CN111974455A - Catalyst PCuMo for catalyzing epoxidation reaction of cyclooctene and cyclododecene11@PC - Google Patents

Abstract

The invention discloses a preparation method of a catalyst PCuMo ₁₁ for catalyzing the oxidation reaction of cyclooctene and cyclododecene. Including: the preparation of copper ion-substituted phosphomolybdic acid PCuMo ₁₁ and the method of loading PCuMo ₁₁ on covalent organic framework material PC to obtain PCuMo ₁₁ @PC new composite material; In addition, the present invention uses PCuMo ₁₁ @PC for catalyzing cyclooctene And cyclododecene oxygen epoxidation reaction. The invention has the characteristics of simple operation, economy and environmental protection, good catalytic performance and the like, and the prepared new composite material PCuMo ₁₁ @PC is an efficient and environment-friendly heterogeneous catalyst for olefin epoxidation reaction.

Description

A kind of catalyst for catalyzing the epoxidation reaction of cyclooctene and cyclododecene PCuMo11@PC

technical field

The invention belongs to the technical field of heterogeneous catalytic materials, in particular to a method for preparing a covalent organic framework material supported by copper ions to replace phosphomolybdic acid and applying it to catalyze the epoxidation reaction of cyclooctene and cyclododecene.

Background technique

Epoxy compound is an important intermediate product with a wide range of uses in the chemical industry, and is widely used in the fields of medicine, material and chemical industry. Olefin epoxidation reaction is the main source of producing epoxy compounds, among which there are methods such as halohydrin method and peracid method for synthesizing olefin epoxy compounds, but the oxidant used has environmental pollution, equipment corrosion, complex production, low yield and consumption. Can higher issues. In order to improve the above problems, many new catalysts have been developed for olefin epoxidation. CN110433826A utilizes co-precipitation method to prepare a single-atom gold catalyst, which catalyzes the epoxidation of styrene with air as the oxidant. Although it has good catalytic performance and good stability, gold is expensive and energy-intensive; CN110694676A discloses a TUD-1 doped lanthanide metal mesoporous catalyst, which can catalyze C ₃ -C in alkyl hydrogen peroxide solution ₁₀ alkene or cycloalkene. The catalyst preparation process is complicated and time-consuming, which is not conducive to industrial production.

Heteropolyacids are oxygen-containing polyacid green catalysts composed of heteroatoms (such as P, Si, Fe, Co, etc.) and polyatoms (such as Mo, W, V, Nb, Ta, etc.). Due to the unique acidity, "quasi-liquid phase" behavior, and multifunctionality of heteropolyacids, they have been widely valued by researchers in the field of catalysis research and olefin epoxidation. CN106975522A developed a phosphorus-molybdenum-tungsten heteropolyacid catalyst, and catalyzed the epoxidation of olefins with tert-butyl hydroperoxide as the oxidant, wherein the tert-butyl hydroperoxide polluted the environment and consumed high energy.

The invention utilizes cheap and readily available transition metal copper-substituted Keggin-type phosphomolybdenum heteropolyacid to prepare an olefin epoxidation catalyst PCuMo ₁₁ @PC with excellent performance, and the catalyst can utilize oxygen to directly catalyze cyclooctene and cyclododecene, The preparation process of the catalyst is simple, the production cost is low, and the catalytic process is green and environmentally friendly, and has popularization and application value.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an economical, green, easy-to-operate and highly efficient catalyst for the epoxidation reaction of cyclooctene and cyclododecene using oxygen as an oxygen source. The catalyst is a heterogeneous catalytic material obtained by using a micro-mesoporous covalent organic framework material PC as a carrier and immobilizing copper-substituted phosphomolybdic acid.

In order to achieve the above object, the present invention adopts the following technical solutions:

A catalyst PCuMo ₁₁ @PC preparation method for catalyzing the epoxidation reaction of cyclooctene and cyclododecene is achieved by the following steps:

(1) Preparation of covalent organic framework material PC: Potassium carbonate, cyanuric chloride and anhydrous piperazine are dissolved in 1,4-dioxane solvent, the mixture is heated at a constant temperature, and the reaction is completed and filtered under reduced pressure , the filter cake was washed with acetone, tetrahydrofuran and dichloromethane, and dried in vacuo to obtain yellow powder PC;

(2) Preparation of copper ion-substituted phosphomolybdic acid PCuMo ₁₁ : adjust the pH of PMo ₁₂ solution to 4-5 by adding saturated sodium bicarbonate solution dropwise, then mix with CuSO ₄ 5H ₂ O solution, stir at constant temperature, and let stand to remove precipitation Sodium sulfate impurity, collect PCuMo ₁₁ crystal;

(3) Preparation of catalyst PCuMo ₁₁ @PC: Add PCuMo ₁₁ aqueous solution to the uniformly dispersed PC aqueous solution, heat and stir at constant temperature, filter, wash, and vacuum dry to obtain a new composite material PCuMo ₁₁ @PC.

Preferably, in the above-mentioned preparation method of a catalyst PCuMo ₁₁ @PC for catalyzing the epoxidation reaction of cyclooctene and cyclododecene, the substances of potassium carbonate, cyanuric chloride and anhydrous piperazine in step (1) The ratio of the amount of the mixture is 6:2:3, the constant temperature stirring temperature is 100-130 °C, the reaction time is 24-72 h, and the more preferred temperature is 110 °C, and the reaction time is 48 h.

Preferably, in the above-mentioned preparation method of a catalyst PCuMo ₁₁ @PC for catalyzing the epoxidation reaction of cyclooctene and cyclododecene, the amount of phosphomolybdic acid and CuSO ₄ · 5H ₂ O in step (2) is Ratio 1:(0.5-3), constant temperature stirring temperature 45-50 ℃, time 30-60min, further preferably phosphomolybdic acid and CuSO _{4.5H 2} O material ratio is 1:3, constant temperature stirring temperature 50 ℃, Time 60min.

The beneficial effects of the above technical solutions are: an appropriate increase in synthesis temperature and temperature is beneficial to increase the product yield, and an increase in the ratio of CuSO ₄ · 5H ₂ O can improve the yield of phenyloxirane.

The present invention also provides the epoxidation reaction of cyclooctene and cyclododecene in the composite material in which the above-mentioned copper ion-substituted phosphomolybdic acid is loaded on the covalent organic framework material PC, and the steps are as follows:

(1) Add catalyst, acetonitrile, isobutyraldehyde, and olefin into the double-necked flask, and introduce molecular oxygen at 10 mL/min. The olefins are cyclooctene and cyclododecene;

(2) The reaction temperature is 40°C-70°C. After a period of reaction, an appropriate amount of the reaction mixture is taken out, filtered through a filter membrane, and detected by gas chromatography.

As can be seen from the above scheme, compared with the prior art, the present invention discloses a preparation method of a catalyst PCuMo ₁₁ @PC composite material for catalyzing the epoxidation reaction of cyclooctene and cyclododecene, and a method for preparing the same in a cyclooctene epoxidation reaction. The application in the oxygen epoxidation of octene and cyclododecene has the following advantages:

(1) In terms of catalyst preparation, the raw materials prepared are economical and easy to obtain, and the catalytic active material PCuMo ₁₁ is cheap and easy to obtain. Since the micro-mesoporous carrier PC is rich in nitrogen, the copper-substituted phosphomolybdic acid active material is loaded relatively firmly;

(2) In terms of catalyzing the epoxidation of cyclooctene and cyclododecene, low-cost, green and environmentally friendly oxygen is used as the oxygen source, and the catalytic effect is good. The prepared new catalyst is in cyclooctene and cyclododecene epoxy. The catalytic performance in the chemical reaction has high reactivity and selectivity.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

Fig. 1 is an infrared spectrum diagram of PCuMo ₁₁ @PC of the present invention.

Figure 2 Figure 2 shows the XRD patterns of PCuMo ₁₁ , PC and PCuMo ₁₁ @PC of the present invention.

Figure 3 Figure 3 shows the nitrogen adsorption and desorption curves and pore size distribution diagrams of (a) PC and (b) PCuMo ₁₁ @PC of the present invention, and the relevant data are listed in attached table 1.

Figure 4 shows the surface area, pore diameter and pore volume of PC and PCuMo ₁₁ @PC of the present invention.

Figure 5 The accompanying drawing is the evaluation of PCuMo ₁₁ @PC catalyzing cyclooctene and cyclododecene of the present invention.

Detailed ways

In order to obtain a clearer and more complete description of the present invention, the following examples are only partial examples of the present invention, and equivalent changes and modifications made by the following examples all belong to the scope of the patent of the present invention.

Example 1

20 mg of PCuMo ₁₁ @PC catalyst, 10 mL of acetonitrile, 2 mmol of cyclooctene and 6 mmol of isobutyraldehyde were added to the double-necked flask, 10 mL/min of oxygen was introduced, and the reaction was performed at 60 °C for 1 h; a small amount was taken out from the flask The solution was filtered through a filter membrane and analyzed by gas chromatography, the conversion rate was 98%, and the selectivity was >99%.

Example 2

Add 20 mg PCuMo ₁₁ @PC catalyst, 10 mL acetonitrile, 2 mmol cyclododecene and 6 mmol isobutyraldehyde to the double-necked flask, pass 10 mL/min oxygen, and react at 60 °C for 1 h; take out from the flask A small amount of solution was filtered through a membrane and analyzed by gas chromatography, the conversion rate was 95%, and the selectivity was >99%.

In addition, in the present invention, the raw materials of PCuMo ₁₁ @PC and the _{PCuMo 11} @PC catalyst were tested by infrared spectrum, XRD, nitrogen adsorption and desorption curves, and pore size distribution, as shown in Figs. Infrared spectrum, in the catalyst PCuMo ₁₁ @PC, the main framework structure of the carrier PC is maintained; Figure 2 is the XRD pattern of the PCuMo ₁₁ @PC of the present invention, the catalyst PCuMo ₁₁ @PC maintains the main framework structure of the carrier PC; Figure 3 and Table 1 are the nitrogen adsorption and desorption curves and pore size distribution of PCuMo ₁₁ @PC of the present invention. Compared with the surface area, pore size and pore volume of the support PC, the surface area, pore size and pore volume of the catalyst PCuMo 11@PC are all reduced, which proves that PCuMo ₁₁ has been loaded on the carrier PC, and there is a chemical interaction between PCuMo ₁₁ and the carrier PC.

The above descriptions are only preferred specific embodiments of the present invention, and the catalyst raw materials, the proportions of components, and the preparation methods of the present invention are all within the scope of protection and disclosure of the present invention. If equivalent replacements or changes are made through examples, they should all be included within the protection scope of the present invention.

Claims (9)

1. a catalyst PCuMo ₁₁ @PC for catalyzing cyclooctene and cyclododecene epoxidation reaction, is characterized in that, comprises the steps as follows: (1) Preparation of covalent organic framework material PC: Potassium carbonate, cyanuric chloride and anhydrous piperazine are dissolved in 1,4-dioxane solvent, the mixture is heated at a constant temperature, and the reaction is completed and filtered under reduced pressure , the filter cake was washed with acetone, tetrahydrofuran and dichloromethane, and dried in vacuo to obtain yellow powder PC; (2) Preparation of copper ion-substituted phosphomolybdic acid PCuMo ₁₁ : adjust the pH of PMo ₁₂ solution to 4-5 by adding saturated sodium bicarbonate solution dropwise, then mix with CuSO ₄ 5H ₂ O solution, stir at constant temperature, and let stand to remove precipitation Sodium sulfate impurity, collect PCuMo ₁₁ crystal; (3) Preparation of catalyst PCuMo ₁₁ @PC: Add PCuMo ₁₁ aqueous solution to the uniformly dispersed PC aqueous solution, heat and stir at constant temperature, filter, wash, and vacuum dry to obtain a new composite material PCuMo ₁₁ @PC. 2. a kind of catalyst PCuMo ₁₁ @PC for catalyzing the epoxidation reaction of cyclooctene and cyclododecene according to claim 1, is characterized in that: in step (1), potassium carbonate, cyanuric acid chloride and The substance amount ratio of anhydrous piperazine is 6:2:3. 3. A kind of catalyst PCuMo ₁₁ @PC for catalyzing the epoxidation reaction of cyclooctene and cyclododecene according to claim 1, is characterized in that: in step (1), the constant temperature stirring temperature is 100-130 ℃, The reaction time is 24-72 h. 4. a kind of catalyst PCuMo ₁₁ @PC for catalyzing cyclooctene and cyclododecene epoxidation reaction according to claim 1, is characterized in that: in step (1), PC productivity 70%-75% . 5. a kind of catalyst PCuMo ₁₁ @PC for catalyzing the epoxidation reaction of cyclooctene and cyclododecene according to claim 1, is characterized in that: in step (2), phosphomolybdic acid and CuSO _4.5H The amount of ₂ O substances is 1:(0.5-3). 6. A kind of catalyst PCuMo ₁₁ @PC for catalyzing the epoxidation reaction of cyclooctene and cyclododecene according to claim 1, is characterized in that: in step (2), the constant temperature stirring temperature is 45-50 ℃, Time 30-60min. 7. a kind of catalyst PCuMo ₁₁ @PC for catalyzing cyclooctene and cyclododecene epoxidation reaction according to claim 1, is characterized in that: in step (3), the mass ratio of PCuMo ₁₁ and PC is 1: (0.5-5), after the reaction, the mixture was separated by suction filtration under reduced pressure, and the solid product was washed 3-5 times with ethanol and deionized water, and dried in vacuum at 80°C for more than 12 hours. 8. A composite material in which copper ion-substituted phosphomolybdic acid prepared by the method of any one of claims 1-7 is supported on a covalent organic framework material PC. 9. a kind of composite material PCuMo ₁₁ @PC that the phosphomolybdic acid substituted with copper ion according to claim 8 is loaded on the covalent organic framework material PC in cyclooctene and cyclododecene oxygen epoxidation reaction Application is characterized in that: the steps are as follows: (1) Add the composite material, acetonitrile, isobutyraldehyde, cyclooctene or cyclododecene in which the catalyst is substituted with copper ion-substituted phosphomolybdic acid supported on the covalent organic framework material PC, and feed 10 mL/min molecular oxygen, react for 1 h at a constant temperature of 40°C-70°C to obtain a mixture; (2) Take out an appropriate amount of the reaction mixture, filter it with a membrane filter, and perform gas chromatography detection.

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