Preparation method and application of catalyst for room-temperature hydrosilylation reaction

Abstract

The invention belongs to the field of chemical engineering, and particularly relates to an ultralow-platinum-doping Raney type catalyst for hydrosilylation as well as a preparation method and application of the ultralow-platinum-doping Raney type catalyst. The catalyst disclosed by the invention is obtained by crushing and leaching the ternary metal alloy, so that the interaction between platinum atoms and skeleton metal is stronger, active metal is more beneficial to adsorption and conversion of reactant molecules in catalysis, and the activity of the catalyst is remarkably improved; and common catalyst sintering and aggregation in the traditional supported catalytic reaction are effectively avoided. The invention also provides a room-temperature hydrosilylation method, which comprises the following steps: placing the ultralow-platinum-doping Raney type skeleton catalyst, unsaturated alkane and hydrogen-containing silane in a reaction tube, and reacting at room temperature to obtain a corresponding product.

Description

Technical Field

[0001] The invention belongs to the field of chemical industry, and in particular relates to an ultra-low platinum doping Raney-type catalyst for hydrosilylation and a preparation method thereof. Background Art

[0002] The hydrosilylation reaction is an addition reaction between unsaturated (such as -CH=CH2, C≡CH, -CH2-CH=CH2, =C=O or =C=N, etc.) hydrocarbon compounds and Si-H-containing organosilicon polymers under certain catalytic conditions. It is one of the most important reaction types in organosilicon chemistry and is widely used in the synthesis of organohalosilanes, the preparation of modified silicone oils, the synthesis of silane coupling agents, liquid silicone rubber and the synthesis of some functional organosilicon materials.

[0003] In the field of hydrosilylation, platinum catalysts dominate the field due to their wide range of raw material sources, excellent catalytic activity and high selectivity. The most widely used catalysts in industry include Speier catalyst (J.Am.Chem.Soc., 1957, 79(4):574) and Karstedt catalyst (US3775452), but homogeneous platinum catalysts are difficult to recycle and reuse, which greatly increases the production cost. In addition, in order to remove the metal components in the product, the difficulty of separation and purification is also increased. The development of efficient heterogeneous catalysts that are easy to separate and recycle for hydrosilylation reactions is conducive to improving the economic benefits of the preparation of organosilicon materials.

[0004] CN116851021 discloses a supported catalyst of platinum-loaded nitrogen-doped porous carbon spheres, which has good catalytic performance and a product yield ranging from 90% to 100%, but its preparation process involves more than six raw materials, high preparation cost, complex raw materials, and a certain degree of resource waste. CN114713258A discloses a method for preparing a platinum atom heterogeneous catalyst, the carrier of which is carbon nitride or carbon nitride derivative, which realizes the recycling of the catalyst, but the catalyst itself has poor stability and cannot be reused. In order to reduce the use of precious metal platinum, the heterogeneous catalyst currently studied has reduced the platinum loading to 1% to 10%, such as CN116003799A, CN116786171A, etc. However, the study also found that when the platinum loading is less than 1%, the catalytic effect will be greatly reduced.

[0005] Moreover, the activity of most catalysts is often limited by the reaction temperature. For example, CN11725880A provides a catalyst with a carrier of palygorskite in situ grown hydrotalcite, which has a high catalytic activity only when the reaction temperature is 50-110°C and cannot be used for hydrogen silane addition at room temperature. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for preparing a catalyst for room temperature hydrosilylation reaction and its application.

[0007] In order to solve the above technical problems, the present invention provides a method for preparing an ultra-low platinum doping Raney-type skeleton catalyst for room temperature hydrosilylation, comprising the following steps:

[0008] ①. Preparation of alloy block:

[0009] A ternary alloy is composed of a skeleton metal, aluminum and platinum, wherein the platinum accounts for 0.1-0.5% of the ternary alloy, the aluminum accounts for 35-65% of the ternary alloy, and the remainder is the skeleton metal;

[0010] According to the above ratio, the skeleton metal, aluminum and platinum are mixed and melted (melted under vacuum conditions), the alloy liquid obtained by melting is made into an ingot (quenched and cast into an ingot), and finally cooled (air cooled) to obtain a skeleton metal-aluminum-platinum ternary alloy block;

[0011] The skeleton metal-aluminum-platinum ternary alloy block is crushed and then ground to obtain ternary alloy powder;

[0012] The above grinding is beneficial to the subsequent leaching of aluminum;

[0013] ②, Alloy dissolution:

[0014] Prepare a sodium hydroxide solution with a mass concentration of 20% to 40%, cool it to 10 to 15°C, and obtain a cooled alkali solution;

[0015] Under magnetic stirring (which can be done in an ice bath), add the ternary alloy powder prepared in step ① to the cooled alkali solution, and control the temperature of the alkali solution not to exceed 25°C during the addition process (addition should be completed within about 1 hour). After the addition is completed, stop magnetic stirring, and the result is named as reaction system;

[0016] The mass ratio of ternary alloy powder to alkali solution after cooling is 1:5-10 (preferably 1:6-7);

[0017] The reaction system is heated to 60-80°C and reacted at this temperature for 10±1 hours (to leach aluminum);

[0018] ③. After step ② is completed (at this time, the hydrogen bubbles slow down), let it stand, pour off the supernatant, and add deionized water for washing (repeat the washing 3 to 4 times);

[0019] Then add the same amount of cooled alkali solution as in step ② again and continue to react at room temperature for 10±1 hours (to react away the residual aluminum); after standing (so that the alloy powder settles), wash with deionized water (wash several times until the eluate is neutral);

[0020] Note: The reactions in step ② and step ③ are carried out under normal stirring conditions;

[0021] ④. Wash with 95% ethanol and anhydrous ethanol respectively (2 to 4 times each) to obtain a platinum-doped Raney nickel catalyst.

[0022] It is a heterogeneous catalyst and can be stored in a ground-mouth bottle containing anhydrous ethanol.

[0023] As an improvement of the preparation method of the ultra-low platinum doping Raney-type skeleton catalyst of the present invention: the skeleton metal is any one of the following: nickel, copper, cobalt, iron;

[0024] The corresponding metal skeletons obtained are Raney nickel, Raney copper, Raney cobalt and Raney iron.

[0025] As a further improvement to the method for preparing the ultra-low platinum doping Raney-type skeleton catalyst of the present invention: the heating rate in step ② is 5 to 10° C. / min.

[0026] As a further improvement of the preparation method of the ultra-low platinum doping Raney-type skeleton catalyst of the present invention: the step ① is ground to pass through a sieve of 80-140 meshes.

[0027] As a further improvement of the preparation method of the ultra-low platinum doping Raney-type skeleton catalyst of the present invention: aluminum accounts for 48-52% of the ternary alloy.

[0028] The present invention also provides a room temperature hydrosilylation method, and an ultra-low platinum doping Raney-type skeleton catalyst is prepared by any of the above methods;

[0029] The catalyst (Raney-type skeleton catalyst with ultra-low platinum doping), unsaturated alkane and hydrosilane are placed in a reaction tube and reacted at room temperature for 2±0.1h to obtain the corresponding product;

[0030] Hydrogen-containing silane: unsaturated alkane = (1 ± 0.1): 1 molar ratio;

[0031] 9 to 11 mg of ultra-low platinum doping Raney-type skeleton catalyst is used for every 10 mmol of unsaturated alkane.

[0032] As an improvement of the room temperature hydrosilylation method of the present invention:

[0033] The hydrogen-containing silane is triethoxyhydrogensilane, methyldiethoxyhydrogensilane, triisopropylhydrogensilane, trichlorosilane, dichlorodihydrogensilane;

[0034] The unsaturated alkane is an olefin or an olefin derivative; the olefin is octene, hexene, or isoprene; and the olefin derivative is 1-octen-3-ol, 1-hexen-3-ol, or 5-hexen-2-one.

[0035] The platinum-doped Raney-type catalyst provided by the present invention has simple raw materials for preparation and low cost; due to the porous skeleton having high mechanical strength and stability, the catalyst has the characteristics of high activity and the like, and can be used for preparing organosilicon monomers through hydrogen-silicon addition reaction at room temperature.

[0036] The beneficial effects of the present invention are:

[0037] The skeleton Raney type prepared by the method of the present invention has a special porous structure, provides a large amount of surface area, increases the active sites of the catalytic reaction, and is conducive to the exposure of platinum at high active sites.

[0038] In the actual catalytic process, the Raney-type catalyst itself can adsorb the reactant silane, promote the hydrosilylation reaction, and show higher catalytic activity and product selectivity.

[0039] The platinum-doped Raney-type catalyst prepared by the method of the present invention has uniform dispersion of metal platinum, high atomic utilization and uniform active sites. Low-doping and high-dispersion platinum improves the utilization of platinum atoms, reduces the amount of precious metals used, and improves the catalyst activity, greatly reducing the cost of the catalyst.

[0040] The catalyst involved in the method of the present invention is obtained by crushing and leaching a ternary metal alloy, so that the interaction between platinum atoms and skeleton metals is stronger, the active metal is more beneficial to the adsorption and conversion of reactant molecules in catalysis, the catalyst activity is significantly improved, and the catalyst sintering and aggregation commonly seen in traditional supported catalytic reactions are effectively avoided.

[0041] The catalyst obtained by the present invention can be used for efficiently carrying out the hydrosilylation reaction under room temperature conditions. The catalyst involved in the method of the present invention has the characteristics of low cost, high activity and mild reaction conditions.

[0042] In summary, the present invention is a platinum catalyst, which is doped in a Raney-type framework with an ultra-low loading, and the doping amount is 0.1-0.5%. The active component is a combination of precious metal platinum, metal aluminum and framework metal. The catalyst provided by the present invention has high catalytic efficiency and can achieve hydrosilylation reaction with high conversion rate and high selectivity at room temperature. At the same time, the raw materials for preparing the catalyst are simple and the cost is low. The special framework structure of the catalyst realizes the high stability of the catalyst and the high dispersibility of platinum atoms, and multiple hydrosilylation reactions can be carried out. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0044] The products obtained in the following cases were verified by conventional NMR to verify their correctness.

[0045] Embodiment 1:

[0046] ① Preparation of alloy block:

[0047] Weigh the skeleton metal raw materials, namely, 50 g of nickel, 49.5 g of aluminum, and 0.5 g of platinum, respectively, put the nickel into a crucible and place it in a vacuum induction furnace for melting under vacuum conditions, then continue to add aluminum and platinum for melting under vacuum conditions, prepare the alloy liquid obtained by melting into an ingot (conventional quenching and casting into an ingot), and finally air cool to obtain a skeleton metal-aluminum-platinum ternary alloy block;

[0048] Add the alloy block into a crusher and crush it into powder, then grind it into 120 mesh. The obtained powder is named ternary alloy powder and set aside.

[0049] The above-mentioned separate melting can make the metal mixing more uniform.

[0050] ② Alloy dissolution:

[0051] In a 1.5L beaker, dissolve 125g of sodium hydroxide in 0.5L of deionized water, stir, and cool to 10°C on an ice bath to obtain cooled lye.

[0052] Under magnetic stirring and ice bath conditions, add all the ternary alloy powders prepared in step ① in small batches to the cooled alkali solution. The addition rate should be controlled so that the temperature of the alkali solution does not exceed 25°C. Stop magnetic stirring after about 1 hour of addition. Remove the beaker from the ice bath, allow the reaction system to warm to room temperature, and then slowly heat it in a water bath (heating rate of 5-10°C / min) until it reaches 60°C. React at this temperature for 10 hours, at which time the hydrogen bubbles slow down.

[0053] illustrate:

[0054] Metallic aluminum and sodium hydroxide react to generate hydrogen bubbles, and the generation of hydrogen bubbles slows down, indicating that the metallic aluminum in the alloy powder has been initially dissolved by the sodium hydroxide.

[0055] Slowly increasing the temperature can prevent excessive bubbles from being generated and causing the reaction liquid to overflow.

[0056] During the reaction, the volume of the reaction system can be maintained substantially stable (ie, maintained substantially the same as the original volume) by adding distilled water to the reaction system.

[0057] ③. After the reaction of step ② is completed for 10 hours, the suspension is allowed to stand to separate into layers, the upper clear liquid is poured off, and deionized water is added for washing. Specifically, deionized water is added to 0.75 L, slightly disturbed to suspend the alloy powder, allowed to stand to settle, and the supernatant is poured off; the above washing steps are repeated three times;

[0058] To further dissolve the metallic aluminum, add the same amount of cooled alkali solution as in step ② again, and continue to react at room temperature for 10 hours to react out the residual aluminum; and let it stand for 10 minutes to allow the alloy powder to settle, and then wash it with deionized water several times until the eluate is neutral.

[0059] The reactions in the above steps ② and ③ are both carried out under conventional stirring conditions.

[0060] ④. After step ③, wash three times with 95% ethanol and anhydrous ethanol respectively (each time washing, the amount of 95% ethanol is 1000 ml, and the amount of anhydrous ethanol is 1000 ml) to obtain a platinum-doped Raney nickel catalyst.

[0061] The platinum-doped Raney nickel catalyst obtained in Example 1 is used for the hydrosilylation reaction of the following Application Examples 1-1 to 1-7:

[0062] Application Example 1-1:

[0063] 10 mg of the catalyst obtained in Example 1, 10 mmol of triethoxysilane and 10 mmol of octene were added to a reaction tube and reacted for 2 hours at room temperature (25°C). After the reaction, the catalyst solid was separated by filtration. The filtrate obtained by filtration was a colorless transparent liquid containing the product n-octyltriethoxysilane.

[0064] Product structure:

[0065] GC-MS analysis showed that the yield of hydrosilylation was 97.1% and the selectivity of terminal addition product was 98.4%.

[0066] The calculation formula of hydrosilylation yield is: The formula for calculating the selectivity of the terminal addition product is:

[0067]

[0068] Note: In addition to the product, the filtrate obtained by filtration also includes tetraethyl silicate, etc. Therefore, the conventional distillation method in this industry can be used for effective separation. The following case is similar; this is a conventional technology and will not be discussed in this invention.

[0069] The catalyst solid obtained by the above separation was reused three times after routine cleaning, and the hydrosilylation yield did not show a significant downward trend.

[0070] Application example 1-2:

[0071] 10 mg of the catalyst obtained in Example 1, 10 mmol of methyldimethoxysilane and 10 mmol of octene were added to a reaction tube and reacted at room temperature of 25° C. for 2 hours. After the reaction was completed, the catalyst solid was separated by filtration, and the filtrate obtained by filtration contained the product n-octylmethyldimethoxysilane.

[0072] Product structure

[0073] GC-MS detection showed that the yield of hydrosilylation was 98.6% and the selectivity of the target addition product was 99.4%.

[0074] Application examples 1-3:

[0075] 10 mg of the catalyst obtained in Example 1, 10 mmol of trimethoxysilane and 10 mmol of hexene were added to a reaction tube and reacted at room temperature of 25° C. for 2 hours. After the reaction was completed, the catalyst solid was separated by filtration. The filtrate obtained by filtration contained the product n-hexyltrimethoxysilane.

[0076] Product structure:

[0077] GC-MS detection showed that the yield of hydrosilylation was 94.6% and the selectivity of target addition product was 97.4%.

[0078] Application examples 1-4:

[0079] 10 mg of the catalyst obtained in Example 1, 10 mmol of triethoxysilane and 10 mmol of isoprene were added to a reaction tube and reacted at room temperature of 25° C. for 2 hours. After the reaction was completed, the catalyst solid was separated by filtration, and the filtrate obtained by filtration contained the product isoprenyltriethoxysilane.

[0080] Product structure:

[0081] GC-MS analysis showed that the yield of hydrosilylation was 89.6% and the selectivity of the target addition product was 93.4%.

[0082] Application examples 1-5:

[0083] 10 mg of the catalyst obtained in Example 1, 10 mmol of triisopropylsilane and 10 mmol of octene were added to a reaction tube and reacted at room temperature of 25° C. for 2 hours. After the reaction was completed, the catalyst solid was separated by filtration, and the filtrate obtained by filtration contained the product n-octyltriisopropylsilane.

[0084] Product structure:

[0085] GC-MS detection showed that the yield of hydrosilylation was 97.4% and the selectivity of the target addition product was 99.2%.

[0086] Application examples 1-6:

[0087] 10 mg of the catalyst obtained in Example 1, 10 mmol of trichlorosilane and 10 mmol of styrene were added to a reaction tube and reacted at room temperature of 25° C. for 2 hours. After the reaction was completed, the catalyst solid was separated by filtration, and the filtrate obtained by filtration contained the product benzyltrichlorosilane.

[0088] Product structure:

[0089] GC-MS detection showed that the yield of hydrosilylation was 97.1% and the selectivity of target addition product was 99.1%.

[0090] Application Examples 1-7:

[0091] 10 mg of the catalyst obtained in Example 1, 10 mmol of trichlorosilane and 10 mmol of isoprene were added to a reaction tube and reacted at room temperature of 25° C. for 2 hours. After the reaction was completed, the catalyst solid was separated by filtration, and the filtrate obtained by filtration contained the product isoprenyltrichlorosilane.

[0092] Product structure:

[0093]

[0094] GC-MS detection showed that the yield of hydrosilylation was 97.3% and the selectivity of target addition product was 99.2%.

[0095] Embodiment 2:

[0096] The “nickel 50 g” was changed to “copper 50 g”, and the rest was the same as in Example 1; the obtained catalyst was named platinum-doped Raney copper catalyst.

[0097] In Application Examples 2-1 to 2-7, the platinum-doped Raney nickel catalyst obtained in Example 1 is replaced by the platinum-doped Raney copper catalyst obtained in Example 2, and the rest is the same as in Application Examples 1-1 to 1-7.

[0098] The results are shown in Table 1 below.

[0099] Table 1

[0100] Hydrosilylation yield Terminal addition product selectivity Application Example 2-1 95.2％ 97.3％ Application Example 2-2 94.0％ 94.9％ Application Example 2-3 94.7％ 95.6％ Application Example 2-4 89.6％ 93.4％ Application Example 2-5 89.4％ 91.2％ Application Example 2-6 92.8％ 93.9％ Application Example 2-7 93.2％ 97.2％

[0101] Embodiment 3:

[0102] The “nickel 50 g” was replaced by “cobalt 50 g”, and the rest was the same as in Example 1; the obtained catalyst was named as platinum-doped Raney cobalt catalyst.

[0103] In Application Examples 3-1 to 3-7, the platinum-doped Raney cobalt catalyst obtained in Example 3 replaces the platinum-doped Raney nickel catalyst obtained in Example 1, and the rest is the same as in Application Examples 1-1 to 1-7.

[0104] The results are shown in Table 2 below.

[0105] Table 2

[0106] Hydrosilylation yield Terminal addition product selectivity Application Example 3-1 92.2％ 93.3％ Application Example 3-2 89.7％ 90.9％ Application Example 3-3 86.7％ 90.6％ Application Example 3-4 88.6％ 92.4％ Application Example 3-5 89.2％ 91.4％ Application Example 3-6 90.4％ 93.8％ Application Example 3-7 91.2％ 93.2％

[0107] Embodiment 4:

[0108] The “nickel 50 g” was changed to “iron 50 g”, and the rest was the same as in Example 1; the obtained catalyst was named as platinum-doped Raney iron catalyst.

[0109] In Application Examples 3-1 to 3-7, the platinum-doped Raney nickel catalyst obtained in Example 1 is replaced by the platinum-doped Raney iron catalyst obtained in Example 4, and the rest is the same as in Application Examples 1-1 to 1-7.

[0110] The results are shown in Table 3 below.

[0111] Table 3

[0112] Hydrosilylation yield Terminal addition product selectivity Application Example 4-1 82.2％ 83.5％ Application Example 4-2 86.7％ 89.9％ Application Example 4-3 86.6％ 94.7％ Application Example 4-4 87.4％ 89.6％ Application Example 4-5 89.6％ 92.2％ Application Examples 4-6 86.4％ 90.2％ Application Example 4-7 86.5％ 88.4％

[0113] Example 5: The "0.5 g of platinum" in Example 1 is changed to "0.1 g of platinum", and the amount of nickel is adjusted accordingly, so that the total amount of nickel, aluminum and platinum is still 100 g, and the rest is the same as Example 1; the obtained catalyst is named platinum-doped Raney nickel catalyst I.

[0114] In Application Examples 5-1 to 5-7, the platinum-doped Raney nickel catalyst I obtained in Example 5 replaces the platinum-doped Raney nickel catalyst obtained in Example 1, and the rest is the same as in Application Examples 1-1 to 1-7.

[0115] The results are shown in Table 4 below.

[0116] Table 4

[0117] Hydrosilylation yield Terminal addition product selectivity Application Example 5-1 82.2％ 83.8％ Application Example 5-2 70.9％ 75.3％ Application Example 5-3 76.5％ 80.6％ Application Example 5-4 72.4％ 78.6％ Application Example 5-5 79.4％ 81.3％ Application Examples 5-6 72.4％ 83.7％ Application Example 5-7 71.2％ 73.2％

[0118] Example 6: The "0.5 g of platinum" in Example 1 is changed to "0.3 g of platinum", and the amount of nickel is adjusted accordingly, so that the total amount of nickel, aluminum and platinum is still 100 g, and the rest is the same as Example 1; the obtained catalyst is named platinum-doped Raney nickel catalyst II.

[0119] In Application Examples 6-1 to 6-7, the platinum-doped Raney nickel catalyst II obtained in Example 6 replaces the platinum-doped Raney nickel catalyst obtained in Example 1, and the rest is the same as in Application Examples 1-1 to 1-7.

[0120] The results are shown in Table 5 below.

[0121] Table 5

[0122] Hydrosilylation yield Terminal addition product selectivity Application Example 6-1 90.2％ 93.5％ Application Example 6-2 83.7％ 90.9％ Application Example 6-3 86.7％ 88.6％ Application Example 6-4 86.4％ 90.6％ Application Example 6-5 89.2％ 90.9％ Application Example 6-6 86.4％ 93.8％ Application Example 6-7 82.3％ 84.2％

[0123] Comparative Example 1: The "0.5 g of platinum" in Example 1 is changed to "0 g of platinum", that is, the use of platinum is cancelled; and the amount of nickel is adjusted accordingly, so that the total amount of nickel and aluminum is still 100 g, and the rest is the same as Example 1; the obtained catalyst is named Raney nickel catalyst.

[0124] In Comparative Application Examples 1-1 to Comparative Application Examples 1-7, the Raney nickel catalyst obtained in Comparative Example 1 is used to replace the platinum-doped Raney nickel catalyst obtained in Example 1, and the rest is the same as Application Examples 1-1 to Application Examples 1-7.

[0125] The results are shown in Table 6 below.

[0126] Table 6

[0127] Hydrosilylation yield Comparative Example 1-1 42.2％ Comparative Example 1-2 59.7％ Comparative Examples 1-3 60.6％ Comparative Examples 1-4 52.5％ Comparative Examples 1-5 41.4％ Comparative Examples 1-6 58.4％ Comparative Examples 1-7 51.2％

[0128] Comparative Example 2: Step ① of Example 1 is changed to the following:

[0129] 50g of nickel, 49.5g of aluminum and 0.5g of platinum were added into a crusher and crushed into powder, and then ground into 120 mesh. The obtained powder was named ternary alloy powder.

[0130] The rest is the same as Example 1; the obtained catalyst is named platinum-doped Raney nickel catalyst III.

[0131] In Comparative Application Examples 1-1 to Comparative Application Examples 1-7, the platinum-doped Raney nickel catalyst III obtained in Comparative Example 2 replaces the platinum-doped Raney nickel catalyst obtained in Example 1, and the rest is the same as Application Examples 1-1 to Application Examples 1-7.

[0132] The results are shown in Table 7 below.

[0133] Table 7

[0134] Hydrosilylation yield Comparative Example 2-1 12.2％ Comparative Example 2-2 16.7％ Comparative Examples 2-3 9.6％ Comparative Examples 2-4 9.4％ Comparative Examples 2-5 11.2％ Comparative Examples 2-6 13.4％ Comparative Examples 2-7 9.2％

[0135] Comparative Example 3: In step ② of Example 1, the cooling treatment of the sodium hydroxide solution and the batch addition of the ternary alloy powder are cancelled;

[0136] That is, change it to the following:

[0137] Dissolve 125g of sodium hydroxide in 0.5L of deionized water, stir, and add all the ternary alloy powder obtained in step ① into the alkali solution at once under magnetic stirring. Then heat it in a water bath until it reaches 60°C and react at this temperature for 10 hours.

[0138] The rest is the same as Example 1.

[0139] The drawback of this comparative example 3 is that the metals are not mixed evenly and cannot form a skeleton structure, and the dispersion of the active metal platinum is low, so it cannot be used.

[0140] Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A method for preparing an ultra-low platinum doping Raney-type skeleton catalyst for room temperature hydrosilylation, characterized in that The following steps are involved: ①. Preparation of alloy block: A ternary alloy is composed of a skeleton metal, aluminum and platinum, wherein the platinum accounts for 0.1-0.5% of the ternary alloy, the aluminum accounts for 35-65% of the ternary alloy, and the remainder is the skeleton metal; According to the above ratio, the skeleton metal, aluminum and platinum are mixed and melted, and the molten alloy is made into an ingot, and finally cooled to obtain a skeleton metal-aluminum-platinum ternary alloy block; The skeleton metal-aluminum-platinum ternary alloy block is crushed and then ground to obtain ternary alloy powder; ②, Alloy dissolution: Prepare a sodium hydroxide solution with a mass concentration of 20% to 40%, cool it to 10 to 15°C, and obtain a cooled alkali solution; Under magnetic stirring, add the ternary alloy powder prepared in step ① into the cooled alkali solution, control the temperature of the alkali solution not to exceed 25°C during the addition process, stop magnetic stirring after the addition is completed, and the result is named as reaction system; The mass ratio of ternary alloy powder to alkali solution after cooling is 1:5-10; The reaction system was heated to 60-80°C and reacted at this temperature for 10±1 hours; ③. After step ②, let it stand, pour off the supernatant, and add deionized water for washing; Then add the same amount of cooled alkali solution as in step ② again and continue to react at room temperature for 10±1 hours; after standing, wash with deionized water; ④. Wash with 95% ethanol and anhydrous ethanol respectively to obtain a platinum-doped Raney nickel catalyst.

2. The method for preparing the ultra-low platinum doping Raney-type skeleton catalyst according to claim 1, characterized in that: The skeleton metal is any one of the following: nickel, copper, cobalt, and iron.

3. The method for preparing the ultra-low platinum doping Raney-type skeleton catalyst according to claim 2, characterized in that: The heating rate in step ② is 5 to 10° C. / min.

4. The method for preparing the ultra-low platinum doping Raney-type skeleton catalyst according to any one of claims 1 to 3, characterized in that: In the step ①, the powder is ground to pass through a sieve of 80 to 140 mesh.

5. The method for preparing the ultra-low platinum doping Raney-type skeleton catalyst according to claim 4, characterized in that: Aluminum accounts for 48-52% of the ternary alloy.

6. A room temperature hydrosilylation method, characterized in that: An ultra-low platinum-doped Raney-type skeleton catalyst prepared by any method as claimed in claims 1 to 5; The catalyst, unsaturated alkane and hydrosilane are placed in a reaction tube and reacted at room temperature for 2±0.1h; Hydrogen-containing silane: unsaturated alkane = (1 ± 0.1): 1 molar ratio; 9 to 11 mg of ultra-low platinum doping Raney-type skeleton catalyst is used for every 10 mmol of unsaturated alkane.

7. The room temperature hydrosilylation method according to claim 6, characterized in that: The hydrogen-containing silane is triethoxyhydrogensilane, methyldiethoxyhydrogensilane, triisopropylhydrogensilane, trichlorosilane, dichlorodihydrogensilane; The unsaturated alkane is an olefin or an olefin derivative; the olefin is octene, hexene, or isoprene; and the olefin derivative is 1-octen-3-ol, 1-hexen-3-ol, or 5-hexen-2-one.

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