Preparation method and application of a novel nickel-based trimetallic catalyst

Abstract

The application discloses a preparation method of a novel nickel-based three-metal catalyst and application thereof, relates to the technical field of catalyst preparation and application, and provides a safe, green and simple nickel-based three-metal catalyst preparation method, wherein the novel nickel-based three-metal catalyst is mainly composed of nickel, a small amount of doped ruthenium and palladium noble metals, the nickel and the small amount of doped ruthenium and palladium exhibit a good synergistic effect, and the catalyst cost is reduced. When the catalyst is applied to catalytic preparation of tricyclohexylphosphine oxide, the nickel, the ruthenium and the palladium exhibit a good synergistic effect, and the catalyst has high activity in reduction of tricyclohexylphosphine oxide, so that high-yield and high-purity products are obtained while the preparation cost is reduced, and better economic advantages are exhibited.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for preparing a catalyst ligand intermediate by catalytic hydrogenation, in particular to a preparation method of a novel nickel-based trimetallic catalyst and its application in preparing tricyclohexylphosphine oxide. BACKGROUND

[0002] Tricyclohexylphosphine oxide has a molecular formula of C 18 H 33 PO, and a structural formula as follows:

[0003]

[0004] In recent years, transition metal catalysts have been widely used in catalytic reactions, and have attracted much attention due to their high activity and good selectivity. In the research of transition metal catalysts, the structure and properties of phosphine ligands have an important influence on the catalytic performance of transition metal catalysts. Therefore, the design and synthesis of phosphine ligands have always been an important research content in the research of transition metal catalysts.

[0005] The cyclohexyl group in tricyclohexylphosphine has good electron-donating effect and steric hindering effect, so that its coordination effect is good, and it has become one of the important catalyst ligands in coupling reactions. Tricyclohexylphosphine oxide can be used as an important intermediate for preparing tricyclohexylphosphine ligand, and the research on its preparation method is of great significance. Krause et al. reduced phenylated phosphonate oxide to the corresponding cyclohexyl derivative by catalytic hydrogenation using Rh / Pt catalyst (Catalysis Letters 8 (1991) 23-26). US 5530162 A reported a method for synthesizing tricyclohexylphosphine directly using triphenylphosphine. The catalyst used in this process is a niobium metal complex which is difficult to prepare and expensive, making it difficult to apply to industrial production. Chinese patent CN 102627667B provides a preparation method of tricyclohexylphosphine oxide. The catalyst used in the preparation of tricyclohexylphosphine oxide in this patent is some expensive Ru / C, Rh / C, Pd / C or Pd / Al2O3. SUMMARY

[0006] Therefore, the first aspect of the present application is to provide a preparation method of a novel nickel-based trimetallic catalyst.

[0007] The technical solutions adopted by the present application are as follows:

[0008] The application relates to a preparation method of a novel nickel-based three-metal catalyst, and has the characteristics that the following steps are included: RuCl3.nH2O, NiCl2.6H2O, PdCl2 and PVP are added into ethylene glycol, stirring is carried out, the solution is homogenized, and no precipitation is generated; then Na2CO3 solution is added to stabilize the pH of the mixture at 9-11, and ultrasonic treatment is carried out for a period of time; the mixed solution is transferred into a reaction kettle, heat preservation is carried out for a period of time, after the reaction kettle is naturally cooled to room temperature, pretreated carbon carriers are added into the solution, ultrasonic treatment and centrifugal treatment are carried out, black solids are obtained, the black solids are washed and dried, and then the black solids are placed into a tube furnace, reduction is carried out in H2 at 250-350 DEG C for 3-9 h, and the novel nickel-based three-metal catalyst is obtained.

[0009] Further settings are as follows:

[0010] The molar ratio of the raw materials RuCl3.nH2O, NiCl2.6H2O and PdCl2, nickel, ruthenium and palladium is 60-20:2-3:1-2.

[0011] After the Na2CO3 solution is added, ultrasonic treatment is carried out for 30-60 min.

[0012] The mixed solution is transferred into a reaction kettle, the heat preservation temperature is 200-220 DEG C, and the heat preservation time is 2-5 h.

[0013] The obtained black solids are washed with anhydrous ethanol and acetone for three times respectively, and finally dried in a vacuum oven at 60 DEG C for 12 h.

[0014] The novel nickel-based three-metal catalyst prepared by the application has the advantages of simple preparation and low price, has very good catalytic effect in the application in the preparation of tricyclohexylphosphine oxide, and has good industrial application prospect.

[0015] The second aspect of the application is to provide the application of the novel nickel-based three-metal catalyst in the preparation of tricyclohexylphosphine oxide, and has the characteristics that triphenylphosphine oxide, the novel nickel-based three-metal catalyst and an organic solvent are added into a high-pressure kettle, and after replacement with argon and hydrogen, catalytic hydrogenation is carried out at 150-200 DEG C and 5-8 MPa, the reaction is stopped after reaction for 48-96 h, the catalyst is removed through centrifugal treatment, and tricyclohexylphosphine oxide solution is obtained; the product tricyclohexylphosphine oxide is obtained through rotary evaporation and drying in a vacuum drying box at 40-60 DEG C for 5-10 h.

[0016] The reaction equation is as follows:

[0017]

[0018] Further settings are as follows:

[0019] The amount of the novel nickel-based three-metal catalyst is 1.0-5.0% of the mass of the triphenylphosphine oxide.

[0020] The reaction temperature is 170 DEG C, the pressure is 6.0 MPa, and the reaction time is 72 h.

[0021] The organic solvent is isopropyl alcohol, tetrahydrofuran or cyclohexane.

[0022] The beneficial effects of the present application are as follows:

[0023] (1) The present application provides a safe, green and simple nickel-based three-metal catalyst preparation method. The novel nickel-based three-metal catalyst provided herein mainly comprises nickel and a small amount of ruthenium and palladium. The combination of nickel, ruthenium and palladium exhibits a good synergistic effect, thereby reducing the cost of the catalyst.

[0024] (2) The present application provides a preparation method of tricyclohexylphosphine oxide. The tricyclohexylphosphine oxide is obtained by hydrogenation of triphenylphosphine oxide under the action of a novel nickel-based three-metal catalyst. Experiments have shown that the combination of nickel, ruthenium and palladium exhibits a good synergistic effect and has a high activity in the reduction of triphenylphosphine oxide. The process provided herein reduces the preparation cost and obtains a product with high yield and high purity, thereby exhibiting better economic advantages. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The XRD pattern of the nickel-based three-metal catalyst prepared in Example 1.

[0026] Figure 2 The nuclear magnetic hydrogen spectrum of the tricyclohexylphosphine oxide prepared in Example 6. DETAILED DESCRIPTION

[0027] The present application will be further described below in combination with the drawings and specific examples, but the following description does not constitute a limitation on the protection scope of the present application.

[0028] Example 1: Preparation of a nickel-based three-metal catalyst

[0029] (1) Pretreatment of the carbon carrier:

[0030] 20.0 g of carbon black was added to 50 mL of a mixed acid solution of HNO3 and H2SO4 with a concentration of 8 mol / L, ultrasonically dispersed for 30 min, then transferred to a 100 mL hydrothermal kettle, reacted at 70 DEG C for 6 h, filtered, then repeatedly washed with deionized water until neutral, and then placed in a vacuum drying oven for drying to obtain a pretreated carbon carrier.

[0031] (2) Preparation of a nickel-based three-metal catalyst

[0032] 3.0 x 10 -4 moles of RuCl3 nH2O, 6.0 x 10 -3Moles of NiCl2·6H2O, 1.0 × 10 -4 moles of PdCl2 and 5.0 × 10 -4 Molar amounts of PVP were added to 60 mL of ethylene glycol and stirred to homogenize the solution until no precipitate formed. Na₂CO₃ solution was then added to ensure the pH of the mixture stabilized at 10.0, and the mixture was sonicated for 30 min. This mixture was transferred to a 100 mL reactor and kept at 200 °C for 3 h. After the reactor cooled naturally to room temperature, a pretreated carbon support was added to the solution and sonicated for 2 h. The mixture was centrifuged to obtain a black solid, which was washed three times each with anhydrous ethanol and acetone, and finally dried in a vacuum oven at 60 °C for 12 h. The sample was placed in a tube furnace and reduced in H₂ at 300 °C for 6 h. The resulting nickel-based trimetallic catalyst was labeled Catalyst A.

[0033] The nickel-based trimetallic catalyst prepared in Example 1 was characterized by X-ray diffraction (XRD). Figure 1 The crystal properties of the catalyst were studied by X-ray diffraction. Since ruthenium and palladium are amorphous, no diffraction peaks of ruthenium and palladium were detected. The broad peaks in the 2θ angle range of 20-30° were diffraction peaks of carbon, and the peaks at 2θ of 44.49°, 52.4° and 75.6° were diffraction peaks of metallic nickel.

[0034] Example 2

[0035] The preparation method is the same as in Example 1, except that the proportion of nickel chloride hexahydrate in step (2) is adjusted as follows:

[0036] 3.0×10 -4 Moles of RuCl3·nH2O, 4.0 × 10 -3 Moles of NiCl2·6H2O, 1.0 × 10 -4 moles of PdCl2 and 5.0 × 10 -4 Molar amounts of PVP were added to 60 mL of ethylene glycol and stirred to homogenize the solution until no precipitate formed. Na₂CO₃ solution was then added to ensure the pH of the mixture stabilized at 10.0, and the mixture was sonicated for 30 min. This mixture was transferred to a 100 mL reactor and kept at 200 °C for 3 h. After the reactor cooled naturally to room temperature, a pretreated carbon support was added to the solution and sonicated for 2 h. The resulting black solid was centrifuged and washed three times each with anhydrous ethanol and acetone, and finally dried in a vacuum oven at 60 °C for 12 h. The sample was then placed in a tube furnace and reduced in H₂ at 300 °C for 6 h. The resulting nickel-based trimetallic catalyst was labeled as Catalyst B.

[0037] Example 3

[0038] The preparation method is the same as in Example 1, except that the proportion of nickel chloride hexahydrate in step (2) is adjusted as follows:

[0039] 3.0 x 10 -4 moles of RuCl3-nH2O, 2.0 x 10 -3 moles of NiCl2-6H2O, 1.0 x 10 -4 moles of PdCl2and 5.0 x 10 -4 moles of PVP were added to 60 mL of ethylene glycol and stirred to make the solution homogeneous without precipitation. Na2CO3solution was added to ensure that the pH of the mixture was stable at 10.0. The mixture was ultrasonicated for 30 min. The mixture was transferred to a 100 mL reactor and kept at 200 °C for 3 h. After the reactor was naturally cooled to room temperature, pretreated carbon support was added to the solution and ultrasonicated for 2 h. The black solid obtained by centrifugation was washed with anhydrous ethanol and acetone three times each, and finally dried in a vacuum oven at 60 °C for 12 h. The above sample was placed in a tube furnace and reduced in H2at 300 °C for 6 h to produce a nickel-based trimetallic catalyst, which was labeled as Catalyst C.

[0040] Example 4

[0041] The preparation method was the same as Example 1, except that no palladium chloride was added in step (2), and the details were as follows:

[0042] 3.0 x 10 -4 moles of RuCl3-nH2O, 6.0 x 10 -3 moles of NiCl2-6H2O and 5.0 x 10 -4 moles of PVP were added to 60 mL of ethylene glycol and stirred to make the solution homogeneous without precipitation. Na2CO3solution was added to ensure that the pH of the mixture was stable at 10.0. The mixture was ultrasonicated for 30 min. The mixture was transferred to a 100 mL reactor and kept at 200 °C for 3 h. After the reactor was naturally cooled to room temperature, pretreated carbon support was added to the solution and ultrasonicated for 2 h. The black solid obtained by centrifugation was washed with anhydrous ethanol and acetone three times each, and finally dried in a vacuum oven at 60 °C for 12 h. The above sample was placed in a tube furnace and reduced in H2at 300 °C for 6 h to produce a nickel-based trimetallic catalyst, which was labeled as Catalyst D.

[0043] Example 5

[0044] The preparation method was the same as Example 1, except that no ruthenium chloride hydrate was added in step (2), and the details were as follows:

[0045] 6.0 x 10 -3 moles of NiCl2-6H2O, 1.0 x 10 -4 moles of PdCl2and 5.0 x 10 -4Mole PVP was added into 60 mL ethylene glycol, stirred to make the solution homogeneous without precipitation. Na2CO3 solution was added to ensure the pH of the mixture was stable at 10.0. The mixture was ultrasonicated for 30 min. The mixture was transferred into a 100 mL reactor, and was kept at 200°C for 3 h. After the reactor was naturally cooled to room temperature, the pretreated carbon carrier was added into the solution and ultrasonicated for 2 h. The black solid obtained by centrifugation was washed with anhydrous ethanol and acetone for 3 times, and was dried in a vacuum oven at 60°C for 12 h. The above sample was placed in a tube furnace, and was reduced in H2 at 300°C for 6 h to obtain a nickel-based trimetallic catalyst, which was labeled as catalyst E.

[0046] Example 6: Preparation of tricyclohexylphosphine oxide

[0047] In a high-pressure reactor, triphenylphosphine oxide 1.000 g, catalyst A 0.050 g and isopropyl alcohol 15 ml were sequentially added. After replacement with argon and hydrogen, catalytic hydrogenation was carried out at a temperature of 170°C and a pressure of 6 MPa. The reaction was stopped after 72 h, the catalyst was removed by centrifugation, and a tricyclohexylphosphine oxide solution was obtained. After rotary evaporation, the product was dried in a vacuum drying oven at 50°C for 8 h to obtain tricyclohexylphosphine oxide. The yield of the product was 99%.

[0048] The nuclear magnetic resonance hydrogen spectrum of the product obtained in Example 6 is shown in Figure 2 , and it can be determined that the obtained product is tricyclohexylphosphine oxide. Figure 2

[0049] Alternative 1

[0050] The catalysts A-E prepared in Examples 1-5 were respectively tested by inductively coupled plasma spectrometry (ICP-AES), as shown in Table 1.

[0051] Then, the catalysts A-E were respectively applied to catalytically prepare tricyclohexylphosphine oxide, and the method was the same as in Example 6, except that the catalyst in Example 6 was adjusted, as shown in Table 1.

[0052] Table 1: ICP test results of five different types of catalysts and comparison of catalytic performance

[0053] Catalyst Ni content / % Ru content / % Pd content / % C content / % Yield / % A 13.12 0.217 0.112 81.31 99 B 11.87 0.224 0.106 82.52 96 C 10.24 0.239 0.124 83.43 92 D 13.54 0.238 0 82.55 87 E 13.25 0 0.127 83.81 89

[0054] In the table, the content of each element is in mass percent.

[0055] As can be seen from Table 1:

[0056] 1. By changing the doping ratio, a new type of nickel-based trimetallic catalyst is obtained, and the catalytic performance of the catalyst is significantly different.

[0057] ​2、From the inductively coupled plasma optical emission spectrometry (ICP-AES) test data in Table 1, it can be seen that the catalytic effect is best when the doping metals are 13.12% nickel, 0.217% ruthenium and 0.112% palladium.

[0058] 3、The catalytic effect of the new nickel-based triple metal catalyst is better than that of the nickel-ruthenium bimetallic catalyst and the nickel-palladium bimetallic catalyst.

[0059] 4、The higher the proportion of nickel in the new nickel-based triple metal catalyst, the better the catalytic effect.

[0060] Alternative 2

[0061] The preparation method is the same as that in Example 6, except that the reaction solvent is adjusted, and the effect of each on the reaction is tested, as shown in Table 2.

[0062] Table 2: Effect of different solvents on the reaction

[0063] Serial number Solvent Yield / % Substitution example 2-1 Isopropyl alcohol 99 Substitution example 2-2 Tetrahydrofuran 94 Substitution example 2-3 Cyclohexane 96 .

[0064] As can be seen from Table 2, under the same preparation conditions, the yield when using tetrahydrofuran and cyclohexane as solvents is slightly lower than that when using isopropanol as a solvent, which shows that the preparation of the nickel-based triple metal catalyst in this patent can well reduce triphenyl phosphine oxide in isopropanol, tetrahydrofuran and cyclohexane solvents.

[0065] Alternative 3

[0066] The preparation method is the same as that in Example 6, except that the amount of catalyst A in the reaction is adjusted, and the effect of each on the reaction is tested, as shown in Table 3.

[0067] Table 3: Effect of the amount of catalyst on the reaction

[0068] Serial number Catalyst A amount / g Yield / % Substitution example 3-1 0.050 99 Substitution example 3-2 0.040 96 Substitution example 3-3 0.030 92 Substitution example 3-4 0.020 91 Substitution example 3-5 0.010 89 .

[0069] As can be seen from Table 3, under the same preparation conditions, the reaction yield is highest when the amount of catalyst A is 0.050 g, and the yield decreases with the decrease of the amount of catalyst, but triphenyl phosphine oxide can still be well reduced.

[0070] Alternative 4

[0071] The catalyst of Example 6 is recycled and reused in the reaction to investigate the performance of the catalyst for repeated use, as follows:

[0072] In a high-pressure reactor, triphenyl phosphine oxide 1.000 g, catalyst A 0.050 g and isopropyl alcohol 15 ml were added in turn, and after replacement with argon and hydrogen, catalytic hydrogenation was carried out at a temperature of 170 DEG C and a pressure of 6 MPa, and the reaction was stopped after 72 h, the catalyst was removed by centrifugation, and a tricyclohexyl phosphine oxide solution was obtained; after rotary evaporation, the product tricyclohexyl phosphine oxide was obtained by drying in a vacuum drying box at 50 DEG C for 8 h. After washing the catalyst with deionized water, ethanol and acetone, the catalyst was reinserted into the reaction to investigate the repeated use performance of the catalyst, and the results are shown in Table 4.

[0073] Table 4: Catalyst repeated use performance

[0074]

[0075] As can be seen from Table 4, the catalyst still shows high activity after being used for 10 times, indicating that the nickel-based three-metal catalyst has good repeated performance.

[0076] Summary:

[0077] The present case provides a new type of nickel-based three-metal catalyst and its application in the preparation of tricyclohexyl phosphine oxide. The process reduces the production cost, and at the same time solves the problem of low product yield existing in the existing process, the method ensures the complete hydrogenation of the reaction substrate and the safety of the reaction conditions, and the post-treatment process is simple, the used catalyst is easy to prepare, can be reused, and is low in price.

Claims

1. A method for preparing a novel nickel-based trimetallic catalyst, characterized in that, Includes the following steps: RuCl3·nH2O, NiCl2·6H2O, PdCl2 and PVP were added to ethylene glycol and stirred to homogenize the solution and remove any precipitate. Then, Na2CO3 solution was added to stabilize the pH of the mixture at 9-11, and the mixture was sonicated for a period of time. The mixture was then transferred to a reaction vessel and kept at a certain temperature for a period of time. After the reaction vessel cooled to room temperature naturally, a pretreated carbon support was added to the solution, and the mixture was sonicated and centrifuged. The resulting black solid was washed, dried, and then placed in a tube furnace and reduced in H2 at 250-350℃ for 3-9 hours to obtain a novel nickel-based trimetallic catalyst. The raw materials RuCl3·nH2O, NiCl2·6H2O, and PdCl2, and the molar ratio of nickel, ruthenium, and palladium are 20–60:2–3:1–2.

2. The method for preparing a novel nickel-based trimetallic catalyst according to claim 1, characterized in that: After adding Na2CO3 solution, sonicate for 30-60 min.

3. The method for preparing a novel nickel-based trimetallic catalyst according to claim 1, characterized in that: The mixture is transferred to a reaction vessel and kept at a temperature of 200-220℃ for 2-5 hours.

4. The method for preparing a novel nickel-based trimetallic catalyst according to claim 1, characterized in that: The obtained black solid was washed three times each with anhydrous ethanol and acetone, and finally dried in a vacuum oven at 60°C for 12 h.

5. The application of a novel nickel-based trimetallic catalyst prepared by the method of claim 1 in the preparation of tricyclohexylphosphine oxide, characterized in that: In a high-pressure reactor, triphenylphosphine oxide, a novel nickel-based trimetallic catalyst, and an organic solvent are added. After purging with argon and hydrogen, catalytic hydrogenation is carried out at 150-200℃ and 5-8MPa for 48-96 hours. The reaction is then stopped, and the catalyst is removed by centrifugation to obtain a tricyclohexylphosphine oxide solution. After rotary evaporation, the solution is dried in a vacuum drying oven at 40-60℃ for 5-10 hours to obtain the product tricyclohexylphosphine oxide.

6. The application of the novel nickel-based trimetallic catalyst according to claim 5 in the preparation of tricyclohexylphosphine oxide, characterized in that: The amount of the novel nickel-based trimetallic catalyst used is 1.0-5.0% of the mass of triphenylphosphine oxide.

7. The application of the novel nickel-based trimetallic catalyst according to claim 5 in the preparation of tricyclohexylphosphine oxide, characterized in that: The reaction temperature was 170℃, the pressure was 6.0MPa, and the reaction time was 72h.

8. The application of the novel nickel-based trimetallic catalyst according to claim 5 in the preparation of tricyclohexylphosphine oxide, characterized in that: The organic solvent is isopropanol, tetrahydrofuran, or cyclohexane.

9. The application of the novel nickel-based trimetallic catalyst according to claim 5 in the preparation of tricyclohexylphosphine oxide, characterized in that: The catalyst, after centrifugation, was washed sequentially with deionized water, ethanol, and acetone before being reintroduced into the reaction. The catalyst still exhibited high activity after being reused 10 times.

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