity of the target product epoxide.

Description

Technical Field

[0001] The invention relates to the technical field of catalysts for olefin epoxidation, and in particular to a heterogeneous catalyst for olefin epoxidation reaction, and a preparation method and application thereof. Background Art

[0002] Epoxidation reaction is a very important type of organic reaction, also known as epoxidation reaction. It refers to the reaction of olefins to generate epoxides under the action of reagents. Epoxide intermediates are widely used in the synthesis of medicines, pesticides and fine chemicals. Epoxide intermediates generated by olefin epoxidation reaction are widely used in the synthesis of antihypertensive drugs, anti-hepatitis C drugs and anti-cancer drugs, and have always been a hot topic in the field of medicinal chemistry.

[0003] Currently, the commonly used catalysts are mainly homogeneous catalysts, and most of them are precious metals. Although the reaction conditions are mild, the selectivity is good, and the conversion rate is high, it is difficult to separate, recycle and reuse them from the reaction system, resulting in high catalyst costs. The catalytic activity of most of the reported solid-supported catalysts is not as good as that of the corresponding homogeneous catalysts. This is because the stability of the solid-supported catalysts is poor, the number of catalyst reuses is limited, and the catalyst has poor universality. It is only effective for specific olefin substrates, and the catalytic activity of the catalyst for substrates such as styrene is poor; more seriously, the solid-supported catalysts need the participation of expensive co-catalysts to obtain higher catalytic activity.

[0004] The oxidation reaction of olefins is a liquid-solid phase reaction. During the reaction, the reactant molecules need to overcome diffusion resistance and approach the active center of the catalyst. However, due to the limitations of the catalyst structure, the pores are easily blocked during the reaction, which not only hinders the diffusion of the substrate, but also limits the contact between the reactants and the active center of the catalyst, resulting in limited reaction progress. Summary of the invention

[0005] Based on the above content, the present invention provides a heterogeneous catalyst for olefin epoxidation reaction and a preparation method and application thereof, so as to improve the yield and selectivity of the epoxide compound produced by olefin epoxidation.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention is a catalyst, the components of which include δ-MnO 2 、MoO 3 , WO 3 and AlPO 4 Carrier;

[0008] The δ-MnO 2 、MoO 3 , WO 3 and AlPO 4The mass ratio of the carrier is (25-50):(1-10):(1-10):100.

[0009] The second technical solution of the present invention is a method for preparing the above catalyst, according to δ-MnO 2 、MoO 3 , WO 3 and AlPO 4 The mass ratio of the carrier is δ-MnO 2 , tungstic acid and ammonium molybdate are kneaded with water, and the kneaded material is crushed and screened and then mixed with AlPO 4 The carrier is ball-rolled to obtain a formed sphere;

[0010] The formed spheres are dried and calcined in sequence to obtain the catalyst.

[0011] The third technical solution of the present invention is the use of the above catalyst in olefin epoxidation reaction.

[0012] The present invention discloses the following technical effects:

[0013] AlPO 4 The carrier has a large pore size and pore volume, which reduces the diffusion resistance encountered by macromolecular reactions and can also serve as a channel and accommodate sediments. The macroporous channel structure provides sufficient contact space for the active center, facilitates the rapid escape of reaction products, increases the reaction rate, promotes the diffusion and transfer of long-chain products, is not prone to carbon deposition, and prolongs the life of the catalyst.

[0014] The catalyst of the present invention combines the advantages of each component, can improve the interaction between active components, has high dispersion and more active sites, can promote the improvement of catalyst performance, and significantly improves various properties of the catalyst. It has a good pore structure and good thermal conductivity, can enhance the diffusion of products in the pores and the transfer of reaction heat, can effectively prevent the catalyst from overheating due to carbon deposition, and ultimately achieves a higher yield and selectivity of the target product epoxide compound.

[0015] By adjusting the preparation process and parameters, the physical structure and surface chemical properties of the catalyst can be adjusted, including adjusting the catalyst pore size and the interaction between the metal Mn and the carrier, and coupling the active component MoO 3 and WO 3 The catalytic effect of the catalyst is used to obtain a multi-component highly efficient coupled composite catalyst, which fundamentally improves the olefin epoxidation performance of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 is α-MnO 2 ,β-MnO 2 ,γ-MnO 2 ,δ-MnO 2 XRD spectrum of .

[0018] Figure 2 is α-MnO 2 ,β-MnO 2 ,γ-MnO 2 ,δ-MnO 2 Microscopic morphology of . DETAILED DESCRIPTION

[0019] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0020] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0021] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0022] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0023] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0024] Transition metals Cr, Ni, Co, Ru and Mn are widely used in the reaction of olefin epoxidation to generate epoxides. Compared with other transition metals, metal Mn is environmentally friendly, has stable oxidation states (II, III, V), has high catalytic efficiency and can form complexes with different ligands, and is widely used as a catalyst in the epoxidation of olefins. However, the catalysts formed by metal Mn (II, III, V) with different oxidation states and different ligands show obvious differences in the homogeneous epoxidation of olefins.

[0025] MnO 2 The inherent properties of MnO, such as morphology, crystal surface and crystal shape, have a great influence on the double bond oxidation performance. 2 Crystal form and crystal shape play a vital role in olefin epoxidation. 2 The octahedral unit [MnO 6 ] is a skeleton structure. MnO 2 It is mainly divided into four crystal forms, namely α-MnO 2 ,β-MnO 2 ,γ-MnO 2 ,δ-MnO 2 Its XRD spectrum is shown in Figure 1 , microscopic morphology Figure 2 . Different crystal forms of MnO 2 The vacancy formation energies of δ-MnO 2 It has lower vacancy formation energy and more oxygen vacancies, which can promote low-temperature activation of double bonds and produce highly active intermediate groups, significantly improving the activity and product selectivity of olefin epoxidation.

[0026] Molybdenum trioxide catalysts can be used in many different reactions, including double bond oxidation reactions. In double bond oxidation reactions, molybdenum trioxide can promote the addition of oxygen atoms on double bonds to molecules, thereby forming new chemical bonds. This reaction is very common in organic synthesis and can be used to prepare many useful compounds.

[0027] Tungsten oxide catalyzed double bond oxidation is a common organic reaction that can oxidize compounds containing double bonds into corresponding aldehydes, ketones or carboxylic acids. Tungsten oxide is an efficient oxidant with high catalytic activity and selectivity. In the reaction, tungsten oxide can attract the π electrons on the double bond to itself to form a tungsten-π complex, and then transfer the electrons on the double bond to the oxygen molecule through oxidation to generate the corresponding oxidation product. Tungsten oxide catalyzed double bond oxidation reactions are widely used in organic synthesis, pharmaceutical chemistry, materials science and other fields.

[0028] Based on the above, the first aspect of the present invention provides a catalyst, the components of which include δ-MnO 2 、MoO 3 , WO 3 and AlPO 4 Carrier;

[0029] The δ-MnO 2 、MoO 3 , WO 3 and AlPO 4 The mass ratio of the carrier is (25-50):(1-10):(1-10):100.

[0030] In some embodiments of the present invention, the δ-MnO 2 The preparation method comprises the following steps:

[0031] KMnO 4 Aqueous solution and MnSO 4 ·H 2 O aqueous solution is mixed and dissolved, and then a hydrothermal reaction is performed, and the obtained precipitate is dried to obtain the δ-MnO 2 .

[0032] In some embodiments of the present invention, the KMnO 4 The concentration of the aqueous solution is 0.1-0.3 mol / L; the MnSO 4 ·H 2 The concentration of the KMnO aqueous solution is 0.01-0.05 mol / L; 4 Aqueous solution and MnSO 4 ·H 2 The volume ratio of O aqueous solution is 0.5 to 2:1.

[0033] In some embodiments of the present invention, the temperature of the hydrothermal reaction is 140-200°C, and the time is 8-24 hours; the temperature of the drying is 80-120°C, and the time is 10-20 hours. Before drying the precipitate, the step of washing the precipitate with deionized water is also included.

[0034] In some embodiments of the present invention, the AlPO 4 The preparation method of the carrier comprises the following steps: co-precipitating a phosphate or hydrogen phosphate aqueous solution with an aluminum salt aqueous solution, then aging, washing, filtering, and drying the obtained filter cake to obtain the AlPO 4 carrier.

[0035] In some embodiments of the present invention, the concentration of the phosphate or hydrogen phosphate aqueous solution is 0.25-2.0 mol / L; the concentration of the aluminum salt aqueous solution is 0.25-2.0 mol / L.

[0036] In some embodiments of the present invention, the temperature of the co-precipitation is 30-90°C; the pH of the reaction system during the co-precipitation is pH=7.0-9.0; the flow rates of the two liquids (phosphate or hydrogen phosphate aqueous solution and aluminum salt aqueous solution) are adjusted to control the system pH=7.0-9.0. 4 The control of precipitation temperature and pH during the preparation process makes AlPO 4 The carrier has a large pore size and a moderate specific surface area and pore volume, so that the prepared catalyst has a large pore size and a moderate specific surface area and pore volume, which is beneficial to the diffusion of reactants and products and the transfer of heat in the olefin epoxidation reaction process.

[0037] The aging temperature is 60-90° C., and the time is 1-12 hours. The washing is specifically washing with deionized water until the impurity ions are less than 5 ppm. The drying temperature is 120-150° C., and the time is 6-24 hours.

[0038] The second technical solution of the present invention is a method for preparing the above catalyst, according to δ-MnO 2 、MoO 3 , WO 3 and AlPO 4 The mass ratio of the carrier is δ-MnO 2 , tungstic acid and ammonium molybdate are kneaded with water, and the kneaded material is crushed and screened and then mixed with AlPO 4 The carrier is ball-rolled to obtain a formed sphere;

[0039] The formed spheres are dried and calcined in sequence to obtain the catalyst.

[0040] In some embodiments of the present invention, the phosphate is one of sodium phosphate, potassium phosphate or ammonium phosphate; the hydrogen phosphate is one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate or potassium dihydrogen phosphate; the aluminum salt is aluminum nitrate or aluminum sulfate; during kneading, the amount of water added is 1.5% to 5.0% of the dry basis mass; the kneading time is 10 to 60 minutes; the amount of water added during ball rolling is 3% to 8.0% of the dry basis mass; the particle size of the crushed and screened material is 5 to 20 meshes; the particle size of the molded sphere is 2 to 10 meshes; the drying temperature is 60 to 90°C, the time is 12 to 24 hours; the roasting temperature is 150 to 250°C, and the time is 6 to 24 hours. The present invention adopts a lower drying temperature and a lower roasting temperature, which weakens the interaction between the carrier and the active component and saves energy. Calcination temperature higher than the parameter range described in the present invention is not conducive to the formation of appropriate surface oxygen vacancies on the surface of some oxides, and even too high a temperature may cause the formation of δ-MnO 2 On the other hand, it will cause AlPO 4 The sintering of the carrier and the active components causes the pore structure of the carrier to collapse and change the pore structure size. Both of these reasons will lead to the deterioration of catalyst activity and selectivity.

[0041] The present invention achieves precise control of the pore volume, pore size, specific surface area and other texture parameters of the olefin epoxidation catalyst by precisely controlling the process parameters on the basis of the above key steps, thereby achieving the control of the catalytic performance.

[0042] The third technical solution of the present invention is the use of the above catalyst in olefin epoxidation reaction, wherein the olefin epoxidation reaction uses 1-decene or 1-dodecene as a reaction substrate and reacts with benzaldehyde in an organic solvent, the above catalyst and an oxygen atmosphere.

[0043] The composite catalyst of the present invention combines the advantages of each component, can improve the interaction between active components, has high dispersion and more active sites, improves the electron cloud density of the catalyst, improves the ability of olefin epoxidation, can promote the improvement of catalyst performance, and significantly improves the various properties of the catalyst. AlPO 4 The carrier has a good pore structure and good thermal conductivity, which can enhance the diffusion of the product in the pores and the transfer of reaction heat, and can effectively prevent the catalyst from overheating due to carbon deposition.

[0044] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0045] The α-MnO used in the comparative example of the present invention 2 ,β-MnO 2 and γ-MnO2 Obtained through commercial sources.

[0046] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0047] Example 1

[0048] 0.1 mol / L KMnO 4 Aqueous solution and 0.01 mol / L MnSO 4 ·H 2 O aqueous solution, at a volume ratio of 0.5:1, was placed in a container and stirred for 20 min until completely dissolved, then transferred to a PTFE liner of appropriate volume and hydrothermally heated at 140 °C for 24 h; after cooling, the obtained precipitate was filtered and washed with deionized water for 5 times, and finally dried in an oven at 80 °C for 20 h to obtain δ-MnO 2 ;

[0049] Prepare a 0.25 mol / L sodium phosphate aqueous solution and then prepare a 0.25 mol / L aluminum nitrate aqueous solution. The two solutions are co-precipitated in a water bath at 40°C. The flow rate of the two liquids is controlled to control the pH to 8.0. After precipitation, age at 70°C for 10 hours. After aging, wash with deionized water until the sodium ion in the filtrate is less than 5 ppm. Dry the filter cake at 120°C for 24 hours to obtain AlPO 4 Carrier;

[0050] Weigh 25g of the above δ-MnO 2 1.08g of tungstic acid and 13.6g of ammonium molybdate are kneaded in a kneader, and the amount of water added is 1.5% of the dry weight, and the kneading time is 60min; the kneaded materials are crushed and sieved, and the materials with a particle size range of 5 to 20 mesh are screened and balled in a ball rolling machine; during ball rolling, 100g of the above AlPO 4 The powder was prepared by adding water in an amount of 8.0% of the dry weight, and the particle size of the spheres was controlled to be in the range of 2 to 10 meshes; the formed spheres were dried at 90°C for 12 hours, and then calcined at 250°C for 6 hours to obtain the final catalyst, whose weight composition was δ-MnO 2 :MoO 3 :WO 3 :AlPO 4 =25:10:1:100.

[0051] Example 2

[0052] 0.15 mol / L KMnO 4 Aqueous solution and 0.02 mol / L MnSO 4 ·H 2O aqueous solution, according to the volume ratio of 0.7:1, was placed in a container and stirred for 30 min until completely dissolved, then transferred to a PTFE liner of appropriate volume and hydrothermally heated at 160 °C for 18 h. After cooling, the resulting precipitate was filtered and washed with deionized water 5 times, and finally dried in an oven at 100 °C for 16 h to obtain δ-MnO 2 .

[0053] Prepare a 0.6 mol / L sodium hydrogen phosphate aqueous solution and a 0.4 mol / L aluminum sulfate aqueous solution, and place the two solutions in a water bath at 30°C for co-precipitation, and adjust the flow rates of the two liquids to control the pH to 9.0; after precipitation, age at 60°C for 12 hours; after aging, wash with deionized water until the sodium ions and sulfate ions in the filtrate are less than 5 ppm, and dry the filter cake at 130°C for 18 hours to obtain AlPO 4 Carrier;

[0054] Weigh 30g of the above δ-MnO 2 3.23g of tungstic acid and 10.89g of ammonium molybdate are kneaded in a kneader, and the amount of water added is 2.0% of the dry weight, and the kneading time is 50min; the kneaded materials are crushed and screened, and the materials with a particle size range of 5 to 20 mesh are screened and balled in a ball rolling machine; during ball rolling, 100g of the above AlPO 4 The powder was prepared by adding 7.0% water to the dry weight, and the particle size of the spheres was controlled to be in the range of 2 to 10 meshes; the formed spheres were dried at 80°C for 14 hours, and then calcined at 240°C for 8 hours to obtain the final catalyst, whose weight composition was δ-MnO 2 :MoO 3 :WO 3 :AlPO 4 =30:8:3:100.

[0055] Example 3

[0056] 0.18 mol / L KMnO 4 Aqueous solution and 0.025 mol / L MnSO 4 ·H 2 O aqueous solution, according to a volume ratio of 0.8:1, was placed in a container and stirred for 40 min until completely dissolved, then transferred to a PTFE liner of appropriate volume and hydrothermally heated at 150 °C for 16 h. After cooling, the resulting precipitate was filtered and washed with deionized water 5 times, and finally dried in an oven at 100 °C for 14 h to obtain δ-MnO 2 .

[0057] Prepare 1.8 mol / L ammonium dihydrogen phosphate aqueous solution and then prepare 0.6 mol / L aluminum nitrate aqueous solution, and place the two solutions in a water bath at 50°C for co-precipitation, and adjust the flow rate of the two liquids to control pH=8.5; after precipitation, age at 70°C for 6h; after aging, wash with deionized water until neutral, and dry the filter cake at 140°C for 15h to obtain AlPO 4 Carrier;

[0058] Weigh 35g of the above δ-MnO 2 5.39g of tungstic acid and 8.17g of ammonium molybdate are kneaded in a kneader, and the amount of water added is 2.5% of the dry weight, and the kneading time is 40min; the kneaded materials are crushed and sieved, and the materials with a particle size range of 5 to 20 mesh are screened and balled in a ball rolling machine; during ball rolling, 100g of the above AlPO 4 The powder was prepared by adding water in an amount of 6.0% of the dry weight, and the particle size of the spheres was controlled to be in the range of 2 to 10 meshes; the formed spheres were dried at 70°C for 16 hours, and then calcined at 230°C for 12 hours to obtain the final catalyst, whose weight composition was δ-MnO 2 :MoO 3 :WO 3 :AlPO 4 =35:6:5:100.

[0059] Example 4

[0060] 0.2 mol / L KMnO 4 Aqueous solution and 0.03 mol / L MnSO 4 ·H 2 O aqueous solution, according to a volume ratio of 1.2:1, was placed in a container and stirred for 50 min until completely dissolved, then transferred to a PTFE liner of appropriate volume and hydrothermally heated at 160 °C for 14 h. After cooling, the resulting precipitate was filtered and washed with deionized water 5 times, and finally dried in an oven at 100 °C for 12 h to obtain δ-MnO 2 .

[0061] Prepare a 1.2 mol / L potassium hydrogen phosphate aqueous solution and a 0.8 mol / L aluminum sulfate aqueous solution, and place the two solutions in a water bath at 70°C for co-precipitation, and adjust the flow rates of the two liquids to control the pH to 7.5; after precipitation, age at 80°C for 2h; after aging, wash with deionized water until the potassium ions and sulfate ions in the filtrate are less than 5ppm, and dry the filter cake at 130°C for 10h to obtain AlPO 4 Carrier;

[0062] Weigh 40g of the above δ-MnO 26.47g of tungstic acid and 6.81g of ammonium molybdate are kneaded in a kneader, and 3.0% of water is added based on the dry weight. The kneading time is 30min. The kneaded materials are crushed and sieved, and the materials with a particle size range of 5 to 20 mesh are sieved and spherical in a spherical machine. During spherical, 100g of the above AlPO 4 The powder was prepared by adding 4.0% water to the dry weight, and the particle size of the spheres was controlled to be in the range of 2 to 10 meshes; the formed spheres were dried at 70°C for 12 hours, and then calcined at 220°C for 12 hours to obtain the final catalyst, whose weight composition was δ-MnO 2 :MoO 3 :WO 3 :AlPO 4 =40:5:6:100.

[0063] Example 5

[0064] 0.25 mol / L KMnO 4 Aqueous solution and 0.04 mol / L MnSO 4 ·H 2 O aqueous solution, according to a volume ratio of 1.5:1, was placed in a container and stirred for 80 min until completely dissolved, then transferred to a PTFE liner of appropriate volume and hydrothermally heated at 180 °C for 12 h. After cooling, the resulting precipitate was filtered and washed with deionized water 5 times, and finally dried in an oven at 110 °C for 10 h to obtain δ-MnO 2 .

[0065] Prepare a 2.0 mol / L ammonium phosphate aqueous solution and a 2.0 mol / L aluminum nitrate aqueous solution, and place the two solutions in a water bath at 90°C for co-precipitation, and adjust the flow rates of the two liquids to control the pH to 7.0; after precipitation, age at 90°C for 1 h; after aging, wash with deionized water until neutral, and dry the filter cake at 150°C for 6 h to obtain AlPO 4 Carrier;

[0066] Weigh 45g of the above δ-MnO 2 8.62g of tungstic acid and 4.08g of ammonium molybdate are kneaded in a kneader, and the amount of water added is 4.0% of the dry weight, and the kneading time is 20min; the kneaded materials are crushed and sieved, and the materials with a particle size range of 5 to 20 mesh are screened and balled in a ball rolling machine; during ball rolling, 100g of the above AlPO 4 The powder is prepared by adding 4.0% water to the dry weight, and the particle size of the spheres is controlled to be in the range of 2 to 10 meshes; the formed spheres are dried at 65°C for 20 hours, and then calcined at 180°C for 20 hours to obtain the final catalyst, whose weight composition is δ-MnO 2 :MoO 3:WO 3 :AlPO 4 =45:3:8:100.

[0067] Example 6

[0068] 0.3 mol / L KMnO 4 Aqueous solution and 0.05 mol / L MnSO 4 ·H 2 O aqueous solution, in a volume ratio of 2:1, was placed in a container and stirred for 90 min until completely dissolved, then transferred to a PTFE liner of appropriate volume and hydrothermally heated at 200 °C for 8 h. After cooling, the resulting precipitate was filtered and washed with deionized water 5 times, and finally dried in an oven at 120 °C for 10 h to obtain δ-MnO 2 .

[0069] Prepare a 1.8 mol / L ammonium phosphate aqueous solution and then prepare a 1.8 mol / L aluminum nitrate aqueous solution. The two solutions are co-precipitated in a water bath at 55°C. The flow rates of the two liquids are adjusted to control the pH to 7.3. After precipitation, age at 75°C for 1.5 h. After aging, wash with deionized water until neutral, and dry the filter cake at 135°C for 7 h to obtain AlPO 4 Carrier;

[0070] Weigh 50g of the above δ-MnO 2 10.78g of tungstic acid and 1.36g of ammonium molybdate are kneaded in a kneader, and the amount of water added is 5.0% of the dry weight, and the kneading time is 10min; the kneaded materials are crushed and screened, and the materials with a particle size range of 5 to 20 mesh are screened and balled in a ball rolling machine; during ball rolling, 100g of the above AlPO 4 The powder was prepared by adding water in an amount of 3.0% of the dry weight, and the particle size of the spheres was controlled to be in the range of 2 to 10 meshes; the formed spheres were dried at 60°C for 24 hours, and then calcined at 150°C for 24 hours to obtain the final catalyst, whose weight composition was δ-MnO 2 :MoO 3 :WO 3 :AlPO 4 =50:1:10:100.

[0071] The epoxidation experiment of long-chain α-olefins was carried out using the catalyst of the above embodiment. The specific performance evaluation operation steps are as follows: (1) 1 mmol of reaction substrate (1-decene or 1-dodecene), 5 mL of reaction solvent acetonitrile, 5 mmol of benzaldehyde and 1.0 g of the catalyst of the embodiment were placed in a reaction kettle in sequence, and then the reaction kettle was sealed. (2) High-purity O 2The air in the reactor was replaced several times, and oxygen was filled in after the replacement was completed, with a total pressure of 0.13 MPa. The reaction was carried out at 60°C for 6 hours, and after the reactor was cooled to room temperature, the mixture was subjected to chromatographic quantitative analysis using an Agilent chromatograph. The results are shown in Table 1.

[0072] Table 1 Reaction results of olefin epoxidation catalyzed by various catalysts

[0073] Substrate Olefin conversion Epoxide selectivity Example 1 1-Decene 91％ 94％ Example 2 1-Decene 90％ 96％ Example 3 1-Dodecene 95％ 95％ Example 4 1-Dodecene 93％ 97％ Example 5 1-Decene 97％ 99％ Example 6 1-Decene 95％ 98％

[0074] As can be seen from Table 1, the catalyst prepared by the method of the present invention has a good catalytic effect on the epoxidation reaction of olefins, greatly improves the conversion rate of olefins, makes the reaction more complete, has high selectivity for the target product epoxide, and has relatively few reaction by-products.

[0075] Comparative Example 1

[0076] The only difference from Example 5 is that δ-MnO is omitted. 2 The preparation of δ-MnO 2 Replaced by α-MnO 2 The remaining steps and parameters are the same as those in Example 5.

[0077] The catalyst prepared in this comparative example was subjected to the above-mentioned epoxidation experiment of long-chain α-olefins. The results showed that the olefin conversion rate of the catalyst prepared in this comparative example was 67%, and the epoxide selectivity was 55%.

[0078] Comparative Example 2

[0079] The only difference from Example 5 is that δ-MnO is omitted. 2 The preparation of δ-MnO 2 Replaced by β-MnO 2 The remaining steps and parameters are the same as those in Example 5.

[0080] The catalyst prepared in this comparative example was subjected to the above-mentioned epoxidation experiment of long-chain α-olefins. The results showed that the olefin conversion rate of the catalyst prepared in this comparative example was 72%, and the epoxide selectivity was 49%.

[0081] Comparative Example 3

[0082] The only difference from Example 5 is that δ-MnO is omitted. 2 The preparation of δ-MnO 2 Replaced by γ-MnO 2 The remaining steps and parameters are the same as those in Example 5.

[0083] The catalyst prepared in this comparative example was subjected to the above-mentioned epoxidation experiment of long-chain α-olefins. The results showed that the olefin conversion rate of the catalyst prepared in this comparative example was 81%, and the epoxide selectivity was 60%.

[0084] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A catalyst, characterized in that The components include δ-MnO2, MoO3, WO3 and AlPO4 carrier; The mass ratio of the δ-MnO2, MoO3, WO3 and AlPO4 carriers is (25-50):(1-10):(1-10):

100.

2. The catalyst according to claim 1, characterized in that The preparation method of the δ-MnO2 comprises the following steps: The KMnO4 aqueous solution and the MnSO4·H2O aqueous solution are mixed and dissolved, and then subjected to a hydrothermal reaction. The obtained precipitate is dried to obtain the δ-MnO2.

3. The catalyst according to claim 2, characterized in that The concentration of the KMnO4 aqueous solution is 0.1-0.3 mol / L; the concentration of the MnSO4·H2O aqueous solution is 0.01-0.05 mol / L; the volume ratio of the KMnO4 aqueous solution to the MnSO4·H2O aqueous solution is 0.5-2:

1.

4. The catalyst according to claim 2, characterized in that The temperature of the hydrothermal reaction is 140-200° C., and the time is 8-24 hours; the temperature of the drying is 80-120° C., and the time is 10-20 hours.

5. The catalyst according to claim 1, characterized in that The preparation method of the AlPO4 carrier comprises the following steps: co-precipitating a phosphate or hydrogen phosphate aqueous solution with an aluminum salt aqueous solution, followed by aging, washing, filtering, and drying the obtained filter cake to obtain the AlPO4 carrier; The phosphate is one of sodium phosphate, potassium phosphate or ammonium phosphate; the hydrogen phosphate is one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate or potassium dihydrogen phosphate; the aluminum salt is aluminum nitrate or aluminum sulfate.

6. The catalyst according to claim 5, characterized in that The concentration of the phosphate or hydrogen phosphate aqueous solution is 0.25-2.0 mol / L; the concentration of the aluminum salt aqueous solution is 0.25-2.0 mol / L.

7. The catalyst according to claim 5, characterized in that The temperature of the co-precipitation is 30-90°C; the pH of the reaction system during the co-precipitation is pH=7.0-9.0; The aging temperature is 60-90° C., and the time is 1-12 hours; the drying temperature is 120-150° C., and the time is 6-24 hours.

8. A method for preparing the catalyst according to any one of claims 1 to 7, characterized in that: According to the mass ratio of δ-MnO2, MoO3, WO3 and AlPO4 carrier, δ-MnO2, tungstic acid and ammonium molybdate are kneaded with water, the kneaded material is crushed and screened, and then rolled with AlPO4 to obtain a formed sphere; The formed spheres are dried and calcined in sequence to obtain the catalyst.

9. The method for preparing a catalyst according to claim 8, characterized in that: The drying temperature is 60-90° C., and the time is 12-24 hours; the calcination temperature is 150-250° C., and the time is 6-24 hours.

10. Use of the catalyst according to any one of claims 1 to 7 in olefin epoxidation reaction.

Images