Method for magnesium-cobalt bimetal pyrophosphate catalyzing hydrosilylation reaction and application
By using a magnesium-cobalt bimetallic pyrophosphate catalyst, the problems of high catalyst cost and difficult separation are solved, enabling the catalyst to be recycled and its activity maintained, making it suitable for hydrosilylation reactions.
Patent Information
- Application Number
- CN202211165577.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-23
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2042-09-23
AI Technical Summary
Existing catalysts for hydrosilylation reactions suffer from problems such as high catalyst cost, difficulty in separating the product from the catalyst, and non-reusability.
A magnesium-cobalt bimetallic pyrophosphate catalyst is used, and the catalyst and product are separated by a simple sedimentation method, allowing the catalyst to be reused.
This enables the recycling of the catalyst, maintains its catalytic activity, and simplifies the separation process between the product and the catalyst.
Smart Images
Figure CN115850320B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalytic chemistry, specifically a method and application of magnesium-cobalt bimetallic pyrophosphate catalyzed hydrosilylation reaction. Background Technology
[0002] Hydrosilylation is an important method for constructing C-Si bonds and is widely used in the synthesis of silane coupling agents, organosilicon polymers, and functional organosilicon compounds. Hydrosilylation reactions are usually carried out under the catalysis of transition metal complexes. Commonly used catalysts in the laboratory and industry include Speier catalysts (isopropanol solution of chloroplatinic acid), Karstedt catalysts (tetramethyldivinyldisiloxane complex of platinum), and Wilkison catalysts [Rh(PPh3)3Cl]. However, these catalysts have drawbacks such as high cost and difficulty in separating the product from the catalyst.
[0003] The inventors previously reported that divalent metal (ferrous, cobalt) complexes of straight-chain aliphatic carboxylic acids with isonitrile groups at the terminal position exhibited high catalytic activity in the hydrosilylation reaction of olefins at a dosage of 0.05–0.5 mol% (Peng Jiajian et al., CN106831850A). The catalysts reported above are all organometallic complexes, which are difficult to prepare, and the ligands have a significant impact on catalytic performance. Furthermore, the reactions are carried out under homogeneous conditions, and the catalysts cannot be reused.
[0004] In addition, scientific researchers have explored the applications of non-noble metal-catalyzed hydrosilylation, including iron, cobalt, nickel, etc. (Tondreau et al Science, 2012, 335, 567; Chen et al J. Am. Chem. Soc., 2015, 137, 13244; Noda et al J. Am. Chem. Soc., 2016, 138, 2480-2483). Metal phosphates have received extensive attention due to their unique structures and adjustable compositions (Llusar et al J. Eur. Cera. Soc., 2010, 30, 1887-1896). Transition metal phosphates have high stability, unique physical / chemical properties, and versatility. They are inexpensive and environmentally friendly. At the same time, transition metal phosphates are prone to form layered structures with open frameworks. The multiple oxidation states of metal ions enrich their redox behaviors, and they have good electrocatalytic oxygen evolution reaction activity in neutral / alkaline electrolytes (Yuan et al ChemCatChem 2020, 12, 3797–3810). In addition, in the field of catalytic chemistry, metal phosphates and pyrophosphates have also been widely studied. Magnesium pyrophosphate is used as a catalyst in the epoxidation of olefins (Dong et al Catal. Lett., 2022, 152, 162–171), and cobalt-magnesium phosphate [Co x Mg 3-x (PO4)2 (0 ≤ x ≤ 3)] is used in the catalytic dehydrogenation of alkanes (Ziyad et al, Catal. Lett., 2001, 73, 47-53), etc. SUMMARY OF THE INVENTION
[0005] Aiming at the deficiencies of the prior art, the first object of the present invention is to provide a method for catalyzing hydrosilylation reaction with magnesium-cobalt bimetallic pyrophosphate. Using a compound containing an alkenyl group and a hydrosilane or a hydrogen-containing silicone oil as raw materials, and magnesium-cobalt bimetallic pyrophosphate as a catalyst, heating and stirring to fully react, the compound containing an alkenyl group and the hydrosilane or the hydrogen-containing silicone oil are added to obtain a hydrosilylation product. Through simple sedimentation, the catalyst and the product can be separated and reused.
[0006] The chemical structural formula of the magnesium-cobalt bimetallic pyrophosphate is Mg x Co 2-x P2O7, where 0 < x < 2, and the molar ratio of magnesium to cobalt is preferably 1:1.
[0007] Preferably, the molar ratio of the magnesium-cobalt bimetallic pyrophosphate catalyst, the compound containing an alkenyl group, and the hydrosilane is 0.08-0.1:100:110, and more preferably 0.08:100:110.
[0008] Preferably, the alkenyl-containing compound is one of allyl glycidyl ether, allyl acrylate, allyl methacrylate, and vinyl silicone oil (vinyl content 1-15 mmol / g).
[0009] Preferably, the hydrogen-containing silane is one of triethoxysilane, methyldichlorosilane, trimethoxysilane, diphenyldihydrosilane, and hydrogen-containing polydimethylsiloxane (0.1-1% hydrogen content).
[0010] Preferably, the hydrosilylation reaction process is as follows: a catalyst, an alkenyl compound, and a hydrosilane or hydrosilicone oil are added to a reactor, the reactor is sealed, and then the temperature is slowly raised to 70-100°C. The reaction is maintained at the temperature and the mixture is stirred for 3-4 hours. The mixture is then allowed to stand, cooled to room temperature, and the product is separated by decantation.
[0011] Preferably, the hydrosilylation reaction is carried out at a temperature of 90°C.
[0012] A second objective of this invention is to provide a hydrosilylation reaction catalyst comprising magnesium-cobalt bimetallic pyrophosphate.
[0013] The third objective of this invention is to provide the application of the above-mentioned hydroaddition reaction catalyst in the catalytic synthesis of crosslinked silicone rubber, using vinyl silicone oil and hydrogen-containing polydimethylsiloxane as reactants to catalyze the generation of crosslinked silicone rubber.
[0014] Compared with the prior art, the present invention has the following beneficial effects:
[0015] The catalyst of this invention is used to catalyze hydrosilylation reactions. Furthermore, after the reaction, the product and catalyst can be separated simply by sedimentation, enabling the catalyst to be recycled. In addition, the catalyst of this invention can replace platinum catalysts in the crosslinking of vinyl silicone oil and hydrogen-containing silicone oil to prepare organosilicon rubber. Attached Figure Description
[0016] Figure 1 The results are the catalytic cycle results of the addition reaction of allyl methacrylate and diphenylsilane catalyzed by C(5 / 5)-900 in Examples 2-18. Detailed Implementation
[0017] As mentioned above, in view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention, which is mainly based on at least the following:
[0018] This invention employs magnesium and cobalt bimetallic pyrophosphate to catalyze hydrosilylation reactions. Hydrosilylation products are obtained from alkenyl compounds and hydrosilanes or hydrosilicone oils. After the reaction, the products and catalysts can be separated by simple sedimentation, enabling the catalyst to be recycled and reused more than ten times while maintaining its catalytic activity.
[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0020] First, magnesium-cobalt bimetallic pyrophosphate (Mg) was prepared in the following Example 1-1. x Co 2-x P2O7,0 <x<2):
[0021] Example 1-1: Preparation of magnesium-cobalt bimetallic pyrophosphate (Mg x Co 2-x P2O7,0 <x<2)
[0022] At room temperature, 6.8 mL of 85% phosphoric acid (0.1 mol) was added to 250 mL of deionized water. Magnesium nitrate hexahydrate was dissolved in the phosphoric acid solution first, followed by cobalt nitrate hexahydrate, with stirring. The amounts of magnesium nitrate and cobalt nitrate were:
[0023] (1) Magnesium nitrate hexahydrate 2.56 g (0.01 mol), cobalt nitrate hexahydrate 26.19 g (0.09 mol);
[0024] (2) Magnesium nitrate hexahydrate 5.12 g (0.02 mol), cobalt nitrate hexahydrate 23.28 g (0.08 mol);
[0025] (3) Magnesium nitrate hexahydrate 7.68g (0.03mol), cobalt nitrate hexahydrate 20.37g (0.07mol);
[0026] (4) 10.24 g (0.04 mol) of magnesium nitrate hexahydrate and 17.46 g (0.06 mol) of cobalt nitrate hexahydrate;
[0027] (5) 12.80 g (0.05 mol) of magnesium nitrate hexahydrate and 14.55 g (0.05 mol) of cobalt nitrate hexahydrate;
[0028] (6) 15.36 g (0.06 mol) of magnesium nitrate hexahydrate and 11.64 g (0.04 mol) of cobalt nitrate hexahydrate;
[0029] (7) 17.92 g (0.07 mol) of magnesium nitrate hexahydrate and 8.73 g (0.03 mol) of cobalt nitrate hexahydrate;
[0030] (8) 20.48 g (0.08 mol) of magnesium nitrate hexahydrate and 5.82 g (0.02 mol) of cobalt nitrate hexahydrate;
[0031] (9) 23.04 g (0.09 mol) of magnesium nitrate hexahydrate and 2.91 g (0.01 mol) of cobalt nitrate hexahydrate.
[0032] After stirring and dissolving, 10% ammonia water was added dropwise to adjust the pH value to 7 - 8, and stirring was continued for 1 hour. Then it was left standing for 5 hours, filtered, and the filter cake was washed with deionized water. The filter cake was dried at 120 °C for 6 hours, and the obtained powder was calcined in a muffle furnace at 800 °C, 900 °C, and 1000 °C for 2 hours (heating rate: 10 °C / minute) to prepare double metal pyrophosphates with different magnesium / cobalt ratios, which are listed in Table 1.
[0033] Table 1 Catalysts Prepared with Different Metal Ratios and Calcination Temperatures
[0034]
[0035]
[0036] Then, the magnesium-cobalt double metal pyrophosphate (Mg x Co 2-x P2O7, 0 < x < 2) prepared in Example 1-1 was used to catalyze the hydrosilylation reaction:
[0037] Example 2-1
[0038] 230.0 mg of catalyst C(1 / 9)-800, 1.0 mol of allyl glycidyl ether, and 1.1 mol of triethoxysilane were placed in a pressure reactor and reacted in an 80 °C silicone oil bath for 6 h. The conversion rate of styrene was 75.7%, and the selectivity of γ-addition product was 90.4%. After standing and cooling to room temperature, C(1 / 9)-800 could be completely separated by decantation.
[0039] Example 2-2
[0040] 225.0 mg of catalyst C(2 / 8)-800, 1.0 mol of allyl glycidyl ether, and 1.1 mol of triethoxysilane were placed in a pressure reactor and reacted in an 80 °C silicone oil bath for 4 h. The conversion rate of allyl glycidyl ether was 89.5%, and the selectivity of γ-addition product was 99.2%. After standing and cooling to room temperature, C(2 / 8)-800 could be completely separated by decantation.
[0041] Example 2-3
[0042] 225.0 mg of catalyst C(2 / 8)-900, 1.0 mol of allyl glycidyl ether, and 1.1 mol of triethoxysilane were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 4 h. The conversion rate of allyl glycidyl ether was 92.3%, and the selectivity of the γ-addition product was 99.4%. After standing and cooling to room temperature, C(2 / 8)-900 could be completely separated by decanting.
[0043] Examples 2-4
[0044] 225.0 mg of catalyst C(2 / 8)-1000, 1.0 mol of allyl glycidyl ether, and 1.1 mol of triethoxysilane were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 4 h. The conversion rate of allyl glycidyl ether was 90.3%, and the selectivity of the γ-addition product was 99.1%. After standing and cooling to room temperature, C(2 / 8)-1000 could be completely separated by decanting.
[0045] Examples 2-5
[0046] 222.5 mg of catalyst C(3 / 7)-800, 1.0 mol of allyl acrylate, 1.1 mol of triethoxysilane, and 0.5 g of phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 4 h. The conversion rate of allyl acrylate was 91.7%, and the selectivity of the γ-addition product was 90.5%. After standing and cooling to room temperature, C(3 / 7)-800 could be completely separated by decanting.
[0047] Examples 2-6
[0048] 219.0 mg of catalyst C(4 / 6)-800, 1.0 mol of allyl methacrylate, 1.1 mol of triethoxysilane, and 0.5 g of phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 4 h. The conversion rate of allyl methacrylate was 92.7%, and the selectivity of the γ-addition product was 99.2%. After standing and cooling to room temperature, C(4 / 6)-800 could be completely separated by decanting.
[0049] Examples 2-7
[0050] 219.0 mg of catalyst C(4 / 6)-900, 1.0 mol of allyl methacrylate, 1.1 mol of triethoxysilane, and 0.5 g of phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 4 h. The conversion rate of allyl methacrylate was 93.5%, and the selectivity of the γ-addition product was 98.9%. After standing and cooling to room temperature, C(4 / 6)-900 could be completely separated by decanting.
[0051] Examples 2-8
[0052] 219.0 mg of catalyst C(4 / 6)-1000, 1.0 mol of allyl methacrylate, 1.1 mol of triethoxysilane, and 0.5 g of phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 4 h. The conversion rate of allyl methacrylate was 86.5%, and the selectivity of the γ-addition product was 98.5%. After standing and cooling to room temperature, C(4 / 6)-1000 could be completely separated by decanting.
[0053] Examples 2-9
[0054] 215.5 mg C(5 / 5)-800, 1.0 mol allyl methacrylate, 1.1 mol triethoxysilane, and 0.5 g phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 4 h. The conversion rate of allyl methacrylate was 94.3%, and the selectivity of the γ-addition product was 99.3%. After standing and cooling to room temperature, C(5 / 5)-800 could be completely separated by decanting.
[0055] Example 2-10
[0056] 215.5 mg C(5 / 5)-900, 1.0 mol allyl methacrylate, 1.1 mol triethoxysilane, and 0.5 g phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 4 h. The conversion rate of allyl methacrylate was 96.4%, and the selectivity of the γ-addition product was 99.0%. After standing and cooling to room temperature, C(5 / 5)-900 could be completely separated by decanting.
[0057] Example 2-11
[0058] 215.5 mg C(5 / 5)-1000, 1.0 mol allyl methacrylate, 1.1 mol triethoxysilane, and 0.5 g phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 4 h. The conversion rate of allyl methacrylate was 86.8%, and the selectivity of the γ-addition product was 98.4%. After standing and cooling to room temperature, C(5 / 5)-1000 could be completely separated by decanting.
[0059] Example 2-12
[0060] 212.0 mg C(6 / 4)-900, 1.0 mol allyl methacrylate, 1.1 mol trimethoxysilane, and 0.5 g phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 3 h. The conversion rate of allyl methacrylate was 87.8%, and the selectivity of the γ-addition product was 98.7%. After standing and cooling to room temperature, C(6 / 4)-900 could be completely separated by decanting.
[0061] Example 2-13
[0062] 208.5 mg C(7 / 3)-900, 1.0 mol allyl methacrylate, 1.1 mol trimethoxysilane, and 0.5 g phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 3 h. The conversion rate of allyl methacrylate was 84.5%, and the selectivity of the γ-addition product was 98.3%. After standing and cooling to room temperature, C(7 / 3)-900 could be completely separated by decanting.
[0063] Example 2-14
[0064] 205.0 mg C(8 / 2)-900, 1.0 mol allyl methacrylate, 1.1 mol trimethoxysilane, and 0.5 g phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 3 h. The conversion rate of allyl methacrylate was 81.4%, and the selectivity of the γ-addition product was 98.6%. After standing and cooling to room temperature, C(8 / 2)-900 could be completely separated by decanting.
[0065] Example 2-15
[0066] 201.5 mg C(9 / 1)-900, 1.0 mol allyl methacrylate, 1.1 mol trimethoxysilane, and 0.5 g phenothiazine (polymerization inhibitor) were placed in a pressure reactor and reacted in a silicone oil bath at 80 °C for 3 h. The conversion rate of allyl methacrylate was 78.5%, and the selectivity of the γ-addition product was 98.6%. After standing and cooling to room temperature, C(9 / 1)-900 could be completely separated by decanting.
[0067] Example 2-16
[0068] 215.5 mg C(5 / 5)-900, 10.0 g vinyl silicone oil (ethylene content 5 mmol / g), and 0.055 mol diphenylsilane were placed in a three-necked flask and reacted in a silicone oil bath at 80 °C for 5 h. After cooling, the product was analyzed by NMR, and the vinyl group in the vinyl silicone oil was completely converted. After standing and cooling to room temperature, C(5 / 5)-900 could be completely separated by decanting.
[0069] Example 2-17
[0070] 350.0 mg C(5 / 5)-900, 10.0 g vinyl silicone oil (ethylene content 5 mmol / g) and 55.0 g hydrogen-containing silicone oil (hydrogen content 0.1%) were placed in a three-necked flask, stirred evenly, and reacted in a silicone oil bath at 100 °C for 4 h. The system gradually thickened, stood, and cooled to room temperature to obtain an elastic solid crosslinked silicone rubber.
[0071] Example 2-18
[0072] 350.0 mg C(5 / 5)-900, 1.0 mol allyl methacrylate, and 1.1 mol diphenyldihydrosilane were placed in a pressure reactor and reacted in an 80°C silicone oil bath for 4 h. After standing and cooling to room temperature, the upper liquid was separated by decanting, and the conversion and product selectivity were obtained by gas chromatography. Another portion of allyl methacrylate and diphenyldihydrosilane were added to the decanted catalyst C(5 / 5)-900, and the above catalytic reaction, separation, and analysis process were repeated. The experimental results are shown in... Figure 1 The catalyst's catalytic activity and selectivity remained unchanged after being recycled nine times.
Claims
1. A method for a magnesium-cobalt bimetallic pyrophosphate-catalyzed hydrosilylation reaction, characterized in that, Using an alkenyl-containing compound and a hydrogen-containing silane as raw materials, a hydrosilylation reaction is carried out under the action of a magnesium-cobalt bimetallic pyrophosphate catalyst to obtain an addition product; wherein the hydrogen-containing silane is one of triethoxysilane, methyldichlorosilane, trimethoxysilane, diphenyldihydrosilane, and hydrogen-containing polydimethylsiloxane. The alkenyl-containing compound is one of allyl glycidyl ether, allyl acrylate, allyl methacrylate, and vinyl silicone oil. The chemical structural formula of the magnesium-cobalt bimetallic pyrophosphate is Mg x Co 2-x P₂O₇, where 0 < x < 2; The molar ratio of the magnesium-cobalt bimetallic pyrophosphate catalyst, the alkenyl-containing compound, and the hydrogen-containing silane or hydrogen-containing silicone oil is 0.08~0.1:100:
110.
2. The method for the catalytic hydrosilylation reaction of magnesium-cobalt bimetallic pyrophosphate according to claim 1, characterized in that, The vinyl content in the vinyl silicone oil is 1~15 mmol / g.
3. The method for the hydrosilylation reaction catalyzed by magnesium-cobalt bimetallic pyrophosphate according to claim 1, characterized in that, The magnesium-cobalt bimetallic pyrophosphate has a magnesium to cobalt molar ratio of 1:
1.
4. The method for the magnesium-cobalt bimetallic pyrophosphate-catalyzed hydrosilylation reaction according to claim 1, characterized in that, The molar ratio of the magnesium-cobalt bimetallic pyrophosphate catalyst, the alkenyl-containing compound, and the hydrogen-containing silane or hydrogen-containing silicone oil is 0.08:100:
110.
5. The method for the catalytic hydrosilylation reaction of magnesium-cobalt bimetallic pyrophosphate according to claim 1, characterized in that, The method specifically involves adding a catalyst, an alkenyl compound, and a hydrogen-containing silane or hydrogen-containing silicone oil to a reactor, sealing it, then heating it to 70–100°C, maintaining the reaction temperature and continuing to stir the reaction for 3–4 hours, allowing it to stand, cooling it to room temperature, and separating the product by decantation.
6. The method for the magnesium-cobalt bimetallic pyrophosphate-catalyzed hydrosilylation reaction according to claim 5, characterized in that, The reaction temperature for the hydrosilylation reaction is 90°C.