Molybdenum-loaded peroxide cluster catalyst as well as preparation method and application thereof

Abstract

The invention discloses a molybdenum-loaded peroxide cluster catalyst as well as a preparation method and application thereof, and aims to solve the problem that the preparation of epoxy cyclooctane by cyclooctene oxidation lacks a high-selectivity efficient catalyst. The invention provides a catalyst which has the characteristics of high substrate conversion rate, target product selectivity, stability and the like when being used for preparing epoxy cyclooctene by catalyzing cyclooctene oxidation. The preparation method comprises the following steps: S1, adding molybdenum trioxide into hydrogen peroxide, stirring for 5-10 hours at 30-60 DEG C, dispersing to obtain a solution A, calcining and activating a catalyst carrier, and dispersing into deionized water to obtain slurry B; s2, mixing the solution A into the slurry B, stirring at 50-100 DEG C for 10-48 hours, and drying to obtain a solid C; and S3, carrying out solution ion exchange on the solid C, drying, and calcining to obtain solid powder, namely the molybdenum-loaded peroxide cluster catalyst. Relates to the technical field of catalysts.

Description

Technical Field

[0001] The present invention relates to a supported molybdenum peroxo cluster catalyst for the oxidation of cyclooctene, and more specifically, to a preparation method of a supported molybdenum peroxo cluster catalyst and a method for preparing epoxycyclooctane by the oxidation of cyclooctene; it relates to the technical field of catalysts. Background Art

[0002] Epoxycyclooctane is an important raw material for organic chemical synthesis, widely used as an intermediate for synthetic substances, pharmaceuticals, cosmetics, polymer resins, etc. Moreover, the number of downstream products derived from it is large and the applications are extensive, showing broad application prospects.

[0003] The traditional industrial methods for preparing epoxycyclooctane mainly include the haloalcohol and peroxyacid oxidation methods. Although they show good catalytic performance for olefin oxidation, they have disadvantages such as the toxicity of by-products and the difficulty in separating oxides. Using peroxides as oxidants is an ideal candidate for oxidation due to their sustainability, high safety, and stable by-products, which is more in line with the theme of green chemistry. Supported transition metal solid catalysts are widely used in the field of olefin oxidation due to their unique properties of variable chemical valence and electron affinity. The catalysts reported currently are mainly noble metal catalysts. As is well known, noble metal catalysts have the disadvantages of high price and limited reserves, and at the same time, the selectivity of epoxycyclooctane also needs to be improved. Therefore, developing non-noble metal solid catalysts with low cost and high activity has become the key to current research.

[0004] Therefore, developing a new process for the oxidation of cyclooctene that is environmentally friendly, low-cost, and high-yield is of great significance for promoting the industrial production of epoxycyclooctane and expanding the market application of epoxycyclooctane. Summary of the Invention

[0005] The primary object of the present invention is to overcome the problem of low selectivity of epoxycyclooctane in the above-mentioned prior art, and at the same time enhance the conversion rate of cyclooctene, and provide a supported molybdenum peroxo cluster catalyst for the efficient preparation of epoxycyclooctane by the oxidation of cyclooctene.

[0006] A further object of the present invention is to provide a supported molybdenum peroxo cluster catalyst.

[0007] Another object of the present invention is to provide a preparation method of a supported molybdenum peroxo cluster catalyst.

[0008] Another object of the present invention is to provide an application of a supported molybdenum peroxo cluster catalyst in the preparation of epoxycyclooctane by the oxidation of cyclooctene.

[0009] A supported molybdenum peroxo cluster catalyst, calculated based on 100% of the total mass of the supported molybdenum peroxo cluster catalyst, the content of molybdenum is 0.1 - 10 wt%, the content of oxygen is 0.07 - 7 wt%, and the balance is the catalyst support.

[0010] Further, in the above-mentioned molybdenum peroxide cluster-loaded catalyst, calculated based on 100% of the total mass of the molybdenum peroxide cluster-loaded catalyst, the content of molybdenum is 1-5 wt%, the content of oxygen is 0.7-3.3 wt%, and the balance is the catalyst support.

[0011] Further, in the above-mentioned molybdenum peroxide cluster-loaded catalyst, the catalyst support is one of TS-1, Al-MCM-41, SBA-15, and Beta zeolite.

[0012] The second technical solution provided by the present invention is a preparation method of the above-mentioned molybdenum peroxide cluster-loaded catalyst, which successively includes the following steps:

[0013] S1. Add molybdenum trioxide to hydrogen peroxide solution, and reflux and stir at 30-60 °C for 5-10 h to obtain solution A;

[0014] S2. Calcinate the catalyst support at 200-600 °C for 0.5-3 h to obtain the activated support;

[0015] S3. Disperse the activated catalyst support in step S2 into deionized water to obtain slurry B;

[0016] S4. Dropwise add the solution A prepared in step S1 to step S3, and stir it open at 50-100 °C for 10-48 h, and then dry it to obtain solid C;

[0017] S5. Ion-exchange solid C with ammonium chloride solution for 0.5-5 h and then dry it to obtain powder, and calcinate it at 300-700 °C for 2-6 h under a nitrogen atmosphere.

[0018] Wherein:

[0019] In step S1, the molar ratio of hydrogen peroxide to molybdenum trioxide is (28-212):1;

[0020] In step S4, the mass ratio of the catalyst support to molybdenum trioxide is (2-50):1.

[0021] Further, in the preparation method of the above-mentioned molybdenum peroxide cluster-loaded catalyst, the mass fraction of the hydrogen peroxide solution is 30%.

[0022] Further, in the preparation method of the above-mentioned molybdenum peroxide cluster-loaded catalyst, the concentration of the ammonium chloride solution is 0.5-5 M.

[0023] A molybdenum peroxide cluster-loaded catalyst provided by the present invention is used for the reaction of catalytically oxidizing cyclooctene to prepare epoxycyclooctane.

[0024] Another technical solution of the present invention is a preparation method of epoxycyclooctane, which comprises the following steps: adding the supported molybdenum peroxo cluster catalyst described in claim 1 into an organic solvent, adding an oxidant and cyclooctene, and reacting at 60-180 °C for 1-10 h to obtain epoxycyclooctane;

[0025] The mass ratio of the oxidant, cyclooctene and catalyst is (1-25):1:(0.0125-0.2).

[0026] Further, in the above method for preparing epoxycyclooctane by oxidizing cyclooctene, the organic solvent is at least one of cumene, cyclohexane, tetrahydrofuran, ethyl acetate, ethanol, dichloromethane, acetonitrile, ethylbenzene, toluene, isopropanol, N,N-dimethylformamide.

[0027] Further, in the above method for preparing epoxycyclooctane by oxidizing cyclooctene, the oxidant is at least one of cumene hydroperoxide, tert-butyl hydroperoxide, and hydrogen peroxide.

[0028] Compared with the prior art, the technical solution provided by the present invention has the following technical advantages:

[0029] 1. The present invention provides a supported molybdenum peroxo cluster catalyst, which has a high cyclooctene conversion rate, epoxycyclooctane selectivity and cumene hydroperoxide utilization rate when used for oxidizing cyclooctene to prepare epoxycyclooctane, and can be used for efficiently preparing epoxycyclooctane from cyclooctene.

[0030] 2. The supported molybdenum peroxo cluster catalyst of the present invention is non-toxic, has stable performance, is easy to separate after the reaction, can be reused, and causes no secondary pollution to the environment. Description of the Drawings

[0031] Figure 1 XRD patterns of the catalyst Mo / TS-1 and the support TS-1 described in Example 1. Detailed Embodiments

[0032] In order to more clearly and completely describe the technical solution of the present invention, the present invention will be further described in detail below through specific examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention, and various changes can be made within the scope defined by the claims of the present invention.

[0033] The reagents in the examples are all commercially available analytical pure reagents.

[0034] Example 1

[0035] A preparation method of a supported molybdenum peroxo cluster catalyst, which comprises the following steps:

[0036] S1. Add 0.1 g of molybdenum trioxide to 7 mL of hydrogen peroxide, and reflux and stir at 45 °C for 9 h to obtain solution A;

[0037] S2. Calcinate TS-1 at 300 °C for 2 h to obtain the activated support.

[0038] S3. Disperse 2 g of the activated catalyst support into 100 mL of deionized water to obtain slurry B;

[0039] S4. Dropwise add the solution A prepared in step S1 to step S3, stir it open at 70 °C for 15 h, and dry it to obtain solid C;

[0040] S5. Ion-exchange solid C with 30 mL (3 M) of ammonium chloride solution for 1 h and then dry it to obtain a powder. Calcinate it at 600 °C for 3 h under a nitrogen atmosphere to obtain the catalyst Mo / TS-1.

[0041] For the XRD patterns of the catalyst Mo / TS-1 and the support TS-1 described in Example 1, refer to Figure 1 , characteristic diffraction peaks of the TS-1 phase were detected at 2θ = 7.8°, 8.8°, 23.2°, 23.8°, and 24.3°, corresponding to the (101), (200), (501), (311), and (303) crystal planes respectively. In addition, after introducing the metal, the XRD pattern of Mo / TS-1 is basically the same as that of TS-1, and the structure of the supported TS-1 support has not changed. In addition, no characteristic diffraction peaks of metals or metal oxides were detected, indicating that the introduced metal species are highly dispersed on the HAP surface and do not aggregate as large nanoparticles.

[0042] Example 2

[0043] A preparation method of a supported molybdenum peroxo cluster catalyst, comprising the following steps:

[0044] S1. Add 0.15 g of molybdenum trioxide to 8 mL of hydrogen peroxide, and reflux and stir at 45 °C for 7 h to obtain solution A;

[0045] S2. Calcinate SBA-15 at 400 °C for 1 h to obtain the activated support.

[0046] S3. Disperse 2 g of the activated catalyst support into 50 mL of deionized water to obtain slurry B;

[0047] S4. Dropwise add the solution A prepared in step S1 to step S3, stir it open at 80 °C for 10 h, and dry it to obtain solid C;

[0048] S5. Ion-exchange solid C with 2 M ammonium chloride solution for 2 h and then dry it to obtain a powder. Calcinate it at 500 °C for 4 h under a nitrogen atmosphere to obtain the catalyst Mo / SBA-15.

[0049] Example 3

[0050] A method for preparing a supported molybdenum peroxide cluster catalyst comprises the following steps:

[0051] S1. Add 0.2 g of molybdenum trioxide to 10 mL of hydrogen peroxide and reflux with stirring at 60°C for 5 h to obtain solution A;

[0052] S2. Calcinate the Beta molecular sieve at 300°C for 2 hours to obtain an activated support.

[0053] S3. 2 g of the activated catalyst support was dispersed in 60 mL of deionized water to obtain slurry B;

[0054] S4. Solution A prepared in step S1 was added dropwise to step S3, stirred open at 60 ° C for 12 h, and dried to obtain a solid C;

[0055] S5. The solid C was ion-exchanged with a 2M ammonium chloride solution for 3 h and then dried to obtain a powder. The powder was calcined at 500° C. for 3 h under a nitrogen atmosphere to obtain the catalyst Mo / Beta.

[0056] Example 4

[0057] A method for preparing cyclooctane oxide comprises the following steps:

[0058] 20 mg of the catalyst prepared in Example 1 was added to a 100 mL pressure tube, 7 mL of isopropanol was added as a solvent, 3 mL of cumene hydroperoxide was added as an oxidant, 0.8 g of cyclooctene was added, and biphenyl was used as an internal standard. After stirring at 100 ° C for 6 h, the product was quantified by the internal standard method.

[0059] The results showed that the conversion of cyclooctene was 45.3% and the selectivity of the product cyclooctane oxide was 78.6%.

[0060] Example 5

[0061] A method for preparing cyclooctane oxide comprises the following steps:

[0062] 20 mg of the catalyst prepared in Example 2 was added to a 100 mL pressure tube, 7 mL of isopropanol was added as a solvent, 3 mL of cumene hydroperoxide was added as an oxidant, 0.8 g of cyclooctene was added, and biphenyl was used as an internal standard. After stirring at 100 ° C for 6 h, the product was quantified by the internal standard method.

[0063] The results showed that the conversion rate of cyclooctene was 90.0% and the selectivity of the product cyclooctane oxide was 94.8%.

[0064] Example 6

[0065] A method for preparing epoxy cyclooctane, comprising the following steps:

[0066] Add 20 mg of the catalyst prepared in Example 3 into a 100 mL pressure-resistant tube, add 7 mL of isopropanol as a solvent, 3 mL of cumene hydroperoxide as an oxidant, add 0.8 g of cyclooctene, use biphenyl as an internal standard, and stir and react at 100 °C for 6 h. Then, use the internal standard method to quantify the product.

[0067] The results show that the conversion rate of cyclooctene is 18.6%, and the selectivity of the product epoxy cyclooctane is 24.6%.

[0068] Example 7

[0069] A method for preparing epoxy cyclooctane, comprising the following steps:

[0070] Add 25 mg of the catalyst prepared in Example 2 into a 100 mL pressure-resistant tube, add 7 mL of isopropanol as a solvent, 3 mL of cumene hydroperoxide as an oxidant, add 0.8 g of cyclooctene, use biphenyl as an internal standard, and stir and react at 100 °C for 6 h. Then, use the internal standard method to quantify the product.

[0071] The results show that the conversion rate of cyclooctene is 93.5%, and the selectivity of the product epoxy cyclooctane is 96.2%.

[0072] Example 8

[0073] A method for preparing epoxy cyclooctane, comprising the following steps:

[0074] Add 25 mg of the catalyst prepared in Example 2 into a 100 mL pressure-resistant tube, add 7 mL of isopropanol as a solvent, 1.5 mL of cumene hydroperoxide as an oxidant, add 0.8 g of cyclooctene, use biphenyl as an internal standard, and stir and react at 100 °C for 6 h. Then, use the internal standard method to quantify the product.

[0075] The results show that the conversion rate of cyclooctene is 75.6%, and the selectivity of the product epoxy cyclooctane is 88.6%.

[0076] Example 9

[0077] A method for preparing epoxy cyclooctane, comprising the following steps:

[0078] Add 25 mg of the catalyst prepared in Example 2 into a 100 mL pressure-resistant tube, add 7 mL of isopropanol as a solvent, 3 mL of cumene hydroperoxide as an oxidant, add 1 g of cyclooctene, use biphenyl as an internal standard, and stir and react at 100 °C for 6 h. Then, use the internal standard method to quantify the product.

[0079] The results showed that the conversion rate of cyclooctene was 84.5%, and the selectivity of the product epoxynorbornane was 93.6%.

[0080] Example 10

[0081] A method for preparing epoxynorbornane, comprising the following steps:

[0082] Add 25 mg of the catalyst prepared in Example 2 to a 100 mL pressure-resistant tube, add 7 mL of isopropanol as a solvent, 3 mL of cumene hydroperoxide as an oxidant, add 0.6 g of cyclooctene, use biphenyl as an internal standard, and stir and react at 80 °C for 3 h, then use the internal standard method to quantify the product.

[0083] The results showed that the conversion rate of cyclooctene was 82.3%, and the selectivity of the product epoxynorbornane was 80.6%.

[0084] Example 11

[0085] A method for preparing epoxynorbornane, comprising the following steps:

[0086] Add 25 mg of the catalyst prepared in Example 2 to a 100 mL pressure-resistant tube, add 7 mL of isopropanol as a solvent, 3 mL of cumene hydroperoxide as an oxidant, add 0.6 g of cyclooctene, use biphenyl as an internal standard, and stir and react at 70 °C for 6 h, then use the internal standard method to quantify the product.

[0087] The results showed that the conversion rate of cyclooctene was 78.1%, and the selectivity of the product epoxynorbornane was 81.9%.

[0088] Example 12

[0089] A method for preparing epoxynorbornane, comprising the following steps:

[0090] Add 25 mg of the catalyst prepared in Example 2 to a 100 mL pressure-resistant tube, add 7 mL of isopropanol as a solvent, 3 mL of cumene hydroperoxide as an oxidant, add 0.6 g of cyclooctene, use biphenyl as an internal standard, and stir and react at 110 °C for 4 h, then use the internal standard method to quantify the product.

[0091] The results showed that the conversion rate of cyclooctene was 98.2%, and the selectivity of the product epoxynorbornane was 94.6%.

[0092] Comparative Example 1

[0093] A method for preparing a molybdenum catalyst, comprising the following steps:

[0094] S1. Add 0.15 g of molybdenum trioxide to 8 mL of deionized water, and reflux and stir at 45 °C for 7 h to obtain solution A;

[0095] S2. Calcinate SBA-15 at 400 °C for 1 h to obtain the activated support.

[0096] S3. Disperse 2 g of the activated catalyst support into 50 mL of deionized water to obtain slurry B;

[0097] S4. Dropwise add the solution A prepared in step S1 to step S3, stir it open at 80 °C for 10 h, and dry it to obtain solid C;

[0098] S5. Ion-exchange solid C with 2 M ammonium chloride solution for 2 h and then dry it to obtain a powder. Calcinate it at 500 °C for 4 h under a nitrogen atmosphere to obtain the catalyst Mo / SBA-15.

[0099] Comparative Example 2

[0100] A method for preparing epoxycyclooctane, comprising the following steps: Add 25 mg of the catalyst prepared according to Comparative Example 1 to a 100 mL pressure-resistant tube, add 7 mL of isopropanol as a solvent, 3 mL of cumene hydroperoxide as an oxidant, add 0.8 g of cyclooctene, use biphenyl as an internal standard, stir and react at 100 °C for 6 h, and then quantitatively analyze the product by the internal standard method.

[0101] The results show that the conversion rate of cyclooctene is 20.5%, and the selectivity of the product epoxycyclooctane is 28.5%.

[0102] It can be seen from the comparison in Comparative Example 2 that when the molybdenum catalyst without hydrogen peroxide treatment is used to catalyze the oxidation of octene to prepare epoxycyclooctane, the conversion rate of cyclooctene and the selectivity of epoxycyclooctane are much lower than those when the supported molybdenum peroxo cluster catalyst is used to catalyze the oxidation of cyclooctene to prepare epoxycyclooctane. It is speculated that the main reason is that hydrogen peroxide interacts with Mo metal, introducing a terminal peroxo bond to form a highly active coordination structure. This structure directly activates the substrate through the electrophilic attack of the peroxo group and transfers the active oxygen by the cleavage of the O-O bond to form an epoxide.

[0103] [[ID=

Claims

1. A molybdenum peroxide cluster-loaded catalyst, characterized in that, Calculated based on 100% of the total mass of the supported molybdenum peroxo cluster catalyst, the content of molybdenum is 0.1 - 10 wt%, the content of oxygen is 0.07 - 7 wt%, and the balance is the catalyst support.

2. For the supported molybdenum peroxo cluster catalyst according to claim 1, calculated based on 100% of the total mass of the supported molybdenum peroxo cluster catalyst, the content of molybdenum is 1 - 5 wt%, the content of oxygen is 0.7 - 3.3 wt%, and the balance is the catalyst support.

3. The molybdenum peroxo cluster catalyst according to claim 1 or 2, characterized in that, The catalyst support is one of TS-1, Al-MCM-41, SBA-15, and Beta zeolite.

4. The preparation method of a catalyst loaded with molybdenum peroxo clusters according to claim 1, characterized in that, It successively includes the following steps: S1. Add molybdenum trioxide to the hydrogen peroxide solution, and reflux and stir at 30 - 60 °C for 5 - 10 h to obtain solution A; S2. Calcinate the catalyst support at 200 - 600 °C for 0.5 - 3 h to obtain the activated support; S3. Disperse the activated catalyst support in step S2 into deionized water to obtain slurry B; S4. Dropwise add the solution A prepared in step S1 to step S3, stir it open at 50 - 100 °C for 10 - 48 h, and dry it to obtain solid C; S5. Ion-exchange solid C with ammonium chloride solution for 0.5 - 5 h and then dry it to obtain a powder, and calcine it at 300 - 700 °C for 2 - 6 h under a nitrogen atmosphere. Wherein: In step S1, the molar ratio of hydrogen peroxide to molybdenum trioxide is (28 - 212):1; In step S4, the mass ratio of the catalyst support to molybdenum trioxide is (2 - 50):

1.

5. The preparation method of a molybdenum peroxo cluster catalyst according to claim 3, characterized in that, The mass fraction of the hydrogen peroxide solution is 30%; the concentration of the ammonium chloride solution is 0.5 - 5 M.

6. The supported molybdenum peroxo cluster catalyst according to claim 1 is used in the reaction for catalytic oxidation of cyclooctene to prepare epoxycyclooctane.

7. A method for preparing epoxy cyclooctane, characterized in that, It includes the following steps: Add the supported molybdenum peroxo cluster catalyst according to claim 1 to an organic solvent, add an oxidant and cyclooctene, and react at 60 - 180 °C for 1 - 10 h to obtain epoxycyclooctane; The mass ratio of the oxidant, cyclooctene, and catalyst is (1 - 25):1:(0.0125 - 0.2).

8. The method for preparing epoxycyclooctane by oxidizing cyclooctene according to claim 7, characterized in that, The organic solvent is at least one of cumene, cyclohexane, tetrahydrofuran, ethyl acetate, ethanol, dichloromethane, acetonitrile, ethylbenzene, toluene, isopropanol, and N,N-dimethylformamide.

9. The method for preparing epoxycyclooctane by oxidizing cyclooctene according to claim 7, wherein The oxidant is at least one of cumene hydroperoxide, tert-butyl hydroperoxide, and hydrogen peroxide.

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