A method for preparing sodium ethoxide from sodium acetate

Abstract

The present invention belongs to the technical field of preparation of organic compounds, and in particular to a method for preparing sodium ethoxide from sodium acetate. The method for preparing sodium ethoxide from sodium acetate of the present invention: first, a cobalt compound is reacted with a tridentate phosphine ligand, and loaded on a 5A molecular sieve to obtain a cobalt-based solid catalyst; then a cobalt-based solid catalyst and sodium acetate are filled into an Ou Shisheng fixed-bed reactor of model H‑Flow‑S30 to form a stacked bed; finally, hydrogen is introduced, and a reduction reaction is performed at a high temperature to obtain a reaction solution, and the reaction solution is separated and treated to obtain sodium ethoxide. The method for preparing sodium ethoxide from sodium acetate provided by the present invention has mild reaction conditions, uses a cobalt catalyst, has a high conversion rate, and is recyclable.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of organic compounds, and particularly relates to a method for preparing sodium ethoxide from sodium acetate. Background Art

[0002] Sodium ethoxide, with the chemical formula C2H5ONa, is an important organic compound with a molecular weight of 132, a boiling point of 91°C, and a density of 1.264 g / mL. This compound plays an indispensable role in many fields due to its unique chemical properties. As a strong alkaline catalyst, sodium ethoxide can efficiently promote the progress of various chemical reactions, increase the reaction rate and yield. At the same time, it is also an important ethoxylation agent, widely used in organic synthesis, and provides strong support for the production of medicines, pesticides, fragrances and other products.

[0003] Among the methods for synthesizing sodium ethoxide, the reaction of ethanol with sodium hydroxide or metallic sodium is the two most common and effective methods. These two methods have their own characteristics and challenges.

[0004] First, the ternary azeotropic method of benzene, ethanol and water is a relatively mature process for preparing sodium ethoxide. This method is to dissolve solid sodium hydroxide in a mixed solution of ethanol and pure benzene (or cyclohexane and ethanol), and gradually remove the water in the reaction system by heating and reflux. In a tower reactor, continuous reaction and dehydration can ensure that the total alkali content and free alkali meet the established standards. During the reaction, a ternary azeotropic mixture of benzene, ethanol and water will be evaporated from the top of the tower, and an ethanol solution of sodium ethoxide will be collected at the bottom of the tower, as described in the patent CN106167469A. Although this method has high reaction efficiency and product purity, it still has some shortcomings. For example, the heating temperature and reflux rate need to be precisely controlled during the reaction to ensure the smooth progress of the reaction; at the same time, the design and operation of the tower reactor are also relatively complex, and the requirements for equipment are relatively high.

[0005] Another method is the sodium metal method, which uses sodium metal to react with anhydrous ethanol under the action of an inhibitor to generate sodium ethoxide. The addition of inhibitors (such as acetonitrile, propionitrile, malononitrile, butyronitrile, etc.) can inhibit some side reactions during the reaction of sodium metal and ethanol, improve the selectivity of the reaction and the purity of the product, as described in the patent CN105294399A. However, this method also has some challenges. Sodium metal is a very active metal, and improper handling can easily cause safety accidents. Therefore, strict safety measures need to be taken during the reaction to ensure the safety of the operator. In addition, the selection and dosage of the inhibitor also have a great influence on the reaction efficiency and product purity, and in-depth experimental research and optimization are required. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a method for preparing sodium ethoxide from sodium acetate. The method has mild reaction conditions, adopts a cobalt catalyst, has a high conversion rate and is recyclable.

[0007] The method for preparing sodium ethoxide from sodium acetate of the present invention comprises the following steps: firstly reacting a cobalt compound with a tridentate phosphine ligand, and loading the cobalt compound on a 5A molecular sieve to obtain a cobalt-based solid catalyst; then filling a H-Flow-S30 Oushisheng fixed bed reactor with the cobalt-based solid catalyst and sodium acetate to form a stacked bed layer of 4 cm to 5 cm; finally introducing hydrogen, heating the reactor to perform a reduction reaction to obtain a reaction solution, and separating the reaction solution to obtain sodium ethoxide.

[0008] The specific process of the cobalt-based solid catalyst is as follows: dissolving the cobalt compound and the tridentate phosphine ligand in an acetonitrile solvent, reacting for 1h to 1.5h at room temperature and pressure, adding a 5A molecular sieve with a diameter of 2.0mm to 3.0mm, heating to 85°C to 90°C, distilling off the acetonitrile solvent, and obtaining the cobalt-based solid catalyst.

[0009] The molar ratio of the cobalt compound to the tridentate phosphine ligand is 1:2.1-1:2.2.

[0010] The addition of the 5A molecular sieve is calculated based on the addition of 1.0 g to 1.2 g of 5A molecular sieve per 1 mmol of the cobalt compound.

[0011] The cobalt compound is Co(BF4)2•6H2O, and the tridentate phosphine ligand is one of the following structures:

[0012] .

[0013] In the above structural formula, the PCy2 group is a dicyclohexylphosphine group, the PPh2 is a diphenylphosphine group, and the PBn2 is a dibenzylphosphine group.

[0014] The molar ratio of the cobalt-based solid catalyst to sodium acetate is 1:5000-1:5500.

[0015] The reduction reaction temperature is 180°C to 220°C, and the reduction reaction time is 12h to 13h.

[0016] The obtained reaction solution is added with anhydrous ethanol to dissolve, thereby obtaining a sodium ethoxide solution; or the obtained reaction solution is heated to 80° C.-85° C. to distill off the ethanol, thereby obtaining a sodium ethoxide solid.

[0017] Specifically, the method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0018] (1) Dissolve cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand in acetonitrile solvent at a molar ratio of 1:2.1~1:2.2, react at room temperature and pressure for 1h~1.5h, add 5A molecular sieve with a diameter of 2.0mm~3.0mm (calculated based on 1.0g~1.2g 5A molecular sieve added to 1mmol cobalt compound), heat to 85℃~90℃, distill off the acetonitrile solvent, and obtain a cobalt-based solid catalyst;

[0019] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5000 to 1:5500 to form a 4 cm to 5 cm high stacked bed layer;

[0020] (3) First, nitrogen is introduced for 0.5 h to remove air, and then hydrogen is introduced. The system is gradually heated to 180°C~220°C and reacted for 12 h~13 h. The obtained reaction solution is cooled to room temperature, anhydrous ethanol is added, and the reaction solution is transferred to another reactor. The system is gradually heated to 80°C~85°C, and part of the ethanol is distilled off to obtain a sodium ethoxide solution of a certain concentration, or all the ethanol is distilled off to obtain a sodium ethoxide solid.

[0021] The method for preparing sodium ethoxide from sodium acetate of the present invention, when loading a cobalt-based solid catalyst and sodium acetate in an Oushisheng fixed-bed reactor of model H-Flow-S30, specifically mentions the influence of the height of the stacked bed on the preparation method. By optimizing the loading volume (although the specific height is 4cm~5cm, it needs to be adjusted according to the specifications of the fixed bed in actual operation), the present invention ensures sufficient contact and effective reaction between the reactant and the catalyst. This innovation not only improves the reaction efficiency, but also makes the reaction process more stable and reliable. In addition, the present invention further improves the yield and quality of sodium ethoxide by accurately controlling the reaction temperature and time. Therefore, the method of the present invention has broad application prospects and important economic value in the industrial production of sodium ethoxide. A granular metal catalyst and sodium acetate are loaded in an Oushisheng fixed-bed reactor of model H-Flow-S30 to form a stacked bed of a certain height, and hydrogen flows through the static fixed bed through the gaps between particles at high temperature, combines with the catalyst to reduce sodium acetate to sodium ethoxide, CH3COONa+H2→C2H5ONa+H2O.

[0022] The present invention takes cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 7A as an example, and the catalytic principle is as follows:

[0023] .

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) Compared with the existing method for preparing sodium ethoxide, the method for preparing sodium ethoxide from sodium acetate of the present invention not only simplifies the operation process and reduces the requirements for equipment, but also significantly improves the conversion rate and purity of sodium ethoxide, and the reaction conditions are mild.

[0026] (2) The method for preparing sodium ethoxide from sodium acetate of the present invention adopts a cobalt-based solid catalyst, which makes the reaction process more environmentally friendly and reduces the emission of harmful substances, which is in line with the development trend of green chemistry; at the same time, the recyclability of the catalyst also reduces the production cost and improves the economic benefit. The catalyst has a high conversion rate and is recyclable, and the catalyst is a cobalt catalyst, which is easily available and suitable for industrial synthesis. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific embodiments.

[0028] The raw materials and additives used in the following examples and comparative examples are all commercially available products unless otherwise specified.

[0029] Example 1

[0030] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0031] (1) Cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 1A were dissolved in acetonitrile solvent at a molar ratio of 1:2.1, reacted at room temperature and pressure for 1 hour, and then 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.0 g of 5A molecular sieve added to 1 mmol of cobalt compound), heated to 90°C, and the acetonitrile solvent was distilled off to obtain a cobalt-based solid catalyst;

[0032] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5000 to form a 5 cm high stacked bed layer;

[0033] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 200°C and reacted for 12 h. The obtained reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 85°C, and part of the ethanol was distilled off to obtain a sodium ethoxide solution with a mass concentration of 20%; the conversion rate of sodium acetate was 70%, the purity of sodium ethoxide was 97%, and the conversion number of the catalyst was 5000. The conversion number TON = number of reaction electrons / number of active sites.

[0034] Example 2

[0035] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0036] (1) Dissolve cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 2A in acetonitrile solvent at a molar ratio of 1:2.1, react at room temperature and pressure for 1 hour, add 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.0 g of 5A molecular sieve added to 1 mmol of cobalt compound), heat to 90°C, distill off the acetonitrile solvent, and obtain a cobalt-based solid catalyst;

[0037] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5000 to form a 5 cm high stacked bed layer;

[0038] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 200°C and reacted for 12 h. The resulting reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 85°C, and part of the ethanol was distilled off to obtain a sodium ethoxide solution with a mass concentration of 25%. The conversion rate of sodium acetate was 73%, the purity of sodium ethoxide was 98%, and the conversion number of the catalyst was 4000.

[0039] Example 3

[0040] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0041] (1) Dissolve cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 3A in acetonitrile solvent at a molar ratio of 1:2.1, react at room temperature and pressure for 1 hour, add 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.0 g of 5A molecular sieve added to 1 mmol of cobalt compound), heat to 90°C, distill off the acetonitrile solvent, and obtain a cobalt-based solid catalyst;

[0042] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5000 to form a 5 cm high stacked bed layer;

[0043] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 200°C and reacted for 12 h. The resulting reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 85°C, and part of the ethanol was distilled off to obtain a sodium ethoxide solution with a mass concentration of 23%; the conversion rate of sodium acetate was 80%, the purity of sodium ethoxide was 98%, and the conversion number of the catalyst was 4000.

[0044] Example 4

[0045] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0046] (1) Cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 4A were dissolved in acetonitrile solvent at a molar ratio of 1:2.2, reacted at room temperature and pressure for 1.5 h, and then 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.2 g of 5A molecular sieve added to 1 mmol of cobalt compound) was added, the temperature was raised to 85°C, and the acetonitrile solvent was distilled off to obtain a cobalt-based solid catalyst;

[0047] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5500 to form a 4 cm high stacked bed;

[0048] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 180°C and reacted for 13 h. The resulting reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 80°C, and part of the ethanol was distilled off to obtain a sodium ethoxide solution with a mass concentration of 20%; the conversion rate of sodium acetate was 72%, the purity of sodium ethoxide was 98%, and the conversion number of the catalyst was 5000.

[0049] Example 5

[0050] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0051] (1) Cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 5A were dissolved in acetonitrile solvent at a molar ratio of 1:2.2, reacted at room temperature and pressure for 1.5 h, and then 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.2 g of 5A molecular sieve added to 1 mmol of cobalt compound) was added, the temperature was raised to 85°C, and the acetonitrile solvent was distilled off to obtain a cobalt-based solid catalyst;

[0052] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5500 to form a 4 cm high stacked bed;

[0053] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 220°C for 12 h. The obtained reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 80°C, and part of the ethanol was distilled off to obtain a sodium ethoxide solution with a mass concentration of 20%; the conversion rate of sodium acetate was 76%, the purity of sodium ethoxide was 97%, and the conversion number of the catalyst was 6000.

[0054] Example 6

[0055] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0056] (1) Cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 6A were dissolved in acetonitrile solvent at a molar ratio of 1:2.2, reacted at room temperature and pressure for 1.5 h, and then 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.2 g of 5A molecular sieve added to 1 mmol of cobalt compound) was added, the temperature was raised to 85°C, and the acetonitrile solvent was distilled off to obtain a cobalt-based solid catalyst;

[0057] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5500 to form a 4 cm high stacked bed;

[0058] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 220°C for 12 h. The reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 80°C to distill off all the ethanol to obtain solid sodium ethoxide. The conversion rate of sodium acetate was 79%, the purity of sodium ethoxide was 98%, and the conversion number of the catalyst was 5000.

[0059] Example 7

[0060] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0061] (1) Cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 7A were dissolved in acetonitrile solvent at a molar ratio of 1:2.2, reacted at room temperature and pressure for 1.5 h, and then 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.2 g of 5A molecular sieve added to 1 mmol of cobalt compound) was added, the temperature was raised to 85°C, and the acetonitrile solvent was distilled off to obtain a cobalt-based solid catalyst;

[0062] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5500 to form a 4 cm high stacked bed;

[0063] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 200°C and reacted for 12 h. The resulting reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 80°C to distill off all the ethanol to obtain solid sodium ethoxide. The conversion rate of sodium acetate was 95%, the purity of sodium ethoxide was 98%, and the conversion number of the catalyst was 8000.

[0064] (4) The catalyst obtained after use in step (3) is taken out and mixed with sodium acetate to repeat steps (2) and (3). The cyclic performance of the catalyst is tested. The data are shown in the following table.

[0065] Table 1 Cyclic performance of catalysts

[0066]

[0067] Example 8

[0068] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0069] (1) Cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 8A were dissolved in acetonitrile solvent at a molar ratio of 1:2.1, reacted at room temperature and pressure for 1 hour, and then 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.0 g of 5A molecular sieve added to 1 mmol of cobalt compound), heated to 90°C, and the acetonitrile solvent was distilled off to obtain a cobalt-based solid catalyst;

[0070] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5000 to form a 5 cm high stacked bed layer;

[0071] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 200°C and reacted for 12 h. The resulting reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 85°C to distill off all the ethanol to obtain solid sodium ethoxide. The conversion rate of sodium acetate was 89%, the purity of sodium ethoxide was 98%, and the conversion number of the catalyst was 6000.

[0072] Example 9

[0073] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0074] (1) Cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 9A were dissolved in acetonitrile solvent at a molar ratio of 1:2.1, reacted at room temperature and pressure for 1 hour, and then 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.0 g of 5A molecular sieve added to 1 mmol of cobalt compound), heated to 90°C, and the acetonitrile solvent was distilled off to obtain a cobalt-based solid catalyst;

[0075] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5000 to form a 5 cm high stacked bed layer;

[0076] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 200 °C and reacted for 12 h. The resulting reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to ~85 °C to distill off all the ethanol to obtain sodium ethoxide solid. The conversion rate of sodium acetate was 59%, the purity of sodium ethoxide was 98%, and the conversion number of the catalyst was 3000.

[0077] Example 10

[0078] The method for preparing sodium ethoxide from sodium acetate comprises the following steps:

[0079] (1) Cobalt tetrafluoroborate hexahydrate [Co(BF4)2•6H2O] and tridentate phosphine ligand 10A were dissolved in acetonitrile solvent at a molar ratio of 1:2.1, reacted at room temperature and pressure for 1 hour, and then 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.0 g of 5A molecular sieve added to 1 mmol of cobalt compound), heated to 90°C, and the acetonitrile solvent was distilled off to obtain a cobalt-based solid catalyst;

[0080] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5000 to form a 5 cm high stacked bed layer;

[0081] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 200°C and reacted for 12 h. The resulting reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 85°C to distill off all the ethanol to obtain solid sodium ethoxide. The conversion rate of sodium acetate was 43%, the purity of sodium ethoxide was 99%, and the conversion number of the catalyst was 3000.

[0082] Comparative Example 1

[0083] (1) CoCl2·6H2O and 1,2-bis(diphenylphosphine)ethane (DPPE) were dissolved in acetonitrile solvent at a molar ratio of 1:2.2, reacted at room temperature and pressure for 1.5 h, and then 5A molecular sieve with a diameter of 2.0 mm to 3.0 mm (calculated based on 1.2 g of 5A molecular sieve added to 1 mmol of cobalt compound) was added, the temperature was raised to 85°C, and the acetonitrile solvent was distilled off to obtain a cobalt-based solid catalyst;

[0084] (2) A cobalt-based solid catalyst and sodium acetate were added to an H-Flow-S30 Oushisheng fixed bed reactor at a molar ratio of 1:5500 to form a 4 cm high stacked bed;

[0085] (3) First, nitrogen was introduced for 0.5 h to remove air, and then hydrogen was introduced at a hydrogen flow rate of 500 sccm. The system was gradually heated to 220°C and reacted for 12 h. The resulting reaction solution was cooled to room temperature, anhydrous ethanol was added, and the reaction solution was transferred to another reactor. The system was gradually heated to 80°C to distill off all the ethanol to obtain sodium ethoxide solid. The conversion rate of sodium acetate was 15%, the purity was 97%, and the conversion number of the catalyst was 1000.

Claims

1. A method for preparing sodium ethoxide from sodium acetate, characterized in that: Firstly, the cobalt compound is reacted with a tridentate phosphine ligand and loaded on a 5A molecular sieve to obtain a cobalt-based solid catalyst; then the cobalt-based solid catalyst and sodium acetate are filled into a fixed bed reactor to form a stacked bed; finally, hydrogen is introduced, the temperature is raised to 180°C to 220°C, a reduction reaction is carried out for 12h to 13h, and anhydrous ethanol is added to the obtained reaction solution to dissolve it, thereby obtaining a sodium ethoxide solution; The specific process of the cobalt-based solid catalyst is as follows: dissolving the cobalt compound and the tridentate phosphine ligand in an acetonitrile solvent, reacting for 1h to 1.5h at room temperature and pressure, adding a 5A molecular sieve with a diameter of 2.0mm to 3.0mm, heating to 85°C to 90°C, distilling off the acetonitrile solvent, and obtaining a cobalt-based solid catalyst; The cobalt compound is Co(BF4)2•6H2O, and the tridentate phosphine ligand is one of the following structures: , where the PCy2 group is a dicyclohexylphosphine group, PPh2 is a diphenylphosphine group, and PBn2 is a dibenzylphosphine group.

2. The method for preparing sodium ethoxide from sodium acetate according to claim 1, wherein: The molar ratio of the cobalt compound to the tridentate phosphine ligand is 1:2.1-1:2.

2.

3. The method for preparing sodium ethoxide from sodium acetate according to claim 1, wherein: The addition of the 5A molecular sieve is calculated based on the addition of 1.0 g to 1.2 g of 5A molecular sieve per 1 mmol of the cobalt compound.

4. The method for preparing sodium ethoxide from sodium acetate according to claim 1, wherein: The molar ratio of the cobalt-based solid catalyst to sodium acetate is 1:5000-1:5500.

5. The method for preparing sodium ethoxide from sodium acetate according to claim 1, wherein: Or the obtained reaction solution is heated to 80°C-85°C to distill off the ethanol to obtain sodium ethoxide solid.

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