Supported catalyst and method for preparing 1, 1, 1, 3-tetrachloropropane

Abstract

The invention discloses a supported catalyst and method for preparing 1, 1, 1, 3-tetrachloropropane, and belongs to the technical field of industrial catalysis and organic chemistry, the supported catalyst comprises an alumina carrier and a ferrous chloride-phosphate ester complex active component supported by the alumina carrier; active components of the ferrous chloride-phosphate complex are loaded on the alumina carrier through an impregnation method, and an impregnation solution is prepared from anhydrous ferrous chloride, anhydrous phosphate and an anhydrous organic solvent in an anhydrous environment. The supported catalyst is simple and convenient in preparation process, low in cost, high in catalytic activity, high in carbon tetrachloride conversion rate, good in 1, 1, 1, 3-tetrachloropropane selectivity, easy to recycle, good in reusability and easy to popularize and use, and the problem that an existing catalyst is difficult to recycle or prone to inactivation can be solved.

Description

Technical Field

[0001] This invention relates to the fields of industrial catalysis and organic chemistry, specifically to a supported catalyst and method for preparing 1,1,1,3-tetrachloropropane. Background Technology

[0002] 1,1,1,3-Tetrachloropropane (HCC-250fb) is a key intermediate in the fine chemical industry, and its core application value is reflected in two dimensions: Firstly, HCC-250fb is a key precursor for the synthesis of 1,1,1,2,3-pentachloropropane (HCC-240db), and HCC-240db is a core intermediate for the preparation of the fourth-generation environmentally friendly refrigerant 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf). HFO-1234yf has become a mainstream alternative to traditional Freon refrigerants and is widely used. It has applications in automotive air conditioning, home refrigeration, and other fields. On the other hand, from the perspective of green chemistry, the HCC-250fb synthesis process provides a key solution for the efficient conversion and resource utilization of carbon tetrachloride. As a typical byproduct of methane chlorination plants, carbon tetrachloride is an ozone-depleting substance whose emissions are clearly restricted. Incinerating carbon tetrachloride is costly and poses a risk of secondary pollution. Therefore, if carbon tetrachloride can be converted into high-value-added HCC-250fb, it will have important practical significance for the green transformation and sustainable development of the chemical industry chain.

[0003] Currently, industry and academia have conducted extensive research on the synthesis of HCC-250fb. The core processes all utilize carbon tetrachloride and ethylene as raw materials, achieving the synthesis of HCC-250fb through a telomerization reaction. The technical bottleneck of this reaction lies in the compatibility between the catalyst system and the reaction process. Existing technical solutions still have several key shortcomings, as detailed below: The complexity of supported iron-based catalyst processes: For example, Chinese patent document CN114835554A discloses a process in which raw materials containing carbon tetrachloride and ethylene are reacted in the presence of a first catalyst and a second catalyst to obtain 1,1,1,3-tetrachloropropane. The first catalyst includes a support and an active component supported on the support. The support is modified bentonite or activated carbon, and the active component includes nano-zero-valent iron. The second catalyst includes an ester compound. Although this invention improves the dispersibility of iron through support modification, nano-zero-valent iron is easily oxidized by oxygen in the air, and the catalyst preparation process is complex. The reduction process requires strict control of nitrogen protection and pH value, and the reducing agent is prone to introducing impurities. Chinese patent document CN117839726A discloses a method for the continuous preparation of 1,1,1,3-tetrachloropropane using a metal-carbon composite catalyst. The main component of this composite catalyst is Cu-Ni-Cl-C / Fe. The catalyst preparation process includes four steps: mixing, carbonization, displacement, and loading. It relies on a special porous substrate of foamed iron and precise bimetallic ratio control, resulting in a preparation cycle of 10-15 hours. Furthermore, the cost of foamed iron raw materials is 3-5 times higher than that of conventional iron-based catalysts, hindering large-scale application. While the aforementioned patents related to supported iron catalysts can solve the agglomeration problem of traditional iron catalysts, they all suffer from complex preparation processes.

[0004] Problems with catalyst separation: For example, Chinese patent document CN120058468A discloses a method for synthesizing 1,1,1,3-tetrachloropropane, which uses a catalytic system composed of a carbon-coated elemental iron catalyst and a co-catalyst to synthesize 1,1,1,3-tetrachloropropane. The carbon-coated elemental iron catalyst is prepared by pyrolysis of ferric citrate. The corresponding process forms a carbon coating layer to inhibit the agglomeration of iron particles. However, the catalyst is in the form of fine powder, and after the reaction, it needs to be filtered through a filter membrane with high precision. The separation time is long, and fine powder residue is easy to be generated. Long-term accumulation can easily cause equipment and pipes to be blocked and worn.

[0005] Traditional iron-based catalysts suffer from activity decay and solid waste issues: Commercially available unmodified iron catalysts, such as iron powder, remain the choice for some companies, but their inherent defects cannot be avoided. On the one hand, iron particles tend to agglomerate and deposit at the bottom of the reactor, resulting in insufficient contact with reactants. On the other hand, during the reaction, co-catalysts (such as ester compounds) easily form a phosphate coating on the iron surface. At the same time, iron exposed to air or in the reaction system easily forms an oxide film (Fe2O3, FeO(OH)), leading to rapid decay of catalyst activity. The single-pass service life is less than 200 hours, requiring frequent shutdowns for replacement. This not only reduces production efficiency but also generates a large amount of iron-containing solid waste, which does not meet the requirements of green chemical development.

[0006] Furthermore, there is still room for optimization in the interaction mode between the co-catalyst and the main catalyst in the existing technology: In some of the aforementioned patents, the co-catalyst is added separately to the reaction system and interacts with the main catalyst in the field to form an active center. This process is prone to uneven mixing, which can lead to the dispersion and disorder of active sites and increase the probability of side reactions.

[0007] In summary, there is an urgent need to develop a catalyst system with a simple preparation process, controllable cost, and stable activity for the synthesis of HCC-250fb, and to match it with an efficient reaction process to meet the comprehensive requirements of industrial production for conversion rate, selectivity, and continuous operation cycle, while providing technical support for the resource utilization of carbon tetrachloride and the green development of the HFO-1234yf industrial chain. Summary of the Invention

[0008] To address the shortcomings of the existing technology, the present invention provides a supported catalyst for the preparation of 1,1,1,3-tetrachloropropane, which has high catalytic activity, can synthesize 1,1,1,3-tetrachloropropane in high yield and with high selectivity, and is easy to recover and has good reusability.

[0009] The specific technical solution adopted is as follows: A supported catalyst for the preparation of 1,1,1,3-tetrachloropropane, comprising an alumina support and a supported ferrous chloride-phosphate complex active component thereof. The active ingredient of ferrous chloride-phosphate complex is loaded onto an alumina support by impregnation. The impregnation solution is prepared in an anhydrous environment using anhydrous ferrous chloride, anhydrous phosphate, and anhydrous organic solvent.

[0010] Furthermore, the alumina support is γ-alumina, η-alumina, or θ-alumina, preferably γ-alumina.

[0011] Furthermore, in the impregnation solution, Fe in anhydrous ferrous chloride 2+ The molar ratio with anhydrous phosphate is 1:0.8~3.

[0012] Preferably, the phosphate ester is tributyl phosphate, trimethyl phosphate, triethyl phosphate, tripropyl phosphate or triisopropyl phosphate, and most preferably tributyl phosphate.

[0013] Phosphate esters were dried using a 5Å molecular sieve to remove water, and anhydrous ferrous chloride was obtained commercially.

[0014] Preferably, the anhydrous organic solvent is selected from one or more of tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, anhydrous ethanol, toluene, chloroform, and n-heptane, and its water content is ≤50 ppm.

[0015] More preferably, the anhydrous organic solvent is one of toluene, tetrahydrofuran, or n-heptane, or a solvent in which anhydrous ethanol and toluene are mixed in a volume ratio of 1:3 to 5, or a solvent in which tetrahydrofuran and n-heptane are mixed in a volume ratio of 1:2 to 4.

[0016] In this supported catalyst, the loading of the ferrous chloride-phosphate complex active component is 5–30 wt%.

[0017] The present invention also provides a method for preparing the supported catalyst, comprising the following steps: (1) The alumina support is vacuum dried, then treated at 400~500℃ for 3~5 hours under nitrogen atmosphere, and then naturally cooled to obtain the pretreated alumina support; (2) In an anhydrous environment protected by an inert gas, anhydrous phosphate ester is added to anhydrous organic solvent, stirred, and then added according to Fe... 2+ Add anhydrous ferrous chloride solid at a molar ratio of 1:0.8~3 to phosphate ester, heat to total reflux and stir for 2~4 hours (heating temperature is near the boiling point of the solvent) to form a homogeneous impregnation solution; (3) Add the alumina support after the pretreatment in step (1) to the impregnation solution obtained in step (2), and stir under the protection of inert gas to load the active ingredient of ferrous chloride-phosphate complex onto the alumina support. (4) The solvent in the mixture obtained in step (3) is removed by vacuum evaporation, and the solid residue is dried under vacuum to obtain the supported catalyst.

[0018] In the preparation of the supported catalyst of this invention, anhydrous phosphate ester is first dissolved in an anhydrous organic solvent, and then anhydrous ferrous chloride solid is added. After the phosphate ester is dispersed in the organic solvent, ferrous chloride, which has poor solubility, is added. The ferrous chloride is coordinated and encapsulated by the surrounding phosphate ester molecules, thereby achieving coordination dissolution. If moisture content is strictly controlled, ferrous chloride can be added first, followed by phosphate ester. The corresponding reaction requires strict control of the anhydrous environment to ensure the successful preparation of the impregnation solution.

[0019] Preferably, in step (1), the vacuum drying conditions for the alumina carrier are 110~130℃ for 4~6 hours.

[0020] Preferably, in step (1), the vacuum-dried alumina support is heated to 400-500°C at a heating rate of 2-5°C / min under a nitrogen atmosphere and held for 3-5 hours.

[0021] The pretreated alumina carrier has removed impurities and chemically bound water, resulting in a more stable physical structure.

[0022] Preferably, in step (2), when preparing the ferrous chloride-phosphate complex impregnation solution, the mass ratio of anhydrous organic solvent to anhydrous phosphate is 2~10:1.

[0023] Preferably, in step (3), the ratio of the pretreated alumina carrier to the impregnation solution is 1g:1~10mL, and the stirring conditions are: stirring at 20~30℃ for 1~3 hours.

[0024] Preferably, in step (4), the conditions for removing the solvent by vacuum evaporation are: 40~100℃, -0.08~-0.1 MPa, and the conditions for vacuum drying the solid residue are: 50~90℃, 4~12 hours.

[0025] The present invention also provides a method for synthesizing 1,1,1,3-tetrachloropropane, wherein carbon tetrachloride and ethylene are used as raw materials in the presence of the supported catalyst to obtain 1,1,1,3-tetrachloropropane after reaction.

[0026] Specifically, the synthesis method includes the following steps: adding carbon tetrachloride and the supported catalyst to a reaction vessel, wherein the mass ratio of carbon tetrachloride to the supported catalyst is 10:0.1~5; after purging ethylene to replace the air in the vessel, reacting for 3~10 hours at a stirring speed of 300~1000 rpm, a reaction pressure of 0.2~1.0 MPa, and a reaction temperature of 80~130℃, wherein the molar ratio of carbon tetrachloride to ethylene is 1:1~2; after the reaction is completed, cooling and depressurizing are performed, and the crude product is obtained by filtration, followed by distillation to obtain 1,1,1,3-tetrachloropropane with a purity ≥99.5%.

[0027] Preferably, the mass ratio of carbon tetrachloride to the supported catalyst is 10:0.1~1.

[0028] Preferably, the stirring speed is 600~800 rpm, the reaction pressure is 0.45~0.65 MPa, the reaction temperature is 95~110℃, and the reaction time is 4~6 hours.

[0029] Preferably, after the reaction is complete, the used supported catalyst is washed with an organic solvent, dried under vacuum, and then reused for the synthesis of 1,1,1,3-tetrachloropropane.

[0030] More preferably, the organic solvent used for washing is anhydrous toluene or tetrahydrofuran, and the vacuum drying conditions are 60~80℃ vacuum drying for 4 hours.

[0031] Experimental data demonstrate that the supported catalyst exhibits a carbon tetrachloride conversion rate of ≥75% and a 1,1,1,3-tetrachloropropane selectivity of ≥95% after being reused three times, indicating good reusability.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The catalyst preparation process is simple and low cost: The supported catalyst provided by the present invention does not require reducing agent, carbonization equipment or precious metals. It can be prepared by conventional complexation and impregnation process. The raw materials are readily available (γ-alumina, anhydrous FeCl2, phosphate esters, etc. are all commercially available conventional chemicals). The preparation cost is significantly lower than that of existing bimetallic catalysts.

[0033] (2) High reaction selectivity and conversion rate: The supported catalyst provided by the present invention includes an alumina support and its supported ferrous chloride-phosphate ester complex active component. The corresponding active component can directionally catalyze the polymerization reaction and inhibit the excessive reaction of ethylene self-polymerization and carbon tetrachloride during the synthesis of 1,1,1,3-tetrachloropropane. The selectivity of 1,1,1,3-tetrachloropropane is ≥97.5% and the conversion rate of carbon tetrachloride is ≥78%, which is a great technical effect.

[0034] (3) The catalyst is easy to recover and stable: The supported catalyst provided by the present invention has good particle properties and can be quickly separated by a simple filtration method. The recovery rate is ≥95%, and the activity does not significantly decrease after being reused 3 times. It can solve the problem of existing catalysts being difficult to recover or easily deactivated.

[0035] (4) Strong process adaptability: When preparing 1,1,1,3-tetrachloropropane using a supported catalyst, the equipment used in this invention is an intermittent high-pressure reactor, and there are no special operating requirements. It can be industrialized without modifying existing equipment, and is easy to promote and scale up production. Attached Figure Description

[0036] Figure 1 The image shows a SEM image of the supported catalyst prepared in Example 1.

[0037] Figure 2 The image shows the gas chromatogram of 1,1,1,3-tetrachloropropane. Detailed Implementation

[0038] To make the objectives, features, and advantages of this invention more apparent and understandable, a detailed description is provided below through specific embodiments. Many specific details are set forth in the following description to provide a thorough understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below. Technical features in various embodiments of the invention can be combined appropriately without mutual conflict.

[0039] Unless otherwise specified, the operating methods in the following examples are generally performed under conventional conditions or as recommended by the manufacturer. Contents not described in detail in this specification are prior art known to those skilled in the art. Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0040] Example 1 Preparation of supported catalysts (1) Pretreatment of alumina support: Take 50 g of γ-alumina support, place it in a vacuum drying oven, and vacuum dry it at 120℃ for 5 h to remove the surface physically adsorbed water. Then transfer the dried alumina to a muffle furnace, raise the temperature to 450℃ at a heating rate of 3℃ / min under a nitrogen atmosphere, keep it at the temperature for 4 h, and cool it naturally to room temperature to obtain the pretreated alumina support.

[0041] (2) Preparation of ferrous chloride-tributyl phosphate complex impregnation solution: In a glove box under high-purity nitrogen protection, 200 g of anhydrous toluene (water content <30 ppm) and 40 g of anhydrous tributyl phosphate were added to a 500 mL three-necked flask and magnetically stirred for 10 min at room temperature. Then, 21 g of anhydrous ferrous chloride solid was slowly added to the above solution, and the mixture was heated to 113℃ (the boiling point of toluene is 110.6℃) and stirred for 2 h under total reflux to form a homogeneous and stable ferrous chloride-tributyl phosphate complex impregnation solution.

[0042] (3) Impregnation loading: 50 g of the pretreated γ-alumina support obtained in step (1) was added to 100 mL of the complex impregnation solution prepared in step (2). Under nitrogen protection, the mixture was magnetically stirred at 25 °C for 2 hours to allow the complex to be fully adsorbed and dispersed on the surface and in the pores of the alumina support.

[0043] (4) Solvent removal and drying: The mixture obtained in step (3) was transferred to a rotary evaporator and the solvent was removed by vacuum evaporation at 75°C and -0.09 MPa. Finally, the solid residue was placed in a vacuum drying oven and dried at 80°C for 8 hours to obtain the supported catalyst Cat-1 for the preparation of 1,1,1,3-tetrachloropropane. The loading of the active component of ferrous chloride-phosphate complex in the catalyst was 17 wt%.

[0044] The SEM image of the supported catalyst prepared in this embodiment is shown below. Figure 1 As shown in the figure, it has a multi-sized porous structure, which helps to provide more contact sites and active centers, thereby improving the catalytic efficiency of the catalyst.

[0045] Example 2: Telomerization reaction 200 g of carbon tetrachloride and 5 g of the supported catalyst Cat-1 prepared in Example 1 were added to a 500 mL stainless steel high-pressure reactor equipped with a mechanical stirrer and an electric heating mantle. The reactor was closed, and the air inside was replaced three times with ethylene gas (each time, ethylene was introduced to 0.05 MPa, and the pressure was maintained for 10 minutes before being released). The mechanical stirrer was turned on and set to a speed of 700 rpm. Ethylene gas was continued to be introduced until the initial pressure inside the reactor reached 0.3 MPa. The temperature was then raised to 100 °C to start the reaction. During the reaction, gas was continuously supplied through an ethylene cylinder to maintain a stable pressure inside the reactor at 0.5 ± 0.02 MPa. The molar ratio of carbon tetrachloride to ethylene was controlled at 1:1.5. The reaction was maintained at 100 °C and pressure for 5 hours. After the reaction was completed, heating and stirring were stopped, and the reactor was allowed to cool naturally to room temperature and then slowly depressurized to atmospheric pressure. The reactor was opened, the reaction liquid was discharged, and the supported catalyst Cat-1 was separated by filtering through a 0.22 μm polytetrafluoroethylene filter membrane. The filtrate is the crude product of 1,1,1,3-tetrachloropropane. The crude product is then purified by distillation to obtain 1,1,1,3-tetrachloropropane with a purity ≥99.5%. The gas chromatogram of 1,1,1,3-tetrachloropropane is shown below. Figure 2 As shown, calculations show that the conversion rate of carbon tetrachloride is 95.2%, and the selectivity for 1,1,1,3-tetrachloropropane is 98.1%.

[0046] Example 3: Catalyst Reuse Performance Test After the reaction was completed, the supported catalyst Cat-1 obtained by filtration in Example 2 was recovered. The catalyst was washed twice with 50 mL of anhydrous toluene and then dried in a vacuum drying oven at 70 °C for 4 hours. The regenerated catalyst was used again for the telomerization reaction under the same conditions as in Example 2. This "reaction-washing-drying" process was repeated three times, and the results for each use were as follows: First use (fresh catalyst): Carbon tetrachloride conversion 95.2%, selectivity for 1,1,1,3-tetrachloropropane 98.1%. Second use: Carbon tetrachloride conversion 87.5%, selectivity for 1,1,1,3-tetrachloropropane 97.3%. Third use: Carbon tetrachloride conversion 82.3%, selectivity for 1,1,1,3-tetrachloropropane 96.0%. The results show that the synthesized supported catalyst maintains high activity and selectivity even after three reuses, exhibiting good stability.

[0047] Example 4 Preparation of supported catalysts The difference between the preparation method of the supported catalyst in this embodiment and the supported catalyst Cat-1 in Example 1 is only that tributyl phosphate is replaced with an equimolar amount of triethyl phosphate, and all other experimental parameters and steps are the same as in Example 1, so that the supported catalyst Cat-2 is prepared.

[0048] The telomerization reaction was carried out using the supported catalyst Cat-2 under the same reaction conditions as in Example 2. The results showed that the conversion rate of carbon tetrachloride was 92.5% and the selectivity of 1,1,1,3-tetrachloropropane was 96.8%.

[0049] Example 5 Preparation of supported catalysts The difference between the preparation method of the supported catalyst in this embodiment and the supported catalyst Cat-1 in Example 1 is only that anhydrous toluene is replaced with a mixed solvent of anhydrous tetrahydrofuran and anhydrous n-heptane (volume ratio 1:3, water content <30ppm). All other experimental parameters and steps are the same as in Example 1, and the supported catalyst Cat-3 is prepared.

[0050] The telomerization reaction was carried out using the supported catalyst Cat-3 under the same reaction conditions as in Example 2. The results showed that the conversion rate of carbon tetrachloride was 93.8% and the selectivity of 1,1,1,3-tetrachloropropane was 97.5%.

[0051] Example 6 Telomerization reaction In this embodiment, the supported catalyst Cat-1 prepared in Example 1 was used for telomerization reaction. The only difference between the telomerization reaction conditions and those in Example 2 was that the reaction temperature was increased to 110°C. All other experimental parameters and steps were the same as in Example 2. The results showed that the conversion rate of carbon tetrachloride was 96.8% and the selectivity of 1,1,1,3-tetrachloropropane was 97.9%.

[0052] Example 7 Telomerization reaction In this embodiment, the supported catalyst Cat-1 prepared in Example 1 was used for telomerization reaction. The only difference between the telomerization reaction conditions and those in Example 2 was that the amount of supported catalyst Cat-1 was increased to 10 g (i.e., the mass ratio of carbon tetrachloride to catalyst was 10:0.5). All other experimental parameters and steps were the same as in Example 2. The test results showed that the conversion rate of carbon tetrachloride was 97.5% and the selectivity of 1,1,1,3-tetrachloropropane was 98.6%.

[0053] Comparative Example 1 This comparative example uses commercially available reduced iron powder as a catalyst for telomerization reaction. The only difference between the telomerization reaction conditions and those in Example 2 is that 200 g of carbon tetrachloride, 1.1 g of tributyl phosphate, and 1 g of commercially available reduced iron powder (200 mesh) were added to the reactor. All other experimental parameters and steps were the same as in Example 2. The test results showed that the conversion rate of carbon tetrachloride was 65.4%, the selectivity of 1,1,1,3-tetrachloropropane was 85.2%, and the iron powder was severely agglomerated and deposited at the bottom of the reactor after the reaction, making it difficult to separate.

[0054] Comparative Example 2 Catalyst preparation: Take 50 g of the pretreated alumina support obtained in step (1) of Example 1, and directly immerse it in 100 mL of N,N-dimethylformamide solution containing anhydrous ferrous chloride (without pre-complexing with phosphate ester), stir for 2 hours and then dry to obtain a catalyst supported only on ferrous chloride.

[0055] Telogenization reaction: 200 g of carbon tetrachloride and 1.2 g of tributyl phosphate were added to the reactor, followed by 4 g of the catalyst (previously loaded only with ferrous chloride). All other experimental parameters and procedures were the same as in Example 2. The conversion rate of carbon tetrachloride was 88.7%, and the selectivity for 1,1,1,3-tetrachloropropane was 91.5%. The types and amounts of byproducts were significantly higher than in Example 2, indicating that physical mixing led to uneven dispersion of active sites, poor reaction orientation, and the inability to recover pure tributyl phosphate.

[0056] The embodiments described above provide a detailed explanation of the technical solutions of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, or similar substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A supported catalyst for the preparation of 1,1,1,3-tetrachloropropane, characterized in that, This includes the alumina carrier and the ferrous chloride-phosphate complex active ingredient supported thereon; The active ingredient of ferrous chloride-phosphate complex is loaded onto an alumina support by impregnation. The impregnation solution is prepared in an anhydrous environment using anhydrous ferrous chloride, anhydrous phosphate, and anhydrous organic solvent.

2. The supported catalyst for preparing 1,1,1,3-tetrachloropropane according to claim 1, characterized in that, The alumina support is γ-alumina, η-alumina, or θ-alumina.

3. The supported catalyst for preparing 1,1,1,3-tetrachloropropane according to claim 1, characterized in that, Fe in anhydrous ferrous chloride in the impregnation solution 2+ The molar ratio with anhydrous phosphate is 1:0.8~3.

4. The supported catalyst for preparing 1,1,1,3-tetrachloropropane according to claim 1, characterized in that, The phosphate ester is tributyl phosphate, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, or triisopropyl phosphate.

5. The supported catalyst for preparing 1,1,1,3-tetrachloropropane according to claim 1, characterized in that, The anhydrous organic solvent is selected from one or more of tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide, anhydrous ethanol, toluene, chloroform, and n-heptane, and its water content is ≤50 ppm.

6. The supported catalyst for preparing 1,1,1,3-tetrachloropropane according to claim 1, characterized in that, The phosphate ester is tributyl phosphate, and the anhydrous organic solvent is one of toluene, tetrahydrofuran or n-heptane, or a solvent of anhydrous ethanol and toluene in a volume ratio of 1:3 to 5, or a solvent of tetrahydrofuran and n-heptane in a volume ratio of 1:2 to 4.

7. The method for preparing the supported catalyst according to any one of claims 1-6, characterized in that, Includes the following steps: (1) The alumina support is vacuum dried, then treated at 400~500℃ for 3~5 hours under nitrogen atmosphere, and then naturally cooled to obtain the pretreated alumina support; (2) In an anhydrous environment protected by an inert gas, anhydrous phosphate ester is added to anhydrous organic solvent, stirred, and then added according to Fe... 2+ Add anhydrous ferrous chloride solid at a molar ratio of 1:0.8~3 with phosphate ester, heat to total reflux and stir for 2~4 hours to form a homogeneous impregnation solution; (3) Add the alumina support after the pretreatment in step (1) to the impregnation solution obtained in step (2), and stir under the protection of inert gas to load the active ingredient of ferrous chloride-phosphate complex onto the alumina support. (4) The solvent in the mixture obtained in step (3) is removed by vacuum evaporation, and the solid residue is dried under vacuum to obtain the supported catalyst.

8. The method for preparing the supported catalyst according to claim 7, characterized in that, In step (1), the alumina support is vacuum dried at 110~130℃ for 4~6 hours; the vacuum-dried alumina support is heated to 400~500℃ at a heating rate of 2~5℃ / min under a nitrogen atmosphere and held for 3~5 hours.

9. The method for preparing the supported catalyst according to claim 7, characterized in that, In step (2), when preparing the ferrous chloride-phosphate complex impregnation solution, the mass ratio of anhydrous organic solvent to anhydrous phosphate is 2~10:

1.

10. The method for preparing the supported catalyst according to claim 7, characterized in that, In step (3), the ratio of the pretreated alumina carrier to the impregnation solution is 1g:1~10mL, and the stirring conditions are: stirring at 20~30℃ for 1~3 hours.

11. The method for preparing the supported catalyst according to claim 7, characterized in that, In step (4), the conditions for removing the solvent by vacuum evaporation are: 40~100℃, -0.08~-0.1 MPa, and the conditions for vacuum drying the solid residue are: 50~90℃, 4~12 hours.

12. A method for synthesizing 1,1,1,3-tetrachloropropane, characterized in that, Under the action of any of the supported catalysts described in claims 1-6, 1,1,1,3-tetrachloropropane is obtained after reaction using carbon tetrachloride and ethylene as raw materials.

13. The method for synthesizing 1,1,1,3-tetrachloropropane according to claim 12, characterized in that, The synthesis method includes the following steps: adding carbon tetrachloride and the supported catalyst to a reactor, wherein the mass ratio of carbon tetrachloride to the supported catalyst is 10:0.1~5; after purging the reactor with ethylene to replace the air, reacting for 3~10 hours at a stirring speed of 300~1000 rpm, a reaction pressure of 0.2~1.0 MPa, and a reaction temperature of 80~130℃, wherein the molar ratio of carbon tetrachloride to ethylene is 1:1~2; after the reaction is completed, cooling and depressurizing are performed, and the crude product is obtained by filtration, followed by distillation to obtain 1,1,1,3-tetrachloropropane with a purity ≥99.5%.

14. The method for synthesizing 1,1,1,3-tetrachloropropane according to claim 13, characterized in that, The mass ratio of carbon tetrachloride to the supported catalyst is 10:0.1~1.

15. The method for synthesizing 1,1,1,3-tetrachloropropane according to claim 13, characterized in that, The stirring speed is 600~800 rpm, the reaction pressure is 0.45~0.65 MPa, the reaction temperature is 95~110℃, and the reaction time is 4~6 hours.

16. The method for synthesizing 1,1,1,3-tetrachloropropane according to claim 13, characterized in that, After the reaction was completed, the used supported catalyst was washed with an organic solvent, dried under vacuum, and reused for the synthesis of 1,1,1,3-tetrachloropropane.

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