Preparation method and application of Ni-based catalyst for carbonyl ester hydrogenation

Abstract

The invention discloses a preparation method of a carbonyl ester hydrogenation Ni-based catalyst, which comprises the following steps: dipping a gamma-Al2O3 carrier in an ammonium phosphate solution, drying and calcining to obtain phosphorylated Al2O3; the method comprises the following steps: immersing phosphorylated Al2O3 into a Ni solution, drying and calcining to obtain a sample A; immersing the sample A into a Mo solution, drying and calcining to obtain a sample B; immersing the sample B into a Bi solution, drying and calcining to obtain a sample C; the sample C is reduced in H2 / N2 mixed gas and then aged in O2 / N2 mixed gas, and finally the required carbonyl ester hydrogenation Ni-based catalyst is obtained. The preparation method is simple to operate, reasonable in process, mild in reaction condition, high in reaction yield and good in product quality, and the hydroxyl ester compound with high selectivity can be obtained by utilizing the catalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of fine chemicals, and in particular to a preparation method of a Ni-based catalyst for hydrogenation of carbonyl esters and application of the catalyst. Background Art

[0002] Hydroxyesters are an important class of fine chemicals used as solvents, resins, or organic synthesis intermediates, and hold significant application prospects in the fine chemical industry. Bifunctional hydroxyesters have a wide range of applications in organic chemistry and polymer chemistry. Optically active β-hydroxyesters, in particular, serve as important chiral sources for numerous pharmaceuticals, agrochemicals, fragrances, and natural products. Numerous methods for synthesizing hydroxyesters have been developed in academia and industry, with the Reformatsky reaction, epoxide ring-opening reactions, and enzyme-catalyzed reactions being the primary methods currently used in industry.

[0003] Among them, the Reformatsky reaction, a classic method for synthesizing hydroxy esters, uses halogenated esters as substrates. However, these compounds are not only difficult to prepare and store, but also require the addition of large amounts of zinc powder during the reaction, resulting in significant environmental pollution. Furthermore, the yield of the resulting hydroxy esters is typically low, limiting their application. In contrast, enzyme-catalyzed reactions are environmentally friendly and selective, but the high cost of the catalysts and the difficulty of recycling and reusing them make them economically disadvantageous. Furthermore, enzyme-catalyzed reactions are often slow, requiring long reaction times, and are highly sensitive to reaction conditions such as pH and temperature. Improper control can lead to enzyme inactivation, increasing the complexity and difficulty of the process. The ring-opening reaction of epoxy compounds is a widely used and important method for synthesizing hydroxy esters. However, the high cost of preparing epoxy compounds significantly increases the economic burden of the overall reaction. This method also faces complex and costly catalyst preparation processes, making it difficult to scale up industrially. Furthermore, ring-opening reactions can face issues with regioselectivity and stereoselectivity, leading to the formation of byproducts and reducing the purity and yield of the target product. Summary of the Invention

[0004] The present invention aims to provide a preparation method of a Ni-based catalyst for hydrogenating carbonyl esters and application of the catalyst. The preparation method has simple operation, reasonable process, mild reaction conditions, high reaction yield and good product quality. Hydroxyl ester compounds with high selectivity can be obtained by using the catalyst.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A Ni-based catalyst for carbonyl ester hydrogenation, wherein the Ni-based catalyst for carbonyl ester hydrogenation is a trimetallic catalyst comprising a main active component, an additive, and a carrier, wherein:

[0007] The main active component is 10-30wt% nickel Ni;

[0008] The additives are 2-5 wt% of molybdenum Mo and 0.1-1.5 wt% of bismuth Bi;

[0009] The carrier is γ-Al2O3, with a pore size of 10-15nm and a specific surface area of ​​200-250m 2 / g.

[0010] A method for preparing a Ni-based catalyst for hydrogenation of carbonyl esters, the method comprising:

[0011] Step 1: Immerse the γ-Al2O3 carrier in an ammonium phosphate solution, stir and react at room temperature, and dry and calcine at a certain temperature to obtain phosphorylated Al2O3;

[0012] Step 2: Immerse the phosphated Al2O3 obtained in step 1 in a Ni-containing solution, use ultrasound to ensure penetration, and then allow to stand for aging, dry, and calcine to obtain Ni / Al2O3, which is designated as sample A.

[0013] Step 3: Sample A is immersed in a Mo-containing solution with ultrasound to ensure penetration. After static aging, drying, and calcination, Ni-Mo / Al2O3 is obtained, which is recorded as sample B.

[0014] Step 4: Sample B was immersed in a Bi-containing solution with ultrasound to ensure penetration. After aging and drying, it was calcined in a N2 atmosphere to obtain Ni-Mo-Bi / Al2O3, which was recorded as sample C.

[0015] Step 5: Reduce sample C in a mixture of H2 and N2, and then age it in a mixture of O2 and N2 to finally obtain the desired carbonyl ester hydrogenation Ni-based catalyst.

[0016] A method for applying a Ni-based catalyst for carbonyl ester hydrogenation is disclosed. The method uses an acyl ester compound as a raw material and a Ni-based catalyst for carbonyl ester hydrogenation to carry out a hydrogenation reaction. After the reaction is completed, the hydroxy ester compound is separated and purified to obtain the hydroxy ester compound. The structural formula of the hydroxy ester compound is:

[0017]

[0018] The structural formula of the acyl acid lipid compound raw material used is:

[0019]

[0020] Wherein, R1 and R2 are one of methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl or tert-butyl.

[0021] It can be seen from the technical solution provided by the present invention that the preparation method is simple to operate, has a reasonable process, mild reaction conditions, high reaction yield, and good product quality. The catalyst can be used to obtain hydroxy ester compounds with high selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic flow chart of a method for preparing a Ni-based catalyst for hydrogenation of carbonyl esters provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments, and do not constitute a limitation of the present invention. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] The Ni-based catalyst for carbonyl ester hydrogenation described in the embodiment of the present invention is a trimetallic catalyst, comprising a main active component, an additive, and a carrier, wherein:

[0026] The main active component is 10-30wt% nickel Ni;

[0027] The additives are 2-5 wt% of molybdenum Mo and 0.1-1.5 wt% of bismuth Bi;

[0028] The carrier is γ-Al2O3, with a pore size of 10-15nm and a specific surface area of ​​200-250m 2 / g.

[0029] like Figure 1 FIG. 1 is a flow chart of a method for preparing a Ni-based catalyst for hydrogenation of carbonyl esters according to an embodiment of the present invention, wherein the method comprises:

[0030] Step 1: Immerse the γ-Al2O3 carrier in an ammonium phosphate solution, stir and react at room temperature, and dry and calcine at a certain temperature to obtain phosphorylated Al2O3;

[0031] In this step, the amount of ammonium phosphate solution used is 0.1-0.3 M; the ratio of the volume of the ammonium phosphate solution to the mass of the alumina is 10:1 mL / g.

[0032] Step 2: Immerse the phosphated Al2O3 obtained in step 1 in a Ni-containing solution, use ultrasound to ensure penetration, and then allow to stand for aging, dry, and calcine to obtain Ni / Al2O3, which is designated as sample A.

[0033] In this step, specifically, the nickel nitrate required to achieve a Ni content of 10-30wt% is calculated and weighed, and a solution is prepared. The phosphated Al2O3 obtained in step 1 is immersed in the Ni solution, ultrasonically assisted to ensure penetration, and aged for 4-6 hours. After drying at 100-120°C for 10-12 hours, it is calcined at 300-500°C for 2-4 hours to obtain Ni / Al2O3, which is recorded as sample A.

[0034] Step 3: Sample A is immersed in a Mo-containing solution with ultrasound to ensure penetration. After static aging, drying, and calcination, Ni-Mo / Al2O3 is obtained, which is recorded as sample B.

[0035] In this step, specifically, the ammonium molybdate required to achieve a Mo content of 2-5wt% is calculated and weighed, a solution is prepared, sample A is immersed in the Mo solution, ultrasonic assistance is used to ensure penetration, and the sample is aged for 4-6 hours. After drying at 100-120°C for 6-8 hours, it is calcined at 300-500°C for 3-6 hours to obtain Ni-Mo / Al2O3, which is recorded as sample B.

[0036] Step 4: Sample B was immersed in a Bi-containing solution with ultrasound to ensure penetration. After aging and drying, it was calcined in a N2 atmosphere to obtain Ni-Mo-Bi / Al2O3, which was recorded as sample C.

[0037] In this step, specifically, the bismuth nitrate required to achieve a Bi content of 0.1-1.5wt% is calculated and weighed, a dilute nitric acid solution is prepared, sample B is immersed in the Bi solution, ultrasound is used to ensure penetration, and the sample is aged for 4-6 hours. After drying in a dark environment at 80-100°C for 8-10 hours, the sample is calcined at 300-500°C in a N2 atmosphere for 2-4 hours to obtain Ni-Mo-Bi / Al2O3, which is recorded as sample C.

[0038] Step 5: Reduce sample C in a mixture of H2 and N2, and then age it in a mixture of O2 and N2 to finally obtain the desired carbonyl ester hydrogenation Ni-based catalyst.

[0039] In this step, specifically, sample C is reduced in a mixture of H2 and N2 at 50-100 ml / min, reduced at 400-500°C for 4-6 hours, and then aged in a mixture of O2 and N2 at 50-100 ml / min to finally obtain the desired carbonyl ester hydrogenation Ni-based catalyst.

[0040] Based on the obtained carbonyl ester hydrogenation Ni-based catalyst, an embodiment of the present invention further provides an application method of the carbonyl ester hydrogenation Ni-based catalyst, using an acyl acid ester compound as a raw material and using the carbonyl ester hydrogenation Ni-based catalyst to carry out a hydrogenation reaction. After the reaction is completed, the hydroxy ester compound is separated and purified to obtain the hydroxy ester compound. The structural formula of the hydroxy ester compound is:

[0041]

[0042] The structural formula of the acyl acid lipid compound raw material used is:

[0043]

[0044] Wherein, R1 and R2 are one of methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl or tert-butyl.

[0045] In a specific implementation, a Ni-based catalyst for carbonyl ester hydrogenation is used to catalytically hydrogenate acyl esters to prepare hydroxy esters. The specific process is as follows:

[0046] A certain amount of acyl ester and catalyst are added to a batch reactor, and after hydrogen replacement, the pressure is pressed to the corresponding pressure, the temperature is raised and stirred to react. During the reaction, the reaction pressure is maintained by adding hydrogen. After a certain reaction time, the temperature is lowered and the reaction is stopped. The obtained hydroxy ester sample is taken for analysis;

[0047] In order to investigate the effect of this reaction in a continuous reaction, a fixed-bed reactor was loaded with a metered catalyst, heated to a certain temperature in a hydrogen atmosphere, and then slowly raised to the corresponding pressure. Acyl ester was injected at a metered space velocity to react, and the obtained hydroxy ester sample was taken for analysis;

[0048] The reaction temperature of the catalytic hydrogenation of the acyl acid ester is 50-120° C., and the hydrogen pressure of the system is 2-10 MPa.

[0049] The preparation process and application of the catalyst described in the embodiment of the present invention are described below with specific examples:

[0050] Example 1

[0051] The γ-Al2O3 support was immersed in a 0.1 M ammonium phosphate ((NH4)2HPO4) solution (liquid-to-solid ratio 10:1 mL / g) and stirred at room temperature for 2 h. The support was dried at 110°C for 12 h and calcined at 550°C for 3 h before use.

[0052] Weigh 7.43g of nickel nitrate hexahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Immerse 10g of the treated γ-Al2O3 in the solution, ultrasonically assist for 30 minutes, let it sit for 4 hours, dry at 110°C for 12 hours, and calcined at 350°C in air for 2 hours to obtain Sample A.

[0053] Weigh 0.37g of ammonium molybdate tetrahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Sample A is immersed in the solution with ultrasonic assistance for 30 minutes, allowed to stand for 4 hours, dried at 110°C for 6 hours, and calcined at 500°C in air for 3 hours to obtain Sample B.

[0054] Weigh 0.046g of bismuth nitrate pentahydrate, add 5.5ml of deionized water, and then add nitric acid dropwise to a pH of 3. Stir thoroughly until completely dissolved. Immerse Sample B in the solution, ultrasonically assist for 30 minutes, let it stand for 4 hours, dry it at 80°C in the dark for 8 hours, and calcine it at 300°C in an N2 atmosphere for 2 hours to obtain Sample C.

[0055] Sample C was reduced in a H2 / N2 (H2 20%) mixed gas at 50 ml / min, reduced at 500°C for 4 hours, and then aged in a O2 / N2 (O2 1%) mixed gas at 50 ml / min to finally obtain the desired catalyst.

[0056] Catalyst evaluation was conducted in a 100ml batch reactor: 70g of ethyl propionylacetate and 10g of ground catalyst were added. The reactor was sealed, replaced with hydrogen, and then pressurized to 3 MPa. The reaction was stirred at 120°C. The reaction pressure was maintained by supplemental hydrogen. The reaction lasted 8 hours. Sampling analysis showed a conversion of 97.8% for ethyl propionylacetate and a selectivity of 96.5% for ethyl 3-hydroxyvalerate.

[0057] Example 2

[0058] The γ-Al2O3 support was immersed in a 0.1 M ammonium phosphate ((NH4)2HPO4) solution (liquid-to-solid ratio 10:1 mL / g) and stirred at room temperature for 2 h. The support was dried at 110°C for 12 h and calcined at 550°C for 3 h before use.

[0059] Weigh 4.95g of nickel nitrate hexahydrate and add 5.5ml of deionized water. Stir thoroughly until completely dissolved. Immerse 10g of the treated γ-Al2O3 in the solution, ultrasonically assisted for 30 minutes, let it rest for 4 hours, dry at 110°C for 12 hours, and calcined at 350°C in air for 2 hours to obtain Sample A.

[0060] Weigh 0.37g of ammonium molybdate tetrahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Sample A is immersed in the solution with ultrasonic assistance for 30 minutes, allowed to stand for 4 hours, dried at 110°C for 6 hours, and calcined at 500°C in air for 3 hours to obtain Sample B.

[0061] Weigh 0.023g of bismuth nitrate pentahydrate, add 5.5ml of deionized water, and then add nitric acid dropwise to a pH of 3. Stir thoroughly until completely dissolved. Immerse Sample B in the solution, ultrasonically assist for 30 minutes, let it stand for 4 hours, dry it at 80°C in the dark for 8 hours, and calcine it at 300°C in an N2 atmosphere for 2 hours to obtain Sample C.

[0062] Sample C was reduced in a H2 / N2 (H2 20%) mixed gas at 50 ml / min, reduced at 500°C for 4 hours, and then aged in a O2 / N2 (O2 1%) mixed gas at 50 ml / min to finally obtain the desired catalyst.

[0063] Catalyst evaluation was conducted in a 100ml batch reactor: 70g of methyl acetoacetate and 10g of ground catalyst were added. The reactor was sealed, replaced with hydrogen, and then pressurized to 3 MPa. The reaction was stirred at 100°C. The reaction pressure was maintained by supplemental hydrogen. The reaction lasted 8 hours. Sampling analysis showed a methyl acetoacetate conversion of 99.7% and a methyl 3-hydroxybutyrate selectivity of 98.1%.

[0064] Example 3

[0065] The γ-Al2O3 support was immersed in a 0.1 M ammonium phosphate ((NH4)2HPO4) solution (liquid-to-solid ratio 10:1 mL / g) and stirred at room temperature for 2 h. The support was dried at 110°C for 12 h and calcined at 550°C for 3 h before use.

[0066] Weigh 12.38g of nickel nitrate hexahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Immerse 10g of the treated γ-Al2O3 in the solution, ultrasonically assisted for 30 minutes, let it sit for 4 hours, dry at 110°C for 12 hours, and calcined at 350°C in air for 2 hours to obtain Sample A.

[0067] Weigh 0.92g of ammonium molybdate tetrahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Sample A is immersed in the solution with ultrasonic assistance for 30 minutes, allowed to stand for 4 hours, dried at 110°C for 6 hours, and calcined at 500°C in air for 3 hours to obtain Sample B.

[0068] Weigh 0.046g of bismuth nitrate pentahydrate, add 5.5ml of deionized water, and then add nitric acid dropwise to a pH of 3. Stir thoroughly until completely dissolved. Immerse Sample B in the solution, ultrasonically assist for 30 minutes, let it stand for 4 hours, dry it at 80°C in the dark for 8 hours, and calcine it at 300°C in an N2 atmosphere for 2 hours to obtain Sample C.

[0069] Sample C was reduced in a H2 / N2 (H2 20%) mixed gas at 50 ml / min, reduced at 500°C for 4 hours, and then aged in a O2 / N2 (O2 1%) mixed gas at 50 ml / min to finally obtain the desired catalyst.

[0070] Catalyst evaluation was conducted in a 100ml batch reactor: 70g of methyl isobutyrylacetate and 10g of ground catalyst were added. The reactor was sealed, replaced with hydrogen, and then pressurized to 3 MPa. The reaction was stirred at 120°C. The reaction pressure was maintained by supplemental hydrogen. The reaction lasted 8 hours. Sampling analysis showed a methyl isobutyrylacetate conversion of 97.5% and a methyl 3-hydroxy-4-methylvalerate selectivity of 98.5%.

[0071] Example 4

[0072] The γ-Al2O3 support was immersed in a 0.1 M ammonium phosphate ((NH4)2HPO4) solution (liquid-to-solid ratio 10:1 mL / g) and stirred at room temperature for 2 h. The support was dried at 110°C for 12 h and calcined at 550°C for 3 h before use.

[0073] Weigh 4.95g of nickel nitrate hexahydrate and add 5.5ml of deionized water. Stir thoroughly until completely dissolved. Immerse 10g of the treated γ-Al2O3 in the solution, ultrasonically assisted for 30 minutes, let it rest for 4 hours, dry at 110°C for 12 hours, and calcined at 350°C in air for 2 hours to obtain Sample A.

[0074] Weigh 0.92g of ammonium molybdate tetrahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Sample A is immersed in the solution with ultrasonic assistance for 30 minutes, allowed to stand for 4 hours, dried at 110°C for 6 hours, and calcined at 500°C in air for 3 hours to obtain Sample B.

[0075] Weigh 0.023g of bismuth nitrate pentahydrate, add 5.5ml of deionized water, and then add nitric acid dropwise to a pH of 3. Stir thoroughly until completely dissolved. Immerse Sample B in the solution, ultrasonically assist for 30 minutes, let it stand for 4 hours, dry it at 80°C in the dark for 8 hours, and calcine it at 300°C in an N2 atmosphere for 2 hours to obtain Sample C.

[0076] Sample C was reduced in a H2 / N2 (H2 20%) mixed gas at 50 ml / min, reduced at 500°C for 4 hours, and then aged in a O2 / N2 (O2 1%) mixed gas at 50 ml / min to finally obtain the desired catalyst.

[0077] Catalyst evaluation was conducted in a 100ml batch reactor: 70g of ethyl acetoacetate and 10g of ground catalyst were added. The reactor was sealed, replaced with hydrogen, and then pressurized to 5 MPa. The reaction was stirred at 100°C. The reaction pressure was maintained by supplemental hydrogen. The reaction lasted 8 hours. Sampling analysis showed a conversion of 98.5% for ethyl acetoacetate and a selectivity of 97.3% for ethyl 3-hydroxybutyrate.

[0078] Example 5

[0079] The γ-Al2O3 support was immersed in a 0.1 M ammonium phosphate ((NH4)2HPO4) solution (liquid-to-solid ratio 10:1 mL / g) and stirred at room temperature for 2 h. The support was dried at 110°C for 12 h and calcined at 550°C for 3 h before use.

[0080] Weigh 12.38g of nickel nitrate hexahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Immerse 10g of the treated γ-Al2O3 in the solution, ultrasonically assisted for 30 minutes, let it sit for 4 hours, dry at 110°C for 12 hours, and calcined at 350°C in air for 2 hours to obtain Sample A.

[0081] Weigh 0.55g of ammonium molybdate tetrahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Sample A is immersed in the solution with ultrasonic assistance for 30 minutes, allowed to stand for 4 hours, dried at 110°C for 6 hours, and calcined at 500°C in air for 3 hours to obtain Sample B.

[0082] Weigh 0.116g of bismuth nitrate pentahydrate, add 5.5ml of deionized water, and then add nitric acid dropwise to a pH of 3. Stir thoroughly until completely dissolved. Immerse Sample B in the solution with ultrasound assistance for 30 minutes, let it stand for 4 hours, dry it at 80°C in the dark for 8 hours, and calcine it at 300°C in an N2 atmosphere for 2 hours to obtain Sample C.

[0083] Sample C was reduced in a H2 / N2 (H2 20%) mixed gas at 50 ml / min, reduced at 500°C for 4 hours, and then aged in a O2 / N2 (O2 1%) mixed gas at 50 ml / min to finally obtain the desired catalyst.

[0084] Catalyst evaluation was conducted in a 100ml batch reactor: 70g of butyl acetoacetate and 10g of ground catalyst were added. The reactor was sealed, replaced with hydrogen, and then pressurized to 4 MPa. The reaction was stirred at 100°C. The reaction pressure was maintained by supplemental hydrogen. The reaction lasted 8 hours. Sampling analysis showed a butyl acetoacetate conversion of 98.9% and a butyl 3-hydroxybutyrate selectivity of 97.8%.

[0085] Example 6

[0086] The γ-Al2O3 support was immersed in a 0.1 M ammonium phosphate ((NH4)2HPO4) solution (liquid-to-solid ratio 10:1 mL / g) and stirred at room temperature for 2 h. The support was dried at 110°C for 12 h and calcined at 550°C for 3 h before use.

[0087] Weigh 4.95g of nickel nitrate hexahydrate and add 5.5ml of deionized water. Stir thoroughly until completely dissolved. Immerse 10g of the treated γ-Al2O3 in the solution, ultrasonically assisted for 30 minutes, let it rest for 4 hours, dry at 110°C for 12 hours, and calcined at 350°C in air for 2 hours to obtain Sample A.

[0088] Weigh 0.55g of ammonium molybdate tetrahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Sample A is immersed in the solution with ultrasonic assistance for 30 minutes, allowed to stand for 4 hours, dried at 110°C for 6 hours, and calcined at 500°C in air for 3 hours to obtain Sample B.

[0089] Weigh 0.046g of bismuth nitrate pentahydrate, add 5.5ml of deionized water, and then add nitric acid dropwise to a pH of 3. Stir thoroughly until completely dissolved. Immerse Sample B in the solution, ultrasonically assist for 30 minutes, let it stand for 4 hours, dry it at 80°C in the dark for 8 hours, and calcine it at 300°C in an N2 atmosphere for 2 hours to obtain Sample C.

[0090] Sample C was reduced in a H2 / N2 (H2 20%) mixed gas at 50 ml / min, reduced at 500°C for 4 hours, and then aged in a O2 / N2 (O2 1%) mixed gas at 50 ml / min to finally obtain the desired catalyst.

[0091] The catalyst evaluation was the same as in Example 2. The sampling and analysis results showed that the conversion of methyl acetoacetate was 99.6%, and the selectivity of methyl 3-hydroxybutyrate was 99.1%.

[0092] Example 7

[0093] The γ-Al2O3 support was immersed in a 0.1 M ammonium phosphate ((NH4)2HPO4) solution (liquid-to-solid ratio 10:1 mL / g) and stirred at room temperature for 2 h. The support was dried at 110°C for 12 h and calcined at 550°C for 3 h before use.

[0094] Weigh 7.43g of nickel nitrate hexahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Immerse 10g of the treated γ-Al2O3 in the solution, ultrasonically assist for 30 minutes, let it sit for 4 hours, dry at 110°C for 12 hours, and calcined at 350°C in air for 2 hours to obtain Sample A.

[0095] Weigh 0.37g of ammonium molybdate tetrahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Sample A is immersed in the solution with ultrasonic assistance for 30 minutes, allowed to stand for 4 hours, dried at 110°C for 6 hours, and calcined at 500°C in air for 3 hours to obtain Sample B.

[0096] Weigh 0.046g of bismuth nitrate pentahydrate, add 5.5ml of deionized water, and then add nitric acid dropwise to a pH of 3. Stir thoroughly until completely dissolved. Immerse Sample B in the solution, ultrasonically assist for 30 minutes, let it stand for 4 hours, dry it at 80°C in the dark for 8 hours, and calcine it at 300°C in an N2 atmosphere for 2 hours to obtain Sample C.

[0097] Sample C was reduced in a H2 / N2 (H2 20%) mixed gas at 50 ml / min, reduced at 500°C for 4 hours, and then aged in a O2 / N2 (O2 1%) mixed gas at 50 ml / min to finally obtain the desired catalyst.

[0098] Catalyst evaluation was conducted in a 100ml batch reactor: 70g of propyl acetoacetate and 10g of ground catalyst were added. The reactor was sealed, replaced with hydrogen, and then pressurized to 3 MPa. The reaction was stirred at 120°C. The reaction pressure was maintained by supplemental hydrogen during the reaction. The reaction lasted 8 hours. Sampling analysis showed a propyl acetoacetate conversion of 99.2% and a 3-hydroxypropyl butyrate selectivity of 98.0%.

[0099] Example 8

[0100] The catalyst was prepared according to the method described in Example 2, and the reaction was also the same as in Example 2.

[0101] The performance of the catalyst was evaluated in a fixed bed. The catalyst was pressed into tablets and sieved to 20-40 mesh. The fixed bed was filled with 10 ml of catalyst. The temperature was raised to 110°C at 1°C / min in a hydrogen atmosphere. The pressure was then slowly raised to 4 MPa. Methyl acetoacetate was added to the fixed bed in 0.05 h. -1 The feed was carried out at a mass space velocity of 50 ml / min and the H2 flow rate was 50 ml / min. Sampling and analysis showed that the conversion rate of methyl acetoacetate was 99.1% and the selectivity of methyl 3-hydroxybutyrate was 98.1%.

[0102] Comparative Example 1

[0103] The γ-Al2O3 support was immersed in a 0.1 M ammonium phosphate ((NH4)2HPO4) solution (liquid-to-solid ratio 10:1 mL / g) and stirred at room temperature for 2 h. The support was dried at 110°C for 12 h and calcined at 550°C for 3 h before use.

[0104] Weigh 4.95g of nickel nitrate hexahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Immerse 10g of the treated γ-Al2O3 in the solution, ultrasonically assist for 30 minutes, let it stand for 4 hours, dry at 110°C for 12 hours, and calcine at 350°C in air for 2 hours to obtain sample A. Sample A is reduced in a 50ml / min H2 / N2 (H2 20%) mixture, reduced at 500°C for 4 hours, and then aged in a 50ml / min O2 / N2 (O2 1%) mixture to obtain the desired catalyst.

[0105] The catalyst evaluation was the same as that in Example 1. The sampling and analysis results showed that the conversion of methyl acetoacetate was 96.3% and the selectivity of methyl 3-hydroxybutyrate was 86.1%.

[0106] Comparative Example 2

[0107] The γ-Al2O3 support was immersed in a 0.1 M ammonium phosphate ((NH4)2HPO4) solution (liquid-to-solid ratio 10:1 mL / g) and stirred at room temperature for 2 h. The support was dried at 110°C for 12 h and calcined at 550°C for 3 h before use.

[0108] Weigh 4.95g of nickel nitrate hexahydrate and add 5.5ml of deionized water. Stir thoroughly until completely dissolved. Immerse 10g of the treated γ-Al2O3 in the solution, ultrasonically assisted for 30 minutes, let it rest for 4 hours, dry at 110°C for 12 hours, and calcined at 350°C in air for 2 hours to obtain Sample A.

[0109] Weigh 0.37g of ammonium molybdate tetrahydrate, add 5.5ml of deionized water, and stir thoroughly until completely dissolved. Sample A is immersed in the solution with ultrasonic assistance for 30 minutes, allowed to stand for 4 hours, dried at 110°C for 6 hours, and calcined at 500°C in air for 3 hours to obtain Sample B.

[0110] Sample B was reduced in a H2 / N2 (H2 20%) mixed gas at 50 ml / min, reduced at 500°C for 4 hours, and then aged in a O2 / N2 (O2 1%) mixed gas at 50 ml / min to finally obtain the desired catalyst.

[0111] The catalyst evaluation was the same as that in Example 2. The sampling and analysis results showed that the conversion of methyl acetoacetate was 97.4% and the selectivity of methyl 3-hydroxybutyrate was 90.3%.

[0112] The following Table 1 shows the results of the various examples and comparative examples:

[0113] Table 1

[0114]

[0115] The above comparison results show that the scheme of the present invention uses the obtained metal catalyst to catalyze acyl esters in a high-pressure reactor and a fixed-bed reactor to successfully prepare hydroxy esters. This method has a simple manufacturing process, excellent catalytic activity, strong stability, and the obtained catalyst has a long service life and is easy to recycle, which greatly reduces the catalyst cost in the product.

[0116] Under the action of the obtained metal catalyst, the present invention can realize the hydrogenation synthesis of acyl esters to hydroxy esters under mild conditions, which not only greatly reduces the production cost, but also significantly improves the chemical purity of hydroxy esters, shortens the reaction time, and improves production efficiency. It truly realizes the continuous and automated production of acyl esters to synthesize hydroxy esters through hydrogenation, and shows broad prospects for industrial application.

[0117] It should be noted that the contents not described in detail in the embodiments of the present invention belong to the prior art known to those skilled in the art.

[0118] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art.

Claims

1. A Ni-based catalyst for hydrogenation of carbonyl esters, characterized in that: The Ni-based catalyst for carbonyl ester hydrogenation is a trimetallic catalyst comprising a main active component, an additive and a carrier, wherein: The main active component is 10-30wt% nickel Ni; The additives are 2-5 wt% of molybdenum Mo and 0.1-1.5 wt% of bismuth Bi; The carrier is γ-Al2O3, with a pore size of 10-15nm and a specific surface area of ​​200-250m 2 / g.

2. A method for preparing a Ni-based catalyst for hydrogenation of carbonyl esters, characterized in that: The method comprises: Step 1: Immerse the γ-Al2O3 carrier in an ammonium phosphate solution, stir and react at room temperature, and dry and calcine at a certain temperature to obtain phosphorylated Al2O3; Step 2: Immerse the phosphated Al2O3 obtained in step 1 in a Ni-containing solution, use ultrasound to ensure penetration, and then allow to stand for aging, dry, and calcine to obtain Ni / Al2O3, which is designated as sample A. Step 3: Sample A is immersed in a Mo-containing solution with ultrasound to ensure penetration. After static aging, drying, and calcination, Ni-Mo / Al2O3 is obtained, which is recorded as sample B. Step 4: Sample B was immersed in a Bi-containing solution with ultrasound to ensure penetration. After aging and drying, it was calcined in a N2 atmosphere to obtain Ni-Mo-Bi / Al2O3, which was recorded as sample C. Step 5: Reduce sample C in a mixture of H2 and N2, and then age it in a mixture of O2 and N2 to finally obtain the desired carbonyl ester hydrogenation Ni-based catalyst.

3. The method for preparing a Ni-based catalyst for carbonyl ester hydrogenation according to claim 2, wherein: In step 1, the amount of ammonium phosphate solution used is 0.1-0.3 M; the ratio of the volume of the ammonium phosphate solution to the mass of the alumina is 10:1 mL / g.

4. The method for preparing a Ni-based catalyst for hydrogenation of carbonyl esters according to claim 2, wherein: The process of step 2 is specifically as follows: Calculate and weigh the nickel nitrate required to achieve a Ni content of 10-30wt% and prepare a solution. Immerse the phosphated Al2O3 obtained in step 1 in the Ni solution, use ultrasound to ensure penetration, and allow to age for 4-6 hours. After drying at 100-120°C for 10-12 hours, calcinate at 300-500°C for 2-4 hours to obtain Ni / Al2O3, which is recorded as sample A.

5. The method for preparing a Ni-based catalyst for hydrogenation of carbonyl esters according to claim 2, wherein: The process of step 3 is specifically as follows: Calculate and weigh the ammonium molybdate required to achieve a Mo content of 2-5 wt% to prepare a solution. Immerse sample A in the Mo solution with ultrasonic assistance to ensure penetration. Allow to age for 4-6 hours, dry at 100-120°C for 6-8 hours, and calcine at 300-500°C for 3-6 hours to obtain Ni-Mo / Al2O3, which is recorded as sample B.

6. The method for preparing a Ni-based catalyst for carbonyl ester hydrogenation according to claim 2, wherein: The process of step 4 is specifically as follows: Calculate and weigh the bismuth nitrate required to achieve a Bi content of 0.1-1.5wt%, prepare a dilute nitric acid solution, immerse sample B in the Bi solution, use ultrasound to ensure penetration, allow to age for 4-6 hours, dry in a dark environment at 80-100°C for 8-10 hours, and calcine at 300-500°C in a N2 atmosphere for 2-4 hours to obtain Ni-Mo-Bi / Al2O3, which is recorded as sample C.

7. The method for preparing a Ni-based catalyst for carbonyl ester hydrogenation according to claim 2, wherein: The process of step 5 is specifically as follows: Sample C was reduced in a mixture of H2 and N2 at 50-100 ml / min, reduced at 400-500°C for 4-6 hours, and then aged in a mixture of O2 and N2 at 50-100 ml / min to finally obtain the desired carbonyl ester hydrogenation Ni-based catalyst.

8. A method for using a Ni-based catalyst for hydrogenation of carbonyl esters, characterized in that: Acyl ester compounds are used as raw materials, and a carbonyl ester hydrogenation Ni-based catalyst is used to carry out a hydrogenation reaction. After the reaction is completed, hydroxy ester compounds are obtained through separation and purification. The structural formula of the hydroxy ester compound is: The structural formula of the acyl acid lipid compound raw material used is: Wherein, R1 and R2 are one of methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl or tert-butyl.

9. The method for using the Ni-based catalyst for carbonyl ester hydrogenation according to claim 8, wherein: Using a Ni-based catalyst for carbonyl ester hydrogenation, acyl esters are catalytically hydrogenated to prepare hydroxy esters. The specific process is as follows: A certain amount of acyl ester and catalyst are added to a batch reactor, and after hydrogen replacement, the pressure is pressed to the corresponding pressure, the temperature is raised and stirred for reaction. During the reaction, the reaction pressure is maintained by adding hydrogen. After a certain reaction time, the temperature is lowered, the reaction is stopped, and the obtained hydroxy ester sample is taken for analysis.

10. The method for using the Ni-based catalyst for carbonyl ester hydrogenation according to claim 9, wherein: To compare the reaction effects, a fixed-bed reactor was loaded with a metered catalyst, heated to a certain temperature in a hydrogen atmosphere, and then slowly raised to the corresponding pressure. Acyl ester was injected at a metered space velocity to react, and the resulting hydroxy ester sample was taken for analysis. The reaction temperature of the catalytic hydrogenation of the acyl acid ester is 50-120° C., and the hydrogen pressure of the system is 2-10 MPa.

Images