A preparation method of a gold catalyst, a gold catalyst and application thereof

Abstract

This invention discloses a pretreatment method for preparing a gold catalyst, the gold catalyst itself, and its applications, belonging to the field of catalyst preparation and application technology. The invention firstly involves preparing a catalyst impregnation solution with gold as the active component and titanium-silicon molecular sieves as the carrier through impregnation. Then, a two-stage freeze-vacuum drying process is used to remove moisture from the catalyst impregnation solution, preventing the migration, reduction, aggregation, and growth of gold species on the catalyst surface under high-temperature air drying conditions. Secondly, a mixture of hydrogen and hydrogen chloride is used to activate the catalyst. Hydrogen primarily serves to transfer heat and inhibit the aggregation and growth of gold particles, while hydrogen chloride primarily activates the gold to its oxidized state. Compared to catalysts obtained through traditional high-temperature drying pretreatment, the catalyst prepared by combining freeze-vacuum drying and two-component gas activation exhibits smaller gold particle sizes and superior activity and stability in the acetylene hydrochlorination reaction to synthesize vinyl chloride.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation and application technology, specifically relating to a pretreatment preparation method for a gold catalyst, the gold catalyst prepared by the pretreatment preparation method, and the application of the gold catalyst in the synthesis of vinyl chloride by the acetylene process. Background Technology

[0002] Polyvinyl chloride (PVC) is one of the world's five most widely used resin materials. The increasing demand for PVC in recent years has also led to a rapid increase in the demand for its synthetic monomer, vinyl chloride. Given my country's abundant coal and scarce oil resources, Chinese chemical companies mainly use the acetylene process to synthesize vinyl chloride. The acetylene process uses acetylene and hydrogen chloride as raw materials and mercuric chloride as a catalyst. The volatile mercury can cause significant harm to the ecological environment and workers. Therefore, research on non-mercury catalysts has been a key focus for many research institutes and enterprises.

[0003] Gold-based non-mercury catalysts (referred to as gold catalysts) have shown superior activity and stability in the acetylene hydrochlorination reaction, making them one of the most promising alternatives to mercury catalysts. Gold catalysts are generally prepared using an impregnation method. The impregnation solution is typically dried at high temperature to remove moisture, and then activated sequentially by nitrogen and hydrogen chloride before being applied to the acetylene hydrochlorination reaction (Green Chemistry, 2015, 17(1), 356-364). Numerous studies have confirmed that oxidized gold particles are the main active sites of gold catalysts. However, oxidized gold particles are extremely unstable at high temperatures, easily reduced to elemental metals, and migrate and aggregate to form larger, less active gold particles. Therefore, gold catalysts prepared using traditional pretreatment methods exhibit low activity and low stability in the acetylene hydrochlorination reaction (JACS, 2015, 137, 14548-14557).

[0004] To improve the activity and stability of gold catalysts, developing an efficient pretreatment method to suppress the reduction and aggregation of gold particles on the catalyst and improve the dispersion of gold particles is of great research significance for increasing the synthesis rate of vinyl chloride. Summary of the Invention

[0005] The purpose of this invention is to address the adverse effects of traditional high-temperature drying methods on catalyst activity, and to provide a pretreatment preparation method for a gold catalyst, the gold catalyst prepared by this pretreatment method, and the application of the gold catalyst in the acetylene synthesis of vinyl chloride. This pretreatment preparation method can improve the catalyst activity and stability.

[0006] The catalyst of this invention uses a porous titanium-silicon molecular sieve as a carrier and gold as the main active component. The catalyst impregnation solution is obtained by impregnation method. The preparation process is as follows: First, 1g of HAuCl4·4H2O is dissolved in a pure aqueous solution to prepare a chloroauric acid solution of 5g / L~15g / L; then, 4mL~8mL of the above chloroauric acid solution is mixed with 5g of titanium-silicon molecular sieve and 5mL~15mL of pure water, and impregnated in a water bath at 30℃~40℃ for 4h~8h to obtain the catalyst impregnation solution.

[0007] The pretreatment preparation method for a gold catalyst according to the present invention comprises the following steps:

[0008] (1) The catalyst impregnation solution is freeze-vacuum dried. The drying process is divided into two stages. In the first stage, the temperature is lowered to -10℃~-20℃ and the vacuum degree is 30Pa~50Pa, and it is maintained for 8h~12h. In the second stage, the temperature is lowered to -20℃~-30℃ and the vacuum degree is 10Pa~30Pa, and it is maintained for 10h~14h to obtain the catalyst with the moisture removed. This step is carried out using Lichen freeze-vacuum dryer.

[0009] (2) The catalyst with water removed in step (1) is placed in a quartz reaction tube and a mixture of hydrogen and hydrogen chloride is introduced to activate the catalyst. The volume of the mixture is calculated as 100%, and the volume content of hydrogen is 0.1%~0.5%, preferably 0.3%. The total gas flow rate is 10mL / min~20mL / min, preferably 15mL / min. The temperature is increased from 25℃ to 180℃ at a rate of 1℃~3℃ and then kept at the temperature for 1h~3h to obtain the pretreated gold catalyst. Then, the acetylene hydrochlorination reaction is carried out.

[0010] The pretreatment method of the gold catalyst in this invention has two characteristics: First, it uses a freeze-vacuum drying method to remove moisture from the catalyst impregnation solution in two stages, avoiding the movement, reduction, aggregation, and growth of gold species on the catalyst surface under high-temperature air drying conditions; second, it uses a mixture of hydrogen and hydrogen chloride to activate the catalyst. Hydrogen mainly plays the role of heat transfer and inhibiting the aggregation and growth of gold particles, while hydrogen chloride mainly plays the role of activating gold to the oxidized state. Compared with the catalyst obtained by traditional high-temperature drying pretreatment, the gold catalyst prepared by combining freeze-vacuum drying and two-component gas activation has smaller gold particle size and exhibits superior activity and stability in the acetylene hydrochlorination to vinyl chloride synthesis reaction.

[0011] The titanium-silicon molecular sieve described in this invention has a porous structure and a specific surface area greater than 800 m². 2 / g, silicate materials containing titanium atoms in the framework, namely one or more of TS-1, Ti-MWW, and Ti-TUD. The specific surface area of ​​the titanium-silicon molecular sieve was measured using a Micromeritics ASAP 2020 physical adsorption instrument (USA), and the size of gold particles on the catalyst surface was measured using a JET-ARM200F electron microscope (Japan).

[0012] The reaction process for the synthesis of vinyl chloride by acetylene hydrochlorination is as follows: After the catalyst is pretreated as described above, acetylene and hydrogen chloride gases are introduced into a quartz reaction tube at a volume ratio of 1:1.1. The reaction temperature is 180℃, the pressure is 0.1 MPa, and the acetylene space velocity is 800 mL g⁻¹ cat h. -1 The gaseous products after the reaction were analyzed by Agilent 8890 gas chromatograph after the remaining hydrogen chloride was absorbed by sodium hydroxide solution.

[0013] The process of synthesizing vinyl chloride by acetylene hydrochlorination adopts an open-type resistance furnace, which is well-known and commonly used in this field, and uses a quartz reaction tube with an outer diameter of 14 mm and an inner diameter of 12 mm as the reactor.

[0014] The beneficial effects of the present invention include, but are not limited to, the following aspects:

[0015] The catalyst pretreatment preparation method used in this invention avoids the traditional air heat treatment process, and the gold particles on the catalyst have good dispersion and small size;

[0016] Compared with catalysts obtained by traditional air-heat drying, the catalysts pretreated in this invention exhibit better activity in the acetylene hydrochlorination reaction.

[0017] Compared with catalysts obtained by traditional air-heat drying methods, the catalyst developed in this invention exhibits better stability in the acetylene hydrochlorination reaction. Attached Figure Description

[0018] Figure 1 The figures (a) show the gold particle size distribution curve on the catalyst prepared by conventional heat treatment in Comparative Example 1 of this invention, and the activity data curve (b) shows the catalyst in the acetylene hydrochlorination reaction.

[0019] Figure 2 The figures (a) show the gold particle size distribution curve on the catalyst prepared by conventional heat treatment in Comparative Example 2 of this invention, and the activity data curve (b) shows the catalyst in the acetylene hydrochlorination reaction.

[0020] Figure 3 The gold particle size distribution curve (a) and the activity data curve (b) of the catalyst in the acetylene hydrochlorination reaction prepared by freeze-vacuum drying and two-component gas activation in Example 1 of the present invention are shown.

[0021] Figure 4 The gold particle size distribution curve (a) and the activity data curve (b) of the catalyst in the acetylene hydrochlorination reaction are shown in Example 2 of this invention.

[0022] Figure 5 The gold particle size distribution curve (a) and the activity data curve (b) of the catalyst in the acetylene hydrochlorination reaction are shown in Example 3 of this invention.

[0023] Figure 6 The gold particle size distribution curve (a) and the activity data curve (b) of the catalyst in the acetylene hydrochlorination reaction are shown in Example 4 of this invention.

[0024] Figure 7 The figures (a) show the gold particle size distribution curve on the catalyst prepared by freeze-drying and two-component gas activation in Example 5 of this invention, and the activity data curve (b) shows the catalyst in the acetylene hydrochlorination reaction. Detailed Implementation

[0025] The present invention will be further described below through specific embodiments and comparative examples, but the scope of protection of the present invention is not limited to the scope of the embodiments.

[0026] The chemical reagents used in the examples and comparative examples were all commercially available pharmaceuticals with analytical purity; the gases used were all commercially available high-purity, clean gases; and the water used was commercially available Wahaha bottled purified water.

[0027] In the comparative example, the catalyst impregnation liquid was dried using a traditional thermal drying method, and the dried sample was then tested for acetylene hydrochlorination performance. In the example, the catalyst impregnation liquid was first dried using a two-stage freeze-vacuum drying method, and then the catalyst was pretreated using a two-component gas activation method of hydrogen and hydrogen chloride, and then the catalyst was tested for acetylene hydrochlorination performance.

[0028] Comparative Example 1:

[0029] This comparative example illustrates the testing results of catalysts prepared by conventional heat treatment in the acetylene hydrochlorination reaction.

[0030] The catalyst preparation method and pretreatment method used in this comparative example are well-known and commonly used methods, and the process is as follows:

[0031] Dissolve 1g of HAuCl4·4H2O in a pure aqueous solution to prepare a 10g / L chloroauric acid solution. Take 7.2mL of the chloroauric acid solution and mix it with 5g of titanium silicate molecular sieve TS-1 (specific surface area 837m²). 2A mixture of (g) of catalyst powder and 10 mL of purified water was prepared and impregnated in a 35°C water bath for 4 hours to obtain a catalyst impregnation solution. The impregnation solution was then dried in a forced-air drying oven at 120°C for 10 hours. Approximately 1 g of the dried catalyst powder was placed in a quartz reaction tube, and high-purity nitrogen gas (flow rate 20 mL / min) was introduced, raising the temperature from 25°C to 120°C at a rate of 2°C / min, and holding the temperature for 1 hour. Subsequently, HCl gas (flow rate 20 mL / min) was introduced, raising the temperature to 180°C at a rate of 2°C / min, and holding the temperature for 1 hour to obtain approximately 1 g of pretreated catalyst. After catalyst pretreatment, high-purity hydrogen chloride and acetylene gas were introduced into the quartz reaction tube to carry out the acetylene hydrochlorination reaction. The gaseous products after the reaction were collected and analyzed by gas chromatography.

[0032] Test data such as Figure 1 As shown, the average size of the gold particles on the catalyst is 4.5 nm, and a 56% acetylene conversion rate is achieved in the acetylene hydrochlorination reaction after 2 h. After 10 h of reaction, the acetylene conversion rate drops to 55%, and the catalyst deactivation rate is 15%.

[0033] Comparative Example 2:

[0034] This comparative example illustrates the testing results of catalysts prepared by conventional heat treatment in the acetylene hydrochlorination reaction.

[0035] The catalyst preparation method and pretreatment method used in this comparative example are well-known and commonly used methods, and the process is as follows:

[0036] Dissolve 1g of HAuCl4·4H2O in a pure aqueous solution to prepare a 5g / L chloroauric acid solution. Take 4.6mL of the chloroauric acid solution and mix it with 5g of titanium silicate molecular sieve Ti-MWW (specific surface area 807m²). 2 The catalyst powder (g) was mixed with 15 mL of purified water and impregnated in a 40°C water bath for 8 hours to obtain a catalyst impregnation solution. The impregnation solution was then dried in a forced-air drying oven at 110°C for 12 hours. Approximately 1 g of the dried catalyst powder was placed in a quartz reaction tube, and high-purity nitrogen gas (flow rate 20 mL / min) was introduced, raising the temperature from 25°C to 120°C at a rate of 2°C / min, and holding the temperature for 1 hour. Subsequently, high-purity HCl gas (flow rate 20 mL / min) was introduced, raising the temperature to 180°C at a rate of 2°C / min, and holding the temperature for 1 hour to obtain approximately 1 g of pretreated catalyst. After catalyst pretreatment, high-purity hydrogen chloride and acetylene gas were introduced into the quartz reaction tube to carry out the acetylene hydrochlorination reaction. The gaseous products after the reaction were collected and analyzed by gas chromatography.

[0037] Test data such as Figure 2 As shown, the average size of the gold particles on the catalyst is 4.3 nm, and a 66% acetylene conversion rate is achieved in the acetylene hydrochlorination reaction after 2 h. After 10 h of reaction, the acetylene conversion rate drops to 54%, and the catalyst deactivation rate is 18%. Example

[0038] This embodiment illustrates the freeze-vacuum drying and two-component gas pretreatment process of the catalyst, as well as the testing of the catalyst in the acetylene hydrochlorination reaction. The specific process is as follows:

[0039] Dissolve 1g of HAuCl4·4H2O in a pure aqueous solution to prepare a 10g / L chloroauric acid solution. Take 7.2mL of the chloroauric acid solution and mix it with 5g of titanium silicate molecular sieve TS-1 (specific surface area 837m²). 2 A mixture of (g) of powder and 10 mL of purified water was prepared and impregnated in a 35°C water bath for 4 hours to obtain a catalyst impregnation solution. The catalyst impregnation solution was then placed in a sample vial and placed in a freeze dryer. The first stage involved cooling to -10°C and maintaining a vacuum of 35 Pa for 12 hours. The second stage involved cooling to -30°C and maintaining a vacuum of 30 Pa for 12 hours to obtain a dehydrated catalyst. 1 g of the dehydrated catalyst was placed in a quartz reaction tube, and a mixture of hydrogen and hydrogen chloride gas was introduced. The volume of the mixture was calculated as 100%, with a hydrogen volume content of 0.5% and a total gas flow rate of 16 mL / min. The temperature was increased from 25°C to 180°C at a rate of 2°C and held for 1 hour to obtain approximately 1 g of pretreated catalyst. After catalyst pretreatment, hydrogen chloride and acetylene gas were introduced into the quartz reaction tube to conduct an acetylene hydrochlorination reaction. The gaseous products after the reaction were collected and analyzed by gas chromatography.

[0040] Test data such as Figure 3 As shown, the average size of the gold particles on the catalyst is 2.3 nm, and a 78% acetylene conversion rate is achieved in the acetylene hydrochlorination reaction after 2 h. After 10 h of reaction, the acetylene conversion rate drops to 72%, and the catalyst deactivation rate is 7.6%.

[0041] Compared with Comparative Examples 1 and 2, the catalyst in this example has a smaller average size of gold particles, and the catalyst exhibits better activity and stability and a lower deactivation rate in the acetylene hydrochlorination reaction. Example

[0042] This embodiment illustrates the freeze-vacuum drying and two-component gas pretreatment process of the catalyst, as well as the testing of the catalyst in the acetylene hydrochlorination reaction. The specific process is as follows:

[0043] Dissolve 1g of HAuCl4·4H2O in a pure aqueous solution to prepare an 8g / L chloroauric acid solution. Take 5.6mL of the chloroauric acid solution and mix it with 5g of titanium silicate molecular sieve TS-1 (specific surface area 837m²). 2A mixture of (g) of powder and 10 mL of purified water was prepared and impregnated in a 38°C water bath for 5 hours to obtain a catalyst impregnation solution. The catalyst impregnation solution was then placed in a sample vial and placed in a freeze dryer. The first stage involved cooling to -16°C and maintaining a vacuum of 45 Pa for 9 hours. The second stage involved cooling to -28°C and maintaining a vacuum of 15 Pa for 11 hours to obtain a dehydrated catalyst. 1 g of the dehydrated catalyst was placed in a quartz reaction tube, and a mixture of hydrogen and hydrogen chloride gas was introduced. The volume of the mixture was calculated as 100%, with a hydrogen volume content of 0.1% and a total gas flow rate of 10 mL / min. The temperature was increased from 25°C to 180°C at a rate of 2°C and held for 1 hour to obtain approximately 1 g of pretreated catalyst. After catalyst pretreatment, hydrogen chloride and acetylene gas were introduced into the quartz reaction tube to carry out the acetylene hydrochlorination reaction. The gaseous products after the reaction were collected and analyzed by gas chromatography.

[0044] Test data such as Figure 4 As shown, the average size of the gold particles on the catalyst is 2.6 nm, and a 74% acetylene conversion rate is achieved in the acetylene hydrochlorination reaction after 2 h. After 10 h of reaction, the acetylene conversion rate drops to 67%, and the catalyst deactivation rate is 9.4%.

[0045] Compared with Comparative Examples 1 and 2, the catalyst in this example has a smaller average size of gold particles, and the catalyst exhibits better activity and stability and a lower deactivation rate in the acetylene hydrochlorination reaction. Example

[0046] This embodiment illustrates the freeze-vacuum drying and two-component gas pretreatment process of the catalyst, as well as the testing of the catalyst in the acetylene hydrochlorination reaction. The specific process is as follows:

[0047] Dissolve 1g of HAuCl4·4H2O in a pure aqueous solution to prepare a 5g / L chloroauric acid solution. Take 4.6mL of the chloroauric acid solution and mix it with 5g of titanium silicate molecular sieve Ti-MWW (specific surface area 807m²). 2 A mixture of (g) of powder and 15 mL of purified water was prepared and impregnated in a 40°C water bath for 8 hours to obtain a catalyst impregnation solution. The catalyst impregnation solution was then placed in a sample vial and placed in a freeze dryer. The first stage involved cooling to -20°C and maintaining a vacuum of 50 Pa for 8 hours; the second stage involved cooling to -24°C and maintaining a vacuum of 10 Pa for 14 hours to obtain a catalyst with removed moisture. 1 g of the catalyst was placed in a quartz reaction tube, and a mixture of hydrogen and hydrogen chloride gas was introduced. Assuming the total volume of the mixture is 100%, the hydrogen volume content was 0.2%, and the total gas flow rate was 14 mL / min. The temperature was increased from 25°C to 180°C at a rate of 2°C and held for 1 hour to obtain approximately 1 g of pretreated catalyst. After catalyst pretreatment, hydrogen chloride and acetylene gas were introduced into the quartz reaction tube to carry out the acetylene hydrochlorination reaction. The gaseous products after the reaction were collected and analyzed by gas chromatography.

[0048] Test data such as Figure 5 As shown, the average size of the gold particles on the catalyst is 2.1 nm, and an acetylene conversion rate of 80% is achieved after 2 h of reaction in acetylene hydrochlorination. After 10 h of reaction, the acetylene conversion rate drops to 74%, and the catalyst deactivation rate is 7.5%.

[0049] Compared with Comparative Examples 1 and 2, the catalyst in this example has a smaller average size of gold particles, and the catalyst exhibits better activity and stability and a lower deactivation rate in the acetylene hydrochlorination reaction. Example

[0050] This embodiment illustrates the freeze-vacuum drying and two-component gas pretreatment process of the catalyst, as well as the testing of the catalyst in the acetylene hydrochlorination reaction. The specific process is as follows:

[0051] Dissolve 1g of HAuCl4·4H2O in a pure aqueous solution to prepare a 12g / L chloroauric acid solution. Take 7.6mL of the chloroauric acid solution and mix it with 5g of titanium-silicon molecular sieve Ti-TUD (specific surface area 975m²). 2 A mixture of (g) of powder and 12 mL of purified water was prepared and impregnated in a 36°C water bath for 7 hours to obtain a catalyst impregnation solution. The catalyst impregnation solution was then placed in a sample vial and placed in a freeze dryer. The first stage involved cooling to -18°C and maintaining a vacuum of 36 Pa for 11 hours; the second stage involved cooling to -26°C and maintaining a vacuum of 16 Pa for 13 hours to obtain a catalyst with removed moisture. 1 g of the catalyst was placed in a quartz reaction tube, and a mixture of hydrogen and hydrogen chloride gas was introduced. Assuming the total volume of the mixture is 100%, the hydrogen volume content was 0.3%, and the total gas flow rate was 14 mL / min. The temperature was increased from 25°C to 180°C at a rate of 2°C and held for 1 hour to obtain approximately 1 g of pretreated catalyst. After catalyst pretreatment, hydrogen chloride and acetylene gas were introduced into the quartz reaction tube to carry out the acetylene hydrochlorination reaction. The gaseous products after the reaction were collected and analyzed by gas chromatography.

[0052] Test data such as Figure 6 As shown, the average size of the gold particles on the catalyst is 2.8 nm, and a 73% acetylene conversion rate is achieved in the acetylene hydrochlorination reaction after 2 h. After 10 h of reaction, the acetylene conversion rate drops to 66%, and the catalyst deactivation rate is 9.6%.

[0053] Compared with Comparative Examples 1 and 2, the catalyst in this example has a smaller average size of gold particles, and the catalyst exhibits better activity and stability and a lower deactivation rate in the acetylene hydrochlorination reaction. Example

[0054] This embodiment illustrates the freeze-vacuum drying and two-component gas pretreatment process of the catalyst, as well as the testing of the catalyst in the acetylene hydrochlorination reaction. The specific process is as follows:

[0055] Dissolve 1g of HAuCl4·4H2O in a pure aqueous solution to prepare a 10g / L chloroauric acid solution. Take 7.2mL of the chloroauric acid solution and mix it with 5g of titanium silicate molecular sieve TS-1 (specific surface area 837m²). 2 A mixture of (g) of powder and 10 mL of purified water was prepared and impregnated in a 35°C water bath for 6 hours to obtain a catalyst impregnation solution. The catalyst impregnation solution was then placed in a sample vial and placed in a freeze dryer. The first stage involved cooling to -15°C and maintaining a vacuum of 40 Pa for 10 hours; the second stage involved cooling to -25°C and maintaining a vacuum of 20 Pa for 12 hours to obtain a catalyst with removed moisture. 1 g of the catalyst was placed in a quartz reaction tube, and a mixture of hydrogen and hydrogen chloride gas was introduced. Assuming the total volume of the mixture is 100%, the hydrogen volume content was 0.3%, and the total gas flow rate was 15 mL / min. The temperature was increased from 25°C to 180°C at a rate of 2°C and held for 1 hour to obtain approximately 1 g of pretreated catalyst. After catalyst pretreatment, hydrogen chloride and acetylene gas were introduced into the quartz reaction tube to carry out the acetylene hydrochlorination reaction. The gaseous products after the reaction were collected and analyzed by gas chromatography.

[0056] Test data such as Figure 7 As shown, the average size of the gold particles on the catalyst is 1.9 nm, and an acetylene conversion rate of 82% is achieved after 2 h of reaction in acetylene hydrochlorination. After 10 h of reaction, the acetylene conversion rate drops to 77%, and the catalyst deactivation rate is 6.1%.

[0057] Compared with Comparative Examples 1 and 2, the catalyst in this example has a smaller average size of gold particles, and the catalyst exhibits better activity and stability and a lower deactivation rate in the acetylene hydrochlorination reaction.

[0058] 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 equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a gold catalyst through pretreatment, comprising the following steps: (1) Dissolve 1g of HAuCl4·4H2O in a pure aqueous solution to prepare a chloroauric acid solution of 5g / L~15g / L; then take 4mL~8mL of the above chloroauric acid solution and mix it with 5g of titanium silicon molecular sieve and 5mL~15mL of pure water, and impregnate it in a water bath at 30℃~40℃ for 4h~8h to obtain a catalyst impregnation solution; freeze-dry the catalyst impregnation solution under vacuum. The drying process is divided into two stages. In the first stage, the temperature is lowered to -10℃~-20℃ and the vacuum degree is 30Pa~50Pa, and it is maintained for 8h~12h; in the second stage, the temperature is lowered to -20℃~-30℃ and the vacuum degree is 10Pa~30Pa, and it is maintained for 10h~14h to obtain a catalyst with water removed. (2) The catalyst with water removed in step (1) is placed in a quartz reaction tube and a mixture of hydrogen and hydrogen chloride is introduced to activate the catalyst. The volume of the mixture is calculated as 100%, the volume content of hydrogen is 0.1%~0.5%, the total gas flow rate is 10mL / min~20mL / min, the temperature is increased from 25℃ to 180℃ at a rate of 1℃~3℃ and then kept at the temperature for 1h~3h to obtain the pretreated gold catalyst.

2. The pretreatment preparation method for a gold catalyst as described in claim 1, characterized in that: Titanium silicate molecular sieves contain a porous structure and have a specific surface area greater than 800 m². 2 / g, silicate materials containing titanium atoms in the framework.

3. The pretreatment preparation method for a gold catalyst as described in claim 2, characterized in that: The titanium-silicon molecular sieve is one or more of TS-1, Ti-MWW, and Ti-TUD.

4. A gold catalyst, characterized in that: It is prepared by the method described in any one of claims 1 to 3.

5. The application of the gold catalyst according to claim 4 in the synthesis of vinyl chloride via acetylene hydrochlorination.

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