Supported platinum catalyst, preparation method thereof and synthesis method of gamma-chloropropyltrichlorosilane

Abstract

The invention provides a supported platinum catalyst, a preparation method of the supported platinum catalyst and a synthesis method of gamma-chloropropyl trichlorosilane, and belongs to the technical field of chemical engineering. The supported platinum catalyst is a superparamagnetic nanoparticle supported chloroplatinic acid catalyst; the synthesis method of the gamma-chloropropyl trichlorosilane comprises the following steps: taking trichlorosilane and chloropropene as raw materials, taking superparamagnetic nanoparticle loaded chloroplatinic acid as a catalyst, and carrying out hydrosilylation reaction under the conditions that the temperature is 130-140 DEG C and the pressure is 0.10-0.15 MPa to obtain the gamma-chloropropyl trichlorosilane; after the reaction is finished, the catalyst is simply recovered through an external magnetic field and can be repeatedly used, and the activity is not obviously reduced. Compared with a traditional process, the method provided by the invention has the advantages that a catalytic system is simple to operate, the yield is high, the reusability is good, and the method has a good industrial prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and particularly relates to a supported platinum catalyst and a preparation method thereof, and a synthesis method of gamma-chloropropyltrichlorosilane. Background Art

[0002] γ-Chloropropyltrichlorosilane is the most basic monomer in silane coupling agent. It can be used as the main raw material for deep processing to produce dozens of high-end silane coupling agents and other products, such as γ-chloropropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, dental composite resin, silicone antibacterial finishing agent, optical glass antifogging agent, etc. γ-Chloropropyltrichlorosilane is mainly prepared by the hydrosilylation reaction of allyl chloride and trichlorosilane catalyzed by platinum complex, and the industrial scale has already exceeded 10,000 tons. However, low selectivity and excessive by-products are key issues that need to be urgently solved in the industrialization process of this product. Through the ligand modification of platinum catalysts and the way of catalyst loading, scientific researchers have made great achievements in developing highly active and highly selective platinum complex catalysts. There are three main production methods at home and abroad: one is the homogeneous platinum complex catalyst catalytic method, using Speier series, Karstedt series homogeneous catalysts and other supported platinum complex catalysts in the hydrosilylation reaction of trichlorosilane and chloropropylene to synthesize γ-chloropropyltrichlorosilane; homogeneous catalytic reaction has better reaction activity than heterogeneous catalysis, the catalyst and substrate are easy to contact, and the reaction is not affected by diffusion, but there are also obvious disadvantages. On the one hand, it is very difficult to separate expensive metal catalysts from the reaction mixture, and a small amount of metal residue in the product is often not allowed; on the other hand, the hydrosilylation reaction of olefins catalyzed by highly active metal complex catalysts is often accompanied by a strong exothermic process. Homogeneous catalysts are prone to cause the temperature of the reaction system to rise rapidly, and olefins are prone to isomerization reactions. Triple-bond compounds are also prone to secondary addition products, which may reduce the selectivity of the reaction. The second is the catalytic method of loaded platinum complex catalyst, which uses SiO2, A12O3, polystyrene and polymethacrylate as carriers for loading. The loaded platinum complex catalyst is used to catalyze the synthesis of γ-chloropropyltrichlorosilane in the hydrosilylation reaction of trichlorosilane and chloropropylene. The loaded organic metal catalyst has many advantages over homogeneous catalysts, such as high catalyst selectivity and easy chemical modification of catalyst active sites. Moreover, after the catalytic reaction is completed, the catalyst can be recovered and reused by simple filtration, and the catalyst and product can be separated at the same time. Therefore, this type of catalyst has always attracted more and more people's interest. Summary of the invention

[0003] In view of this, the present invention aims to provide a supported platinum catalyst and a preparation method thereof and a synthesis method of γ-chloropropyltrichlorosilane, aiming to solve at least one technical problem in the background technology.

[0004] The present invention is achieved in that:

[0005] The first aspect of the present invention provides a supported platinum catalyst, which is a chloroplatinic acid catalyst supported by superparamagnetic nanoparticles, and its schematic structural formula is:

[0006]

[0007] The second aspect of the present invention provides a method for preparing a supported platinum catalyst, the synthesis route of which is:

[0008]

[0009] The preparation method comprises the following steps:

[0010] The silica-coated magnetic nanoparticles SiO2@Fe3O4 (MNP) were ultrasonically dispersed in anhydrous toluene, and 3-aminopropyltriethoxysilane was added and refluxed under a protective atmosphere for reaction. After the reaction, the magnetic field was collected, the anhydrous toluene was repeatedly washed, and the mixture was dried to obtain compound 2.

[0011] The compound 2 is ultrasonically dispersed in anhydrous toluene, 2-acetylpyridine is dissolved in anhydrous toluene, and the 2-acetylpyridine solution is then added dropwise to the dispersion of the compound 2, and refluxed and stirred under a protective atmosphere for reaction. After the reaction is completed, the mixture is collected by a magnet, repeatedly washed with anhydrous toluene, and dried to obtain a compound 3;

[0012] The compound 3 and chloroplatinic acid are added to ethanol, and stirred to react under a protective atmosphere. After the reaction is completed, the solid and liquid are separated, and the solid product is washed with deionized water, washed with anhydrous ethanol, and dried in sequence to obtain compound 4, which is chloroplatinic acid loaded on superparamagnetic nanoparticles.

[0013] The third aspect of the present invention provides a method for synthesizing γ-chloropropyltrichlorosilane. The method uses the above-mentioned supported platinum catalyst to catalyze the hydrosilylation reaction of trichlorosilane and allyl chloride to synthesize γ-chloropropyltrichlorosilane. The synthesis route is:

[0014]

[0015] Furthermore, the specific steps of the synthesis method are: trichlorosilane, chloropropylene, and the supported platinum catalyst are mixed in a preset ratio, replaced with nitrogen, and reacted at a pressure of 0.10MPa to 0.15MPa and a temperature of 130°C to 140°C for 1h to 10h (preferably 5h to 10h, most preferably 10h) to obtain the γ-chloropropyltrichlorosilane.

[0016] Furthermore, in terms of molar ratio, trichlorosilane: allyl chloride = (1.0-1.5):1, preferably 1.1:1-1.5:1, and more preferably 1.1:1-1.2:1.

[0017] Furthermore, in terms of weight ratio, the supported platinum catalyst:trichlorosilane=(0.001-0.02):1, preferably 0.008-0.02:1, and more preferably 0.012-0.02:1.

[0018] Furthermore, after the hydrosilylation reaction is completed, an external magnetic field is applied to recover the supported platinum catalyst, which is then washed with ethanol and then vacuum dried at 50° C. to 65° C. for 4 h to 6 h.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention provides superparamagnetic nanoparticle-supported chloroplatinic acid as a new type of supported platinum catalyst, which has good catalytic effect, is easy to recycle, and has strong cycle stability.

[0021] 2. The method provided by the present invention has a relatively high yield and purity for catalytic synthesis of γ-chloropropyltrichlorosilane. In addition, chloroplatinic acid supported by superparamagnetic nanoparticles is used as a catalyst to prepare γ-chloropropyltrichlorosilane. Compared with the traditional process, the operation is simple, and the catalyst has a high specific surface area and good catalytic activity. It is recovered by an external magnetic field, and the recovery process is simple. The catalyst can also be reused, which reduces the cost, is easy to promote industrialization, and has a good industrialization prospect. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific implementation cases described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] Example 1

[0024] The preparation method of the supported platinum catalyst has the following synthesis route:

[0025]

[0026] The preparation method comprises steps S1 to S3:

[0027] S1: Weigh 1.0g of silica-coated magnetic nanoparticles SiO2@Fe3O4 into a reaction container, add 60ml of dried anhydrous toluene, and ultrasonicate for 30min. After the ultrasonication, add 3.6g of 3-aminopropyltriethoxysilane, reflux and stir under nitrogen protection for 12h. After the reaction, collect with a magnet and wash with anhydrous toluene three times, then vacuum dry at 60℃ for 6h to obtain a solid compound 2;

[0028] S2: 4.0 g of the solid 2 prepared in step S1 was placed in a reaction container, 100 ml of anhydrous toluene was added, and ultrasonic treatment was performed for 1 h. After the ultrasonic treatment, 1.8 g (15 mmol) of 2-acetylpyridine was dissolved in 20 ml of anhydrous toluene, and then added dropwise to the reaction system. The reaction was refluxed for 12 h under N2 protection. After the reaction was completed, the solid was collected with a magnet and washed three times with anhydrous toluene, and then vacuum dried at 60°C for 6 h to obtain a solid compound 3;

[0029] S3: Take 5.0 g of the solid 3 prepared in step S2 and 6.2 g (12 mmol) of chloroplatinic acid hexahydrate, add them to 50 mL of 50% ethanol, stir mechanically at 60° C. for 10 h under nitrogen protection, filter, wash the filter cake twice with 20 ml of deionized water and twice with 10 ml of anhydrous ethanol, respectively, and vacuum dry to obtain solid compound 4, i.e. 10 g of chloroplatinic acid catalyst supported on superparamagnetic nanoparticles, with a yield of 80.5% based on chloroplatinic acid.

[0030] Example 2

[0031] This embodiment provides a method for catalytically synthesizing γ-chloropropyltrichlorosilane, comprising the following steps:

[0032] In a 250mL autoclave, 30.4g (0.4mol, 1.0eq) of allyl chloride, 53.6g (0.40mol, 1.0eq) of trichlorosilane and 0.30g of the superparamagnetic nanoparticle-supported chloroplatinic acid catalyst prepared in Example 1 were added, nitrogen replacement was performed, the pressure was controlled at 0.10MPa-0.15MPa, the temperature was raised to 130°C-140°C with stirring, the reaction was carried out for about 10h, and the reaction was terminated when the peak of the liquid raw material was <1% after sampling and detection. The temperature was lowered by 25°C, the catalyst was attracted by an external magnetic field, and the reaction liquid was poured into a 250ml three-necked flask, and the fore fraction (mainly unreacted raw materials) was first distilled under atmospheric pressure, and then distilled under reduced pressure to obtain 69.0g of γ-chloropropyltrichlorosilane, with a yield of 82.2% based on allyl chloride and a purity of 99.3% (GC detection).

[0033] Example 3

[0034] This Example 3 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 2 only in the amount of trichlorosilane used, and the other reaction conditions and steps are consistent with Example 2.

[0035] In this Example 3, the amount of trichlorosilane used was 58.9 g (0.44 mol, 1.1 eq), and 72.7 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 86.6% based on allyl chloride and a purity of 99.5% (GC detection).

[0036] Example 4

[0037] This Example 4 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 2 only in the amount of trichlorosilane used, and the other reaction conditions and steps are consistent with Example 2.

[0038] In this Example 4, the amount of trichlorosilane used was 65.0 g (0.48 mol, 1.2 eq), and 73.0 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 87.0% based on allyl chloride and a purity of 99.6% (GC detection).

[0039] Example 5

[0040] This Example 5 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 2 only in the amount of trichlorosilane used, and the other reaction conditions and steps are consistent with Example 2.

[0041] In this Example 5, the amount of trichlorosilane used was 75.0 g (0.56 mol, 1.4 eq), and 72.9 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 86.8% based on allyl chloride and a purity of 99.5% (GC detection).

[0042] Example 6

[0043] This Example 6 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 2 only in the amount of trichlorosilane used, and the other reaction conditions and steps are consistent with Example 2.

[0044] In this Example 6, the amount of trichlorosilane used was 87.2 g (0.60 mol, 1.5 eq), and 72.7 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 86.6% based on allyl chloride and a purity of 99.5% (GC detection).

[0045] The difference between Examples 2 to 6 is the molar ratio of trichlorosilane to allyl chloride. The yield of the target product γ-chloropropyltrichlorosilane (based on allyl chloride) of Examples 2 to 6 was calculated, and its purity was tested. The results are shown in Table 1.

[0046] Table 1

[0047]

[0048] It can be seen from the data in Table 1 that when the molar ratio of trichlorosilane to allyl chloride is between 1 and 1.5:1, the yield and purity of chloropropyltrichlorosilane are relatively high; as the amount of trichlorosilane increases, its yield and purity both increase, but when increased to a certain proportion, the yield and purity do not change significantly, so the molar ratio of trichlorosilane to allyl chloride is preferably between 1 and 1.5:1, preferably 1.1:1 to 1.5:1, more preferably 1.1:1 to 1.2:1, and the optimal value is 1.2:1.

[0049] Example 7

[0050] This Example 7 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 3 only in the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles, and the other reaction conditions and steps are consistent with Example 3.

[0051] In this Example 7, the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles was 0.03 g, and 63.5 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 75.6% based on allyl chloride and a purity of 97.1% (GC detection).

[0052] Example 8

[0053] This Example 8 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 3 only in the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles, and the other reaction conditions and steps are consistent with Example 3.

[0054] In this Example 8, the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles was 0.06 g, and 65.7 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 78.3% based on allyl chloride and a purity of 97.4% (GC detection).

[0055] Example 9

[0056] This Example 9 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 3 only in the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles, and the other reaction conditions and steps are consistent with Example 3.

[0057] In this Example 9, the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles was 0.12 g, and 67.8 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 80.7% based on allyl chloride and a purity of 98.2% (GC detection).

[0058] Example 10

[0059] This Example 10 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 3 only in the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles, and the other reaction conditions and steps are consistent with Example 3.

[0060] In this Example 10, the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles was 0.24 g, and 71.9 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 85.6% based on allyl chloride and a purity of 98.8% (GC detection).

[0061] Embodiment 11

[0062] This Example 11 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 3 only in the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles, and the other reaction conditions and steps are consistent with Example 3.

[0063] In this Example 11, the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles was 0.36 g, and 73.5 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 87.5% based on allyl chloride and a purity of 99.6% (GC detection).

[0064] Example 12

[0065] This Example 12 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 3 only in the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles, and the other reaction conditions and steps are consistent with Example 3.

[0066] In this Example 12, the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles was 0.48 g, and 73.6 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 87.7% based on allyl chloride and a purity of 99.6% (GC detection).

[0067] Embodiment 13

[0068] This Example 13 provides a method for catalytic synthesis of γ-chloropropyltrichlorosilane, which differs from Example 3 only in the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles, and the other reaction conditions and steps are consistent with Example 3.

[0069] In this Example 13, the amount of chloroplatinic acid catalyst supported by superparamagnetic nanoparticles was 0.60 g, and 73.9 g of the target product γ-chloropropyltrichlorosilane was obtained, with a yield of 88.0% based on allyl chloride and a purity of 99.6% (GC detection).

[0070] The difference between Examples 7 to 13 is the amount of catalyst used. The yield of the target product γ-chloropropyltrichlorosilane (based on allyl chloride) of Examples 7 to 13 was calculated, and its purity was tested. The results are shown in Table 2.

[0071] Table 2

[0072]

[0073] As can be seen from Table 2, as the amount of catalyst increases, its yield and purity both increase, but when the catalyst is increased to a certain proportion, the yield and purity do not change significantly. When the yield and purity of γ-chloropropyltrichlorosilane are relatively high, the weight ratio of the catalyst to trichlorosilane is 0.001 to 0.02:1, and the yield and purity of γ-chloropropyltrichlorosilane are both high, so the weight ratio of the catalyst to trichlorosilane is set to between 0.008 and 0.02:1, so the weight ratio of the catalyst to trichlorosilane is further preferably 0.008 to 0.02:1, and more preferably 0.012 to 0.02:1. The yield of γ-chloropropyltrichlorosilane is higher than 87% and the purity is higher than 99.5%.

[0074] Comparative Example 1

[0075] This comparative example 1 provides a method for synthesizing γ-chloropropyltrichlorosilane, which differs from Example 3 only in that there is no catalyst, and the other reaction conditions and steps are consistent with Example 3, and the target product γ-chloropropyltrichlorosilane is not obtained.

[0076] Comparative Example 2

[0077] This comparative example 2 provides a method for synthesizing γ-chloropropyltrichlorosilane, which differs from Example 3 only in that the catalyst is adjusted to a conventional chloroplatinic acid catalyst, and the chloroplatinic acid catalyst is not loaded with superparamagnetic nanoparticles. The other reaction conditions and steps are consistent with those of Example 3, and 65.8 g of the target product γ-chloropropyltrichlorosilane is obtained, with a yield of 78.4% based on allyl chloride and a purity of 99.5% (GC detection).

[0078] The difference between Comparative Examples 1 and 2 and Example 3 lies in the catalyst. The yield of the target product γ-chloropropyltrichlorosilane (in terms of allyl chloride) of Comparative Examples 1 and 2 was calculated, and its purity was tested. The results were compared with those of Example 3, as shown in Table 3.

[0079] Table 3

[0080]

[0081] It can be seen from Table 3 that in the absence of a catalyst, trichlorosilane and chloropropylene do not react to form γ-chloropropyltrichlorosilane. In terms of the effect of catalyzing the synthesis of γ-chloropropyltrichlorosilane, the superparamagnetic nanoparticle-supported chloroplatinic acid catalyst is greater than the conventional chloroplatinic acid catalyst.

[0082] Embodiment 14

[0083] In order to verify the effect of repeated use of the superparamagnetic nanoparticle-loaded chloroplatinic acid catalyst prepared in Example 1 of the present invention on the yield and purity of γ-chloropropyltrichlorosilane, the catalytic synthesis process of Example 3 is used as a reference, and the process parameters are controlled unchanged. The superparamagnetic nanoparticle-loaded chloroplatinic acid catalyst is recovered by an external magnetic field after use, washed with ethanol, and vacuum dried at 60°C for 5 hours, and reused 5 times, and compared with Example 3, as shown in Table 4.

[0084] Table 4

[0085]

[0086]

[0087] It can be seen from Table 4 that after the superparamagnetic nanoparticle-supported chloroplatinic acid catalyst prepared by the method provided by the present invention was reused 5 times, the yield and purity of γ-chloropropyltrichlorosilane did not decrease significantly.

[0088] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A supported platinum catalyst, characterized in that: The supported platinum catalyst is a chloroplatinic acid catalyst supported by superparamagnetic nanoparticles, and its schematic structural formula is as follows:

2. A method for preparing a supported platinum catalyst, characterized in that: The preparation method is used to prepare the supported chloroplatinic acid catalyst according to claim 1, and the synthetic route of the preparation method is: The preparation method comprises the following steps: The silica-coated magnetic nanoparticles SiO2@Fe3O4 were ultrasonically dispersed in anhydrous toluene, and 3-aminopropyltriethoxysilane was added and refluxed under a protective atmosphere for reaction. After the reaction, the magnetic field was collected, the anhydrous toluene was repeatedly washed, and the mixture was dried to obtain compound 2. The compound 2 is ultrasonically dispersed in anhydrous toluene, 2-acetylpyridine is dissolved in anhydrous toluene, and the 2-acetylpyridine solution is then added dropwise to the dispersion of the compound 2, and refluxed and stirred under a protective atmosphere for reaction. After the reaction is completed, the mixture is collected by a magnet, repeatedly washed with anhydrous toluene, and dried to obtain a compound 3; The compound 3 and chloroplatinic acid are added to ethanol, and stirred to react under a protective atmosphere. After the reaction is completed, the solid and liquid are separated, and the solid product is washed with deionized water, washed with anhydrous ethanol, and dried in sequence to obtain compound 4, which is chloroplatinic acid loaded on superparamagnetic nanoparticles.

3. A method for synthesizing γ-chloropropyltrichlorosilane, characterized in that: The synthesis method uses the supported platinum catalyst according to claim 1 to catalyze the hydrosilylation reaction of trichlorosilane and allyl chloride to synthesize γ-chloropropyltrichlorosilane.

4. The method for synthesizing γ-chloropropyltrichlorosilane according to claim 3, characterized in that: The specific steps of the synthesis method are: trichlorosilane, chloropropylene and the supported platinum catalyst are mixed according to a preset ratio, replaced with nitrogen, and reacted at a pressure of 0.10MPa to 0.15MPa and a temperature of 130°C to 140°C for 1h to 10h to obtain the γ-chloropropyltrichlorosilane.

5. The method for synthesizing γ-chloropropyltrichlorosilane according to claim 4, characterized in that: According to the molar ratio, trichlorosilane: allyl chloride = (1.0-1.5):

1.

6. The method for synthesizing γ-chloropropyltrichlorosilane according to claim 4 or 5, characterized in that: According to the molar ratio, trichlorosilane: allyl chloride = (1.1-1.5):

1.

7. The method for synthesizing γ-chloropropyltrichlorosilane according to claim 4, characterized in that: According to the weight ratio, the supported platinum catalyst: trichlorosilane = (0.001-0.02):

1.

8. The method for synthesizing γ-chloropropyltrichlorosilane according to claim 7, characterized in that: According to the weight ratio, the supported platinum catalyst: trichlorosilane = (0.008-0.02):

1.

9. The method for synthesizing γ-chloropropyltrichlorosilane according to claim 3, characterized in that: After the hydrosilylation reaction is completed, an external magnetic field is applied to recover the supported platinum catalyst, which is then washed with ethanol and then vacuum dried at 50° C. to 65° C. for 4 h to 6 h.

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