A method for continuous photocatalytic hydrochlorination of acetylene to produce vinyl chloride at room temperature

Abstract

The present invention proposes a method for producing vinyl chloride by continuous photocatalytic acetylene hydrochlorination at room temperature, belonging to the technical field of organic synthesis. The method comprises the following steps: adding an organic solvent to a device with a sealed lid, adding a photocatalyst, a chlorine source, and a hydrogen source to the organic solvent, exposing the organic solvent to an inert gas removal device and impurity gases in the solvent before the reaction, then exposing the acetylene raw material to the organic solvent and irradiating it with a light source under continuous stirring, with vinyl chloride being the gas product emerging from the device. Using hydrochloric acid as the hydrogen and chlorine sources, the method achieves highly selective photocatalytic acetylene hydrochlorination to produce vinyl chloride at room temperature and pressure. The reaction has low energy consumption and avoids the use of mercury-containing catalysts, HCl gas, and additional heat sources. The method has a simple reaction system, mild reaction conditions, a simple process, and high activity selectivity, meeting the requirements of green chemical development and possessing great application value.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, specifically to a method for producing vinyl chloride through continuous photocatalytic hydrochlorination of acetylene at room temperature. Background Technology

[0002] Vinyl chloride monomer (VCM) is an important chemical commodity, with a projected production capacity of 60 million tons per year by 2030. It is a crucial monomer for producing polyvinyl chloride (PVC), one of the five major general-purpose plastics. Due to PVC's strong resistance to light and chemical degradation, it has a wide range of applications, particularly in the construction industry. Currently, VCM is produced using three methods: the acetylene process, the ethylene process, and the ethane process. The ethylene process is complex, requires large-scale investment, and produces hydrogen chloride as a byproduct gas. While the ethane process is simpler, it involves higher reaction temperatures and generates more byproducts. These issues limit their practical application.

[0003] Based on my country's energy structure, coal-to-acetylene production using the acetylene process will become the primary method for producing vinyl chloride in my country. Currently, industrially, mercuric chloride (HgCl2) is mainly used as the active component, with activated carbon as the support catalyst in the acetylene hydrochlorination reaction. However, mercuric chloride is volatile and toxic, causing catalyst instability and easy deactivation, leading to serious environmental problems and harming human health. To achieve the goals of the Minamata Convention on Mercury, the search for green catalysts to replace toxic mercuric chloride has attracted widespread attention from researchers. Although significant progress has been made in the research of environmentally friendly mercury-free catalysts, these mainly utilize expensive and limited precious metals such as Au and Pd. Even though some non-metallic catalysts (e.g., silicon-carbon derived carbon nanocomposites, nitrogen-doped carbon derived from ZIF-8) have been developed for the acetylene hydrochlorination reaction, the reaction still occurs at high temperatures of around 200°C, posing a significant challenge to the catalyst. Therefore, developing a new green, economical, and efficient process technology remains highly desirable.

[0004] Photocatalysis, which directly converts solar energy into chemical energy, has attracted considerable attention from researchers in recent years. Furthermore, photoredox catalysis has become a powerful synthetic platform, for example, in the complete hydrolysis of water and the activation of CH and C-C bonds. Similarly, the hydrochlorination of acetylene requires simultaneous oxidation and reduction reactions to add a chlorine atom and a hydrogen atom to the acetylene molecule. Achieving acetylene hydrochlorination via photoredox reactions is a sustainable and green synthetic strategy, but it faces two major challenges: the extremely low solubility of acetylene in water and the poor photocatalytic hydrochlorination activity of gaseous acetylene. Recently, researchers reported a sequencing batch photocatalytic strategy that achieved the production of vinyl chloride from acetylene in chloride-containing aqueous solutions using a g-C3N4 / BiOCl catalyst. However, due to mass transport limitations and low reactivity, the yield was very low (47.26 μmol VCM produced in 8 hours), making it difficult to achieve practical applications. Summary of the Invention

[0005] The purpose of this invention is to propose a method for the continuous photocatalytic hydrochlorination of acetylene to produce vinyl chloride at room temperature. Using hydrochloric acid as both a hydrogen and chlorine source, this method achieves highly selective photocatalytic hydrochlorination of acetylene to produce vinyl chloride at room temperature and pressure. The reaction has low energy consumption and avoids the use of mercury-containing catalysts, HCl gas, and additional heat sources. The reaction system is simple, the reaction conditions are mild, the process is simple, and the activity and selectivity are high, meeting the requirements of green chemical development and possessing great application value.

[0006] The technical solution of this invention is implemented as follows:

[0007] This invention provides a method for the continuous photocatalytic hydrochlorination of acetylene to produce vinyl chloride at room temperature. The principle is as follows: In an organic solvent containing a chlorine source and a hydrogen source, under the action of light and a photocatalyst, the continuous photocatalytic hydrochlorination of acetylene to produce vinyl chloride is achieved at room temperature and pressure, including the following steps:

[0008] An organic solvent is added to a device with a sealed cap. A photocatalyst, a chlorine source, and a hydrogen source are added to the organic solvent. Before the reaction, an inert gas is introduced to remove impurities from the device and the solvent. Then, acetylene is introduced into the organic solvent and irradiated with a light source while continuously stirring. The gaseous product exiting the device is vinyl chloride.

[0009] As a further improvement of the present invention, the organic solvent is selected from one or more organic solvents selected from N,N-dimethylformamide, acetone, N-methylpyrrolidone, dimethyl sulfoxide, formic acid, acetic acid, ethyl acetate, glycerol, ethylene glycol, methanol, and isopropanol.

[0010] As a further improvement of the present invention, the photocatalyst is a semiconductor photocatalyst supported on one or more metals or metal oxides.

[0011] As a further improvement of the present invention, the photocatalyst is an A / B type catalyst, wherein the active component A is selected from one or more alloys or one or more metal oxides of ruthenium, palladium, gold, platinum, silver, rhodium, iridium, copper, nickel, cobalt, iron and manganese; and the semiconductor carrier B is selected from at least one or a combination of titanium dioxide, sodium tantalate, tungsten trioxide, niobium pentoxide, bismuth vanadate, cuprous oxide, cadmium sulfide, molybdenum disulfide, indium phosphide, and graphitic carbon nitride to form a heterojunction composite material.

[0012] As a further improvement of the present invention, the loading of the active component A is 0.1-8.0 wt.% by mass, with the balance being the semiconductor carrier B.

[0013] As a further improvement of the present invention, the hydrogen source is selected from any one or a mixture of multiple of the following: water, ethanol, methanol, tert-butanol, isopropanol, hydrochloric acid, hydrogen chloride gas, hypochlorous acid, perchloric acid, chloroacetyl, nitric acid, nitrous acid, sulfuric acid, sulfurous acid, phosphoric acid, boric acid, hydroiodic acid, hydrofluoric acid, hydrobromic acid, formic acid, acetic acid, ascorbic acid, citric acid, oxalic acid, and lactic acid.

[0014] As a further improvement of the present invention, the chlorine source includes any one or a mixture of lithium chloride, hydrochloric acid, hydrogen chloride gas, cobalt chloride hexahydrate, copper chloride dihydrate, ferric chloride trihydrate, ferrous chloride tetrahydrate, manganese dichloride tetrahydrate, chromium trichloride hexahydrate, cerium trichloride heptahydrate, magnesium dichloride hexahydrate, hypochlorous acid, tert-butyl hypochlorite, chloroacetyl, N-succinimide chloride, trichloroisocyanuric acid, dichlorohydantoin, and chloramine-T.

[0015] As a further improvement of the present invention, the acetylene raw material is selected from at least one of pure acetylene or mixed acetylene gas balanced with an inert gas or other alkyne compounds; the light source is selected from at least one of real sunlight, xenon lamp, mercury lamp, and LED lamp.

[0016] As a further improvement of the present invention, the device with the sealing cap is a single chamber or multiple chambers connected in series.

[0017] As a further improvement of the present invention, the amount of photocatalyst added is 0.01-10 g / L.

[0018] The present invention has the following beneficial effects:

[0019] In the transportation of acetylene gas and the industrial removal of acetylene impurities from ethylene streams, organic solvents are typically used to dissolve the acetylene before transportation, or to selectively remove it based on solubility differences. Since the solubility of acetylene in organic solvents (such as N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), and acetone) is almost two orders of magnitude higher than its solubility in water, this facilitates the diffusion of acetylene to photocatalysts. Therefore, this offers a possibility to overcome mass transport limitations, transforming the classic gas-phase reaction of acetylene hydrochlorination into a liquid-phase reaction. Numerous studies have shown that photocatalytic reactions are crystal face-dependent. By controlling the ratio of the {101} and {001} crystal faces of anatase TiO2 through crystal face engineering, photogenerated electrons / holes can be promoted to migrate to the {101} and {001} crystal faces, respectively, to undergo reduction and oxidation reactions, adding hydrogen and chlorine atoms to the acetylene molecule. Furthermore, TiO2 possesses a suitable redox potential to simultaneously oxidize chloride ions and reduce hydrogen ions. Supporting a co-catalyst on the TiO2 photocatalyst can further promote the separation of photogenerated carriers and catalytic activity. Based on this, under mild conditions, photocatalytic hydrochlorination of acetylene was achieved using an A / B type catalyst in an organic solution containing organic or inorganic hydrogen and chlorine sources, and the performance in organic solvents was much better than in water. Among them, DMF solvent showed the best photocatalytic performance, with the highest acetylene conversion efficiency and vinyl chloride selectivity.

[0020] This invention proposes a continuous photocatalytic acetylene hydrochlorination method that combines the advantages of acetylene solvent absorption and in-situ photocatalytic hydrochlorination, enabling efficient and highly selective conversion of acetylene to vinyl chloride under mild conditions. This method overcomes the key challenges encountered in traditional catalytic processes (using mercury-containing catalysts, high energy consumption and carbon emissions, and the need for corrosive HCl gas as a hydrogen and chlorine source), and has broad application prospects in the coal chemical vinyl chloride production industry.

[0021] The vinyl chloride synthesis method described in this invention is a green, safe, low-energy-consumption, and highly efficient photocatalytic synthesis method. Compared with traditional thermocatalytic technology, it utilizes light energy (or sunlight) to replace the heat source, significantly reducing the energy consumption of the acetylene hydrochlorination reaction. Simultaneously, hydrochloric acid can be used as a hydrogen and chlorine source to replace corrosive HCl gas, effectively solving the safety issues caused by the use of HCl gas and meeting the needs of green chemical engineering. Through the screening and design control of the photocatalyst, near 100% selectivity for vinyl chloride can be obtained.

[0022] Furthermore, the catalyst preparation process in the method described in this invention is simple, reusable, and easy to recover (collected by centrifugation or filtration). After a 48-hour durability test, the acetylene conversion rate and vinyl chloride selectivity remained above 80% and 99%, respectively. The catalyst exhibits good versatility and is suitable for photocatalytic hydrochlorination reactions of various alkynes. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a comparison chart of the catalytic performance of different catalyst loadings in Example 1;

[0025] Figure 2 This is a comparison chart of the catalytic performance of different catalyst dosages in Example 2;

[0026] Figure 3 The graph shows the performance of acetylene hydrochlorination to vinyl chloride production under real sunlight catalysis in Example 3.

[0027] Figure 4 This is a qualitative analysis diagram of the continuous photocatalytic hydrochlorination of acetylene to produce vinyl chloride in a small chamber in Example 4;

[0028] Figure 5 The graph shows the effect of different gas flow rates on the continuous photocatalytic hydrochlorination of acetylene to produce vinyl chloride in a small chamber in Example 5.

[0029] Figure 6 The figure shows the effect of different gas flow rates on the continuous photocatalytic hydrochlorination of acetylene to produce vinyl chloride in a dual-chamber series configuration in Example 6.

[0030] Figure 7 The figure shows the durability evaluation results of the continuous photocatalytic hydrochlorination of acetylene to produce vinyl chloride in a dual-chamber series configuration. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] [Example 1] Catalytic performance of active component A with different loadings

[0033] (1) Preparation of catalyst

[0034] Preparation of TiO2 nanosheets (TNS). 25 mL of tetrabutyl titanate and 5 mL of HF solution (40 wt.%) were mixed under stirring for 30 min. The solution was then transferred to a 50 mL Teflon-lined stainless steel autoclave and maintained at 180°C for 24 h. After cooling to room temperature, the white precipitate was separated, collected by high-speed centrifugation, and washed at least 10 times with ultrapure water and ethanol to remove residual organic matter and fluoride ions. Finally, the sample was dried in an oven at 80°C for 12 h and then ground to obtain TNS.

[0035] Synthesis of RuO2 / TNS. 0.5 g of TNS powder was dispersed in 50 mL of 0.05 M NaIO3 solution, and 1.88 mL of 0.01 M RuCl3·3H2O solution was added. After sonication for 15 min, the solution was placed under a 300 W xenon lamp (PLS-SXE300 / 300UV, 300 < λ < 780 nm) and stirred for 2 h. The powdered catalyst was collected by rinsing and filtration with ultrapure water, and dried in a vacuum oven at 60°C for 12 h. RuO2 / TNS was then obtained by grinding and collecting, with a theoretical RuO2 loading of 0.5 wt.%. For RuO2 catalyst loadings of 1.0 wt.%, 2.0 wt.%, 4.0 wt.%, and 8.0 wt.%, the volume of 0.01 M RuCl3·3H2O solution was increased proportionally, while other synthesis conditions remained the same. Unless otherwise stated, this article generally uses a catalyst with a RuO2 mass loading of 4.0 wt.%, named RuO2 / TNS.

[0036] (2) Experiment on photocatalytic hydrochlorination of acetylene to produce vinyl chloride

[0037] Add 10 mL of DMF solvent to a 20 mL screw-cap quartz glass headspace vial equipped with a magnetic stirrer. Then add 40 mg of RuO2 / TNS (RuO2 mass loadings of 0.0 wt.%, 0.5 wt.%, 1.0 wt.%, 2.0 wt.%, 4.0 wt.%, and 8.0 wt.%) to the DMF solvent, followed by 100 μL of concentrated hydrochloric acid (36.0-38.0%). Purge the vial with argon for at least 30 min to remove gaseous impurities. Then, screw the headspace vial cap on to seal the vial. Next, inject 1 mL of acetylene gas (35.0 vol.% + Ar equilibrium gas) into the DMF mixture using a syringe, and turn on the magnetic stirrer. Stir for 30 min to achieve gas-liquid equilibrium. Then, turn on a 300W xenon lamp (PLS-SXE300 / 300UV, 300 < λ < 780 nm) and react for 1 h. At 20-minute intervals, 100 μL of gas was taken from the headspace of the reaction flask and introduced into the gas chromatograph for analysis.

[0038] The conversion rate of acetylene and the selectivity of vinyl chloride were calculated as follows:

[0039] ;

[0040] ;

[0041] in, It refers to the concentration of acetylene in the feed. , and It represents the concentrations of acetylene, ethylene, and ethane in the exported product.

[0042] Test results are as follows Figure 1 As shown, RuO2 plays a key role in the generation of vinyl chloride. As the loading increases from 0.0 wt.% to 4.0 wt.%, the conversion rate of acetylene gradually increases. However, when the loading is further increased to 8.0 wt.%, the conversion rate of acetylene decreases. This may be because more RuO2 leads to the recombination of photogenerated carriers, thereby reducing the catalytic activity. Here, 4.0 wt.% is the optimal loading.

[0043] [Example 2] Catalytic performance with different catalyst dosages

[0044] 10 mL of N,N-dimethylformamide (DMF) solvent was added to a 20 mL screw-cap quartz glass headspace vial equipped with a magnetic stirrer. Different masses of RuO2 / TNS (10 mg, 20 mg, 30 mg, 40 mg, and 50 mg, respectively) were added to the DMF solvent. Then, 100 μL of concentrated hydrochloric acid (36.0-38.0%) was added to the DMF solvent. The vial was then purged with argon for at least 30 min to remove gaseous impurities. The headspace vial cap was then screwed on to seal the vial. Next, 1 mL of acetylene gas (35.0 vol.% + Ar equilibrium gas) was injected into the DMF mixture using a syringe, and the magnetic stirrer was turned on. The mixture was stirred for 30 min to achieve gas-liquid equilibrium. A 300W xenon lamp (PLS-SXE300 / 300UV, 300 < λ < 780 nm) was then turned on to react for 1 h. At 20-minute intervals, 100 μL of gas was taken from the headspace of the reaction flask and introduced into the gas chromatograph for analysis.

[0045] Test results are as follows Figure 2 As shown in the figure, the conversion rate of acetylene gradually increases as the catalyst dosage increases from 10 mg to 40 mg. However, when the dosage increases to 50 mg, the conversion rate does not increase significantly, and the selectivity for vinyl chloride decreases. This may be because the increased catalyst dosage affects the transmittance of light and the absorption of light by the catalyst, thereby reducing the catalytic activity. Therefore, 40 mg is selected as the optimal dosage.

[0046] [Example 3] Performance of real sunlight photocatalytic acetylene hydrochlorination to produce vinyl chloride

[0047] In a 250 mL quartz glass reaction chamber equipped with a magnetic stirrer, 150 mL of N,N-dimethylformamide (DMF) solvent, 150 mg RuO2 / TNS, and 1.5 mL of concentrated hydrochloric acid (36.0-38.0%) were added to the DMF solvent. The quartz apparatus was then capped, and the DMF mixture was exposed to Ar for 30 min. After that, the ball valve knob on the cap was closed to ensure a sealed reaction chamber. Next, 15 mL of acetylene gas (35.0 vol.% acetylene + Ar equilibrium gas) was injected into the DMF mixture through the sampling port using a syringe. The magnetic stirrer was then turned on, and the mixture was stirred for 30 min. The apparatus was then placed under real sunlight for 6 h. During this period, 100 μL of gas was taken from the headspace of the reaction chamber every 1 h and analyzed by a gas chromatograph. The real-world photocatalytic hydrochlorination experiment of acetylene was conducted under solar radiation in Changsha, China (location: 28.184141°N, 112.950264°E, dates: July 21-23, 2024, temperature: 29-39℃, average light power: 79.45 mW / cm²). -2 Illuminance: 103697.29±15003.12 LUX.

[0048] Test results are as follows Figure 3 As shown in the figure, the conversion rate of acetylene gradually increases with time and exhibits high selectivity for vinyl chloride, indicating that it is feasible to use real sunlight for photocatalytic hydrochlorination of acetylene.

[0049] Examples 4-7: Photocatalytic hydrochlorination of acetylene to produce vinyl chloride under continuous conditions.

[0050] [Example 4] Qualitative Analysis of Continuous Photocatalytic Acetylene Hydrochlorination for Vinyl Chloride Production in a Small Chamber

[0051] A continuous-flow photocatalytic hydrochlorination reaction of acetylene was carried out in a 40 mL quartz glass reactor. First, 30 mL of DMF, concentrated hydrochloric acid (36.8-38.0%, 500 μL), and 30 mg of RuO2 / TNS photocatalyst were added to the reactor; then, the reactor was purged with Ar for at least 30 min to remove impurity gases from the photocatalytic cell. Next, under stirring conditions, the flow rate was controlled using a mass flow controller (AST10 series, ASERT Instruments (Beijing) Co., Ltd.) to introduce the acetylene feedstock (1.0 vol.% acetylene + Ar equilibrium; 2 sccm) into the DMF solvent. A 300 W xenon lamp (PLS-SXE300 / 300UV, 300 < λ < 780 nm) was turned on. The photocatalytic hydrochlorination reaction of acetylene was carried out for 0.5 h. The outlet gas sample was injected into a gas chromatograph-mass spectrometer for product analysis.

[0052] Test results are as follows Figure 4 As shown in the figure, the chromatogram contains two peaks: the first is acetylene, and the second is vinyl chloride. Furthermore, scanning and analysis of the second peak revealed a mass-to-weight ratio (m / z) of a specific fragment from the standard mass spectrum of vinyl chloride in the database. This result demonstrates that we have achieved the continuous-phase conversion of acetylene to vinyl chloride.

[0053] [Example 5] Performance Evaluation of Continuous Photocatalytic Acetylene Hydrochlorination for Vinyl Chloride Production in a Small Chamber

[0054] A continuous-flow photocatalytic hydrochlorination reaction of acetylene was carried out in a 40 mL quartz glass reactor. First, 30 mL of DMF, concentrated hydrochloric acid (38.0%, 500 μL), and 30 mg of RuO2 / TNS photocatalyst were added to the reactor; then, the reactor was purged with Ar for at least 30 min to remove impurity gases from the photocatalytic cell. Next, under stirring conditions, the flow rate was controlled using a mass flow controller (AST10 series, ASERT Instruments (Beijing) Co., Ltd.) to introduce acetylene feedstock (1.0 vol.% acetylene + Ar equilibrium; 2, 5, and 10 sccm) into the DMF solution. A 300 W xenon lamp (PLS-SXE300 / 300UV, 300 < λ < 780 nm) was turned on. The photocatalytic hydrochlorination reaction of acetylene was carried out for 3 h when the effluent gas product stabilized. After 30 min intervals, effluent gas samples were injected into a gas chromatograph for immediate product analysis.

[0055] Test results are as follows Figure 5 As shown in the figure, as the gas flow rate increases from 2 sccm to 10 sccm, the acetylene conversion rate decreases from an average of 50% to about 28%. This can be further improved by increasing the gas residence time at high flow rates, as shown in Example 6.

[0056] [Example 6] Performance evaluation of continuous photocatalytic hydrochlorination of acetylene to vinyl chloride production in a dual-chamber series configuration

[0057] Continuous-flow photocatalytic hydrochlorination of acetylene was carried out in 250 mL and 100 mL quartz glass reactors connected in series. First, 220 mL and 90 mL of DMF, 500 μL of concentrated hydrochloric acid (36.8-38.0%), and 220 mg and 90 mg of RuO2 / TNS photocatalyst were added to each reactor, respectively. The reactors were then purged with Ar for at least 30 min to remove impurities. Next, under stirring conditions, the flow rate was controlled using a mass flow controller (AST10 series, ASERT Instruments (Beijing) Co., Ltd.) to introduce acetylene feedstock (1.0 vol.% acetylene + Ar equilibrium; 2, 5, and 10 sccm) into the DMF solution. A 300 W xenon lamp (PLS-SXE300 / 300 UV, 300 < λ < 780 nm) was turned on. The initial reaction time was defined as the stable product in the outlet gas, and the photocatalytic hydrochlorination of acetylene was carried out for 3 h. After 30 min intervals, the outlet gas sample was injected into a gas chromatograph for immediate product analysis.

[0058] Test results are as follows Figure 6 As shown in the figure, as the gas flow rate increases from 2 sccm to 10 sccm, the acetylene conversion rate decreases from an average of 95% to about 52%, but its conversion rate is significantly higher than that of the 40 mL chamber, which verifies our hypothesis in Example 5.

[0059] [Example 7] Durability evaluation of continuous photocatalytic hydrochlorination of acetylene to vinyl chloride production in a dual-chamber series configuration

[0060] Continuous-flow photocatalytic hydrochlorination of acetylene was carried out in 250 mL and 100 mL quartz glass reactors connected in series. First, 220 mL and 90 mL of DMF, 500 μL of concentrated hydrochloric acid (38.0%), and 220 mg and 90 mg of RuO2 / TNS photocatalyst were added to each reactor, respectively. The reactors were then purged with Ar for at least 30 min to remove impurities. Next, under stirring conditions, the flow rate was controlled using a mass flow controller (AST10 series, ASERT Instruments (Beijing) Co., Ltd.) to introduce acetylene feedstock (1.0 vol.% acetylene + Ar equilibrium; 2 sccm) into the DMF solvent. A 300 W xenon lamp (PLS-SXE300 / 300 UV, 300 < λ < 780 nm) was turned on. The initial reaction time was defined as the stable product in the outlet gas, and the photocatalytic hydrochlorination of acetylene was carried out for 48 h. After 2 h intervals, outlet gas samples were injected into a gas chromatograph for immediate product analysis.

[0061] Test results are as follows Figure 7 As shown in the figure, a high acetylene conversion rate and vinyl chloride selectivity were achieved during the 48-hour durability test, indicating that the method of the present invention has good durability and certain potential for practical industrial application.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the continuous photocatalytic hydrochlorination of acetylene to produce vinyl chloride at room temperature, characterized in that, Includes the following steps: An organic solvent is added to a device with a sealed cap. A photocatalyst, a chlorine source, and a hydrogen source are added to the organic solvent. Before the reaction, an inert gas is introduced to remove impurities from the device and the solvent. Then, acetylene is introduced into the organic solvent and irradiated with a light source while continuously stirring. The gaseous product coming out of the device is vinyl chloride. The organic solvent is N,N-dimethylformamide; the photocatalyst is an A / B type catalyst, with active group A consisting of RuO2 and semiconductor support B consisting of TiO2 nanosheets.

2. The method according to claim 1, characterized in that, The loading of the active component A is 0.1-8.0 wt.% by mass, with the balance being the semiconductor carrier B.

3. The method according to claim 1, characterized in that, The hydrogen source is selected from any one or a mixture of multiple of the following: water, ethanol, methanol, tert-butanol, isopropanol, hydrochloric acid, hydrogen chloride gas, hypochlorous acid, perchloric acid, chloroacetyl, nitric acid, nitrous acid, sulfuric acid, sulfurous acid, phosphoric acid, boric acid, hydroiodic acid, hydrofluoric acid, hydrobromic acid, formic acid, acetic acid, ascorbic acid, citric acid, oxalic acid, and lactic acid.

4. The method according to claim 1, characterized in that, The chlorine source includes any one or a mixture of lithium chloride, hydrochloric acid, hydrogen chloride gas, cobalt chloride hexahydrate, copper chloride dihydrate, ferric chloride trihydrate, ferrous chloride tetrahydrate, manganese dichloride tetrahydrate, chromium trichloride hexahydrate, cerium trichloride heptahydrate, magnesium dichloride hexahydrate, hypochlorous acid, tert-butyl hypochlorite, chloroacetyl, N-succinimide chloride, trichloroisocyanuric acid, dichlorohydantoin, and chloramine-T.

5. The method according to claim 1, characterized in that, The acetylene feedstock is selected from at least one of pure acetylene or a mixed acetylene gas balanced with an inert gas or other alkyne compounds; the light source is selected from at least one of real sunlight, xenon lamp, mercury lamp, and LED lamp.

6. The method according to claim 1, characterized in that, The device with a sealing cap is a single chamber or multiple chambers connected in series.

7. The method according to claim 1, characterized in that, The amount of photocatalyst added is 0.01-10 g / L.

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