Catalyst for preparing 1, 2-octanediol as well as preparation method and application of catalyst
By using metalporphyrin and nanocd cadmium sulfide catalysts, the problem of low selectivity and activity of existing catalysts in 1,2-octanediol epoxidation reactions is solved, and the catalytic effect is achieved with high efficiency and good selectivity. Extend the service life of the catalyst and reduce costs.
Patent Information
- Application Number
- CN202411284269.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-13
- Publication Date
- 2024-12-27
AI Technical Summary
The existing catalysts have poor selectivity and low catalytic activity in the epoxidation reaction of 1,2-octanediol, resulting in low substrate conversion rate, making it difficult to meet the demand for efficient and selective catalysts in the chemical and cosmetics industries.
Using metalporphyrin and nanocd sulfide as catalysts for active components, metalporphyrin composite catalysts are formed through sonication and dropwise reactions, adjusting the active site environment to improve catalytic efficiency and selectivity, and optimizing process conditions such as temperature and Drop acceleration extends the service life of the catalyst.
The catalytic synthesis of 1,2-octanediol with high selectivity and high conversion is achieved, which extends the service life of the catalyst, reduces the reaction cost, and improves the stability of the catalyst and material purity.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of catalyst preparation, and in particular relates to a catalyst for preparing 1,2-octanediol, a preparation method and an application thereof. Background Art
[0002] 1,2-Octanediol is an important chemical raw material that can be mixed with a variety of organic chemicals in any proportion and has good compatibility. It can be used not only in the fields of surfactants, wetting agents, emulsifiers, preservatives, but also in synthetic flavors, lubricant additives, plasticizers, adhesives and other industries.
[0003] As a preservative, 1,2-octanediol is mild and effective, and is suitable for a wide pH range. As a humectant, it captures water molecules through hydrophilic groups to moisturize the skin, which can moisturize and soften the skin. With the rapid development of the cosmetics industry and the rise of the concept of "additive-free" preservative products, functional preservatives have gradually attracted attention, and composite preservatives have become inevitable. The market space for new raw materials such as 1,2-octanediol is expected to continue to grow.
[0004] At present, the synthesis of 1,2-octanediol is mainly carried out through the epoxidation reaction of olefins and alkaline hydrolysis reaction, among which the epoxidation process of olefins is the main factor affecting the yield of 1,2-octanediol. However, the existing catalysts have poor selectivity and low catalytic activity, resulting in low substrate conversion rate and poor target product selectivity. Therefore, it is particularly important to develop a catalyst suitable for preparing 1,2-octanediol by epoxidation reaction. Summary of the invention
[0005] The invention provides a catalyst for preparing 1,2-octanediol, a preparation method and an application thereof. The catalyst provided by the invention has high selectivity, high product conversion rate and long service life.
[0006] In order to achieve the above object, the present invention provides a catalyst for preparing 1,2-octanediol, wherein the active components of the catalyst include metal porphyrin and nano-cadmium sulfide.
[0007] Preferably, the molar ratio of the metal porphyrin to the cadmium element in the catalyst is 1:1-10.
[0008] The present invention provides a method for preparing the catalyst described in the above scheme, comprising the following steps:
[0009] 1) mixing tetraphenylcobalt porphyrin with an organic solvent and ultrasonicating to obtain a CoTPP homogeneous solution;
[0010] 2) mixing the aqueous solution of cadmium salt with the CoTPP homogeneous solution to obtain solution A;
[0011] 3) mixing sodium sulfide with an organic solvent to obtain a sodium sulfide solution;
[0012] 4) Under stirring, sodium sulfide solution is added dropwise to solution A. After the addition is complete, the mixture is reacted to obtain a metal porphyrin composite catalyst.
[0013] Preferably, the organic solvent used in step 1) and / or 3) includes one or more of anhydrous ethanol, tetrahydrofuran, dichloromethane, isopropanol, methanol, toluene and a methanol-toluene mixture.
[0014] Preferably, after obtaining solution A in step 2), the method further comprises adjusting the pH of solution A to acidic.
[0015] Preferably, the dropping speed in step 4) is 10 to 60 drops / min.
[0016] Preferably, the reaction temperature in step 4) is 30-60° C. and the reaction time is 1-5 h.
[0017] Preferably, after the reaction in step 4) is completed, drying is further performed; the drying temperature is 50 to 80° C. and the drying time is 10 to 26 hours.
[0018] The present invention also provides the use of any one of the above-mentioned catalysts in the epoxidation synthesis of 1,2-octanediol, wherein the 1,2-octanediol is synthesized by the following steps:
[0019] (1) using 1-octene, hydrogen peroxide and formic acid as reaction raw materials to carry out epoxidation reaction to obtain a reaction solution;
[0020] (2) The reaction solution is subjected to a hydrolysis reaction to obtain 1,2-octanediol.
[0021] Preferably, the molar ratio of 1-octene, hydrogen peroxide and formic acid in step (1) is 1:1.1-1.5:4-6; the temperature of the epoxidation reaction is 40-55°C, and the reaction time is 6-12h.
[0022] Compared with the prior art, the advantages and positive effects of the present invention are:
[0023] The catalyst for preparing 1,2-octanediol provided by the present invention uses metal porphyrin and nano-cadmium sulfide as active components. Metal porphyrin uses its coordinated metal ion as the active center, provides a series of π electrons to the surrounding porphyrin ring, and forms a planar structure, which can coordinate with the substance to be catalyzed. This coordination enables the metal ion to form an active center around it, which is conducive to the catalytic reaction; nano-cadmium sulfide has a high specific surface area, provides more active sites, is conducive to the occurrence of catalytic reactions, and has high catalytic efficiency; and nano-cadmium sulfide has a certain stability and can participate in catalytic reactions multiple times. In this experiment, a metal porphyrin composite catalyst is formed by combining metal porphyrin and nano-cadmium sulfide. The combination of the two can adjust the environment of the active site, making it more selective for the product, and can not only catalyze and oxidize 1,2-octanediol with high selectivity, but also improve the stability of metal porphyrin. Under the condition of protecting the metal porphyrin from inactivation, the catalyst can be reused to reduce the reaction cost. DETAILED DESCRIPTION
[0024] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0025] The invention provides a catalyst for preparing 1,2-octanediol. The active components of the catalyst include metal porphyrin and nano cadmium sulfide.
[0026] In the present invention, the molar ratio of the metal porphyrin to the cadmium element in the catalyst is preferably 1:1-10.
[0027] The catalyst for preparing 1,2-octanediol provided by the present invention has metal porphyrin and nano-cadmium sulfide as active components. Metal porphyrin uses its coordinated metal ion as the active center, provides a series of π electrons to the surrounding porphyrin ring, and forms a planar structure, which can coordinate with the substance to be catalyzed. This coordination enables the metal ion to form an active center around it, which is conducive to the catalytic reaction; nano-cadmium sulfide has a high specific surface area, provides more active sites, and is conducive to the occurrence of the catalytic reaction; at the same time, nano-cadmium sulfide has a certain stability and can participate in the catalytic reaction multiple times. In this experiment, a metal porphyrin composite catalyst is formed by combining metal porphyrin and nano-cadmium sulfide. The combination of the two can adjust the environment of the active site, making it more selective to the product, thereby highly selectively catalyzing and oxidizing the synthesis of 1,2-octanediol, and at the same time can improve the stability of the metal porphyrin, and the catalyst can be reused while protecting the metal porphyrin from inactivation, thereby reducing the reaction cost.
[0028] The present invention provides a method for preparing the catalyst described in the above scheme, comprising the following steps:
[0029] 1) mixing tetraphenylcobalt porphyrin with an organic solvent and ultrasonicating to obtain a CoTPP homogeneous solution;
[0030] 2) mixing the aqueous solution of cadmium salt with the CoTPP homogeneous solution to obtain solution A;
[0031] 3) mixing sodium sulfide with an organic solvent to obtain a sodium sulfide solution;
[0032] 4) Under stirring, sodium sulfide solution is added dropwise to solution A. After the addition is complete, the mixture is reacted to obtain a metal porphyrin composite catalyst.
[0033] The present invention mixes tetraphenylcobalt porphyrin with an organic solvent and ultrasonicates to obtain a CoTPP homogeneous solution. In the present invention, the organic solvent preferably includes one or more of anhydrous ethanol, tetrahydrofuran, dichloromethane, isopropanol, methanol, toluene and a methanol-toluene mixture. In the present invention, the ultrasonication time is preferably 20 to 40 minutes.
[0034] After obtaining the CoTPP homogeneous solution, the present invention mixes the aqueous solution of cadmium salt with the CoTPP homogeneous solution to obtain solution A. In the present invention, the cadmium salt is preferably cadmium nitrate or cadmium acetate. In the present invention, after obtaining solution A, it is preferred to further include adjusting the pH of solution A to acidity. In the present invention, it is preferred to use one or more of dilute hydrochloric acid, dilute nitric acid, dilute sulfuric acid, sodium hydroxide solution and ammonia solution to adjust the pH. In the present invention, it is preferred to place solution A in a light-proof, room temperature environment for standby use.
[0035] The present invention mixes sodium sulfide with an organic solvent to obtain a sodium sulfide solution. In the present invention, the organic solvent preferably includes one or more of anhydrous ethanol, tetrahydrofuran, dichloromethane, isopropanol, methanol, toluene and a methanol-toluene mixture.
[0036] After obtaining the sodium sulfide solution, the present invention drips the sodium sulfide solution in solution A under stirring, and after the dripping is completed, reacts to obtain a metal porphyrin composite catalyst. In the present invention, the dripping speed is preferably 10 to 60 drops / min, and more preferably 30 to 55 drops / min. If the dripping speed of sodium sulfide is too high, it is easy to cause agglomeration and form particles, which is not conducive to the formation of nano-scale cadmium sulfide, thereby affecting the catalytic performance. It can be understood that: the present application controls the dripping speed at 10 to 60 drops / min, which is conducive to improving the catalytic performance. In the present invention, the temperature during the reaction is preferably 30 to 60°C, more preferably 40 to 50°C; the time is preferably 1 to 5h, more preferably 2 to 4h. In the present invention, it is preferably dried after the reaction is completed; the drying temperature is preferably 50 to 80°C, more preferably 60 to 75°C; the time is preferably 10 to 26h, more preferably 16 to 24h.
[0037] The method provided by the present invention combines cadmium salt with porphyrin first, and then adds sodium sulfide solution to prepare a cadmium sulfide and metal porphyrin composite catalyst material. This method can achieve higher material purity and uniformity, and improve the stability and catalytic performance of the material.
[0038] The present invention also provides the use of any one of the above-mentioned catalysts in the epoxidation synthesis of 1,2-octanediol, wherein the 1,2-octanediol is synthesized by the following steps:
[0039] (1) using 1-octene, hydrogen peroxide and formic acid as reaction raw materials to carry out epoxidation reaction to obtain a reaction solution;
[0040] (2) The reaction solution is subjected to a hydrolysis reaction to obtain 1,2-octanediol.
[0041] In the present invention, the molar ratio of 1-octene, hydrogen peroxide and formic acid in step (1) is preferably 1:1.1-1.5:4-6; the temperature of the epoxidation reaction is preferably 40-55°C, and the reaction time is preferably 6-12h. In the present invention, after the hydrolysis reaction is completed, it is preferably further subjected to reduced pressure distillation for purification. In the present invention, the distillation temperature is preferably 120-145°C.
[0042] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.
[0043] Example 1
[0044] Tetraphenylcobalt porphyrin (CoTPP) was dissolved in tetrahydrofuran to prepare a 10 mM CoTPP solution, and then subjected to ultrasonic treatment for 30 min to form a CoTPP homogeneous solution; the CoTPP homogeneous solution was mixed with a 10 mM cadmium nitrate aqueous solution in a volume ratio of 1:1, and the pH of the solution was adjusted to 3 with dilute hydrochloric acid to obtain solution A, which was placed in a light-proof and room temperature environment for use.
[0045] Sodium sulfide (Na2S) solid was dissolved in tetrahydrofuran to prepare a 50mM sodium sulfide solution for use. Solution A was placed in a heatable magnetic stirrer, and the sodium sulfide solution (the volume ratio of solution A to nano sodium sulfide solution was 1:1) was added dropwise while stirring, and the dropping speed was 60 drops / min. After the addition was completed, it was heated to 50°C and reacted for 3h. After the reaction was completed, it was washed with deionized water and dried at 75°C for 24h to obtain a metal porphyrin composite catalyst, which was recorded as catalyst 1.
[0046] Example 2
[0047] Tetraphenylcobalt porphyrin (CoTPP) was dissolved in dichloromethane to prepare a 10 mM CoTPP solution, and then subjected to ultrasonic treatment for 30 min to form a CoTPP homogeneous solution; the CoTPP homogeneous solution was mixed with a 10 mM cadmium nitrate aqueous solution in a volume ratio of 1:5, and the pH of the solution was adjusted to 3 with dilute hydrochloric acid to obtain solution A, which was placed in a light-proof and room temperature environment for use.
[0048] Sodium sulfide (Na2S) solid was dissolved in tetrahydrofuran to prepare a 50mM sodium sulfide solution for use. Solution A was placed in a heatable magnetic stirrer, and the sodium sulfide solution (the volume ratio of solution A to nano sodium sulfide solution was 1:5) was added dropwise while stirring, and the dropping speed was 60 drops / min. After the addition was completed, it was heated to 30°C and reacted for 5h. After the reaction was completed, it was washed with deionized water and dried at 50°C for 26h to obtain a metal porphyrin composite catalyst, which was recorded as catalyst 2.
[0049] Example 3
[0050] Tetraphenylcobalt porphyrin (CoTPP) was dissolved in dichloromethane to prepare a 10 mM CoTPP solution, and then subjected to ultrasonic treatment for 30 min to form a CoTPP homogeneous solution; the CoTPP homogeneous solution was mixed with a 10 mM cadmium nitrate aqueous solution in a volume ratio of 1:1, and the pH of the solution was adjusted to 4 with dilute hydrochloric acid to obtain solution A, which was placed in a light-proof and room temperature environment for use.
[0051] Sodium sulfide (Na2S) solid was dissolved in dichloromethane to prepare a 50mM sodium sulfide solution for use. Solution A was placed in a heatable magnetic stirrer, and the sodium sulfide solution (the volume ratio of solution A to nano sodium sulfide solution was 1:1) was added dropwise while stirring, and the dropping speed was 30 drops / min. After the addition was completed, it was heated to 60°C and reacted for 2h. After the reaction was completed, it was washed with deionized water and dried at 75°C for 24h to obtain a metal porphyrin composite catalyst, which was recorded as catalyst 3.
[0052] Example 4
[0053] Tetraphenylcobalt porphyrin (CoTPP) was dissolved in isopropanol to prepare a 10 mM CoTPP solution, and then subjected to ultrasonic treatment for 30 min to form a CoTPP homogeneous solution; the CoTPP homogeneous solution was mixed with a 10 mM cadmium nitrate aqueous solution at a volume ratio of 1:10, and the pH of the solution was adjusted to 6 with dilute hydrochloric acid to obtain solution A, which was placed in a light-proof and room temperature environment for use.
[0054] Sodium sulfide (Na2S) solid was dissolved in isopropanol to prepare a 50mM sodium sulfide solution for use. Solution A was placed in a heatable magnetic stirrer, and the sodium sulfide solution (the volume ratio of solution A to nano sodium sulfide solution was 1:10) was added dropwise while stirring, and the dropping speed was 10 drops / min. After the addition was completed, it was heated to 60°C and reacted for 2h. After the reaction was completed, it was washed with deionized water and dried at 80°C for 10h to obtain a metal porphyrin composite catalyst, which was recorded as catalyst 4.
[0055] Comparative Example 1
[0056] The difference from Example 1 is that the speed of adding the sodium sulfide solution is different, that is, 100 drops / min, and the other operations are the same as those in Example 1. The specific operations are as follows:
[0057] Tetraphenylcobalt porphyrin (CoTPP) was dissolved in tetrahydrofuran to prepare a 10 mM CoTPP solution, and then subjected to ultrasonic treatment for 30 min to form a CoTPP homogeneous solution; the CoTPP homogeneous solution was mixed with a 10 mM cadmium nitrate aqueous solution in a volume ratio of 1:1, and the pH of the solution was adjusted to 3 with dilute hydrochloric acid to obtain solution A, which was placed in a light-proof and room temperature environment for use.
[0058] Sodium sulfide (Na2S) solid was dissolved in tetrahydrofuran to prepare a 50mM sodium sulfide solution for use. Solution A was placed in a heatable magnetic stirrer, and the sodium sulfide solution (the volume ratio of solution A to nano sodium sulfide solution was 1:1) was added dropwise while stirring, and the dropping speed was 100 drops / min. After the addition was completed, it was heated to 50°C and reacted for 3h. After the reaction was completed, it was washed with deionized water and dried at 75°C for 24h to obtain a metal porphyrin composite catalyst, which was recorded as catalyst 5.
[0059] Comparative Example 2
[0060] Tetraphenylcobalt porphyrin (CoTPP) was dissolved in tetrahydrofuran to prepare a 10 mM CoTPP solution, and then subjected to ultrasonic treatment for 30 minutes to form a CoTPP homogeneous solution.
[0061] Preparation of cadmium sulfide: Weigh 125 parts of cadmium nitrate tetrahydrate and 30 parts of thioacetamide, dissolve them in 1780 parts of ethylene glycol, stir them magnetically for 5 minutes, then heat them with microwave for 20 seconds, stop for 60 seconds, heat them again for 20 seconds, stop for 60 seconds, repeat the heating cycle 20 times, cool them naturally to room temperature, put them in a centrifuge with a speed of 6000r / min, wash them repeatedly with deionized water and anhydrous ethanol, and finally dry them in vacuum at 100°C for 10 hours to obtain cadmium sulfide. Dissolve cadmium sulfide in tetrahydrofuran to prepare a 10mM cadmium sulfide solution.
[0062] The CoTPP homogeneous solution was stirred while cadmium sulfide solution was added dropwise (the volume ratio of solution A and nano sodium sulfide solution was 1:1) at a dropping speed of 60 drops / min. After the addition was completed, the solution was heated to 50°C and reacted for 3 hours. After the reaction was completed, the solution was washed with deionized water and dried at 75°C for 24 hours to obtain a metal porphyrin composite catalyst, which was recorded as catalyst 6.
[0063] Example 5
[0064] Peroxyformic acid generated by the reaction of formic acid and hydrogen peroxide was used as an oxidant, and the catalysts prepared in the above examples or comparative examples were added to cause epoxidation of 1-octene, with a molar ratio of 1-octene: hydrogen peroxide: formic acid = 1: 1.2: 6, the hydrogen peroxide was added for 5 hours, the reaction temperature was 45°C, and the reaction time was 11 hours. A mixed product containing formic acid, water and epoxy compounds was obtained, and the excess formic acid, water and other impurities were removed after reduced pressure distillation (vacuum pressure 0.08 MPa, distillation temperature 120-145°C), and the obtained epoxidized compound was adjusted to pH 11 with a NaOH aqueous solution, and stirred at room temperature for 2 hours to obtain a mixture of 1,2-octanediol, which was extracted with methyl tert-butyl ether, distilled, washed and dried to obtain 1,2-octanediol. The sample was analyzed by gas chromatography, and the results are shown in Table 1.
[0065] Table 1
[0066]
[0067] The method of Example 5 was used to recycle each catalyst 10 times, and the catalytic performance after 10 uses was tested. The specific results are shown in Table 2.
[0068] Table 2
[0069]
[0070] It can be seen from Table 2 that after being used continuously for 10 times, the catalytic activity of the metal porphyrin composite catalyst did not decrease significantly.
[0071] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A catalyst for preparing 1,2-octanediol, characterized in that: The active components of the catalyst include metal porphyrin and nano cadmium sulfide.
2. The catalyst according to claim 1, characterized in that The molar ratio of the metal porphyrin to the cadmium element in the catalyst is 1:1-10.
3. The method for preparing the catalyst according to claim 1 or 2, characterized in that: The steps include: 1) mixing tetraphenylcobalt porphyrin with an organic solvent and ultrasonicating to obtain a CoTPP homogeneous solution; 2) mixing the aqueous solution of cadmium salt with the CoTPP homogeneous solution to obtain solution A; 3) mixing sodium sulfide with an organic solvent to obtain a sodium sulfide solution; 4) Under stirring, sodium sulfide solution is added dropwise to solution A. After the addition is complete, the mixture is reacted to obtain a metal porphyrin composite catalyst.
4. The preparation method according to claim 3, characterized in that: The organic solvent used in step 1) and / or 3) includes one or more of anhydrous ethanol, tetrahydrofuran, dichloromethane, isopropanol, methanol, toluene and a methanol-toluene mixture.
5. The preparation method according to claim 3, characterized in that: After obtaining solution A in step 2), the step further includes adjusting the pH of solution A to acidic.
6. The preparation method according to claim 3, characterized in that: In step 4), the dropping speed is 10 to 60 drops / min.
7. The preparation method according to claim 3, characterized in that: The reaction temperature in step 4) is 30-60°C and the reaction time is 1-5h.
8. The preparation method according to claim 3, characterized in that: After the reaction in step 4 is completed, drying is further performed; the drying temperature is 50 to 80° C. and the drying time is 10 to 26 hours.
9. Use of the catalyst according to any one of claims 1 to 8 in the epoxidation synthesis of 1,2-octanediol, characterized in that: 1,2-Octanediol was synthesized using the following steps: (1) using 1-octene, hydrogen peroxide and formic acid as reaction raw materials to carry out epoxidation reaction to obtain a reaction solution; (2) The reaction solution is subjected to a hydrolysis reaction to obtain 1,2-octanediol.
10. The use according to claim 9, characterized in that: The molar ratio of 1-octene, hydrogen peroxide and formic acid in step (1) is 1:1.1-1.5:4-6; the temperature of the epoxidation reaction is 40-55°C, and the reaction time is 6-12h.