Gold-based catalyst, preparation method and application

Abstract

The present invention discloses a gold-based catalyst, preparation method, and application. The catalyst relates to a catalyst for preparing vinyl chloride by acetylene hydrochlorination, solving the problem of easy agglomeration of existing gold-based catalysts. The technical solution comprises the following key points: the catalyst is used to catalyze acetylene hydrochlorination; the raw materials used in the preparation method include a carrier, a gold precursor, and an additive; and the steps include: Step 1: preparing a solution, dissolving the gold precursor and the additive in a solvent, wherein the solvent is an alcohol; Step 2: stirring and mixing, wherein the gold precursor solution and the carrier are mixed and stirred, and then the additive solution is added dropwise to form a mixture, or the gold precursor solution is added dropwise to the additive solution, mixed, and then the carrier is added and stirred to form a mixture; Step 3: immersion and drying, wherein the mixture is immersed at 50-150°C for 6-12 hours, dried, and finally dried at 100-120°C for 12 hours to obtain the gold-based catalyst. The gold-based catalyst prepared by the above-mentioned scheme has good active ingredient dispersion, high catalytic activity, and good stability.

Description

Technical Field

[0001] The present invention relates to a catalyst for preparing vinyl chloride by acetylene hydrochlorination, and more particularly to a gold-based catalyst, a preparation method and application thereof. Background Art

[0002] Polyvinyl chloride (PVC) is a polymer material produced by the polymerization of vinyl chloride (VCM). It ranks third among polymer materials in global usage and is widely used in industry, agriculture, daily life, and other fields. VCM production methods are mainly divided into the acetylene process and the ethylene process. Due to my country's "rich in coal, poor in oil, and little gas" energy structure, the coal-based acetylene process accounts for a much larger proportion (over 80%) than the oil and gas-based ethylene process. With the rapid development of the national economy, my country's PVC production capacity has been rapidly increasing. Since 2007, my country's PVC production capacity has generally shown an upward trend. According to data from the China Chlor-Alkali Industry Association, China's total polyvinyl chloride (PVC) production capacity reached 27.13 million tons / year in 2021, an increase of 490,000 tons / year from 2020. However, current industrial production still uses HgCl2 / C as an industrial catalyst to catalyze the acetylene hydrochlorination reaction. According to statistics, the production of each ton of PVC consumes 1.02-1.41 kg of catalyst, of which approximately 25% of the HgCl2 component is lost during the production cycle. Based on an estimated catalyst lifespan of 10,000 hours, China currently consumes 8,000 tons of mercuric chloride catalyst coal annually, equivalent to 500 tons of mercury resources. This represents approximately 70% of my country's total mercury consumption and 20% of global mercury demand for VCM production. my country has signed the Minamata Convention on Limiting the Use and Emissions of Mercury, requiring the elimination of production processes using mercury or mercury compounds by 2025. Mercury, a scarce resource and a highly environmentally sensitive heavy metal, is in declining supply, while the calcium carbide-based PVC industry's consumption of mercury resources is increasing. This excessive consumption and reliance on mercury resources presents a significant obstacle to the development of calcium carbide-based PVC. Furthermore, mercury-containing wastes emitted during the production process pose a serious threat to human health and the ecological balance. Reducing mercury consumption and pollution is a pressing task for the PVC industry and a key component in achieving sustainable and healthy growth.

[0003] Under the dual constraints of the "Minamata Convention" and the "Dual Carbon Target", higher requirements are placed on the green and sustainable development of the polyvinyl chloride industry. Therefore, this project aims to develop non-mercury precious metal catalysts with high catalytic efficiency and green economy to lay the foundation for the application of mercury-free catalysts in the production of VCM process, which has distinct national characteristics. At present, the common preparation method for supported catalysts in acetylene hydrochlorination reaction is to load metal precursors and additives onto the carrier by impregnation under certain conditions. However, Au n+The complexes of (n=1 or 3) with the auxiliary agents in the prior art will lead to the agglomeration of large particles, which will cause the active components to be unable to be evenly dispersed on the carrier during the impregnation process and further lead to the problem of low utilization rate of precious metal atoms. Summary of the Invention

[0004] In a first aspect, the purpose of the present invention is to provide a gold-based catalyst whose active substances are in a highly dispersed state, thereby significantly improving the catalytic activity and stability of existing metal catalysts.

[0005] The present invention provides a gold-based catalyst for catalyzing acetylene hydrochlorination reaction; the raw materials for manufacturing the gold-based catalyst include a carrier, a gold precursor and an auxiliary agent; in a transmission electron microscope (TEM) image of the gold-based catalyst, its active components are in the form of dots and are evenly distributed in the catalyst.

[0006] Furthermore, the carrier is coal-based columnar activated carbon; the gold precursor is AuCl3, HAuCl4, (NH4)AuCl4, C 16 H 36 At least one of AuCl2N; the auxiliary agent is at least one of phenylphosphonyl dichloride, nitrosobenzene, methyl phenyl sulfoxide, and acetophenone.

[0007] Furthermore, the gold precursor is HAuCl4; and the auxiliary agent is nitrosobenzene.

[0008] In a second aspect, the present invention provides a method for preparing a gold-based catalyst, which is used to catalyze the hydrochlorination reaction of acetylene; the raw materials produced by the preparation method include a carrier, a gold precursor and an auxiliary agent; the method includes the following steps: step 1, preparing a solution, dissolving the gold precursor and the auxiliary agent in a solvent respectively; the solvent is an alcohol solvent; step 2, stirring and mixing, mixing the gold precursor solution with the carrier and then dropping the auxiliary agent solution to form a mixture, or dropping the gold precursor solution into the auxiliary agent solution and mixing, then adding the carrier and stirring to form a mixture; step 3, immersion drying, immersing the mixture at 50-150°C for 6-12 hours, then drying, and finally drying at 100-120°C for 12 hours to obtain the gold-based catalyst.

[0009] Furthermore, the carrier is coal-based columnar activated carbon; the gold precursor is AuCl3, HAuCl4, (NH4)AuCl4, C 16 H 36 At least one of AuCl2N; the auxiliary agent is at least one of phenylphosphonyl dichloride, nitrosobenzene, methyl phenyl sulfoxide, and acetophenone.

[0010] Furthermore, the raw materials are proportioned as follows: based on the total mass of the raw materials, the amount of the gold precursor is 0.05-0.4 wt%; the molar ratio of the metal precursor to the auxiliary agent is 1:1-15; and the remainder is the carrier.

[0011] Furthermore, the amount of the gold precursor is 0.05-0.2 wt %; and the molar ratio of the gold precursor to the auxiliary agent is 1:5-10.

[0012] Furthermore, the carrier has a particle size of 1.5 to 5 mm.

[0013] The present invention also provides a gold-based catalyst prepared by the method.

[0014] In a third aspect, the present invention provides the use of the above-mentioned gold-based catalyst in the preparation of vinyl chloride by acetylene hydrochlorination.

[0015] In summary, the present invention has the following beneficial effects: compared with existing metal catalysts for acetylene hydrochlorination reactions, the active components in the gold-based catalyst of the present invention are highly dispersed, not easily lost or agglomerated, and simultaneously activate the acetylene and hydrogen chloride reactants, thereby improving the catalytic activity and stability of existing metal catalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a transmission electron microscope (TEM) image of the gold-based catalyst provided in Example 1.

[0017] Figure 2 The relationship between acetylene conversion and reaction time is shown in the graph below, using the catalysts provided in Examples 1 to 4 and Comparative Example 1 under the conditions of Example 5.

[0018] Figure 3 The relationship between vinyl chloride selectivity and reaction time is shown in the graph below using the catalysts provided in Examples 1 to 4 and Comparative Example 1 under the conditions of Example 5.

[0019] Figure 4 The relationship between acetylene conversion and reaction time is shown in FIG. 1 , FIG. 2 and FIG. 3 under the conditions of Example 6 using the catalysts provided in Example 1 and Comparative Examples 1-3.

[0020] Figure 5 Figure 2 is a graph showing the relationship between vinyl chloride selectivity and reaction time using the catalysts provided in Example 1 and Comparative Examples 1-3 under the conditions of Example 6.

[0021] Figures 6 to 8 , is the TPD curve of the gold-based catalyst provided in Examples 1 to 4 for the reactants hydrogen chloride, acetylene and the reaction product vinyl chloride DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0023] First, the present embodiment provides a gold-based catalyst for catalyzing the hydrochlorination of acetylene and a preparation method thereof. The catalyst uses coal-based columnar carbon as a carrier, different types of gold precursors as the main active components, and compounds containing the same heteroatoms (N, O, S, P) as additives. The preparation method is as follows: first, two components of the carrier, the gold precursor, and the stabilizer are evenly mixed, and then a third component is added, and then simply impregnated and dried to obtain a gold-based catalyst. The present embodiment proposes a method for uniformly loading a gold complex on a coal-based columnar carbon carrier, and using it for the hydrochlorination of acetylene. The active components in the gold-based catalyst of this embodiment are highly dispersed, which greatly improves the catalytic activity and stability of existing metal catalysts.

[0024] The selected auxiliary agent is at least one of phenylphosphonyl dichloride, nitrosobenzene, methylphenyl sulfoxide, and acetophenone; preferably, the auxiliary agent is nitrosobenzene.

[0025] The gold precursors are AuCl3, HAuCl4, (NH4)AuCl4, C 16 H 36 At least one of AuCl2N; preferably, the gold precursor is HAuCl4.

[0026] The preparation method of the gold-based catalyst provided in this embodiment is as follows:

[0027] Method 1: First, add the coal-based columnar activated carbon (CAC) carrier to the prepared gold precursor solution and mix evenly; optionally, stirring and mixing are carried out at room temperature for 2 to 10 hours. Then, add the auxiliary agent solution to the above mixture; optionally, stirring and mixing are carried out at room temperature for 6 to 10 hours. The gold-based catalyst is obtained by impregnation and drying; the impregnation temperature is 25 to 100°C and the impregnation time is 2 to 24 hours. Preferably, the impregnation temperature is 50 to 80°C and the impregnation time is 4 to 12 hours. The drying temperature is 100 to 120°C and the drying time is 10 to 12 hours.

[0028] Method 2: First, slowly dropwise add the additive solution to the prepared gold precursor solution for mixing reaction; optionally, stirring and mixing are carried out at room temperature for 2 to 10 hours. Then, add the coal-based columnar activated carbon (CAC) carrier to the above-mentioned mixed solution; optionally, stirring and mixing are carried out at room temperature for 6 to 10 hours. The gold-based catalyst is obtained by impregnation and drying. The impregnation temperature is 25 to 100°C and the impregnation time is 2 to 24 hours. Preferably, the impregnation temperature is 50 to 80°C and the impregnation time is 4 to 12 hours. The drying temperature is 100 to 120°C and the drying time is 10 to 12 hours.

[0029] Furthermore, based on the total weight of the catalyst, the loading amount of Au is 0.05-0.4 wt%, preferably 0.05-0.2 wt%.

[0030] The total weight of the catalyst is calculated as follows: m 总 =m 载体 +m 金前驱体 +m 助剂 .

[0031] In the formula, the calculation method of gold element loading is: m Au / (m 载体 +m 金前驱体 +m 助剂 );m Au is the mass of gold element;

[0032] The molar ratio of the metal precursor to the stabilizer is 1:0.1-5. Preferably, the molar ratio of the metal precursor to the ligand is 1:0.5-2.

[0033] This embodiment provides a gold-based catalyst; the gold precursor and the auxiliary agent form an insoluble complex; after sufficient stirring and impregnation, the insoluble complex is evenly distributed on the carrier. Figure 1 As shown in the transmission electron microscope (TEM) image, the active components of the catalyst appear as dots and are evenly distributed in the catalyst. The bright spots are the active components.

[0034] The method provided in this embodiment also includes pre-treating coal-based activated carbon (CAC) before preparing the catalyst: Method 1: Activated carbon (CAC) is used as a carrier. After purchase, it is pre-treated before use. The prepared 1 mol / L hydrochloric acid and 40-60 mesh coal-based activated carbon are refluxed and stirred at 70°C for 6 hours, washed with deionized water until neutral, and then dried in a 120°C oven for 12 hours. Method 2: Pre-treat the coal-based columnar activated carbon (CAC). First, it is acid-washed with an acid solution (0.01-0.1 mol / L), dried at 140°C, and the acid used is one of hydrochloric acid, nitric acid, and phosphoric acid, or a mixture of the two. Then, it is modified with potassium salt and / or copper salt, and dried at 120 degrees Celsius. The potassium salt used is one of potassium chloride, potassium bromide, potassium sulfide, and potassium azide; the copper salt is one of copper chloride, cuprous chloride, copper nitrate, and copper sulfate. Preferably, method 2 is used for treatment.

[0035] Next, this embodiment provides a method for preparing vinyl chloride by hydrochlorinating acetylene using the gold-based catalyst. The method comprises mixing acetylene with hydrogen chloride to produce vinyl chloride, wherein the reaction is carried out under the catalysis of the gold-based catalyst.

[0036] The reaction is a gas phase reaction.

[0037] The main reactions involved in the acetylene hydrochlorination process include:

[0038] Main reaction: C2H2+HCl→CH2=CHCl

[0039] Non-polymerization side reactions:

[0040] CH2=CHCl+HCl→CH3CHCl2

[0041] CH2=CHCl+HCl→CH2ClCH2Cl

[0042] Polymerization side reactions:

[0043] 2CH2=CHCl→CH2ClCH=CCl-CH3

[0044] 2C2H2→CH2=CH-C≡CH

[0045] Existing thermodynamic studies have shown that the above-mentioned main reaction is greatly affected by the polymerization side reaction, and the non-polymerization side reaction has little effect on the main reaction. The above-mentioned main and side reactions are all exothermic reactions, but the thermal effect of the polymerization side reaction is greater than that of the main reaction. Higher temperatures are more conducive to inhibiting the polymerization side reaction (polymerization products may be deposited on the catalyst surface to form carbon deposits), improving the selectivity of the main reaction and reducing carbon deposits. However, at high temperatures, metal catalysts have the problem of valence deactivation. After comprehensively considering the effect of temperature on polymerization side reactions and catalyst reduction deactivation, the reaction temperature is controlled at 110 to 300 ° C, more preferably, the reaction temperature is controlled at 140 to 280 ° C, and most preferably, the reaction temperature is controlled at 180 to 260 ° C.

[0046] The volume ratio of acetylene to hydrogen chloride adopts the commonly used volume ratio in this field, specifically 1:1-2, more preferably, the volume ratio of acetylene to hydrogen chloride is 1:1-1.5, and most preferably, the volume ratio of acetylene to hydrogen chloride is 1:1.02-1.2.

[0047] The gas phase reaction is carried out in a fixed bed reactor, and the catalyst is loaded in the fixed bed reactor. The acetylene space velocity control range adopts the control range commonly used in this field, specifically 30 to 1000 h -1 Preferably, the acetylene space velocity is controlled at 30 to 180 h -1 .

[0048] The present invention provides the use of a gold-based catalyst as a catalyst in an acetylene hydrochlorination reaction; the acetylene hydrochlorination reaction is the reaction of acetylene with hydrogen chloride to generate vinyl chloride.

[0049] The reaction is a gas phase reaction, and the reaction temperature is 110-300°C.

[0050] Examples 1 to 4 and Comparative Examples 1 to 3 provide methods for preparing gold-based catalysts using different raw materials or different ratios, and the specific conditions are as follows:

[0051] Example 1

[0052] The preparation method of the gold-based catalyst for catalyzing the acetylene hydrochlorination reaction is as follows:

[0053] In a 50-mL beaker, 0.0173 g of HAuCl₄ was dissolved in 15 mL of isopropanol. 9.9746 g of coal-based columnar activated carbon (CAC) was added and stirred for 2 hours. Then, 15 mL of a prepared isopropanol solution of 0.0082 g of nitrosobenzene was slowly added dropwise to the mixture, and stirring continued for 2 hours. The beaker was sealed with plastic wrap and allowed to stand at 60°C for 6 hours. The solvent was then slowly dried by puncturing the beaker, and the mixture was then dried at 120°C for 12 hours. The resulting catalyst was named Au1-L1 / CAC.

[0054] Example 2

[0055] The preparation method of the gold-based catalyst for catalyzing the acetylene hydrochlorination reaction is as follows:

[0056] In a 50mL beaker, 0.0173g of HAuCl4 was dissolved in 15mL of isopropanol. 9.9679g of coal-based columnar activated carbon (CAC) was added and stirred for 2 hours. Then, 15mL of a prepared isopropanol solution of phenylphosphonyl dichloride (0.0148g) was slowly added dropwise to the mixture, and stirring continued for 2 hours. The beaker was sealed with plastic wrap and allowed to stand at 60°C for 6 hours. The solvent was then slowly dried by puncturing the beaker, and the mixture was then dried at 120°C for 12 hours. The resulting catalyst was named Au1-L2 / CAC.

[0057] Example 3

[0058] The preparation method of the gold-based catalyst for catalyzing the acetylene hydrochlorination reaction is as follows:

[0059] In a 50 mL beaker, 0.0173 g of HAuCl₄ was dissolved in 15 mL of isopropanol. 9.9721 g of coal-based columnar activated carbon (CAC) was added and stirred for 2 hours. Then, 15 mL of a prepared isopropanol solution of methyl phenyl sulfoxide (0.0107 g) was slowly added dropwise to the mixture and stirred for another 2 hours. The beaker was sealed with plastic wrap and allowed to stand at 60°C for 6 hours. The solvent was then slowly dried by puncturing the beaker and then dried at 120°C for 12 hours. The resulting catalyst was named Au1-L3 / CAC.

[0060] Example 4

[0061] The preparation method of the gold-based catalyst for catalyzing the acetylene hydrochlorination reaction is as follows:

[0062] In a 50 mL beaker, 0.0173 g of HAuCl₄ was dissolved in 15 mL of isopropanol. 9.9736 g of coal-based columnar activated carbon (CAC) was added and stirred for 2 hours. Then, 15 mL of acetophenone (0.0091 g) in isopropanol was slowly added dropwise to the mixture and stirring continued for 2 hours. The beaker was sealed with plastic wrap and allowed to stand at 60°C for 6 hours. The solvent was then slowly dried by puncturing the beaker, and the mixture was then dried at 120°C for 12 hours. The resulting catalyst was named Au1-L₄ / CAC.

[0063] Comparative Example 1

[0064] The preparation method of the gold-based catalyst for catalyzing the acetylene hydrochlorination reaction is as follows:

[0065] In a 50-mL beaker, 0.0173 g of HAuCl₄ was dissolved in 15 mL of isopropanol. 9.9827 g of coal-based columnar activated carbon (CAC) was added and stirred for 2 hours. The beaker was then sealed with plastic wrap and incubated at 60°C for 6 hours. The solvent was then slowly dried by puncturing the beaker, and the mixture was then dried at 120°C for 12 hours. The resulting catalyst was designated Au₁ / CAC.

[0066] Comparative Example 2

[0067] The preparation method of the gold-based catalyst for catalyzing the acetylene hydrochlorination reaction is as follows:

[0068] In a 50mL beaker, 0.0345g of HAuCl4 was dissolved in 15mL of isopropanol. 9.9492g of coal-based columnar activated carbon (CAC) was added and stirred for 2 hours. Then, 15mL of a prepared isopropanol solution of nitrosobenzene (0.0163g) was slowly added dropwise to the mixture and stirring continued for 2 hours. The beaker was sealed with plastic wrap and allowed to stand at 60°C for 6 hours. The solvent was then slowly dried by puncturing the beaker, and the mixture was then dried at 120°C for 12 hours. The resulting catalyst was named Au2-L1 / CAC.

[0069] Comparative Example 3

[0070] The preparation method of the gold-based catalyst for catalyzing the acetylene hydrochlorination reaction is as follows:

[0071] In a 50mL beaker, 0.0690g of HAuCl4 was dissolved in 15mL of isopropanol. 9.8984g of coal-based columnar activated carbon (CAC) was added and stirred for 2 hours. Then, 15mL of a prepared isopropanol solution of 0.0326g of nitrosobenzene was slowly added dropwise to the mixture and stirring continued for 2 hours. The beaker was sealed with plastic wrap and allowed to stand at 60°C for 6 hours. The solvent was then slowly dried by puncturing the beaker and then dried at 120°C for 12 hours. The resulting catalyst was named Au4-L1 / CAC.

[0072] In order to verify the effect of adding different additives on the catalyst, Example 5 provides verification methods for different catalysts:

[0073] Example 5

[0074] 5 mL of each catalyst prepared in Examples 1-4 and Comparative Example 1 was loaded into a fixed-bed reactor. Acetylene and hydrogen chloride reactant gases were introduced at 180°C, an acetylene hourly space velocity (GHSV) of 90 h⁻¹, and an acetylene:hydrogen chloride volume ratio of 1:1.15. The reaction was carried out for 24 hours. The acetylene conversion and vinyl chloride selectivity were then measured. Coal-based columnar activated carbon (CAC) was used as a blank control.

[0075] In order to verify the effect of the amount of nitrosobenzene added on the catalytic efficiency, Example 6 provides a verification method:

[0076] Example 6

[0077] 5 mL of each catalyst prepared in Example 1 and Comparative Examples 1-3 was loaded into a fixed-bed reactor. Acetylene and hydrogen chloride reactant gases were introduced at 200°C, an acetylene hourly space velocity (GHSV) of 90 h⁻¹, and an acetylene:hydrogen chloride volume ratio of 1:1.15. The reaction was carried out for 24 hours. The acetylene conversion and vinyl chloride selectivity were measured. Coal-based columnar activated carbon (CAC) was used as a blank control.

[0078] Table 1 Conversion and selectivity of acetylene hydrochlorination catalyzed by different catalysts

[0079]

[0080]

[0081] From the catalytic test results of the above catalyst for acetylene hydrochlorination reaction, it can be seen that the stability of the catalyst is significantly improved after adding the additive.

[0082] By comparison, it can be concluded that the active components of the catalyst prepared by the method of Example 1 are evenly dispersed on the carrier, exposing more active sites to enhance the adsorption capacity of the reactants hydrogen chloride and acetylene, thereby improving the catalytic activity and stability of the catalyst.

[0083] Figure 2 The figure shows the relationship between acetylene conversion and reaction time when the catalysts provided in Examples 1 to 4 and Comparative Example 1 are used under the conditions of Example 5. As can be seen from the figure, the catalyst with the addition of gold precursor and additive has a higher acetylene conversion rate.

[0084] Figure 3The relationship between vinyl chloride selectivity and reaction time is shown in the figure using the catalysts provided in Examples 1 to 4 and Comparative Example 1 under the conditions of Example 5. As can be seen from the figure, the vinyl chloride selectivity of the gold-based catalyst reaches more than 90%.

[0085] Figure 4 This is a graph showing the relationship between acetylene conversion and reaction time using the catalysts provided in Example 1 and Comparative Examples 1-3 under the conditions of Example 6. It can be seen from the graph that the catalyst with the additive has a higher acetylene conversion rate; and the gold precursor loading has little to do with the acetylene conversion rate.

[0086] Figure 5 The relationship between vinyl chloride selectivity and reaction time is shown in the figure using the catalysts provided in Example 1 and Comparative Examples 1-3 under the conditions of Example 6. It can be seen from the figure that the loading of the gold precursor is not highly correlated with the selectivity of vinyl chloride.

[0087] Figures 6 to 8 , are the TPD curves of the gold-based catalysts provided in Examples 1-4 for the reactants hydrogen chloride and acetylene, and the reaction product vinyl chloride. It can be seen that the catalyst has a strong adsorption capacity for the reactants hydrogen chloride and acetylene, which is beneficial for improving the activity and stability of the catalyst.

[0088] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A method for preparing a gold-based catalyst, characterized in that: The catalyst is used to catalyze the acetylene hydrochlorination reaction; the raw materials prepared by the preparation method include a carrier, a gold precursor and an auxiliary agent; and the preparation method includes the following steps: Step 1: Prepare the solution, dissolve the gold precursor and the auxiliary agent in the solvent respectively; the solvent is an alcohol solvent; the carrier is coal-based columnar activated carbon; the gold precursor is AuCl3, HAuCl4, (NH4)AuCl4, C 16 H 36 At least one of AuCl2N; the auxiliary agent is nitrosobenzene; the molar ratio of the gold precursor to the auxiliary agent is 1:1~15; Step 2: Stirring and mixing: mixing the gold precursor solution with the carrier and stirring, then dropping the auxiliary solution into the mixture to form a mixture, or dropping the gold precursor solution into the auxiliary solution and mixing, then adding the carrier and stirring to form a mixture; Step 3: impregnation and drying: impregnate the mixture at 50-150° C. for 6-12 hours, then dry it, and finally dry it at 100-120° C. for 12 hours to obtain a gold-based catalyst.

2. The method for preparing a gold-based catalyst according to claim 1, wherein The raw materials are proportioned as follows: The gold element loading amount is 0.05-0.4 wt %; the molar ratio of the gold precursor to the auxiliary agent is 1:1-15; and the remainder is the carrier.

3. The method for preparing a gold-based catalyst according to claim 2, wherein: The gold element loading is 0.05-0.2 wt %; the molar ratio of the gold precursor to the auxiliary agent is 1:5-10.

4. The method for preparing a gold-based catalyst according to claim 3, wherein: The carrier has a particle size of 1.5 to 5 mm.

5. A gold-based catalyst, characterized in that: The gold-based catalyst is prepared by the preparation method of any one of claims 1 to 4.

6. Use of a gold-based catalyst as claimed in claim 5 in the preparation of vinyl chloride by acetylene hydrochlorination.

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