A supported platinum catalyst, its preparation and use

Abstract

The application belongs to the technical field of silicon hydride addition reaction catalysts, and particularly relates to a supported platinum catalyst and a preparation method and application thereof. The application mixes ferroferric oxide, tetraethoxysilane and an organic solvent to perform a hydrolysis reaction, mixes silica-coated ferroferric oxide, organoligand functionalized trialkoxysilane and an organic solvent to perform a condensation reaction, mixes organoligand functionalized ferroferric oxide, a platinum compound and an organic solvent to perform a coordination reaction, and obtains the supported platinum catalyst. The preparation method provided by the application successfully grafts platinum complexes on the surface of ferroferric oxide by using a chemical coupling method. When the obtained supported platinum catalyst is used for a heterogeneous catalytic reaction, the catalyst is easy to separate from a reaction system, the yield of an addition reaction product is high, the catalyst has high stability, can be recycled, and has a long service life.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrosilylation catalysts, and particularly relates to a supported platinum catalyst and a preparation method and application thereof. BACKGROUND

[0002] Hydrosilylation of unsaturated hydrocarbons is the most important route for the synthesis of organosilicon coupling agents and functional organosilicon compounds, and plays an important role in organosilicon chemistry and organosilicon industry. Since it was found that isopropanol solution of chloroplatinic acid has very effective catalytic effect on hydrosilylation, many transition metal complexes have been proved to be high-efficiency catalysts for hydrosilylation, and platinum catalysts are the most commonly used catalysts at present. However, most of these catalysts are homogeneous catalysts, which are difficult to separate and recover from the reaction system, corrode metal containers, have low catalytic activity for some reactions, and are difficult to control the induction period, so their application is limited to a certain extent. Therefore, it is of great industrial value to develop supported platinum group metal coordination catalysts which can overcome the above-mentioned shortcomings, and has attracted widespread attention.

[0003] At present, organic silicon researchers have designed and prepared a new generation of heterogeneous catalysts, and inorganic support and organic polymer supported metal catalysts have gradually become an important research field of organosilicon chemistry. The inorganic support loaded catalyst has good stability in the reaction medium, high mechanical strength, and greatly avoids the swelling of the support and the side effects derived therefrom, so it can be applied in continuous reaction system.

[0004] However, the prior supported platinum catalysts have poor catalytic activity and poor stability when used in hydrosilylation, and cannot be repeatedly used for many times. SUMMARY

[0005] The purpose of the present application is to provide a supported platinum catalyst and a preparation method and application thereof. The supported platinum catalyst provided by the present application has high product yield and high catalyst stability when catalyzing the addition reaction of unsaturated hydrocarbons and hydrogen-containing silane, and has long service life.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0007] The present application provides a preparation method of a supported platinum catalyst, comprising the following steps:

[0008] Fe3O4, tetraethoxysilane and an organic solvent are mixed to carry out a hydrolysis reaction, so as to obtain Fe3O4 coated with SiO2;

[0009] The silica-coated ferroferric oxide, the organic ligand functionalized trialkoxysilane and the organic solvent are mixed to carry out a condensation reaction to obtain the organic ligand functionalized ferroferric oxide; the organic ligand functionalized trialkoxysilane contains groups including amino, mercapto or phosphino;

[0010] The organic ligand functionalized ferroferric oxide, the platinum compound and the organic solvent are mixed to carry out a coordination reaction to obtain the supported platinum catalyst.

[0011] Preferably, the organic ligand functionalized trialkoxysilane includes γ-aminopropyl triethoxysilane, γ-mercaptopropyl triethoxysilane or 2-(diphenyl phosphino) ethyl triethoxysilane.

[0012] Preferably, the ferroferric oxide has a particle size of 50-100 nm, a saturation magnetic moment of 60-90 emu / g and a specific surface area of 40-50 m 2 / g.

[0013] Preferably, the silica-coated ferroferric oxide has a mass content of tetraethoxysilane ≥30%; and an acidity of the tetraethoxysilane <0.001% as calculated by HCl.

[0014] Preferably, the platinum compound includes one or more of PtCl4, chloroplatinic acid and K2PtCl4.

[0015] Preferably, the molar ratio of the ferroferric oxide to the tetraethoxysilane is (1-3):1.

[0016] Preferably, the molar ratio of the ferroferric oxide to the organic ligand functionalized trialkoxysilane is (0.1-0.8):1.

[0017] Preferably, the mass ratio of the organic ligand functionalized ferroferric oxide to the platinum compound is (7-8):1.

[0018] The application provides a supported platinum catalyst prepared by the preparation method, which includes silica-coated ferroferric oxide and platinum complexes coupled to the surface of the silica-coated ferroferric oxide.

[0019] The application provides an application of the supported platinum catalyst in an addition reaction of unsaturated hydrocarbon and hydrogen-containing silane, wherein the unsaturated hydrocarbon includes olefin and / or alkyne.

[0020] The application provides a preparation method of a supported platinum catalyst, which comprises the following steps: mixing ferriferrous oxide, tetraethoxysilane and an organic solvent to perform a hydrolysis reaction, so as to obtain ferriferrous oxide coated with silicon dioxide; mixing the ferriferrous oxide coated with silicon dioxide, organically ligand-functionalized trialkoxysilane and an organic solvent to perform a condensation reaction, so as to obtain organically ligand-functionalized ferriferrous oxide; the organically ligand-functionalized trialkoxysilane contains groups including amino, mercapto or phosphino; mixing the organically ligand-functionalized ferriferrous oxide, a platinum compound and an organic solvent to perform a coordination reaction, so as to obtain the supported platinum catalyst. The preparation method provided by the application coats a silicon dioxide layer on the surface of ferriferrous oxide through the hydrolysis reaction of tetraethoxysilane, then grafts organically ligands on the silicon dioxide layer on the surface of ferriferrous oxide through the condensation reaction of the silicon dioxide layer and organically ligand-functionalized trialkoxysilane, obtains organically ligand-functionalized ferriferrous oxide, and finally obtains chemically grafted platinum complexes on the surface of ferriferrous oxide through the coordination reaction of platinum ions and organically ligands. The preparation method provided by the application successfully grafts platinum complexes on the surface of ferriferrous oxide by using a chemical coupling method, and the obtained supported platinum catalyst is easy to separate from a reaction system when performing a heterogeneous catalytic reaction, the yield of an addition reaction product is high, the catalyst stability is high, the catalyst can be recycled, and the service life is long. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A synthesis route diagram of the supported platinum catalyst Fe3O4@SiO2-N-Pt provided for the application example 1;

[0022] Figure 2 A TEM spectrum of Fe3O4@SiO2-P-Pt prepared for the application example 2;

[0023] Figure 3 An EDS spectrum of Fe3O4@SiO2-P-Pt prepared for the application example 2;

[0024] Figure 4 An XRD spectrum of Fe3O4@SiO2-P-Pt (curve 1), Fe3O4@SiO2-N-Pt (curve 2) and Fe3O4@SiO2-P-Pt (curve 3) prepared for the application example 2; Figure 4 An XRD spectrum of Fe3O4@SiO2-P-Pt (curve 1), Fe3O4@SiO2-N-Pt (curve 2) and Fe3O4@SiO2-P-Pt (curve 3) prepared for the application example 2; Figure 4 An XRD spectrum of Fe3O4@SiO2-P-Pt (curve 1), Fe3O4@SiO2-N-Pt (curve 2) and Fe3O4@SiO2-P-Pt (curve 3) prepared for the application example 2; Figure 4 An XRD spectrum of Fe3O4@SiO2-P-Pt (curve 1), Fe3O4@SiO2-N-Pt (curve 2) and Fe3O4@SiO2-P-Pt (curve 3) prepared for the application example 2;

[0025] Figure 5 An infrared spectrum of Fe3O4@SiO2-P-Pt prepared for the application example 2;

[0026] Figure 6 A chemical reaction principle diagram of the supported platinum catalyst provided by the application for catalyzing an olefin addition reaction;

[0027] Figure 7 Chemical reaction scheme of addition reaction of conjugated alkenes and conjugated alkynes catalyzed by the supported platinum catalyst provided in the present application;

[0028] Figure 8 Chemical reaction scheme of addition reaction of non-conjugated dienes and non-conjugated diynes catalyzed by the supported platinum catalyst provided in the present application;

[0029] Figure 9 Cyclic use effect diagram of the supported platinum catalyst Fe3O4@SiO2-N-Pt provided in Example 1 of the present application. DETAILED DESCRIPTION

[0030] The present application provides a preparation method of a supported platinum catalyst, comprising the following steps:

[0031] Fe3O4, tetraethoxysilane and an organic solvent are mixed to perform a hydrolysis reaction, to obtain Fe3O4 coated with SiO2.

[0032] The Fe3O4 coated with SiO2, trialkoxysilane functionalized with an organic ligand and an organic solvent are mixed to perform a condensation reaction, to obtain Fe3O4 functionalized with an organic ligand; the trialkoxysilane functionalized with an organic ligand contains groups including amino, mercapto or phosphino.

[0033] The Fe3O4 functionalized with an organic ligand, a platinum compound and an organic solvent are mixed to perform a coordination reaction, to obtain a supported platinum catalyst.

[0034] In the present application, all the preparation raw materials / components are commercially available products well known to those skilled in the art, unless otherwise specified.

[0035] In the present application, Fe3O4, tetraethoxysilane and an organic solvent (hereinafter referred to as the first organic solvent) are mixed (hereinafter referred to as the first mixing) to perform a hydrolysis reaction, to obtain Fe3O4 coated with SiO2.

[0036] In the present application, the particle size of the Fe3O4 is preferably 50-100 nm, and more preferably 60-80 nm. The saturation magnetic moment of the Fe3O4 is preferably 60-90 emu / g. The specific surface area of the Fe3O4 is preferably 40-50 m 2In the present application, the preparation method of the ferroferric oxide preferably comprises the following steps: mixing ferric chloride, a complexing agent, a surfactant and a solvent to obtain a mixed solution, adjusting the pH value of the mixed solution to 7-9 by using a pH adjuster to obtain a sol, removing the solvent from the sol to obtain a dry gel, drying the dry gel and then performing a combustion reaction, and cooling to obtain ferroferric oxide. The ferric chloride is preferably ferric chloride hexahydrate. The complexing agent is preferably salicylic acid, and the surfactant is preferably polyvinyl alcohol. The solvent is preferably ethylene glycol. The molar ratio of the ferric chloride, the complexing agent and the surfactant is preferably 1:2:1. The present application does not have special requirements for the amount of solvent, as long as the ferric chloride, the complexing agent and the surfactant can be completely dissolved. The pH adjuster is preferably ethylenediamine, and the temperature for removing the solvent is preferably room temperature. The drying temperature is preferably 70°C.

[0037] In the present application, the mass content of the silicon dioxide of the tetraethoxysilane is preferably ≥30%, and the acidity of the tetraethoxysilane, calculated as HCl, is preferably <0.001%. The molar ratio of the ferroferric oxide and the tetraethoxysilane is preferably (1-3):1, and more preferably (1.3-2.6):1. The first organic solvent is preferably toluene and trichloromethane. The toluene is preferably anhydrous toluene. The trichloromethane is preferably anhydrous trichloromethane. The first mixing preferably comprises the following steps: dispersing the ferroferric oxide in part of the first organic solvent to obtain a ferroferric oxide dispersion; dissolving the tetraethoxysilane in the remaining first organic solvent to obtain a tetraethoxysilane solution; and adding the tetraethoxysilane solution to the ferroferric oxide dispersion. The part of the first organic solvent is preferably toluene, and the remaining first organic solvent is preferably trichloromethane. The temperature of the hydrolysis reaction is preferably 100°C, and the holding time is preferably 24 h. The hydrolysis reaction is preferably performed under stirring. After the hydrolysis reaction, a hydrolysis reaction liquid is obtained, and the present application preferably performs solid-liquid separation on the hydrolysis reaction liquid to obtain a solid-phase product. The solid-phase product is washed with trichloromethane and then dried to obtain ferroferric oxide coated with silicon dioxide. In the present application, the solid-liquid separation is preferably filtration. The washing is preferably performed twice. The drying is preferably vacuum drying, and the temperature of the vacuum drying is preferably 160°C, and the time is preferably 5 hours.

[0038] After obtaining the ferroferric oxide coated with silicon dioxide, the present application mixes (hereinafter referred to as second mixing) the ferroferric oxide coated with silicon dioxide, the trialkoxysilane functionalized with an organic ligand and an organic solvent (hereinafter referred to as a second organic solvent) to perform a condensation reaction, thereby obtaining ferroferric oxide functionalized with an organic ligand. The organic ligand contained in the trialkoxysilane functionalized with an organic ligand includes amino, mercapto or phosphino.

[0039] In the present application, the organic ligand functionalized trialkoxysilane preferably comprises γ-aminopropyl triethoxysilane, γ-mercaptopropyl triethoxysilane or 2-(diphenylphosphino)ethyl triethoxysilane. The second organic solvent preferably is toluene. The molar ratio of the ferroferric oxide and the organic ligand functionalized trialkoxysilane preferably is (0.1-0.8):1, more preferably (0.3-0.5):1. The present application does not have special requirements for the amount of the second organic solvent. The second mixing preferably is that the silica-coated ferroferric oxide is soaked in a solution formed by the organic ligand functionalized trialkoxysilane and the second organic solvent. The temperature of the condensation reaction preferably is room temperature, and the time of the condensation reaction preferably is 24 hours. The condensation reaction is carried out under stirring. After the condensation reaction, a condensation reaction liquid is obtained. The present application preferably carries out solid-liquid separation on the condensation reaction liquid to obtain a solid phase product. The solid phase product is sequentially washed by acetone and diethyl ether. The washed solid phase product is dried to obtain the organic ligand functionalized ferroferric oxide. In the present application, the solid-liquid separation preferably is filtration. The number of times of the acetone washing preferably is 3. The number of times of the diethyl ether washing preferably is 3. The drying preferably is vacuum drying. The temperature of the vacuum drying preferably is 160°C, and the time of the vacuum drying preferably is 5 hours.

[0040] After obtaining the organic ligand functionalized ferroferric oxide, the present application mixes (hereinafter referred to as third mixing) the organic ligand functionalized ferroferric oxide, a platinum compound and an organic solvent (hereinafter referred to as third organic solvent) to carry out a coordination reaction to obtain a supported platinum catalyst.

[0041] In the present application, the platinum compound preferably comprises one or more of PtCl4, chloroplatinic acid and K2PtCl4, more preferably K2PtCl4. The third organic solvent preferably is acetone. The mass ratio of the organic ligand functionalized ferroferric oxide and the platinum compound preferably is (7-8):1. The present application does not have special requirements for the amount of the third organic solvent, as long as the platinum compound is completely dissolved. The third mixing preferably is that the platinum compound is dissolved in the third organic solvent and then added to the organic ligand functionalized ferroferric oxide. The coordination reaction is carried out in a protective gas atmosphere, and the protective gas preferably is nitrogen. The coordination reaction is carried out under heating reflux. The time of the coordination reaction preferably is 72 hours. After the coordination reaction, a coordination reaction liquid is obtained. The present application preferably carries out solid-liquid separation on the coordination reaction liquid to obtain a solid phase product. The solid phase product is sequentially washed by acetone first, distilled water second and acetone third. The washed solid phase product is dried to obtain the supported platinum catalyst. The solid-liquid separation preferably is suction filtration. The drying preferably is carried out in a protective gas atmosphere. The protective gas preferably is nitrogen, and the pressure of the protective gas preferably is 26.7 Pa. The temperature of the drying preferably is 70°C, and the time of the drying preferably is 3 hours.

[0042] The application provides a supported platinum catalyst prepared by the preparation method.

[0043] In the application, the molar amount of platinum in the supported platinum catalyst preferably accounts for 0.2-0.4 mol / g of the mass percentage (loading amount) of the supported platinum catalyst.

[0044] In the supported platinum catalyst provided by the application, the platinum complex is connected with the ferroferric oxide carrier through an intermediate silica layer, and the platinum complex is connected on the surface of the silica layer through a chemical bond, so that the connection strength between the platinum complex and the ferroferric oxide is high, and the cycle stability of the obtained supported platinum catalyst is high, and the service life is long in the catalytic addition reaction of olefins and hydrogen-containing silane.

[0045] The application provides an application of the supported platinum catalyst in the addition reaction of unsaturated hydrocarbons and hydrogen-containing silane.

[0046] In the application, the application preferably includes mixing the unsaturated hydrocarbons, the supported platinum catalyst and the hydrogen-containing silane to perform a catalytic addition reaction.

[0047] R in formula 1 is alkyl or aryl; 1 R in formula 1 is alkyl or aryl;

[0048] R in formula 2 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 2 R in formula 2 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 3 R in formula 2 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 2 R in formula 2 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 3 R in formula 2 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 2 R in formula 2 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 3 R in formula 2 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 2 R in formula 2 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 3 R in formula 2 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl;

[0049] R in formula 3 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 1 R in formula 3 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 2 R in formula 3 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 1 R in formula 3 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 2 R in formula 3 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 1 R in formula 3 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 2 R in formula 3 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 1 R in formula 3 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl; 2 R in formula 3 is alkyl or aryl when R ≠ R is alkyl or aryl, and R is SiMe3 when R = R is alkyl or aryl;

[0050] X is O, S, NH, CH2, CHCH3, or CH2CH2CH2in formula 4.

[0051] The alkyne preferably includes an alkyne having a structure shown in formula 5, an alkyne having a structure shown in formula 6, an alkyne having a structure shown in formula 7, or an alkyne having a structure shown in formula 8.

[0052] R in formula 5 1 is an alkyl group or an aryl group;

[0053] R in formula 6 2 = R 3 , R 2 and R 3 are alkyl groups or aryl groups; and when R 2 ≠ R 3 , R 2 is an alkyl group or an aryl group, and R 3 is SiMe3;

[0054] R in formula 7 1 = R 2 , R 1 and R 2 are alkyl groups or aryl groups; and when R 1 ≠ R 2 , R 1 is an alkyl group or an aryl group, and R 2 is SiMe3;

[0055] X is O, S, NH, CH2, CHCH3, or CH2CH2CH2in formula 8.

[0056] In the present application, the chemical formula of the hydrosilane is shown in formula 9: HSiR3 formula 9; SiR3 in formula 9 is SiMe2Ph, SiMe2(OSiMe3), SiMe(OSiMe3)2, SiEt3, or SiPh3, and is preferably triethoxysilane. The molar ratio of the olefin to the hydrosilane is preferably 5:5.5. The molar amount of the supported platinum catalyst is 0.05 to 0.2 mol% of the molar amount of the olefin. The temperature of the catalytic addition reaction is preferably 100 to 120°C, and the time is preferably 1 to 2 hours. The catalytic addition reaction is performed under stirring. In the present application, the product in the catalytic addition reaction liquid is separated by a reduced pressure distillation after the catalytic addition reaction.

[0057] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0058] Example 1

[0059] according to Figure 1 The synthesis route of the supported platinum catalyst Fe3O4@SiO2-N-Pt: 1 mol of ferric chloride hexahydrate, 1 mol of salicylic acid, and 0.01 mol of polyvinyl alcohol were added to 500 mL of ethylene glycol to form a mixed solution. The pH of the mixed solution was adjusted to 7 to form a sol. The ethylene glycol was removed at room temperature, and the solution was dried at low temperature. The sol was then combusted in an inert atmosphere reactor. After cooling, magnetic nanoparticles of magnetite (Fe3O4@SiO2-N-Pt) were obtained. The particle size of the magnetite nanoparticles was 50–100 nm, the saturation magnetic moment was 60–90 emu / g, and the specific surface area was 40–50 m² / g. 2 / g.

[0060] Magnetic ferric oxide nanoparticles (2.20 g) and dry toluene (120 mL) were added to a reactor and stirred to form a suspension. Then, a solution of tetraethoxysilane (1.70 g, 7.1 mmol) dissolved in dry CHCl3 (12 mL) was added to the reactor. The mixture was heated to 100 °C and stirred for 24 hours. The solid was filtered and washed twice with CHCl3 (20 mL). Finally, it was vacuum dried at 160 °C for 5 hours to obtain silica-coated iron oxide nanoparticles.

[0061] The dried silica-coated iron oxide nanoparticles were immersed in a solution of γ-aminopropyltriethoxysilane (28 mmol) and toluene (100 mL) for 24 hours with stirring at room temperature. The solid was then filtered, washed three times with acetone (20 mL) and diethyl ether (20 mL), and dried under vacuum at 160 °C for 5 hours to obtain amino-functionalized iron oxide nanoparticles, denoted as Fe3O4@SiO2-N.

[0062] The above-mentioned amino-functionalized iron(III) oxide nanoparticles (1.51 g) were added to an acetone (50 mL) solution of K2PtCl4 (0.205 g). The mixture was heated under reflux for 72 hours under nitrogen. The solid product was filtered by suction filtration, washed successively with acetone, distilled water, and acetone, and dried under nitrogen at 70 °C / 26.7 Pa for 3 hours to obtain the supported platinum catalyst, denoted as Fe3O4@SiO2-N-Pt.

[0063] Table 1 is a comparison of XPS data for Fe3O4@SiO2-N and Fe3O4@SiO2-N-Pt prepared in Example 1.

[0064] Sample Pt 4f7 / 2 ]] [0003N 1s ]]> Si 2p ]]> O 1s ]]> Fe3O4@SiO2-N-Pt 72.0 400.7 103.5 532.9 Fe304@Si02-N 0 399.8 103.4 532.6

[0065] Example 2

[0066] The method of Example 1 was used to prepare the Fe3O4 magnetic nanoparticles with a particle size of 50-100 nm, a saturation magnetization of 60-90 emu / g, and a specific surface area of 40-50 m2 / g. 2 / g.

[0067] The magnetic nanoparticles Fe3O4 (2.20 g) and dry toluene (120 mL) were added to a reactor, stirred to form a suspension liquid, and then a solution of tetraethoxysilane (1.70 g, 7.1 mmol) dissolved in dry CHCl3 (12 mL) was added to the reactor, heated and stirred at 100°C for 24 hours. The solid was filtered and washed with CHCl3 (20 mL) twice, and finally vacuum dried at 160°C for 5 hours to obtain the Fe3O4@SiO2 nanoparticles.

[0068] The dried Fe3O4@SiO2 nanoparticles were immersed in a solution of 2-(diphenylphosphino)ethyltriethoxysilane (28 mmol) and toluene (100 mL) at room temperature for 24 hours with stirring, and then the solid was filtered, washed with acetone (20 mL) and diethyl ether (20 mL) three times respectively, and vacuum dried at 160°C for 5 hours to obtain the phosphine-functionalized Fe3O4@SiO2-P nanoparticles.

[0069] The phosphine-functionalized Fe3O4@SiO2-P nanoparticles (1.51 g) were added to a solution of K2PtCl4 (0.205 g) in acetone (50 mL). The mixture was heated and refluxed under nitrogen for 72 hours. The solid product was filtered by suction, washed with acetone, distilled water and acetone in turn, and dried at 70°C / 26.7 Pa under nitrogen for 3 hours to obtain the supported platinum catalyst, denoted as Fe3O4@SiO2-P-Pt.

[0070] Table 2 is a comparison table of XPS data of Fe3O4@SiO2-P and Fe3O4@SiO2-P-Pt prepared in Example 2

[0071] Sample Pt 4f7 / 2 ]]> P 2p ]]> Si 2p ]]> O 1s ]]> Fe3O4@SiO2-P-Pt 72.3 131.7 103.2 532.8 Fe304@Si02-P 0 132.2 103.2 533.0

[0072] Figure 2 The TEM spectrum of Fe3O4@SiO2-P-Pt prepared in Example 2 of the present application is shown in Figure 2. Figure 2 It can be seen that the Fe3O4@SiO2-P-Pt prepared in the present application is spherical, and the surface of the Fe3O4 is coated with a layer of SiO2. Figure 3EDS spectrum of Fe3O4@SiO2-P-Pt prepared for the embodiment 2 of the present application.

[0073] Figure 4 XRD spectrum of Fe3O4@SiO2-P-Pt prepared for the embodiment 2 of the present application. Figure 4 XRD spectrum of Fe3O4@SiO2-P-Pt prepared for the embodiment 2 of the present application. Figure 4 XRD spectrum of Fe3O4@SiO2-P-Pt prepared for the embodiment 2 of the present application. Figure 4 XRD spectrum of Fe3O4@SiO2-P-Pt prepared for the embodiment 2 of the present application. Figure 4 It can be seen that the basic structure of the matrix Fe3O4@SiO2 is not damaged in the whole process of preparing the catalyst.

[0074] Figure 5 Infrared spectrum of Fe3O4@SiO2-P-Pt prepared for the embodiment 2 of the present application. Figure 5 It can be seen that the coordination reaction is successful.

[0075] Application Example

[0076] Unsaturated olefin (diphenyl ethylene) and Fe3O4@SiO2-N-Pt prepared in the embodiment 1 are added into a three-necked reactor equipped with a magnetic stirrer and a reflux condenser, the upper part of which is connected with a drying system; after stirring for 30 minutes at the reaction temperature (100-120℃), triethoxysilane is added dropwise, and the product is separated by vacuum distillation after reaction for 1-2 hours. The amount of the olefin is 5.0 mmol, the amount of triethoxysilane is 5.5 mmol, and the amount of the platinum-loaded catalyst is controlled at 0.1 mol%, 0.05 mol% or 0.2 mol%.

[0077] Table 3 is the experimental data of the catalytic addition reaction of the application example

[0078] Serial number Temperature / °C Catalyst loading amount / mol% Time / h Yield / % 1 100 0.1 2.0 82 2 110 0.1 1.8 88 3 120 0.1 1.6 94 4 130 0.1 1.2 90 5 120 0.05 2.2 91 6 120 0.2 1.2 85

[0079] After the Fe3O4@SiO2-N-Pt prepared in the embodiment 1 is recovered, it is recycled, Figure 9 The catalytic effect diagram of Fe3O4@SiO2-N-Pt prepared in the embodiment 1 recycled for 1-10 times, by Figure 9 It can be seen that the yield of the product is basically flat during the recycling of the Fe3O4@SiO2-N-Pt prepared in the embodiment 1 for 10 times, which indicates that the prepared platinum-loaded catalyst has good recycling stability, wherein Figure 9 The "green text" in the table is the background, and has no actual meaning.

[0080] From table 3 and Figure 9It is known that the supported platinum catalyst prepared by the application is easy to separate from the reaction system when carrying out heterogeneous catalytic reaction, the yield of addition reaction product is high, the catalyst stability is high, the catalyst can be recycled, and the service life is long.

[0081] Although the above embodiment has made a detailed description of the application, it is only a part of the embodiments of the application, not all the embodiments, and other embodiments can be obtained according to the embodiment without creativity, and these embodiments all belong to the protection scope of the application.

Claims

1. A process for the preparation of a supported platinum catalyst, characterized in that, The method comprises the following steps: mixing the ferroferric oxide, tetraethoxysilane and organic solvent to perform hydrolysis reaction, to obtain the ferroferric oxide coated with silica, the molar ratio of the ferroferric oxide and the tetraethoxysilane being (1-3) : 1; mixing the ferroferric oxide coated with silica, organo-ligand functionalized trialkoxysilane and organic solvent to perform condensation reaction, to obtain the organo-ligand functionalized ferroferric oxide, the organo-ligand functionalized trialkoxysilane including γ-aminopropyl triethoxysilane, γ-mercapto propyl triethoxysilane or 2-(diphenyl phosphino) ethyl triethoxysilane, the molar ratio of the ferroferric oxide and the organo-ligand functionalized trialkoxysilane being (0.1-0.8) : 1; mixing the organo-ligand functionalized ferroferric oxide, platinum compound and organic solvent to perform coordination reaction, to obtain the supported platinum catalyst, the platinum compound including one or more of PtCl4, chloroplatinic acid and K2PtCl4, the mass ratio of the organo-ligand functionalized ferroferric oxide and the platinum compound being (7-8) :

1.

2. The production method according to claim 1, characterized by, The ferriferrous oxide has a particle size of 50-100 nm, a saturated magnetic moment of 60-90 emu / g, and a specific surface area of 40-50 m 2 / g.

3. The preparation method according to claim 1, characterized in that, The mass content of silica in the tetraethoxysilane is ≥ 30%, and the acidity of the tetraethoxysilane is < 0.001% in terms of HCl.

4. The supported platinum catalyst obtainable by the process according to any one of claims 1 to 3, characterized in that The method comprises the following steps:

5. The use of the supported platinum catalyst of claim 4 in the addition reaction of unsaturated hydrocarbon and hydrogen-containing silane, the unsaturated hydrocarbon including olefin and / or alkyne.

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