A catalyst for catalyzing the epoxidation reaction of long-chain alpha-olefins and a preparation method thereof

Abstract

The present invention discloses a heterogeneous catalyst for catalyzing the epoxidation reaction of long-chain α-olefins and a preparation method thereof. The catalyst comprises an active component and a carrier, wherein the active component is CuO nanoparticles and the carrier is a CuO nanoparticle with a specific surface area of ​​100 m 2 / g~300m 2 / g porous Al2O3, wherein the carrier is one or more of α-Al2O3, β-Al2O3, and γ-Al2O3. The heterogeneous catalyst provided by the present invention can catalyze the epoxidation reaction of long-chain α-olefins with oxygen to produce high-carbon epoxides. The catalyst of the present invention has good catalytic activity, target product selectivity, and economic advantages, and the reaction conditions of the corresponding catalytic system are mild, making it very suitable for industrial applications.

Description

Technical Field

[0001] The present invention belongs to the field of heterogeneous catalysis, and in particular relates to a catalyst for catalyzing the epoxidation reaction of long-chain alpha-olefins and a preparation method thereof. Background Art

[0002] Olefin epoxides are a class of organic synthesis intermediates with high added value and are widely used in the fields of medicine, pesticides, textiles, daily chemicals, materials, fragrances, food, electronics, etc. Iron-based Fischer-Tropsch synthetic oils contain a large amount of long-chain (C≥6) linear α-olefins. However, due to their similar physical properties, these unique α-olefins cannot be separated from the Fischer-Tropsch oil mixture by simple separation operations, which hinders their subsequent industrial application. Therefore, if the long-chain mixed α-olefins obtained from Fischer-Tropsch oil products can be converted into olefin epoxides through epoxidation technology, it will not only have important economic value, but also effectively expand the downstream industry chain of coal-to-liquids. At present, a large amount of related research work has been carried out in the field of olefin epoxidation, involving technologies such as air / oxygen oxidation, hydrogen peroxide oxidation, and organic peracid method.

[0003] The core of olefin epoxidation technology is the development of highly active and selective catalysts, including homogeneous and heterogeneous catalysts. In the field of homogeneous catalysis, Costas et al. (Angew. Chem. Int. Ed., 2016, 55(21): 6310-6314) reported that a terpyridine-iron catalyst exhibited excellent reactivity for olefin epoxidation. Montserrat et al. (Inorg Chem., 2013, 52(9): 5077-5087) used a ruthenium catalytic system in which a stable, strong electron-donating NHC ligand was coordinated with a terpyridine ligand to achieve a catalytic selectivity of 99.6% for 1-octene and to obtain the corresponding epoxide in a yield of 96%. Domestic scholars have also reported some excellent related catalytic systems: Xia Chungu et al. (Appl. Catal. A., 2003, 252(1):17-21) found that in a mixed solvent of ionic liquid [bmim]PF6 and CH2Cl2, using a manganese porphyrin catalyst system, they achieved the epoxidation of 1-heptene and 1-decene, with epoxide yields and selectivities exceeding 90%. Although research on homogeneous olefin epoxidation has made great progress, in homogeneous reactions, the ligands in the catalyst are prone to shedding after long-term reaction, resulting in reduced catalyst activity and stability. In addition, the difficulty in separating the homogeneous catalyst from the product has restricted the industrial application of homogeneous catalysts.

[0004] In addition to the above-mentioned homogeneous catalysts and corresponding catalytic systems, some heterogeneous catalysts and their systems have also been reported for olefin epoxidation. Cao Zhi et al. (Fuel, 2022, 326: 125050) used Co-Ir as a catalyst, azobisisobutyronitrile as a free radical initiator, and air as an oxidant to carry out the epoxidation reaction of long-chain α-olefins. The olefin conversion rate and the selectivity of the target product were both less than 50%. CN114713242A discloses the epoxidation catalysis of 1-hexene using Co-WOx-X as a catalyst (where X is the molar ratio of Co to W), 30% hydrogen peroxide as an oxidant, and acetonitrile as a solvent. The conversion rate of 1-hexene was 39.8%, and the highest selectivity of the target product 1,2-epoxyhexane was only 55.7%. CN104841486A discloses a porous organic polymer catalyst synthesized from Salen-Mn ligands and 1,3,5-triethynylbenzene. It uses oxygen as the oxidant, isobutyraldehyde as the co-reducing agent, and 1,2-dichloroethane as the solvent to catalyze the epoxidation of 1-hexene and 1-octene. The conversion of 1-hexene is 59% with a selectivity of 95%, and the conversion of 1-octene is 37% with a selectivity of 94%. CN111253342A discloses a quaternary ammonium salt catalyst of a tungstophosphoric acid heteropolyacid. It uses 30% hydrogen peroxide as the oxidant and sodium dihydrogen phosphate as the acid-base buffer to co-epoxidize 3-chloropropylene and 1-octene. After the reaction, the yield of 1,2-epoxyoctane to hydrogen peroxide is 65%, and the yield of the co-product epichlorohydrin to hydrogen peroxide is 30%.

[0005] In general, the current research and development of heterogeneous catalysts for the epoxidation of long-chain α-olefins is still relatively slow, mainly due to the following problems: (1) Existing catalysts and catalytic systems suitable for the epoxidation of medium- and short-chain α-olefins have low catalytic performance and selectivity in the epoxidation of long-chain α-olefins; (2) Some existing catalysts and catalytic systems for the epoxidation of long-chain α-olefins have problems such as poor catalytic performance, high cost, and complicated preparation processes. In view of these various factors, if we want to achieve the industrialization of heterogeneous catalysis for the epoxidation of high-chain olefins, we still need to develop catalysts that can overcome the above difficulties. Summary of the Invention

[0006] The technical problems to be solved by the present invention are: (1) to develop a heterogeneous catalyst with excellent catalytic performance and high selectivity for the target product for catalyzing the epoxidation reaction of long-chain α-olefins; and (2) the developed catalyst should be economical and convenient for large-scale industrial application.

[0007] Through research, the inventors of the present invention have discovered for the first time that using copper oxide as an active component in a long-chain α-olefin epoxidation catalytic system, small-sized copper oxide nanoparticles can be prepared through a complex adsorption loading method using alumina with a large specific surface area as a support, thereby achieving size effect modulation and endowing the catalyst with higher catalytic activity. At the same time, the strong interaction between the active component and the support facilitates the modulation of the electronic effect of the active component, and through the influence of the active component on the intermediate product, high selectivity for the target product is achieved. Furthermore, the large specific surface area of ​​the support helps to improve the stability of the catalyst performance. In addition, the reaction temperature of the catalytic system designed by the present invention makes the catalyst almost free of conventional factors that cause catalyst deactivation, such as carbon deposition, migration, and sintering, during use, allowing the catalyst to be reused multiple times. The catalyst developed by the present invention is a heterogeneous catalyst that overcomes the disadvantage of homogeneous catalysts that are difficult to separate from the product; at the same time, it has more obvious advantages in terms of economic efficiency and catalytic performance compared to other heterogeneous catalysts. Therefore, the catalyst provided by the present invention has high industrial application value.

[0008] In one aspect, the present invention provides a heterogeneous catalyst for catalyzing the epoxidation reaction of long-chain α-olefins, wherein the catalyst comprises: an active component, wherein the active component is CuO nanoparticles; and a carrier, wherein the carrier is a CuO nanoparticle with a specific surface area of ​​100 m 2 / g~300m 2 / g of porous Al2O3, wherein the Al2O3 is one or more of α-Al2O3, β-Al2O3 and γ-Al2O3.

[0009] In another aspect, the present invention provides a method for preparing the heterogeneous catalyst, comprising:

[0010] (1) mixing a water-soluble copper source and ultrapure water, stirring and dissolving them at room temperature to obtain a copper source solution;

[0011] (2) adding an ammonia solution to the copper source solution according to a metered amount, and then stirring to allow copper ions to complex with ammonia molecules to form copper ammonia complex ions, thereby obtaining a copper ammonia solution;

[0012] (3) Adding Al2O3 powder as a carrier to the copper ammonia solution and stirring to allow the copper ammonia cations to be adsorbed on the surface of the carrier, and then filtering, washing with ultrapure water, and drying to obtain a blue solid powder, wherein the specific surface area of ​​the Al2O3 powder is 100m 2 / g~300m 2 / g;

[0013] (4) calcining the blue solid powder in an air atmosphere to obtain the heterogeneous catalyst.

[0014] In another aspect, the present invention provides use of the above-mentioned heterogeneous catalyst for catalyzing the epoxidation reaction of C6-C14 long carbon chain α-olefins to prepare high carbon epoxides.

[0015] On the other hand, the present invention provides a method for preparing high-carbon epoxy compounds by catalyzing the epoxidation reaction of long-chain α-olefins of C6 to C14, comprising: using the above-mentioned multiphase catalyst to catalyze the epoxidation reaction of the long-chain α-olefins with oxygen in the presence of a co-reducing agent aldehyde and a solvent, thereby generating the corresponding high-carbon epoxy compounds.

[0016] The exemplary embodiments of the present invention have at least the following innovations and advantages, but are not limited thereto:

[0017] 1. The catalyst provided by the present invention uses copper oxide as the active catalytic component and uses alumina with a large specific surface area as the carrier, forming a new catalytic system for the epoxidation reaction of long-chain α-olefins.

[0018] 2. The present invention is the first to achieve size modulation of copper oxide nanoparticles by means of complex adsorption loading, thus giving the catalyst high activity.

[0019] 3. The catalyst of the present invention modulates the electronic effect of the active component through the strong interaction between the active component and the support, affecting the selection of intermediate products, thereby giving the target product high carbon chain epoxide high selectivity.

[0020] 4. The catalyst provided by the present invention has a very high economic advantage, and the preparation method is easy to control and can be industrialized. Moreover, the catalyst is suitable for catalytic systems with mild reaction conditions, thus meeting the industrial application of long-chain α-olefin epoxidation reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figures show the scanning transmission electron microscopy results and the particle size distribution of the active component nanoparticles of the 8 wt % CuO / γ-Al 2 O 3 catalyst prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0022] In the present invention, unless otherwise specified, the term "room temperature" refers to ambient temperature, which is generally 15°C to 40°C.

[0023] In one embodiment, the present invention relates to a heterogeneous catalyst for catalyzing the epoxidation of long-chain α-olefins, wherein the catalyst comprises: an active component, wherein the active component is CuO nanoparticles; and a support, wherein the support is a CuO nanoparticle having a specific surface area of ​​100 m 2 / g~300m 2 / g of porous Al2O3, wherein the Al2O3 is one or more of α-Al2O3, β-Al2O3 and γ-Al2O3.

[0024] In the heterogeneous catalyst described herein, the active components and the carrier are combined in the form of adsorption loading, thereby showing good effects in terms of economy and catalytic performance.

[0025] In some embodiments, the average particle size of the CuO nanoparticles is 1.0 to 2.9 nm, preferably 1.3 to 2.5 nm, 1.5 to 2.0 nm (eg, 1.55 nm, 1.71 nm, or 1.78 nm).

[0026] In some embodiments, the specific surface area of ​​the porous Al2O3 is 100m 2 / g~250m 2 / g, 150m 2 / g~200m 2 / g (e.g. 150m 2 / g, 180m 2 / g, 200m 2 / g).

[0027] In some embodiments, the average pore size of the porous Al2O3 is 14 to 20 nm.

[0028] In some embodiments, the content of the CuO nanoparticles is 3 wt% to 20 wt%, such as 5 wt% to 15 wt% or 4 wt% to 10 wt% (such as 5 wt%, 8 wt% or 10 wt%) relative to the total mass of the heterogeneous catalyst.

[0029] In one embodiment, the present invention provides a method for preparing the above-mentioned heterogeneous catalyst, comprising:

[0030] (1) mixing a water-soluble copper source and ultrapure water, stirring and dissolving them at room temperature to obtain a copper source solution;

[0031] (2) adding an ammonia solution to the copper source solution according to a metered amount, and then stirring to allow copper ions to complex with ammonia molecules to form copper ammonia complex ions, thereby obtaining a copper ammonia solution;

[0032] (3) Adding Al2O3 powder as a carrier to the copper ammonia solution and stirring to allow the copper ammonia cations to be adsorbed on the surface of the carrier, and then filtering, washing with ultrapure water, and drying to obtain a blue solid powder, wherein the specific surface area of ​​the Al2O3 powder is 100m 2 / g~300m 2 / g;

[0033] (4) calcining the blue solid powder in an air atmosphere to obtain the heterogeneous catalyst.

[0034] In some embodiments, the water-soluble copper source is a water-soluble inorganic copper salt, for example, copper nitrate (eg, copper nitrate trihydrate), copper chloride, or copper sulfate, but is not limited thereto.

[0035] Herein, there is no particular limitation on the amount of ultrapure water used in step (1), as long as it can achieve complete dissolution of the water-soluble copper source, for example, by adding ultrapure water to obtain a saturated or unsaturated copper source solution. In some embodiments, the concentration of the copper source solution is 0.1 to 1 mol / L, for example, 0.2 to 0.9 mol / L, 0.3 to 0.85 mol / L, or 0.4 to 0.85 mol / L.

[0036] In some embodiments, in step (1), stirring is carried out at room temperature for 10 min to 1 h, for example, 0.5 h.

[0037] In some embodiments, in step (2), the concentration of the ammonia solution is 5 wt% to 30 wt%, for example, 10 wt% to 26 wt%, or 20 wt%.

[0038] In some embodiments, in step (2), stirring is performed at 20°C to 50°C for 0.5 to 4 hours, for example, stirring is performed at 30°C to 40°C for 1 to 3 hours.

[0039] In some embodiments, in step (3), the specific surface area of ​​the Al2O3 powder is 100m 2 / g~250m 2 / g, 150m 2 / g~200m 2 / g (e.g. 150m 2 / g, 180m 2 / g, 200m 2 / g).

[0040] In some embodiments, in step (3), the average pore size of the Al2O3 powder is 14 to 20 nm.

[0041] In some embodiments, in step (3), stirring is performed at -5°C to 15°C for 10 min to 3.0 h, for example, stirring is performed at 0°C to 10°C for 0.4 h to 2.0 h.

[0042] In this article, in step (3), by stirring, the copper ammonia cations are adsorbed on the surface of the carrier by means of electrostatic interaction, which is beneficial to the modulation of the electronic effect of the active component. Through the influence of the active component on the intermediate product, high selectivity of the target product is achieved.

[0043] In some embodiments, in step (3), the filtrate is washed with ultrapure water until the pH value of the filtrate is 7.0-8.0, for example, the filtrate is washed with ultrapure water until the pH value of the filtrate is 7.0-7.5, 7.3 or 7.5.

[0044] In some embodiments, in step (3), the drying temperature is 100° C. to 130° C. (eg, 100° C. to 120° C.) and the drying time is 5 to 12 hours (eg, 5 to 8 hours).

[0045] In some embodiments, in step (4), the blue solid powder is calcined at 300°C to 500°C for 1 to 10 hours, for example, at 350°C to 450°C for 1 to 5 hours, preferably 2 to 4 hours.

[0046] In some embodiments, the heterogeneous catalyst comprises 3 wt% to 20 wt% (e.g., 5 wt% to 15 wt% or 4 wt% to 10 wt%, 5 wt%, 8 wt% or 10 wt%) CuO nanoparticles relative to the total mass of the heterogeneous catalyst.

[0047] In one embodiment, the present invention relates to the use of the above-mentioned heterogeneous catalyst for catalyzing the epoxidation reaction of C6 to C14 long carbon chain α-olefins to prepare high carbon epoxides.

[0048] In some embodiments, the long carbon chain α-olefin is a C6 to C12 long carbon chain α-olefin (eg, hexene, decene, dodecene).

[0049] In one embodiment, the present invention relates to a method for preparing a high-carbon epoxy compound by catalyzing the epoxidation reaction of a C6 to C14 long-chain α-olefin, comprising: using the above-mentioned heterogeneous catalyst to catalyze the epoxidation reaction of the long-chain α-olefin with oxygen in the presence of a co-reducing agent aldehyde and a solvent, thereby generating the corresponding high-carbon epoxy compound.

[0050] In some embodiments, the long carbon chain α-olefin is a C6 to C12 long carbon chain α-olefin (eg, hexene, decene, dodecene).

[0051] In some embodiments, the co-reducing agent is one or more of benzaldehyde, tert-butylaldehyde, phenylacetaldehyde, acetaldehyde, and propionaldehyde, preferably benzaldehyde and phenylacetaldehyde.

[0052] In some embodiments, the solvent is one or more of toluene, ethylbenzene, acetonitrile, and tetrahydrofuran.

[0053] In some embodiments, the epoxidation reaction temperature is 50-100°C, the pressure is 0.1-0.5 MPa, and the time is 4-10 h (for example, the temperature is 50-80°C, 60-70°C; the pressure is 0.1-0.2 MPa, 0.1-0.15 MPa, 0.13 MPa; and the time is 4-7 h, 5-6 h).

[0054] Herein, in the epoxidation reaction, O2 is used as an oxidant to cause epoxidation of long-chain α-olefins.

[0055] In some embodiments, the epoxidation reaction is carried out batchwise in a reactor, or continuously in a fixed bed or fluidized bed.

[0056] The exemplary technical solutions of this article can be described and illustrated by the contents of the following numbered paragraphs:

[0057] 1. A heterogeneous catalyst for catalyzing the epoxidation of long-chain α-olefins, wherein the catalyst comprises: an active component, wherein the active component is CuO nanoparticles; and a carrier, wherein the carrier is a CuO nanoparticle having a specific surface area of ​​100 m 2 / g~300m 2 / g of porous Al2O3, wherein the Al2O3 is one or more of α-Al2O3, β-Al2O3 and γ-Al2O3.

[0058] 2. The heterogeneous catalyst according to paragraph 1, wherein the average particle size of the CuO nanoparticles is 1.0 to 2.9 nm.

[0059] 3. The heterogeneous catalyst according to paragraph 1 or 2, wherein the specific surface area of ​​the porous Al2O3 is 100 m 2 / g~250m 2 / g.

[0060] 4. The heterogeneous catalyst according to any one of paragraphs 1 to 3, wherein the average pore size of the porous Al2O3 is 14 to 20 nm.

[0061] 5. The heterogeneous catalyst according to any one of paragraphs 1 to 4, wherein the content of the CuO nanoparticles is 3 wt% to 20 wt% relative to the total mass of the heterogeneous catalyst.

[0062] 6. A method for preparing the heterogeneous catalyst described in any one of paragraphs 1 to 5, comprising:

[0063] (1) mixing a water-soluble copper source and ultrapure water, stirring and dissolving them at room temperature to obtain a copper source solution;

[0064] (2) adding an ammonia solution to the copper source solution according to a metered amount, and then stirring to allow copper ions to complex with ammonia molecules to form copper ammonia complex ions, thereby obtaining a copper ammonia solution;

[0065] (3) Adding Al2O3 powder as a carrier to the copper ammonia solution and stirring to allow the copper ammonia cations to be adsorbed on the surface of the carrier, and then filtering, washing with ultrapure water, and drying to obtain a blue solid powder, wherein the specific surface area of ​​the Al2O3 powder is 100m 2 / g~300m 2 / g;

[0066] (4) calcining the blue solid powder in an air atmosphere to obtain the heterogeneous catalyst.

[0067] 7. The method of paragraph 6, wherein the water-soluble copper source is a water-soluble inorganic copper salt.

[0068] 8. The method of paragraph 6 or 7, wherein the water-soluble inorganic copper salt is selected from copper nitrate, copper chloride or copper sulfate.

[0069] 9. The method according to any one of paragraphs 6 to 8, wherein the concentration of the copper source solution is 0.1 to 1 mol / L.

[0070] 10. The method according to any one of paragraphs 6 to 9, wherein in step (1), the stirring is carried out at room temperature for 10 min to 1 h.

[0071] 11. The method of any one of paragraphs 6 to 10, wherein in step (2), the concentration of the aqueous ammonia solution is 5 wt% to 30 wt%.

[0072] 12. The method of any one of paragraphs 6 to 11, wherein in step (2), the stirring is performed at 20° C. to 50° C. for 0.5 to 4 hours.

[0073] 13. The method of any one of paragraphs 6 to 12, wherein in step (3), the specific surface area of ​​the Al2O3 powder is 100 m 2 / g~250m 2 / g.

[0074] 14. The method of any one of paragraphs 6 to 13, wherein in step (3), the average pore size of the Al2O3 powder is 14 to 20 nm.

[0075] 15. The method of any one of paragraphs 6 to 14, wherein in step (3), the stirring is performed at -5°C to 15°C for 10 min to 3.0 h.

[0076] 16. The method of any one of paragraphs 6 to 15, wherein in step (3), the filtrate is washed with ultrapure water until the pH value is 7.0 to 8.0.

[0077] 17. The method of any one of paragraphs 6 to 16, wherein in step (3), the drying temperature is 100° C. to 130° C., and the drying time is 5 to 12 hours.

[0078] 18. The method of any one of paragraphs 6 to 17, wherein in step (4), the blue solid powder is calcined at 300° C. to 500° C. for 1 to 10 hours.

[0079] 19. The method of any of paragraphs 6 to 18, wherein the heterogeneous catalyst comprises 3 wt% to 20 wt% of CuO nanoparticles relative to the total mass of the heterogeneous catalyst.

[0080] 20. Use of the heterogeneous catalyst described in any one of paragraphs 1 to 5 for catalyzing the epoxidation reaction of C6 to C14 long-chain α-olefins to produce high-carbon epoxides.

[0081] 21. The use according to paragraph 20, wherein the long carbon chain α-olefin is a C6 to C12 long carbon chain α-olefin.

[0082] 22. A method for preparing a higher carbon epoxy compound by catalyzing the epoxidation reaction of a C6-C14 long-chain α-olefin, comprising: catalyzing the epoxidation reaction of the long-chain α-olefin with oxygen using the heterogeneous catalyst described in any one of paragraphs 1-5 in the presence of a co-reducing agent, an aldehyde, and a solvent, thereby producing the corresponding higher carbon epoxy compound.

[0083] 23. The method of paragraph 22, wherein the long carbon chain α-olefin is a C6 to C12 long carbon chain α-olefin.

[0084] 24. The method of paragraph 22 or 23, wherein the co-reducing agent is one or more of benzaldehyde, tert-butylaldehyde, phenylacetaldehyde, acetaldehyde, and propionaldehyde.

[0085] 25. The method of any one of paragraphs 22 to 24, wherein the solvent is one or more of toluene, ethylbenzene, acetonitrile, and tetrahydrofuran.

[0086] 26. The method of any one of paragraphs 22-25, wherein the epoxidation reaction is carried out at a temperature of 50 to 100°C, a pressure of 0.1 to 0.5 MPa, and a time of 4 to 10 hours.

[0087] 27. The method of any one of paragraphs 22 to 26, wherein the epoxidation reaction is carried out batchwise in a reactor, or continuously in a fixed bed or fluidized bed.

[0088] Next, the present invention is further described in detail through examples, but the protection scope of the present invention is not limited to these examples. Those skilled in the art may make other modifications, adjustments or combinations based on the following examples, which also fall within the protection scope of the present invention.

[0089] Unless otherwise stated, the reagents, materials and devices involved in the following examples and comparative examples are commercially available.

[0090] The product analysis methods in the following examples and comparative examples were analyzed using an Agilent chromatograph, and the specific detection method for the epoxidation product was as follows:

[0091] Injection volume: 0.5 μL; chromatographic column: Agilent HP-5 model (30m*320μm*0.25μm); column temperature: 40°C for 5 min, heated to 200°C at 10°C / min, held for 3 min, heated to 240°C at 5°C / min, held for 3 min; injection port temperature: 220°C; detector temperature: 250°C.

[0092] Septum purge gas flow rate: 3 ml / min; column flow rate (N2): 1 mL / min; split injection, split ratio is 4:1; hydrogen flow rate: 30 mL / min; air flow rate: 400 mL / min; tail gas purge flow rate: 25 mL / min.

[0093] Example 1

[0094] The catalyst prepared in this example is 8wt% CuO / γ-Al2O3 and is prepared according to the following method:

[0095] (1) Dissolve 5 g of Cu(NO3)2·3H2O in 30 mL of ultrapure water and stir at room temperature for 0.5 h to obtain a copper nitrate solution with a concentration of 0.69 mol / L.

[0096] (2) Add 10 mL of 26 wt % ammonia solution to the copper source solution according to the metered amount, and then stir at 30° C. for 2 h to obtain the corresponding copper ammonia solution.

[0097] (3) Add 20g of γ-Al2O3 carrier powder (specific surface area of ​​150m2) to the copper ammonia solution of step (2). 2 / g, with an average pore size of 14 nm), stirred at 0°C for 0.4 h to allow the copper ammonia cation to be adsorbed on the surface of the carrier, then filtered and washed with ultrapure water until the pH value of the filtrate was 7.3, and finally dried at 110°C for 8 h to obtain a blue solid powder.

[0098] (4) The blue solid powder obtained in step (3) was calcined at 350°C in air for 4 h to obtain a heterogeneous catalyst 8 wt% CuO / γ-Al2O3, which was recorded as catalyst 1# (wherein the average particle size of the active component CuO nanoparticles was 1.55 nm).

[0099] The STEM results of the catalyst prepared above and the particle size distribution of the active component CuO nanoparticles were analyzed in Figure 1 As shown in . Among them, from Figure 1 (a) It can be clearly seen that the CuO nanoparticles are evenly distributed on the carrier without agglomeration. At the same time, the particle size of the CuO nanoparticles was statistically analyzed. The results are as follows: Figure 1 As shown in (b), the average particle size of CuO nanoparticles is 1.55 nm, and the distribution is relatively concentrated, meeting the synthesis expectations.

[0100] The above catalyst #1 was used to conduct epoxidation experiments on long-chain α-olefins. The specific performance evaluation steps were as follows:

[0101] (1) 1 mmol of the reaction substrate 1-hexene, 5 mL of the reaction solvent acetonitrile, 5 mmol of benzaldehyde, and 0.8 mol% of catalyst #1 were placed in a reaction kettle, and then the reaction kettle was sealed. (2) The air in the reaction kettle was repeatedly replaced with high-purity O2. After the replacement was completed, oxygen was introduced to a total pressure of 0.13 MPa. The reaction was carried out at 60°C for 6 hours. After the reaction kettle was cooled to room temperature, the mixture was subjected to chromatographic quantitative analysis using an Agilent chromatograph. The results are shown in Table 1.

[0102] Example 2

[0103] Except that the reaction substrate in the performance evaluation operation was replaced with 1-decene, the rest was the same as in Example 1. The results are shown in Table 1.

[0104] Example 3

[0105] Except that the reaction substrate in the performance evaluation operation was replaced with 1-dodecene, the rest was the same as in Example 1. The results are shown in Table 1.

[0106] Example 4

[0107] The catalyst prepared in this example is 5wt% CuO / α-Al2O3 and is prepared according to the following method:

[0108] (1) Dissolve 3 g of Cu(NO3)2·3H2O in 30 mL of ultrapure water and stir at room temperature for 0.5 h to obtain a copper nitrate solution with a concentration of 0.41 mol / L.

[0109] (2) Add 10 mL of a 20 wt% ammonia solution to the copper source solution according to the metered amount, and then stir at 35° C. for 3 h to obtain the corresponding copper ammonia solution.

[0110] (3) Add 20g of α-Al2O3 carrier powder (specific surface area of ​​180m2) to the copper ammonia solution of step (2). 2 / g, with an average pore size of 20 nm), stirred at 10°C for 2.0 h to allow the copper ammonia cation to be adsorbed on the surface of the support, then filtered and washed with ultrapure water until the pH value of the filtrate was 7.5, and finally dried at 100°C for 8 h to obtain a blue solid powder.

[0111] (4) The blue solid powder obtained in step (3) was calcined at 450°C in air for 2 h to obtain a heterogeneous catalyst 12 wt% CuO / α-Al2O3, which was recorded as catalyst 2# (wherein the average particle size of the active component CuO nanoparticles was 1.71 nm).

[0112] The above catalyst #2 was used to conduct epoxidation experiments on long-chain α-olefins. The specific performance evaluation steps were as follows:

[0113] (1) 1 mmol of the reaction substrate 1-decene, 5 mL of the reaction solvent toluene, 5 mmol of benzaldehyde, and 0.8 mol% of catalyst 2# were placed in a reaction kettle, and then the reaction kettle was sealed. (2) The air in the reaction kettle was repeatedly replaced with high-purity O2. After the replacement was completed, oxygen was introduced to a total pressure of 0.13 MPa. The reaction was carried out at 70°C for 5 hours. After the reaction kettle was cooled to room temperature, the mixture was subjected to chromatographic quantitative analysis using an Agilent chromatograph. The results are shown in Table 1.

[0114] Example 5

[0115] The catalyst prepared in this example is 10 wt% CuO / β-Al2O3 and is prepared according to the following method:

[0116] (1) Dissolve 6 g of Cu(NO3)2·3H2O in 30 mL of ultrapure water and stir at room temperature for 0.5 h to obtain a copper nitrate solution with a concentration of 0.83 mol / L.

[0117] (2) Add 10 mL of a 10 wt% ammonia solution to the copper source solution according to the metered amount, and then stir at 40° C. for 1 h to obtain the corresponding copper ammonia solution.

[0118] (3) Add 20g of β-Al2O3 carrier powder (specific surface area of ​​200m2) to the copper ammonia solution of step (2). 2 / g, with an average pore size of 18 nm), stirred at 5°C for 1.0 h to allow the copper ammonia cation to be adsorbed on the surface of the carrier, then filtered and washed with ultrapure water until the pH value of the filtrate was 7.5, and finally dried at 120°C for 5 h to obtain a blue solid powder.

[0119] (4) The blue solid powder obtained in step (3) was calcined at 400° C. in air for 3 h to obtain a heterogeneous catalyst 10 wt% CuO / β-Al2O3, which was designated as catalyst 3# (wherein the average particle size of the active component CuO nanoparticles was 1.78 nm).

[0120] The above catalyst #2 was used to conduct epoxidation experiments on long-chain α-olefins. The specific performance evaluation steps were as follows:

[0121] (1) 1 mmol of the reaction substrate 1-decene, 5 mL of the reaction solvent ethylbenzene, 5 mmol of benzaldehyde, and 0.8 mol% of catalyst #3 were placed in a reaction kettle, and then the reaction kettle was sealed. (2) The air in the reaction kettle was repeatedly replaced with high-purity O2. After the replacement was completed, oxygen was introduced to a total pressure of 0.13 MPa. The reaction was carried out at 70°C for 5 hours. After the reaction kettle was cooled to room temperature, the mixture was subjected to chromatographic quantitative analysis using an Agilent chromatograph. The results are shown in Table 1.

[0122] Comparative Example 1

[0123] The catalyst prepared in this comparative example is 8wt% CuO / TiO2 and is prepared according to the following method:

[0124] (1) Dissolve 5 g of Cu(NO3)2·3H2O in 30 mL of ultrapure water and stir at room temperature for 0.5 h to obtain a copper nitrate solution with a concentration of 0.69 mol / L.

[0125] (2) Add 10 mL of 26 wt % ammonia solution to the copper source solution according to the metered amount, and then stir at 30° C. for 2 h to obtain the corresponding copper ammonia solution.

[0126] (3) 20 g of TiO2 carrier powder was added to the copper ammonia solution of step (2), stirred at 0°C for 0.4 h, then filtered and washed with ultrapure water until the pH value of the filtrate was 7.3. Finally, dried at 110°C for 8 h to obtain a blue solid powder.

[0127] (4) The blue solid powder obtained in step (3) was calcined at 350°C in air for 4 h to obtain a heterogeneous catalyst 8 wt% CuO / TiO2, which was recorded as comparative example catalyst 1# (wherein the average particle size of the active component CuO nanoparticles was 1.68 nm).

[0128] The epoxidation experiment of long-chain α-olefins was carried out using the comparative example catalyst 1#. The specific performance evaluation steps are as follows:

[0129] (1) 1 mmol of the reaction substrate 1-decene, 5 mL of the reaction solvent acetonitrile, 5 mmol of benzaldehyde, and 0.8 mol% of the comparative example catalyst 1# were placed in a reaction kettle, and then the reaction kettle was sealed. (2) The air in the reaction kettle was repeatedly replaced with high-purity O2. After the replacement was completed, oxygen was filled in, and the total pressure was 0.13 MPa. The reaction was carried out at 60°C for 6 hours. After the reaction kettle was cooled to room temperature, the mixture was subjected to chromatographic quantitative analysis using an Agilent chromatograph. The results are shown in Table 1.

[0130] Comparative Example 2

[0131] The catalyst prepared in this comparative example is 8wt% CuO / MgO and is prepared according to the following method:

[0132] (1) Dissolve 5 g of Cu(NO3)2·3H2O in 30 mL of ultrapure water and stir at room temperature for 0.5 h to obtain a copper nitrate solution with a concentration of 0.69 mol / L.

[0133] (2) Add 10 mL of 26 wt % ammonia solution to the copper source solution according to the metered amount, and then stir at 30° C. for 2 h to obtain the corresponding copper ammonia solution.

[0134] (3) 20 g of MgO carrier powder was added to the copper ammonia solution of step (2), stirred at 0° C. for 0.4 h, filtered, washed with ultrapure water until the pH value of the filtrate was 7.3, and finally dried at 110° C. for 8 h to obtain a blue solid powder.

[0135] (4) The blue solid powder obtained in step (3) was calcined at 350° C. in air for 4 h to obtain a heterogeneous catalyst 8 wt % CuO / MgO, which was designated as comparative catalyst 2# (wherein the average particle size of the active component CuO nanoparticles was 1.77 nm).

[0136] The epoxidation experiment of long-chain α-olefins was carried out using the above comparative example catalyst 2#. The specific performance evaluation operation steps are as follows:

[0137] (1) 1 mmol of the reaction substrate 1-decene, 5 mL of the reaction solvent acetonitrile, 5 mmol of benzaldehyde, and 0.8 mol% of the comparative example catalyst 2# were placed in a reaction kettle, and then the reaction kettle was sealed. (2) The air in the reaction kettle was repeatedly replaced with high-purity O2. After the replacement was completed, oxygen was filled in, and the total pressure was 0.13 MPa. The reaction was carried out at 60°C for 6 hours. After the reaction kettle was cooled to room temperature, the mixture was subjected to chromatographic quantitative analysis using an Agilent chromatograph. The results are shown in Table 1.

[0138] Comparative Example 3

[0139] The catalyst prepared in this comparative example is 8wt% CuO / Nb2O3 and is prepared according to the following method:

[0140] (1) Dissolve 5 g of Cu(NO3)2·3H2O in 30 mL of ultrapure water and stir at room temperature for 0.5 h to obtain a copper nitrate solution with a concentration of 0.69 mol / L.

[0141] (2) Add 10 mL of 26 wt % ammonia solution to the copper source solution according to the metered amount, and then stir at 30° C. for 2 h to obtain the corresponding copper ammonia solution.

[0142] (3) Add 20 g of Nb2O3 carrier powder to the copper ammonia solution of step (2), stir at 0°C for 0.4 h, then filter and wash with ultrapure water until the pH value of the filtrate is 7.3, and finally dry at 110°C for 8 h to obtain a blue solid powder.

[0143] (4) The blue solid powder obtained in step (3) was calcined at 350°C in air for 4 h to obtain a heterogeneous catalyst 8 wt% CuO / Nb2O3, which was designated as comparative catalyst 3# (wherein the average particle size of the active component CuO nanoparticles was 1.58 nm).

[0144] The epoxidation experiment of long-chain α-olefins was carried out using the above comparative example catalyst 3#. The specific performance evaluation operation steps are as follows:

[0145] (1) 1 mmol of the reaction substrate 1-decene, 5 mL of the reaction solvent acetonitrile, 5 mmol of benzaldehyde, and 0.8 mol% of the comparative example catalyst 3# were placed in a reaction kettle, and then the reaction kettle was sealed. (2) The air in the reaction kettle was repeatedly replaced with high-purity O2. After the replacement was completed, oxygen was filled in, and the total pressure was 0.13 MPa. The reaction was carried out at 60°C for 6 hours. After the reaction kettle was cooled to room temperature, the mixture was subjected to chromatographic quantitative analysis using an Agilent chromatograph. The results are shown in Table 1.

[0146] Comparative Example 4

[0147] The catalyst prepared in this comparative example is 8wt% CuO / γ-Al2O3-S, wherein the surface area of ​​the γ-Al2O3 carrier is 2m 2 / g, recorded as γ-Al2O3-S, and the catalyst was prepared according to the following method:

[0148] (1) Dissolve 5 g of Cu(NO3)2·3H2O in 30 mL of ultrapure water and stir at room temperature for 0.5 h to obtain a copper nitrate solution with a concentration of 0.69 mol / L.

[0149] (2) Add 10 mL of 26 wt % ammonia solution to the copper source solution according to the metered amount, and then stir at 30° C. for 2 h to obtain the corresponding copper ammonia solution.

[0150] (3) Add 20g of γ-Al2O3 carrier powder (specific surface area of ​​2m2) to the copper ammonia solution of step (2). 2 / g, with an average pore size of 300 nm), stirred at 0°C for 0.4 h to allow the copper ammonia cation to be adsorbed on the surface of the carrier, then filtered and washed with ultrapure water until the pH value of the filtrate was 7.3, and finally dried at 110°C for 8 h to obtain a blue solid powder.

[0151] (4) The blue solid powder obtained in step (3) was calcined at 350°C in an air atmosphere for 4 h to obtain a heterogeneous catalyst 8wt% CuO / γ-Al2O3-S, which was recorded as comparative example catalyst 4# (wherein the average particle size of the active component CuO nanoparticles was 10.52 nm).

[0152] The epoxidation experiment of long-chain α-olefins was carried out using the comparative example catalyst 4#. The specific performance evaluation steps are as follows:

[0153] (1) 1 mmol of the reaction substrate 1-decene, 5 mL of the reaction solvent acetonitrile, 5 mmol of benzaldehyde, and 0.8 mol% of the comparative example catalyst 4# were placed in a reaction kettle, and then the reaction kettle was sealed. (2) The air in the reaction kettle was repeatedly replaced with high-purity O2. After the replacement was completed, oxygen was introduced to a total pressure of 0.13 MPa. The reaction was carried out at 60°C for 6 hours. After the reaction kettle was cooled to room temperature, the mixture was subjected to chromatographic quantitative analysis using an Agilent chromatograph. The results are shown in Table 1.

[0154] Comparative Example 5

[0155] The catalyst prepared in this comparative example is 8wt% CuO / γ-Al2O3-L, wherein the surface area of ​​the γ-Al2O3 carrier is 20m 2 / g, recorded as γ-Al2O3-L, and the catalyst was prepared according to the following method:

[0156] (1) Dissolve 5 g of Cu(NO3)2·3H2O in 30 mL of ultrapure water and stir at room temperature for 0.5 h to obtain a copper nitrate solution with a concentration of 0.69 mol / L.

[0157] (2) Add 10 mL of 26 wt % ammonia solution to the copper source solution according to the metered amount, and then stir at 30° C. for 2 h to obtain the corresponding copper ammonia solution.

[0158] (3) Add 20g of γ-Al2O3 carrier powder (specific surface area of ​​20m2) to the copper ammonia solution of step (2). 2 / g, with an average pore size of 100 nm), stirred at 0°C for 0.4 h to allow the copper ammonia cation to be adsorbed on the surface of the carrier, then filtered and washed with ultrapure water until the pH value of the filtrate was 7.3, and finally dried at 110°C for 8 h to obtain a blue solid powder.

[0159] (4) The blue solid powder obtained in step (3) was calcined at 350°C in air for 4 h to obtain a heterogeneous catalyst 8 wt% CuO / γ-Al2O3-L, which was recorded as comparative example catalyst 5# (wherein the average particle size of the active component CuO nanoparticles was 6.35 nm).

[0160] The epoxidation experiment of long-chain α-olefins was carried out using the comparative example catalyst 5#. The specific performance evaluation steps are as follows:

[0161] (1) 1 mmol of the reaction substrate 1-decene, 5 mL of the reaction solvent acetonitrile, 5 mmol of benzaldehyde, and 0.8 mol% of the comparative example catalyst #5 were placed in a reaction kettle, and then the reaction kettle was sealed. (2) The air in the reaction kettle was repeatedly replaced with high-purity O2. After the replacement was completed, oxygen was introduced to a total pressure of 0.13 MPa. The reaction was carried out at 60°C for 6 hours. After the reaction kettle was cooled to room temperature, the mixture was subjected to chromatographic quantitative analysis using an Agilent chromatograph. The results are shown in Table 1.

[0162] Table 1 Reaction results of olefin epoxidation catalyzed by various catalysts

[0163] Catalyst No. Substrate (olefin) Conversion rate (%) Epoxide selectivity (%) Example 1 1# 1-Hexene 99 99 Example 2 1# 1-Decene 99 99 Example 3 1# 1-Dodecene 98 99 Example 4 2# 1-Decene 95 97 Example 5 3# 1-Decene 94 95 Comparative Example 1 Comparative Example 1# 1-Decene 75 80 Comparative Example 2 Comparative Example 2# 1-Decene 70 75 Comparative Example 3 Comparative Example 3# 1-Decene 55 70 Comparative Example 4 Comparative Example 4# 1-Decene 36 72 Comparative Example 5 Comparative Example 5# 1-Decene 67 78

[0164] As can be seen from the table above, the heterogeneous catalyst provided by the present invention is suitable for catalyzing the epoxidation reaction of long-chain α-olefins, and has advantages such as high catalytic activity (conversion rate can reach over 90%, preferably over 94%) and high selectivity (target product selectivity can reach over 90%, preferably over 95%). The long-chain epoxy compounds obtained by catalyzing the epoxidation reaction using the catalyst of the present invention can be further applied in the fields of synthetic detergents, surfactants, dyes, plasticizers, cosmetics, pharmaceuticals, fragrances, etc., achieving higher added value. Therefore, the technology of the present invention has very important industrial application value.

Claims

1. A heterogeneous catalyst for catalyzing the epoxidation of long-chain α-olefins, wherein: The catalyst comprises: an active component, wherein the active component is CuO nanoparticles, wherein the average particle size of the CuO nanoparticles is 1.0 to 2.9 nm; and a carrier, wherein the carrier has a specific surface area of ​​150 m 2 / g~200m 2 / g of porous Al2O3, wherein the Al2O3 is one or more of α-Al2O3, β-Al2O3 and γ-Al2O3, and the average pore size of the porous Al2O3 is 14-20 nm; And wherein, relative to the total mass of the heterogeneous catalyst, the content of the CuO nanoparticles is 5 wt % to 10 wt %.

2. A method for preparing the heterogeneous catalyst according to claim 1, comprising: (1) Mixing a water-soluble copper source and ultrapure water, stirring and dissolving them at room temperature to obtain a copper source solution; (2) adding an ammonia solution to the copper source solution according to a metered amount, and then stirring to allow copper ions to complex with ammonia molecules to form copper ammonia complex ions, thereby obtaining a copper ammonia solution; (3) Adding Al2O3 powder as a carrier to the copper ammonia solution and stirring to allow the copper ammonia cations to be adsorbed on the surface of the carrier, followed by filtering, washing with ultrapure water, and drying to obtain a blue solid powder, wherein the specific surface area of ​​the Al2O3 powder is 150 m 2 / g~200m 2 / g, the average pore size of the Al2O3 powder is 14-20nm; (4) calcining the blue solid powder in an air atmosphere to obtain the heterogeneous catalyst, wherein the heterogeneous catalyst contains 5 wt% to 10 wt% of CuO nanoparticles relative to the total mass of the heterogeneous catalyst.

3. The method according to claim 2, wherein: The water-soluble copper source is a water-soluble inorganic copper salt.

4. The method according to claim 3, wherein: The water-soluble inorganic copper salt is selected from copper nitrate, copper chloride or copper sulfate.

5. The method according to any one of claims 2 to 4, wherein The concentration of the copper source solution is 0.1-1 mol / L.

6. The method according to any one of claims 2 to 4, wherein In step (1), stir at room temperature for 10 min to 1 h.

7. The method according to any one of claims 2 to 4, wherein In step (2), the concentration of the ammonia solution is 5 wt% to 30 wt%.

8. The method according to any one of claims 2 to 4, wherein In step (2), the mixture is stirred at 20°C to 50°C for 0.5 to 4 hours.

9. The method according to any one of claims 2 to 4, wherein In step (3), stir at -5°C to 15°C for 10 min to 3.0 h.

10. The method according to any one of claims 2 to 4, wherein In step (3), the filtrate is washed with ultrapure water until the pH value is 7.0-8.

0.

11. The method according to any one of claims 2 to 4, wherein In step (3), the drying temperature is 100°C to 130°C, and the drying time is 5 to 12 hours.

12. The method according to any one of claims 2 to 4, wherein In step (4), the blue solid powder is calcined at 300° C. to 500° C. for 1 to 10 hours.

13. Use of the heterogeneous catalyst according to claim 1 for catalyzing the epoxidation reaction of C6-C14 long carbon chain α-olefins to prepare high carbon epoxides.

14. The use according to claim 13, wherein The long carbon chain α-olefin is a C6~C12 long carbon chain α-olefin.

15. A method for preparing a high-carbon epoxy compound by catalyzing the epoxidation reaction of a C6-C14 long-chain α-olefin, comprising: In the presence of a co-reducing agent aldehyde and a solvent, the long-chain α-olefin is catalyzed by the heterogeneous catalyst according to claim 1 to undergo epoxidation reaction with oxygen to generate a corresponding high-carbon epoxy compound.

16. The method of claim 15, wherein: The long-chain α-olefin is a C6-C12 long-chain α-olefin.

17. The method according to claim 15 or 16, wherein The co-reducing agent is one or more of benzaldehyde, tert-butylaldehyde, phenylacetaldehyde, acetaldehyde, and propionaldehyde.

18. The method according to claim 15 or 16, wherein The solvent is one or more of toluene, ethylbenzene, acetonitrile and tetrahydrofuran.

19. The method according to claim 15 or 16, wherein The epoxidation reaction is carried out at a temperature of 50-100° C., a pressure of 0.1-0.5 MPa, and a time of 4-10 hours.

20. The method according to claim 15 or 16, wherein The epoxidation reaction is carried out batchwise in a reactor, or continuously in a fixed bed or fluidized bed.

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