A supported gold catalyst for the hydrochlorination of acetylene and its preparation and use

Abstract

The application discloses a supported gold catalyst for acetylene hydrochlorination reaction and preparation and application thereof. The supported gold catalyst comprises a carrier and a gold active component supported on the carrier, and the carrier is a rare earth element nitride. The application adopts a rare earth metal nitride as the carrier, supports gold to form a catalyst for acetylene hydrochlorination reaction, and can obviously improve acetylene conversion rate and catalyst stability compared with a conventional activated carbon carrier.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a supported gold catalyst for the hydrochlorination reaction of acetylene, its preparation method, and its application. Background Technology

[0002] Polyvinyl chloride (PVC), one of the world's five major engineering plastics, has widespread applications in the chemical industry. Vinyl chloride (VCM) is the monomer for synthesizing PVC. Currently, the annual demand for PVC is 400 million tons, making VCM a very important chemical raw material, with approximately 90% of VCM used in PVC production. There are three main chemical synthesis processes for vinyl chloride: the C2H2 method, the C2H4 method, and the C2H6 method. my country's resource structure of "abundant coal, scarce oil, and limited gas" dictates that for a considerable period of time, the calcium carbide acetylene method will be the main process for vinyl chloride production in my country. This method involves the reaction of acetylene and hydrogen chloride catalyzed by mercuric chloride to produce vinyl chloride. This catalyst has relatively high activity and selectivity, but poor thermal stability. During use, mercury loss from the catalyst can occur, affecting its activity. More seriously, the highly toxic mercuric chloride causes severe environmental pollution. Currently, many scholars are actively exploring how to replace mercury catalysts in the acetylene hydrochlorination reaction, seeking a green and efficient technical route. People are gradually focusing their research on mercury-free chlorides with metal chlorides as active components. Among them, noble metal chlorides have shown the best catalytic activity. For example, metals such as gold, palladium, ruthenium, and copper have been reported to have higher catalytic activity than mercury when used as active components.

[0003] In 1985, it was predicted that gold would be the optimal catalyst for the hydrochlorination of acetylene, a prediction that was later confirmed. This sparked the development of numerous gold-catalyzed reactions. Supported gold catalysts are highly stable and do not leach metal from the catalyst, unlike supported mercuric chloride catalysts. Research has revealed that gold catalysts contain gold nanoparticles, and early studies indicated that the Au on the surface of these nanoparticles... 3+ It exhibits high activity. However, this assumption is primarily based on the characterization and comparison of new and old catalysts. Recently, interest has been rekindled in the search for commercially viable mercury-free catalysts for this important industrial process, with most studies focusing on the use of gold as a catalyst.

[0004] Many previous studies have shown that Au 3+ The presence of lanthanides is important, as high activity has been observed in the hydrochlorination of acetylene. In some catalysts, lanthanides are intentionally added to stabilize the high valence state of gold. Evidence supporting this hypothesis comes from X-ray photoelectron spectroscopy (XPS) of fresh and deactivated catalysts, in which Au in the deactivated catalyst... 3+The concentration of gold was largely depleted. Interestingly, transmission electron microscopy studies showed that the gold nanoparticles hardly sintered after deactivation. Although Au 3+ It is important in the initial stage, but to observe high activity, Au + It must exist. During the reaction, the combination of acetylene and HCl establishes an active Au group. 3+ -Au + Yes, and it is proposed that these pairs are formed and continuously reformed during the reaction, resulting in a long catalyst lifetime for the supported gold catalyst used in the hydrochlorination of acetylene.

[0005] Therefore, developing an active-center-stable supported gold catalyst for the acetylene hydrochlorination reaction has significant industrial application potential. Summary of the Invention

[0006] The purpose of this invention is to solve the problem of Au catalysts at high temperatures in catalytic reactions. 3+ This study investigates phenomena such as reduction and low-temperature carbon deposition, and proposes a supported gold catalyst that can be directly used in the hydrochlorination reaction of acetylene, along with its preparation method and application. The catalyst exhibits good stability and high activity.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a supported gold catalyst for the hydrochlorination reaction of acetylene, comprising a support and a gold active component on the support, wherein the support is a rare earth nitride, and the rare earth nitride is prepared by a method comprising the following steps:

[0009] Step 1: Add rare earth metal powder to anhydrous ethanol, disperse it evenly by ultrasonication, then wash and dry; the rare earth metal powder is at least one of La (lanthanum), Ce (cerium), Pr (praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Eu (europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Yb (ytterbium), Lu (lutetium), Sc, and Y;

[0010] Step 2: Place the dried rare earth metal from Step 1 into a Joule-heated high-temperature sample stage, introduce a nitrogen-argon mixture, and perform Joule heating at a temperature of 1000–3000℃ for 10–60 min to obtain the product.

[0011] Step 3: Take out the product obtained in Step 2, soak it in an acid solution to remove unreacted rare earth metals, then wash the resulting solid powder until neutral, and dry it to obtain rare earth nitrides.

[0012] Preferably, in step two, the Joule heating temperature is 2000–3000°C, and the heating time is 10–30 min. More preferably, the Joule heating temperature is 2500°C, and the heating time is 10 min.

[0013] Preferably, in step two, the volume ratio of the mixed gas nitrogen to argon is 3:1 to 4:1.

[0014] Preferably, in step three, the acid solution is a 1-2 mol / L HCl solution.

[0015] Preferably, in step three, the product obtained in step two is taken out, soaked in an acid solution, sealed and stirred for 10-20 minutes to remove unreacted rare earth metals.

[0016] Preferably, in step three, the rinsing agent is deionized water.

[0017] Preferably, in step three, the drying conditions are: a drying temperature of 100-150℃ and a drying time of 10-15 hours.

[0018] In this invention, the rare earth metal powder used is a commercially available product. If the purity is lower than AR, it can be cleaned and dried in step one before use.

[0019] In the supported gold catalyst of the present invention, the gold active component can be the gold active component of a conventional supported gold catalyst used for the hydrochlorination reaction of acetylene, such as single-atom gold. The loading amount of the gold active component also uses a conventional loading amount, for example, the gold element loading amount is 0.8-10:100 according to the mass ratio of gold element to support.

[0020] Secondly, the present invention provides a method for preparing the supported gold catalyst for the acetylene hydrochlorination reaction, comprising the following steps:

[0021] Step 1: Dissolve the gold precursor in an acidic solution and then sonicate it.

[0022] Step 2: Add the solution obtained in Step 1 dropwise to the rare earth metal nitride while stirring, until all the solution is added and completely wets the rare earth metal nitride, and then dry to obtain the supported gold catalyst.

[0023] Preferably, in step 1, the gold precursor is tetrachloroauric acid.

[0024] Preferably, the acidic solution in step 1 is concentrated hydrochloric acid, concentrated nitric acid, or aqua regia, with aqua regia being the most preferred.

[0025] Preferably, in step 1, the ultrasonic treatment time is 5 to 10 minutes.

[0026] Preferably, in step 2, the drying conditions are: drying at 100-120℃ for 8-12 hours.

[0027] Preferably, in step 2, the ratio of the solution obtained in step 1 to the rare earth metal nitride is 0.8-10:100, calculated as the mass ratio of the gold element contained therein to the rare earth metal nitride.

[0028] Thirdly, the present invention provides the application of the supported gold catalyst in the catalytic hydrochlorination of acetylene to synthesize vinyl chloride.

[0029] The specific application is as follows: In a fixed-bed reactor, the supported gold catalyst is loaded, and the raw material gases HCl and C2H2 are introduced to react and obtain vinyl chloride.

[0030] Preferably, the molar ratio of the raw material gases is n(HCl):n(C2H2) = 1:1 to 1.2:1, the reaction temperature is 120 to 200°C, and the acetylene volume hourly space velocity is 30 to 500 h⁻¹. -1 .

[0031] As a further preferred embodiment, the reaction temperature is 150°C, the molar ratio of the raw material gases is n(HCl):n(C₂H₂) = 1.1:1, and the acetylene volume hourly space velocity is 30 h⁻¹. -1 .

[0032] Compared with the prior art, the present invention has the following innovations and technical advantages:

[0033] (1) The present invention uses rare earth metal nitrides prepared by a specific method as a support, and supports gold to make a catalyst for the acetylene hydrochlorination reaction. Compared with conventional activated carbon support, it can significantly improve the acetylene conversion rate and catalyst stability.

[0034] (2) This invention applies Joule heating technology to the generation process of rare earth metal nitrides. With the extremely fast heating rate of Joule heating and the fact that the metal is heated in a very small closed space, the efficiency of the reaction is improved, the oxidation of the metal is prevented, and the purity of rare earth metal nitrides is improved, so that the supported gold catalyst used as a carrier for the acetylene hydrochlorination reaction has better performance.

[0035] (3) The rare earth metal nitrides prepared by this invention, due to the effect of lanthanide metals, solve the shortcomings of high-valence Au active centers in supported gold catalysts used for acetylene hydrochlorination reaction being easily reduced and agglomerated at high temperatures, thus making them more stable and active.

[0036] (4) The method for preparing rare earth metal nitrides of the present invention is simple, safe to operate, simple in process, and saves time and effort.

[0037] (5) In the process of preparing a supported gold catalyst for the acetylene hydrochlorination reaction using rare earth metal nitrides, the gold precursor is pretreated with aqua regia, which helps to improve the acetylene conversion rate and vinyl chloride selectivity of the catalyst, especially the catalyst stability.

[0038] (6) The rare earth metal nitride supported gold catalyst of the present invention is used in the reaction of acetylene hydrochlorination to synthesize vinyl chloride. It exhibits good catalytic performance, with high acetylene conversion rate and vinyl chloride selectivity, and good stability. Detailed Implementation

[0039] The present invention will be illustrated below with specific embodiments. It should be noted that the embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention, which is not limited thereto in any way. Those skilled in the art can make some non-essential improvements and adjustments based on the above description of the invention.

[0040] In this embodiment of the invention, hydrochloric acid, nitric acid, and other pharmaceuticals can be purchased directly from the market.

[0041] Example 1

[0042] A method for preparing and applying a terbium nitride-supported gold catalyst for the hydrochlorination of acetylene includes the following steps:

[0043] 1) Add terbium metal powder to anhydrous ethanol, sonicate for 30 min, then rinse repeatedly with anhydrous ethanol. Place the rinsed metal powder in a vacuum oven at 60℃ for 8 h. Take 100 mg of dried terbium metal and place it in a Joule-heated high-temperature sample stage. Purge with a nitrogen-argon mixture (nitrogen to argon volume ratio of 4:1), raise the temperature to 2500℃, and heat for 10 min to obtain solid powder. Remove the powder and immerse it in a 1 mol / L HCl solution. Seal and stir for 10 min, then rinse repeatedly with deionized water until neutral. Place it in a vacuum oven at 120℃ for 12 h to dry. Store the obtained sufficient terbium nitride solid powder in an argon atmosphere for later use.

[0044] 2) Dissolve the gold precursor HAuCl4·xH2O (40 mg, Au content 49 wt%, the same below) in 4 ml of aqua regia solution (3:1 HCl (32 wt%): HNO3 (70 wt%)) and sonicate for 10 min. Add the resulting solution dropwise to the prepared terbium nitride (1.98 g) powder while stirring until all the solution is added and the nitride is completely impregnated. Place in an oven at 120 °C for 12 h to obtain a catalyst with a final gold loading of 1 wt%; denoted as catalyst 1.

[0045] 3) Application of Catalyst 1 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated in a fixed-bed reactor under the following conditions: temperature 150℃, acetylene space velocity 30h⁻¹. -1 The reaction was carried out under the condition that n(HCl):n(C2H2) = 1.1:1. Initially, the acetylene conversion rate was 98.25%, and the vinyl chloride selectivity was 96.81%; after 1000 hours of reaction, the acetylene conversion rate was 78.26%, and the vinyl chloride selectivity was 93.04%.

[0046] Example 2: Without using aqua regia as a solvent

[0047] 1) Same as in Example 1, prepare a sufficient amount of terbium nitride solid powder and store it in an argon atmosphere for later use.

[0048] 2) Dissolve the gold precursor HAuCl4·xH2O (40 mg, 49 wt%) in 4 ml of 32% hydrochloric acid solution and sonicate for 10 min. Add the resulting solution dropwise to the prepared terbium nitride (1.98 g) powder while stirring until all the solution is added and the nitride is completely impregnated. Place the mixture in an oven at 120 °C for 12 h to obtain a catalyst with a final gold loading of 1 wt%; this is designated as catalyst 2.

[0049] 3) Application of Catalyst 2 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated in a fixed-bed reactor under the following conditions: temperature 150℃, acetylene space velocity 30h⁻¹. -1 The reaction was carried out under the condition that n(HCl):n(C2H2) = 1.1:1. Initially, the acetylene conversion rate was 96.25%, and the vinyl chloride selectivity was 94.81%; after 1000 hours of reaction, the acetylene conversion rate was 68.26%, and the vinyl chloride selectivity was 91.12%.

[0050] A comparison of Examples 1 and 2 shows that when the gold precursor is pretreated with aqua regia in catalyst preparation, the acetylene conversion and vinyl chloride selectivity of the obtained acetylene hydrochlorination catalyst are only slightly improved compared to pretreatment with hydrochloric acid, but the catalyst stability is significantly improved.

[0051] Example 3: Catalyst prepared by changing the Joule heating temperature

[0052] A method for preparing and applying a dysprosium nitride-supported gold catalyst for the hydrochlorination of acetylene includes the following steps:

[0053] 1) Add terbium metal powder to anhydrous ethanol, sonicate for 30 min, then rinse repeatedly with anhydrous ethanol. Place the rinsed metal powder in a vacuum oven at 60℃ for 8 h. Take 100 mg of dried terbium metal and place it in a Joule-heated high-temperature sample stage. Pour in a nitrogen-argon mixture (nitrogen to argon volume ratio of 4:1), raise the temperature to 1500℃, and heat for 10 min to obtain solid powder. Remove the powder and immerse it in a 1 mol / L HCl solution. Seal and stir for 10 min, then rinse repeatedly with deionized water until neutral. Place it in a vacuum oven at 120℃ for 12 h to dry. Store the obtained sufficient terbium nitride solid powder in an argon atmosphere for later use.

[0054] 2) Dissolve the gold precursor HAuCl4·xH2O (40 mg, 49 wt%) in 4 ml of aqua regia solution (3:1 HCl (32 wt%): HNO3 (70 wt%)) and sonicate for 10 min. Add the resulting solution dropwise to the prepared terbium nitride (1.98 g) powder while stirring until all the solution is added and the nitride is completely impregnated. Place the mixture in an oven at 120 °C for 12 h to obtain a catalyst with a final gold loading of 1 wt%; this is designated as catalyst 3.

[0055] 3) Application of catalyst 3 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated in a fixed-bed reactor under the following conditions: temperature 150℃, acetylene space velocity 30h⁻¹. -1 The reaction was carried out under the condition that n(HCl):n(C2H2) = 1.1:1. Initially, the acetylene conversion rate was 90.25%, and the vinyl chloride selectivity was 95.89%; after 1000 hours of reaction, the acetylene conversion rate was 66.26%, and the vinyl chloride selectivity was 92.42%.

[0056] Example 4: Catalysts prepared by changing the type of metal

[0057] A method for preparing and applying a holmium nitride-supported gold catalyst for the hydrochlorination of acetylene includes the following steps:

[0058] 1) Add holmium metal powder to anhydrous ethanol, sonicate for 30 min, then rinse repeatedly with anhydrous ethanol. Place the rinsed metal powder in a vacuum oven at 60℃ for 8 h. Take 100 mg of dried holmium metal and place it in a Joule-heated high-temperature sample stage. Purge with a nitrogen-argon mixture (nitrogen to argon volume ratio of 4:1), raise the temperature to 2500℃, and heat for 10 min to obtain solid powder. Remove the powder and immerse it in a 1 mol / L HCl solution. Seal and stir for 10 min, then rinse repeatedly with deionized water until neutral. Place it in a vacuum oven at 120℃ for 12 h to dry. Repeat the above operation multiple times. Store the obtained sufficient holmium nitride solid powder in an argon atmosphere for later use.

[0059] 2) Dissolve the gold precursor HAuCl4·xH2O (40 mg, 49 wt%) in 4 ml of aqua regia solution (3:1 HCl (32 wt%): HNO3 (70 wt%)) and sonicate for 10 min. Add the resulting solution dropwise to the prepared holmium nitride (1.98 g) powder while stirring until all the solution is added and the nitride is completely impregnated. Place the mixture in an oven at 120 °C for 12 h to obtain a catalyst with a final gold loading of 1 wt%; this is designated as catalyst 4.

[0060] 3) Application of catalyst 4 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated in a fixed-bed reactor under the following conditions: temperature 150℃, acetylene space velocity 30h⁻¹. -1 The reaction was carried out under conditions where n(HCl):n(C2H2) = 1.1:1. Initially, the acetylene conversion rate was 88.37%, and the vinyl chloride selectivity was 93.94%. After 1000 hours of reaction, the acetylene conversion rate was 65.25%, and the vinyl chloride selectivity was 90.31%.

[0061] Example 5

[0062] A method for preparing and applying a gadolinium nitride-supported gold catalyst for the hydrochlorination of acetylene includes the following steps:

[0063] 1) Add gadolinium metal powder to anhydrous ethanol, sonicate for 30 min, then rinse repeatedly with anhydrous ethanol. Place the rinsed metal powder in a vacuum oven at 60℃ for 8 h. Take 100 mg of dried gadolinium metal and place it in a Joule-heated high-temperature sample stage. Pour in a nitrogen-argon mixture (nitrogen to argon volume ratio of 4:1), raise the temperature to 2500℃, and heat for 10 min to obtain solid powder. Remove the powder and immerse it in a 1 mol / L HCl solution. Seal and stir for 10 min, then rinse repeatedly with deionized water until neutral. Place it in a vacuum oven at 120℃ for 12 h to dry. Repeat the above operation multiple times. Store the obtained sufficient gadolinium nitride solid powder in an argon atmosphere for later use.

[0064] 2) Dissolve the gold precursor HAuCl4·xH2O (40 mg, 49 wt%) in 4 ml of aqua regia solution (3:1 HCl (32 wt%): HNO3 (70 wt%)) and sonicate for 10 min. Add the resulting solution dropwise to the prepared gadolinium nitride (1.98 g) powder while stirring until all the solution is added and the nitride is completely impregnated. Place the mixture in an oven at 120 °C for 12 h to obtain a catalyst with a final gold loading of 1 wt%; this is designated as catalyst 5.

[0065] 3) Application of Catalyst 5 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated in a fixed-bed reactor under the following conditions: temperature 150℃, acetylene space velocity 30h⁻¹. -1 The reaction was carried out under the condition that n(HCl):n(C2H2) = 1.1:1. Initially, the acetylene conversion rate was 90.96%, and the vinyl chloride selectivity was 95.22%; after 1000 hours of reaction, the acetylene conversion rate was 68.37%, and the vinyl chloride selectivity was 91.31%.

[0066] Comparative Example 1: Terbium nitride as a catalyst

[0067] 1) Add terbium metal powder to anhydrous ethanol, sonicate for 30 min, then rinse repeatedly with anhydrous ethanol. Place the rinsed metal powder in a vacuum oven at 60℃ for 8 h. Take 100 mg of dried terbium metal and place it in a Joule-heated high-temperature sample stage. Purge with a nitrogen-argon mixture (nitrogen to argon volume ratio of 4:1), raise the temperature to 2500℃, and heat for 10 min to obtain solid powder. Remove the powder and immerse it in a 1 mol / L HCl solution. Seal and stir for 10 min, then rinse repeatedly with deionized water until neutral. Place it in a vacuum oven at 120℃ for 12 h to dry. Store the obtained sufficient terbium nitride solid powder in an argon atmosphere for later use.

[0068] 2) The prepared terbium nitride was tested for acetylene hydrochlorination reaction and designated as catalyst 6.

[0069] 3) Application of Catalyst 6 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated in a fixed-bed reactor under the following conditions: temperature 150℃, acetylene space velocity 30h⁻¹. -1 Under the condition that n(HCl):n(C2H2)=1.1:1, in the initial stage of the reaction, the acetylene conversion rate was 10.35% and the vinyl chloride selectivity was 70.23%; after 1000 hours of reaction, the acetylene conversion rate was 2.23% and the vinyl chloride selectivity was 50.39%.

[0070] As can be seen from Comparative Example 1, terbium nitride itself has a poor catalytic effect on the hydrochlorination of acetylene.

[0071] Comparative Example 2: Preparation of Nitrides from Rare Earth Metals under Ordinary High Temperature Environment

[0072] 1) Add terbium metal powder to anhydrous ethanol and sonicate for 30 min. Then rinse with anhydrous ethanol several times. Place the rinsed metal powder in a vacuum oven and maintain the temperature at 60℃ for 8 h. Take 5 g of dried terbium metal and put it into a muffle furnace. Pour in a nitrogen-argon mixture (nitrogen to argon volume ratio of 4:1) and raise the temperature to 2500℃ at a rate of 10℃ / min for 12 h to obtain solid powder. Take out the powder and soak it in 1 mol / L HCl solution. Seal and stir for 10 min. Then rinse with deionized water several times until neutral. Place it in a vacuum oven and dry at 120℃ for 12 h. Store the obtained solid powder in an argon atmosphere for later use.

[0073] 2) Dissolve the gold precursor HAuCl4·xH2O (40 mg, 49 wt%) in 4 ml of aqua regia solution (3:1 HCl (32 wt%): HNO3 (70 wt%)) and sonicate for 10 min. Add the resulting solution dropwise to the prepared terbium nitride (1.98 g) powder while stirring until all the solution is added and the nitride is completely impregnated. Place the mixture in an oven at 120 °C for 12 h to obtain a catalyst with a final gold loading of 1 wt%; this is designated as catalyst 7.

[0074] 3) Application of Catalyst 7 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated in a fixed-bed reactor under the following conditions: temperature 150℃, acetylene space velocity 30h⁻¹. -1 The reaction was carried out under the condition that n(HCl):n(C2H2) = 1.1:1. Initially, the acetylene conversion rate was 87.25%, and the vinyl chloride selectivity was 90.81%. After 1000 hours of reaction, the acetylene conversion rate was 65.26%, and the vinyl chloride selectivity was 83.04%.

[0075] By comparing Comparative Example 2 with Example 1, it can be seen that, compared with rare earth nitrides prepared by processing rare earth metals under ordinary high temperature environment, the present invention applies Joule heating technology to the generation process of rare earth nitrides. The supported gold catalyst prepared by using rare earth nitrides prepared by this method as a support has better acetylene conversion rate, vinyl chloride selectivity and catalyst stability in the acetylene hydrochlorination reaction.

[0076] Comparative Example 3: Activated carbon as a carrier

[0077] 1) Take 5g of activated carbon carrier (Norit ROX 0.8) and soak it in 1mol / L HCl solution for 2h. Rinse it repeatedly with deionized water until neutral. Place it in an oven and dry it at 120℃ for 12h.

[0078] 2) Dissolve the gold precursor HAuCl4·xH2O (40 mg, 49 wt%) in 4 ml of aqua regia solution (3:1 HCl (32 wt%): HNO3 (70 wt%)) and sonicate for 10 min. Add the resulting solution dropwise to the treated activated carbon (1.98 g) support while stirring until all the solution is added and the support is completely wetted. Place the solution in an oven at 120 °C for 12 h to obtain a catalyst with a final gold loading of 1 wt%; this is designated as catalyst 8.

[0079] 3) Application of Catalyst 8 in the acetylene hydrochlorination reaction: The acetylene hydrochlorination reaction was evaluated in a fixed-bed reactor under the following conditions: temperature 150℃, acetylene space velocity 30h⁻¹. -1 The reaction was carried out under the condition that n(HCl):n(C2H2) = 1.1:1. Initially, the acetylene conversion rate was 74.25%, and the vinyl chloride selectivity was 94.81%; after 1000 hours of reaction, the acetylene conversion rate was 40.86%, and the vinyl chloride selectivity was 90.72%.

[0080] A comparison of Comparative Example 4 and Example 1 shows that, compared with the activated carbon-supported gold catalyst prepared by conventional methods, the supported gold catalyst prepared in this invention exhibits significantly improved acetylene conversion rate and catalyst stability in the acetylene hydrochlorination reaction.

Claims

1. A supported gold catalyst for the hydrochlorination of acetylene, comprising a support and a gold active component on the supported support, characterized in that: The carrier is a rare earth element nitride, which is prepared by a method including the following steps: Step 1: Add rare earth metal powder to anhydrous ethanol, disperse it evenly by ultrasonication, then wash and dry; the rare earth metal powder is at least one of Gd, Tb, and Ho. Step 2: Place the dried rare earth metal from Step 1 into a Joule-heated high-temperature sample stage, introduce a nitrogen-argon mixture, and perform Joule heating at a temperature of 1000~3000℃ for 10~60 min to obtain the product. Step 3: Take out the product obtained in Step 2, soak it in an acid solution to remove unreacted rare earth metals, then wash the resulting solid powder until neutral, and dry it to obtain rare earth nitrides; The preparation method of the supported gold catalyst includes the following steps: Step 1: Dissolve the gold precursor in an acidic solution and then sonicate it. Step 2: Add the solution obtained in Step 1 dropwise to the rare earth metal nitride while stirring, until all the solution is added and completely wets the rare earth metal nitride, and then dry to obtain the supported gold catalyst.

2. The supported gold catalyst for hydrochlorination of acetylene according to claim 1, wherein: In step two, the Joule heating temperature is 2000~3000℃, and the heating time is 10~30min.

3. The supported gold catalyst for hydrochlorination of acetylene according to claim 1, wherein: In step two, the Joule heating temperature is 2500℃ and the heating time is 10 minutes.

4. The supported gold catalyst for the hydrochlorination reaction of acetylene as described in claim 1, characterized in that: In step two, the volume ratio of the mixed gas nitrogen to argon is 3:1 to 4:

1.

5. The supported gold catalyst for the hydrochlorination reaction of acetylene as described in claim 1, characterized in that: In step three, the acid solution is a 1-2 mol / L HCl solution.

6. The supported gold catalyst for hydrochlorination of acetylene according to claim 1, wherein: In step three, the drying conditions are: drying temperature of 100-150℃ and drying time of 10-15 hours.

7. A method for preparing a supported gold catalyst for the hydrochlorination reaction of acetylene as described in any one of claims 1-6, characterized in that: The preparation method includes the following steps: Step 1: Dissolve the gold precursor in an acidic solution and then sonicate it. Step 2: Add the solution obtained in Step 1 dropwise to the rare earth metal nitride while stirring, until all the solution is added and completely wets the rare earth metal nitride, and then dry to obtain the supported gold catalyst.

8. The production method according to claim 7, characterized by: In step 1, the gold precursor is tetrachloroauric acid, and the acidic solution is concentrated hydrochloric acid, concentrated nitric acid, or aqua regia.

9. The production method according to claim 7, wherein: In step 2, the feeding ratio of the solution obtained in step 1 to the rare earth metal nitride is 0.8-10:100, calculated as the mass ratio of the gold element contained therein to the rare earth metal nitride.

10. The application of the supported gold catalyst as described in claim 1 in the catalytic hydrochlorination of acetylene to synthesize vinyl chloride.