Vinyl acetate catalyst as well as preparation method and application thereof

Abstract

The invention discloses a vinyl acetate catalyst and a preparation method and application thereof, and the method comprises the following steps: crushing a carbonized raw material, adding an acidic solution, dipping for a period of time, washing, drying, then adding an alkaline solution, stirring, and carrying out air isolation treatment to obtain a carbon-based material; the preparation method comprises the following steps: mixing a carbon-based material and a Y-type molecular sieve, then carrying out segmented calcination, and then introducing a proper amount of water vapor, carbon dioxide and nitrogen mixed gas to obtain a composite catalytic carrier; mixing the composite catalyst carrier with sodium hydroxypropyl sulfonate methacrylate, adding deionized water, and stirring to obtain a carrier suspension; dropwise adding a palladium chloride solution and a tungsten chloride solution into the carrier suspension at the same time, stirring, centrifuging, drying, grinding, and calcining to obtain a modified catalyst carrier; and mixing the modified catalyst carrier with zinc acetate and an auxiliary agent, stirring, preserving heat, filtering and drying to obtain the vinyl acetate catalyst. The vinyl acetate catalyst provided by the invention has a good conversion rate.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a vinyl acetate catalyst and a preparation method and application thereof. Background Art

[0002] Vinyl acetate (VAC) is an important chemical raw material, widely used in the production of polymers, coatings and adhesives. The fixed-bed gas-phase synthesis of vinyl acetate by the acetylene method is one of the main synthesis routes in the industry. The process uses acetylene and acetic acid as raw materials and uses an activated carbon catalyst loaded with zinc acetate (Zn(AC)2). The reaction has exothermic characteristics and is accompanied by the occurrence of various side reactions during the reaction, resulting in the formation of various by-products such as benzene, acetaldehyde, and crotonaldehyde, which affects the yield of vinyl acetate and the purity of the product.

[0003] In the synthesis process of vinyl acetate, the selection of catalyst is crucial. High-quality catalysts can not only improve the selectivity and conversion rate of the reaction, but also significantly extend the service life of the catalyst and reduce the operating cost of the reactor. Fixed-bed catalysts often face problems such as reduced activity, low VAC yield and many by-products during use. Studies have shown that the specific surface area, pore structure and distribution characteristics of the carrier have a significant effect on the activity and stability of the catalyst.

[0004] The Chinese invention patent with the publication number CN103934030A relates to a method for producing a catalyst for synthesizing vinyl acetate by the acetylene method. The catalyst used for synthesizing vinyl acetate is composed of a carrier and an active component loaded on the carrier, wherein the active component is zinc acetate and bismuth subcarbonate; the content of zinc acetate in the catalyst is 90-180 g / L, and the content of bismuth subcarbonate is 0.1-0.3 g / L; the carrier of the catalyst is a porous carbon material, and the pore volume of the porous carbon material with a pore size of 3-10 nm accounts for 20%-80% of the total pore volume, and the pore volume of the pore size of 30-40 nm accounts for 10%-60% of the total pore volume. The method uses ordinary activated carbon as a carrier, operates at normal pressure, does not reflect the expansion of the carrier, has a low content of zinc acetate, and the auxiliary agent is a single bismuth subcarbonate. The pore volume structure is not rich enough, the reaction site is small, the catalytic conversion efficiency for the synthesis reaction is low, and the performance is general. Therefore, the development of new catalysts to improve reaction efficiency and economic benefits has become the focus of research. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a vinyl acetate catalyst and a preparation method and application thereof, so as to solve the technical problems that the existing catalysts are prone to loss of activity, have low VAC yields, and produce a large number of by-products.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] The present invention provides a method for preparing a vinyl acetate catalyst, comprising the following steps:

[0008] S1. The carbonized raw material is crushed to obtain carbonized particles, an acidic solution is added, the particles are immersed for a period of time, washed, dried, and then an alkaline solution is added and stirred, and the particles are isolated from air to obtain a carbon-based material;

[0009] S2, mixing the carbon-based material and the Y-type molecular sieve, and then calcining them in stages, and then introducing a mixed gas of water vapor, carbon dioxide and nitrogen to obtain a composite catalytic carrier;

[0010] S3, mixing the composite catalyst carrier and sodium hydroxypropane sulfonate methacrylate, adding deionized water, stirring, and obtaining a carrier suspension;

[0011] S4, adding palladium chloride solution and tungsten chloride solution to the carrier suspension at the same time, stirring, centrifuging, drying, grinding, and calcining to obtain a modified catalyst carrier;

[0012] S5. Mixing the modified catalyst carrier, zinc acetate and an auxiliary agent, stirring, heat-insulating, filtering and drying to obtain a vinyl acetate catalyst.

[0013] Preferably, in step S1, the carbonized raw material includes any one of coconut shell carbonized material powder, sawdust, coal powder, petroleum coke, apricot shell, and bamboo processing debris.

[0014] Preferably, in step S1, the acidic solution includes at least one of acetic acid, dilute hydrochloric acid, and nitric acid, and the mass fraction of the acidic solution is 1% to 5%;

[0015] The immersion time is 100 to 150 minutes;

[0016] The alkaline solution includes at least one of sodium hydroxide, potassium hydroxide and barium hydroxide, and the mass fraction of the alkaline solution is 2% to 6%;

[0017] The air isolation treatment is carried out in an anti-corrosion pressure vessel, the time of the air isolation treatment is 100 to 150 minutes, and the temperature of the air isolation treatment is 300 to 500°C.

[0018] Preferably, in step S2, the mass ratio of the base carbon material to the Y-type molecular sieve is (8-10):(2-3).

[0019] Preferably, in step S2, the specific steps of the staged calcination are: calcining at 800-1000°C for 0.5-1.5h, and then heating to 1000-1100°C for 1.5-2.5h;

[0020] The flow rate of the mixed gas is 5 to 20 m3 / min.

[0021] Preferably, in step S3, the usage ratio of the composite catalyst carrier, sodium methacrylate hydroxypropane sulfonate and deionized water is (5-8 g): (2-5 g): (10-20 mL).

[0022] Preferably, in step S4, the concentration of the palladium chloride solution is 0.1-0.2 mol / L, the concentration of the tungsten chloride solution is 0.1-0.2 mol / L, and the volume ratio of the carrier suspension, the palladium chloride solution and the tungsten chloride solution is (6-10): (2-3): (2-3);

[0023] The stirring time is 2 to 4 hours;

[0024] The calcination temperature is 500-550°C.

[0025] Preferably, in step S5, the mass fraction of zinc acetate is 6-12%;

[0026] The auxiliary agent includes any one of ammonium paramolybdate solution, lanthanum acetate solution, and acidic barium solution;

[0027] The drying temperature is 170-240°C.

[0028] The present invention also provides a vinyl acetate catalyst, which is prepared by the above-mentioned preparation method.

[0029] The present invention further proposes an application of the above vinyl acetate catalyst, which is applied to the acetylene process fixed bed gas phase synthesis of vinyl acetate.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The method for preparing a vinyl acetate catalyst provided by the present invention comprises the following steps: adding an acidic solution to anthracite, sawdust, coconut shell and other carbon-containing materials for impregnation treatment, thereby improving the pyrolysis and gasification capabilities of the materials, followed by alkalization treatment to obtain a base carbon material, and then mixing the base carbon material with a Y-type molecular sieve, calcining and activating the material in stages, and then mixing the material with a surfactant, sodium methacrylate hydroxypropane sulfonate, and then loading palladium and tungsten to improve the conversion rate and selectivity of the catalyst.

[0032] (2) The method for preparing vinyl acetate catalyst provided by the present invention is to mix the base carbon material with the Y-type molecular sieve and perform segmented calcination, combining the high specific area characteristics of the carbon material with the molecular screening ability of the molecular sieve to form a composite catalytic carrier. By mixing with the dispersant sodium methacrylate hydroxypropanesulfonate, it not only helps to evenly distribute the loaded components later, but also plays a bonding role, so that the loaded components are more firmly loaded on the carrier, and the carrier is introduced with sulfur doping to improve the catalytic activity and stability of the catalyst. The modified catalyst carrier is prepared by loading the active component palladium and the auxiliary component tungsten, and the catalytic activity, thermal stability, durability and anti-poisoning ability of the catalytic carrier are synergistically improved, which can effectively promote the synthesis reaction of vinyl acetate. This bimetallic loading method not only improves the activity of the catalyst, but also improves its stability under high temperature and complex reaction conditions. This composite structure can effectively improve the selectivity and stability of the catalyst, ensuring good catalytic activity in the synthesis process of vinyl acetate.

[0033] (3) The vinyl acetate catalyst provided by the present invention has a VAC yield of up to 120 g / ml·h, which is much higher than that of traditional catalysts, indicating that the method has significant advantages in improving the efficiency of vinyl acetate synthesis; the concentrations of acetaldehyde and crotonaldehyde in the by-products are less than 0.2% and 0.003%, respectively, ensuring the purity of the product and meeting the requirements of high-end applications; its high strength and low average resistance (40 kPa) enable the output of a single-row reactor to reach 145 t / d, further demonstrating the superiority of the catalyst in industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a process flow chart of the method for preparing vinyl acetate catalyst provided by the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0036] It should be noted that, unless otherwise specified, the chemical reagents involved in the present invention were purchased through commercial channels.

[0037] In the present invention, the SiO2 / Al2O3 ratio in the Y-type molecular sieve is 5.0.

[0038] Example 1

[0039] A method for preparing a vinyl acetate catalyst comprises the following steps:

[0040] (1) 150 g of anthracite was crushed to obtain carbonized particles, a 3% by mass acetic acid solution was added, the particles were immersed for a period of time, washed and dried, and then a 3% by mass sodium hydroxide solution was added and stirred, and the particles were treated at 400° C. in an airtight state for 120 min to obtain a base carbon material;

[0041] (2) 100 g of the carbon material and 25 g of Y-type molecular sieve were mixed, and then calcined at 900° C. for 1 h, and then heated to 1050° C. for 2 h, and then a mixed gas of water vapor, carbon dioxide and nitrogen in a volume ratio of 1:1:1 was introduced to obtain a composite catalytic carrier;

[0042] (3) 120 g of the composite catalyst carrier and 60 g of sodium methacrylate hydroxypropanesulfonate were mixed, 300 mL of deionized water was added, and the mixture was stirred to obtain a carrier suspension;

[0043] (4) 80 mL of 0.15 mol / L palladium chloride solution and 80 mL of 0.12 mol / L tungsten chloride solution were simultaneously added dropwise to 300 mL of the carrier suspension, stirred for 3 h, centrifuged, dried, ground, and calcined at 520° C. to obtain a modified catalyst carrier;

[0044] (5) 120 g of the modified catalyst carrier was mixed with 50 mL of 6% zinc acetate and 30 mL of 4% ammonium paramolybdate, stirred, kept at 40° C. for 4 h, filtered, and dried at 170° C. under nitrogen protection to obtain a vinyl acetate catalyst.

[0045] Example 2

[0046] A method for preparing a vinyl acetate catalyst comprises the following steps:

[0047] (1) 150 g of coconut shell carbonized material was crushed to obtain carbonized particles, a 3% by mass dilute hydrochloric acid solution was added, the particles were immersed for a period of time, washed and dried, and then a 3% by mass potassium hydroxide solution was added and stirred, and the particles were treated at 400° C. in an airtight state for 120 min to obtain a base carbon material;

[0048] (2) 100 g of the carbon material and 20 g of the Y-type molecular sieve were mixed, and then calcined at 800° C. for 1 h, and then heated to 1000° C. for 2 h, and then a mixed gas of water vapor, carbon dioxide and nitrogen in a volume ratio of 1:1:1 was introduced to obtain a composite catalytic carrier;

[0049] (3) 120 g of the composite catalyst carrier and 60 g of sodium methacrylate hydroxypropanesulfonate were mixed, 300 mL of deionized water was added, and the mixture was stirred to obtain a carrier suspension;

[0050] (4) Add 80 mL of 0.15 mol / L palladium chloride solution and 80 mL of 0.12 mol / L tungsten chloride solution to 300 mL of the carrier suspension, stir for 3 h, centrifuge, dry, grind, and calcine at 500° C. to obtain a modified catalyst carrier;

[0051] (5) 120 g of the modified catalyst carrier was mixed with 50 mL of 6% zinc acetate and 30 mL of 4% ammonium paramolybdate, stirred, kept at 40° C. for 4 h, filtered, and dried at 200° C. under nitrogen protection to obtain a vinyl acetate catalyst.

[0052] Example 3

[0053] A method for preparing a vinyl acetate catalyst comprises the following steps:

[0054] (1) 150 g of coconut shell carbonized material was crushed to obtain carbonized particles, a 3% nitric acid solution was added, the particles were immersed for a period of time, washed and dried, and then a 3% barium hydroxide solution was added and stirred, and the particles were treated at 400° C. in an airtight state for 120 min to obtain a base carbon material;

[0055] (2) 100 g of the carbon material and 30 g of the Y-type molecular sieve were mixed, and then calcined at 1000° C. for 1 h, and then heated to 1100° C. for 2 h, and then a mixed gas of water vapor, carbon dioxide and nitrogen in a volume ratio of 1:1:1 was introduced to obtain a composite catalytic carrier;

[0056] (3) 120 g of the composite catalyst carrier and 60 g of sodium methacrylate hydroxypropanesulfonate were mixed, 300 mL of deionized water was added, and the mixture was stirred to obtain a carrier suspension;

[0057] (4) Add 80 mL of 0.15 mol / L palladium chloride solution and 80 mL of 0.12 mol / L tungsten chloride solution to 300 mL of the carrier suspension, stir for 3 h, centrifuge, dry, grind, and calcine at 550° C. to obtain a modified catalyst carrier;

[0058] (5) 120 g of the modified catalyst carrier was mixed with 50 mL of 6% by mass zinc acetate and 30 mL of 4% by mass ammonium paramolybdate, stirred, kept at 40° C. for 4 h, filtered, and dried at 240° C. under nitrogen gas protection to obtain a vinyl acetate catalyst.

[0059] Comparative Example 1

[0060] A method for preparing a vinyl acetate catalyst comprises the following steps:

[0061] (1) 150 g of anthracite was crushed to obtain carbonized particles, a 3% by mass acetic acid solution was added, the particles were immersed for a period of time, washed and dried, and then a 3% by mass sodium hydroxide solution was added and stirred, and the particles were treated at 400° C. in an airtight state for 120 min to obtain a base carbon material;

[0062] (2) 100 g of the carbon material and 25 g of Y-type molecular sieve were mixed, and then calcined at 900° C. for 1 h, and then heated to 1050° C. for 2 h, and then a mixed gas of water vapor, carbon dioxide and nitrogen in a volume ratio of 1:1:1 was introduced to obtain a composite catalytic carrier;

[0063] (3) 120 g of the composite catalyst support and 300 mL of deionized water were mixed and stirred to obtain a support suspension;

[0064] (4) 80 mL of 0.15 mol / L palladium chloride solution and 80 mL of 0.12 mol / L tungsten chloride solution were simultaneously added dropwise to 300 mL of the carrier suspension, stirred for 3 h, centrifuged, dried, ground, and calcined at 520° C. to obtain a modified catalyst carrier;

[0065] (5) 120 g of the modified catalyst carrier was mixed with 50 mL of 6% zinc acetate and 30 mL of 4% ammonium paramolybdate, stirred, kept at 40° C. for 4 h, filtered, and dried at 170° C. under nitrogen protection to obtain a vinyl acetate catalyst.

[0066] Compared with Example 1, in Comparative Example 1, the composite catalyst carrier is not mixed with a surfactant in step (3).

[0067] Comparative Example 2

[0068] A method for preparing a vinyl acetate catalyst comprises the following steps:

[0069] (1) 150 g of anthracite was crushed to obtain carbonized particles, a 3% by mass acetic acid solution was added, the particles were immersed for a period of time, washed and dried, and then a 3% by mass sodium hydroxide solution was added and stirred, and the particles were treated at 400° C. in an airtight state for 120 min to obtain a base carbon material;

[0070] (2) 100 g of the carbon material and 25 g of Y-type molecular sieve were mixed, and then calcined at 900° C. for 1 h, and then heated to 1050° C. for 2 h, and then a mixed gas of water vapor, carbon dioxide and nitrogen in a volume ratio of 1:1:1 was introduced to obtain a composite catalytic carrier;

[0071] (3) 120 g of the composite catalyst carrier and 60 g of sodium methacrylate hydroxypropanesulfonate were mixed, 300 mL of deionized water was added, and the mixture was stirred to obtain a carrier suspension;

[0072] (4) 80 mL of 0.12 mol / L tungsten chloride solution was added dropwise to 300 mL of the carrier suspension, stirred for 3 h, centrifuged, dried, ground, and calcined at 520° C. to obtain a modified catalyst carrier;

[0073] (5) 120 g of the modified catalyst carrier was mixed with 50 mL of 6% zinc acetate and 30 mL of 4% ammonium paramolybdate, stirred, kept at 40° C. for 4 h, filtered, and dried at 170° C. under nitrogen protection to obtain a vinyl acetate catalyst.

[0074] Compared with Example 1, in Comparative Example 2, no palladium chloride solution was added to the carrier suspension in step (4).

[0075] Comparative Example 3

[0076] A method for preparing a vinyl acetate catalyst comprises the following steps:

[0077] (1) 150 g of anthracite was crushed to obtain carbonized particles, a 3% by mass acetic acid solution was added, the particles were immersed for a period of time, washed and dried, and then a 3% by mass sodium hydroxide solution was added and stirred, and the particles were treated at 400° C. in an airtight state for 120 min to obtain a base carbon material;

[0078] (2) 100 g of the carbon material and 25 g of Y-type molecular sieve were mixed, and then calcined at 900° C. for 1 h, and then heated to 1050° C. for 2 h, and then a mixed gas of water vapor, carbon dioxide and nitrogen in a volume ratio of 1:1:1 was introduced to obtain a composite catalytic carrier;

[0079] (3) 120 g of the composite catalyst carrier and 60 g of sodium methacrylate hydroxypropanesulfonate were mixed, 300 mL of deionized water was added, and the mixture was stirred to obtain a carrier suspension;

[0080] (4) adding 80 mL of 0.15 mol / L palladium chloride solution to 300 mL of the carrier suspension, stirring for 3 h, centrifuging, drying, grinding, and calcining at 520° C. to obtain a modified catalyst carrier;

[0081] (5) 120 g of the modified catalyst carrier was mixed with 50 mL of 6% zinc acetate and 30 mL of 4% ammonium paramolybdate, stirred, kept at 40° C. for 4 h, filtered, and dried at 170° C. under nitrogen protection to obtain a vinyl acetate catalyst.

[0082] Compared with Example 1, in Comparative Example 3, no tungsten chloride solution was added to the carrier suspension in step (4).

[0083] Comparative Example 4

[0084] A method for preparing a vinyl acetate catalyst comprises the following steps:

[0085] (1) 150 g of anthracite was crushed to obtain carbonized particles, a 3% by mass acetic acid solution was added, the particles were immersed for a period of time, washed and dried, and then a 3% by mass sodium hydroxide solution was added and stirred, and the particles were treated at 400° C. in an airtight state for 120 min to obtain a base carbon material;

[0086] (2) 100 g of the carbon material and 25 g of Y-type molecular sieve were mixed, and then calcined at 900° C. for 1 h, and then heated to 1050° C. for 2 h, and then a mixed gas of water vapor, carbon dioxide and nitrogen in a volume ratio of 1:1:1 was introduced to obtain a composite catalytic carrier;

[0087] (3) 120 g of the composite catalyst carrier and 60 g of sodium methacrylate hydroxypropanesulfonate were mixed, 300 mL of deionized water was added, and the mixture was stirred to obtain a carrier suspension;

[0088] (4) centrifuging 300 mL of the carrier suspension, drying, grinding, and calcining at 520° C. to obtain a catalyst carrier;

[0089] (5) 120 g of the catalyst carrier was mixed with 50 mL of 6% zinc acetate and 30 mL of 4% ammonium paramolybdate, stirred, kept at 40° C. for 4 h, filtered, and dried at 170° C. under nitrogen protection to obtain a vinyl acetate catalyst.

[0090] Compared with Example 1, in Comparative Example 3, no palladium chloride solution and tungsten chloride solution were added to the carrier suspension in step (4).

[0091] The acetylene method was used to synthesize vinyl acetate in a fixed bed gas phase. The specific conditions were as follows: catalyst loading volume: 40 ml; reaction raw material composition (in terms of molar ratio): acetylene: acetic acid = 6:1; reaction raw material volume space velocity: 300 h -1 ; Reaction pressure: 0.3atm; Reaction temperature: 180℃; Reaction time: 100h; After 100h of reaction, the content of each component in the reaction product was analyzed by gas chromatography, and the space-time yield of the catalyst was calculated. The results are shown in Table 1 below.

[0092] Table 1 Summary of experimental results of Examples 1 to 3 and Comparative Examples 1 to 3

[0093]

[0094]

[0095] It can be seen from the above table that, compared with Comparative Examples 1 to 3, the vinyl acetate catalyst prepared by the present invention has a better space-time yield, less catalytic by-product content, higher purity and higher selectivity.

[0096] Finally, it should be noted that the above embodiments do not limit the present invention in any form. For those skilled in the art, some modifications and improvements can be made to the present invention. Therefore, any modification or improvement made without departing from the spirit of the present invention belongs to the scope of protection claimed in the present invention.

Claims

1. A method for preparing a vinyl acetate catalyst, characterized in that: The following steps are involved: S1. The carbonized raw material is crushed to obtain carbonized particles, an acidic solution is added, the particles are immersed for a period of time, washed, dried, and then an alkaline solution is added and stirred, and the particles are isolated from air to obtain a carbon-based material; S2, mixing the carbon-based material and the Y-type molecular sieve, and then calcining them in stages, and then introducing a mixed gas of water vapor, carbon dioxide and nitrogen to obtain a composite catalytic carrier; S3, mixing the composite catalyst carrier and sodium hydroxypropane sulfonate methacrylate, adding deionized water, stirring, and obtaining a carrier suspension; S4, adding palladium chloride solution and tungsten chloride solution to the carrier suspension at the same time, stirring, centrifuging, drying, grinding, and calcining to obtain a modified catalyst carrier; S5. Mixing the modified catalyst carrier, zinc acetate and an auxiliary agent, stirring, heat-insulating, filtering and drying to obtain a vinyl acetate catalyst.

2. The method for preparing vinyl acetate catalyst according to claim 1, characterized in that: In step S1, the carbonized raw material includes any one of coconut shell carbonized material powder, sawdust, coal powder, petroleum coke, apricot shell, and bamboo processing debris.

3. The method for preparing vinyl acetate catalyst according to claim 1, characterized in that: In step S1, the acidic solution includes at least one of acetic acid, dilute hydrochloric acid, and nitric acid, and the mass fraction of the acidic solution is 1% to 5%; The immersion time is 100 to 150 minutes; The alkaline solution includes at least one of sodium hydroxide, potassium hydroxide and barium hydroxide, and the mass fraction of the alkaline solution is 2% to 6%; The air isolation treatment is carried out in an anti-corrosion pressure vessel, the time of the air isolation treatment is 100 to 150 minutes, and the temperature of the air isolation treatment is 300 to 500°C.

4. The method for preparing vinyl acetate catalyst according to claim 1, characterized in that: In step S2, the mass ratio of the base carbon material to the Y-type molecular sieve is (8-10): (2-3).

5. The method for preparing vinyl acetate catalyst according to claim 1, characterized in that: In step S2, the specific steps of the staged calcination are: calcining at 800-1000°C for 0.5-1.5h, then heating to 1000-1100°C for 1.5-2.5h; The flow rate of the mixed gas is 5 to 20 m 3 / min.

6. The method for preparing vinyl acetate catalyst according to claim 1, characterized in that: In step S3, the usage ratio of the composite catalyst carrier, sodium methacrylate hydroxypropane sulfonate and deionized water is (5-8 g): (2-5 g): (10-20 mL).

7. The method for preparing vinyl acetate catalyst according to claim 1, characterized in that: In step S4, the concentration of the palladium chloride solution is 0.1-0.2 mol / L, the concentration of the tungsten chloride solution is 0.1-0.2 mol / L, and the volume ratio of the carrier suspension, the palladium chloride solution and the tungsten chloride solution is (6-10): (2-3): (2-3); The stirring time is 2 to 4 hours; The calcination temperature is 500-550°C.

8. The method for preparing vinyl acetate catalyst according to claim 1, characterized in that: In step S5, the mass fraction of zinc acetate is 6-12%; The auxiliary agent includes any one of ammonium paramolybdate solution, lanthanum acetate solution, and acidic barium solution; The drying temperature is 170-240°C.

9. A vinyl acetate catalyst, characterized in that: The preparation is obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the vinyl acetate catalyst as claimed in claim 9, characterized in that: It is used in the fixed-bed gas-phase synthesis of vinyl acetate by the acetylene process.

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