A method for preparing 1,1,1,3-tetrachloropropane

Abstract

The present application discloses a method for preparing 1,1,1,3-tetrachloropropane, comprising: reacting a raw material containing carbon tetrachloride and ethylene in the presence of a first catalyst and a second catalyst to obtain the 1,1,1,3-tetrachloropropane; the first catalyst comprises a carrier and an active component supported on the carrier; the active component comprises nano zero-valent iron; and the second catalyst comprises an ester compound. The preparation method adopts a supported iron catalyst, which can significantly improve the problem of easy agglomeration when pure commercially available iron powder is used as a catalyst, and at the same time increases the specific surface area of ​​iron, which is conducive to the reaction.

Description

Technical Field

[0001] The present application relates to a method for preparing 1,1,1,3-tetrachloropropane, and belongs to the technical field of chemical industry. Background Art

[0002] Carbon tetrachloride is a by-product of the methane chloride plant. Carbon tetrachloride is a controlled substance that depletes the ozone layer as stipulated in the Montreal Protocol, referred to as CTC. Except for raw material use, reagent use and special exemption use, the production and consumption of CTC will be completely stopped. In recent years, China's methane chloride has developed rapidly. It is difficult to digest the produced CTC by relying on the raw material market. The cost of incineration of carbon tetrachloride is about 3,000 to 4,000 yuan per ton. Therefore, the comprehensive utilization of CTC is of great practical significance and is related to the survival and safety of the entire industrial chain.

[0003] The metals and co-catalysts reported in the literature mainly include: organic copper compounds and organic nitrile compounds; iron or its compounds, and organic phosphorus compounds.

[0004] The iron powder currently used in the iron or its compound and organophosphorus compound catalysts is commercially available iron powder. When the commercially available iron powder is used as the main catalyst, it is easy to agglomerate at the bottom of the reactor. Due to long-term contact with air, an oxide film is formed on the surface, which reduces the reaction activity.

[0005] In summary, the art still lacks a catalyst for the synthesis of 1,1,1,3-tetrachloropropane from carbon tetrachloride which has better dispersibility, larger contact area with reactants and higher selectivity than commercially available iron powder. Summary of the invention

[0006] According to one aspect of the present application, a method for preparing 1,1,1,3-tetrachloropropane is provided. The preparation method uses a supported iron main catalyst, which can significantly improve the problem of easy agglomeration of commercially available iron powder, while increasing the specific surface area of ​​iron. At the same time, a second nano-metal component is added to effectively solve the problem that the freshly prepared nano-iron catalyst is easily oxidized when exposed to air, which is beneficial to the reaction.

[0007] A method for preparing 1,1,1,3-tetrachloropropane, the method comprising:

[0008] In the presence of a first catalyst and a second catalyst, reacting a raw material containing carbon tetrachloride and ethylene to obtain the 1,1,1,3-tetrachloropropane;

[0009] The first catalyst comprises a carrier and an active component supported on the carrier;

[0010] The active component includes nano zero-valent iron;

[0011] The second catalyst includes an ester compound.

[0012] Optionally, the active component also includes at least one of platinum and copper.

[0013] Optionally, the active ingredient is selected from any one of zero-valent iron nanoparticles, Pd-Fe bimetallic nanoparticles, and Cu-Fe bimetallic nanoparticles.

[0014] Optionally, the carrier comprises at least one of the porous materials

[0015] Optionally, the porous material comprises bentonite and / or activated carbon.

[0016] Optionally, the bentonite is obtained by modification with a surfactant;

[0017] The activated carbon is obtained through acid modification treatment.

[0018] Optionally, the surfactant includes at least one of a quaternary ammonium salt;

[0019] The acid includes any one of HCl, H3PO4, and HNO3.

[0020] Optionally, the quaternary ammonium salt comprises cetyltrimethylammonium bromide.

[0021] Optionally, the acid modification treatment is: mixing the activated carbon with an acid solution and refluxing at 80-100° C. for 3-8 hours.

[0022] Optionally, the concentration of the acid solution is 10-30%.

[0023] Optionally, the mass volume ratio of the activated carbon to the acid solution is 5-15:80-120 g / mL.

[0024] Optionally, the surfactant modification treatment is: mixing the bentonite aqueous solution with the surfactant, adjusting the pH value to acidic, stirring and washing at 50-80°C.

[0025] Optionally, the mass ratio of the bentonite to the surfactant is 30-60:15-25.

[0026] Optionally, the surfactant modification treatment is more specifically as follows: 50g of bentonite is used to prepare 10% mud; 19.2g of hexadecyltrimethylammonium bromide is added. PH=5; 70°C, stirred for 2h, filtered, washed with deionized water for 3 times; analysis: 2% AgNO3 does not detect bromine. Oven at 100°C overnight.

[0027] Optionally, in the first catalyst, the loading amount of the active component is 5.01 to 50.1 wt %.

[0028] Optionally, in the first catalyst, the upper limit of the loading amount of the active component is selected from 8wt%, 13wt%, 20wt%, 25wt%, 30wt%, 40wt%, or 50.1wt%; the lower limit is selected from 5.01wt%, 8wt%, 13wt%, 20wt%, 25wt%, 30wt% or 40wt%.

[0029] Optionally, in the Pd-Fe bimetallic nanoparticles, the mass ratio of the Fe to the Pd is 5-50:0.01-0.1;

[0030] In the Cu-Fe bimetallic nanoparticles, the mass ratio of the Cu to the Fe is 0.5-1.5:0.5-1.5.

[0031] Optionally, in the Pd-Fe bimetallic nanoparticles, the mass ratio of the Fe to the Pd is 10-30:0.01-0.08.

[0032] Optionally, in the Pd-Fe bimetallic nanoparticles, the mass ratio of the Fe to the Pd is 13-25:0.01-0.04.

[0033] Optionally, in the Cu-Fe bimetallic nanoparticles, the mass ratio of the Cu to the Fe is 0.8-1.2:0.8-1.2.

[0034] Optionally, the mass ratio of the carbon tetrachloride to the first catalyst is 50:1 to 10;

[0035] The first catalyst is calculated based on the mass of the first catalyst itself.

[0036] Optionally, the mass ratio of the carbon tetrachloride to the first catalyst is 50:1-6.

[0037] Optionally, the mass ratio of the carbon tetrachloride to the first catalyst is 50:1-4.

[0038] Optionally, the mass ratio of the carbon tetrachloride to the first catalyst is 50:3-6.

[0039] Optionally, the second catalyst comprises at least one of a phosphate ester or a phosphite ester.

[0040] Optionally, the phosphate ester includes at least one of tributyl phosphate, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and dibutyl phosphate;

[0041] The phosphite includes tributyl phosphite.

[0042] Optionally, the mass ratio of the second catalyst to the first catalyst is 1.25-5:1-6;

[0043] The second catalyst is measured by the mass of the second catalyst itself, and the first catalyst is measured by the mass of the first catalyst itself.

[0044] Optionally, the mass ratio of the second catalyst to the first catalyst is 1.25-3:1-6.

[0045] Optionally, the mass ratio of the second catalyst to the first catalyst is 1.25-2:3-6.

[0046] Optionally, the preparation method comprises: placing the carbon tetrachloride, the first catalyst and the second catalyst into a reactor, introducing the ethylene, reacting, and obtaining the 1,1,1,3-tetrachloropropane.

[0047] Optionally, the introducing of ethylene is specifically: before the reaction, ethylene is introduced into the air in the reactor to replace the air for more than two times, and then ethylene is continuously introduced to carry out the reaction.

[0048] Optionally, the reaction conditions include: pressure 0.04-0.08 MPa.

[0049] Optionally, the upper limit of the pressure is selected from 0.05, 0.06, 0.07, 0.08 MPa; the lower limit is selected from 0.04, 0.05, 0.06, 0.07 MPa.

[0050] Optionally, the reaction conditions include: a temperature of 60 to 140°C.

[0051] Optionally, the upper temperature limit is selected from 80, 100, 120, 140°C; the lower temperature limit is selected from 60, 80, 100, 120°C.

[0052] Optionally, the reaction conditions include: a reaction time of 2 to 10 hours.

[0053] Optionally, the upper limit of the time is selected from 3, 5, 8, and 10 hours; the lower limit is selected from 2, 3, 5, and 8 hours.

[0054] Optionally, the reaction conditions include: reacting under stirring at a stirring speed of 800 to 2000 rpm.

[0055] Optionally, the upper limit of the rotation speed is selected from 1000, 1200, 1500, 1800, 2000 rpm; the lower limit is selected from 800, 1000, 1200, 1500, 1800 rpm.

[0056] The beneficial effects of this application include:

[0057] 1) The preparation method of 1,1,1,3-tetrachloropropane provided in the present application loads the active ingredient iron of the catalyst on a carrier, which can significantly improve the problem of easy agglomeration of commercially available iron powder when used as a catalyst, has good catalytic performance, and the catalyst is easy to remove from the reactor after the reaction is completed.

[0058] 2) The method for preparing 1,1,1,3-tetrachloropropane provided in the present application uses nanoparticles of catalytic iron, which have smaller particle size, larger specific surface area and better catalytic effect compared with commercially available iron powder or inorganic salt and other compound catalysts.

[0059] 3) In the method for preparing 1,1,1,3-tetrachloropropane provided in the present application, the carrier is modified so that the active ingredient can be better attached, the contact area with the nano zero-valent iron is increased, and it is beneficial to the reaction. DETAILED DESCRIPTION

[0060] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0061] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0062] Among them, commercially available iron powder was purchased from Sinopharm Chemical Reagent Co., Ltd., CAS: 7439-89-6.

[0063] In the present application, the first catalyst is equivalent to the main catalyst; the second catalyst is equivalent to the co-catalyst.

[0064] As a specific embodiment, the present application provides a method for synthesizing 1,1,1,3-tetrachloropropane from carbon tetrachloride and ethylene. The catalyst used in the method has the advantages of high utilization rate and good selectivity.

[0065] In a first aspect of the present invention, a catalyst for the reaction of synthesizing 1,1,1,3-tetrachloropropane from the chlorinated byproduct carbon tetrachloride is provided. The catalyst comprises a catalytically effective amount of a metal component: nano zero-valent iron or nano Pd-Fe bimetallic; and an organic bentonite or activated carbon carrier.

[0066] In another preferred embodiment, the catalyst is selected from the following group: Fe / organic bentonite, Pd-Fe / organic bentonite, Pd-Fe / modified activated carbon.

[0067] In another preferred embodiment, the method for preparing the catalyst comprises the steps of:

[0068] (i) A metal salt (FeSO4·7H2O) ethanol-water solution with a carrier (organic bentonite) and a reducing agent (NaBH4) solution are used for reduction reaction to obtain nanometer zero-valent iron supported by organic bentonite; a second metal component (PdCl2) is added; the reduction reaction is continued; the Pd content in the obtained catalyst is: 0.04%. Filter and dry in a vacuum drying oven. Nitrogen is continuously introduced during the entire reaction process to isolate the air.

[0069] In another preferred embodiment, the metal salt is FeCl2·4H2O.

[0070] In another preferred embodiment, the carrier is modified activated carbon.

[0071] In another preferred embodiment, the reducing agent is KBH4.

[0072] In another preferred example, the second metal component is K2PdCl6.

[0073] In another preferred embodiment, the solvent is an aqueous solution.

[0074] The second aspect of the present invention provides a method for synthesizing 1,1,1,3-tetrachloropropane by reacting carbon tetrachloride with ethylene, the method comprising the steps of: mixing the catalyst described in the first aspect with carbon tetrachloride, adding a co-catalyst triethyl phosphite to form a catalyst-carbon tetrachloride mixed solution, continuously introducing ethylene gas, and reacting at high temperature and high pressure.

[0075] In another preferred embodiment, the co-catalyst is: tributyl phosphate, trimethyl phosphate, tributyl phosphite, triethyl phosphate, triphenyl phosphate, dibutyl phosphate.

[0076] In another preferred embodiment, the reaction is carried out in a closed reactor.

[0077] In another preferred embodiment, the mass ratio of the catalyst (calculated as nano zero-valent iron) to carbon tetrachloride is 0.0025-0.04:1.

[0078] In another preferred embodiment, the feed ratio of the triethyl phosphite to the catalyst (calculated as nano zero-valent iron) is 1.25-5.

[0079] In another preferred embodiment, the reaction temperature is 80-140°C.

[0080] In another preferred embodiment, the reaction time is 2 to 7 hours.

[0081] In another preferred embodiment, the pressure during the reaction is 0.04-0.08 MPa.

[0082] In another preferred embodiment, the stirring speed is 1200 rpm.

[0083] In another preferred embodiment, after the catalyst is recovered, the reaction is repeated twice to observe the conversion rate and selectivity.

[0084] As a specific implementation scheme, the preparation method of 1,1,1,3-tetrachloropropane provided in the present application is:

[0085] In a 100ml stainless steel autoclave with mechanical stirring, add 50g of carbon tetrachloride, then add 1-10g of catalyst, iron loading: 5-25%; (iron loading is based on the input material) then pass ethylene to replace the residual air in the reactor twice, after this step is completed, fill with ethylene gas to 0.04-0.08MPa, heat to 60-140°C), react for 2-10 hours; keep passing ethylene until the reaction is completed, after the reaction is completed, cool naturally, and take the reaction liquid for gas chromatography analysis.

[0086] As a specific embodiment, the present application provides a catalyst for the synthesis of 1,1,1,3-tetrachloropropane from carbon tetrachloride and ethylene, wherein the main catalyst is nano-Fe / organic bentonite or nano-Pd-Fe / organic bentonite or nano-Pd-Fe / activated carbon, and the co-catalyst is triethyl phosphite.

[0087] As a specific embodiment, the present application provides a method for preparing a catalyst for the synthesis of 1,1,1,3-tetrachloropropane from carbon tetrachloride and ethylene, the method comprising the steps of:

[0088] (i) reacting cetyltrimethylammonium bromide (CTMAB) with bentonite to obtain CTMAB-modified organobentonite;

[0089] (ii) Modified bentonite is impregnated with ferrous salt; for example, FeSO4·7H2O or FeCl2·4H2O, and the solvent is an ethanol-water system or pure water.

[0090] (iii) The ferrous solution is reduced by a reducing agent such as NaBH4 or KBH4. Nitrogen is continuously introduced throughout the reduction process to maintain an oxygen-free environment.

[0091] (iv) Continue to add K2PdCl4 or PdCl2 and stir until the reaction is complete.

[0092] (v) Drying in a vacuum oven, avoiding long-term contact with air during the whole process to prevent the prepared nano-iron from being oxidized.

[0093] The preferred solvent is ethanol-water to dissolve the ferrous salt. On the one hand, a large number of bubbles will be generated during the reduction process, and ethanol can be used as a solvent to eliminate the bubbles. The newly prepared catalyst is easily oxidized if it is not exposed to air for a long time.

[0094] As a specific embodiment, the present application provides a method for synthesizing 1,1,1,3-tetrachloropropane by reacting carbon tetrachloride with ethylene, the method comprising the steps of: mixing the catalyst described in the present invention with a co-catalyst and carbon tetrachloride, adding the mixture into a stainless steel high-pressure reactor with mechanical stirring, introducing ethylene gas, and heating for reaction.

[0095] The reaction generates hydrogen chloride, which is very likely to corrode equipment. Preferably, a corrosion-resistant, high-temperature and high-pressure reactor is used.

[0096] Preferably, in the catalyst, the co-catalyst / main catalyst feed ratio is 3 to 4 (molar ratio).

[0097] Preferably, the main catalyst / carbon tetrachloride feed ratio is 0.006-0.01 (molar ratio). After the feed is completed, the reactor needs to be replaced with ethylene gas three times to remove the remaining air in the reactor. During the reaction, ethylene is continuously passed until the reaction is completed.

[0098] In a preferred embodiment, the reaction temperature is 80-120° C. More preferably, the reaction temperature is 100-110° C. The preferred reaction time is 3-6 hours.

[0099] As a specific embodiment, the present application provides a method for recovering catalyst in the reaction of carbon tetrachloride and ethylene to synthesize 1,1,1,3-tetrachloropropane. The method comprises the steps of: filtering after the catalytic reaction using the catalyst of the present invention is completed, separating the reaction liquid and the catalyst, adding a co-catalyst, and re-reacting.

[0100] It should be understood that within the scope of this application, the above-mentioned technical features of this application and the technical features specifically described below (such as specific embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here.

[0101] In the present application, conversion rate = (amount of carbon tetrachloride added - amount of carbon tetrachloride remaining) / amount of carbon tetrachloride added * 100%;

[0102] Selectivity = (tetrachloropropane yield / conversion rate) * 100%;

[0103] Yield = actual tetrachloropropane production / theoretical production.

[0104] Example 1 Preparation of Catalyst

[0105] Add 5g of organic bentonite to 250mL of 0.054mol / L FeSO4·7H2O solution and stir for 6h; adjust pH to <3 with 1mol / L HCl; drop 250mL of 0.108mol / L KBH4 aqueous solution into the above solution and stir for 2h. During the whole process, nitrogen is passed and air is isolated to prevent nano zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven.

[0106] Example 2 Preparation of Catalyst

[0107] Add 5g of organic bentonite to 250mL of 0.054mol / L FeCl2·4H2O solution and stir for 6h; adjust pH to <3 with 1mol / L HCl; drop 250mL of 0.108mol / L KBH4 aqueous solution into the above solution and stir for 2h. During the whole process, nitrogen is passed and air is isolated to prevent nano zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven.

[0108] Example 3 Preparation of Catalyst

[0109] Add 5g of organic bentonite to 250mL of 0.162mol / L FeSO4·7H2O ethanol-water mixed solution (ethanol: water = 5:1) and stir for 6h; adjust pH to <3 with 1mol / L HCl; drop 250mL of 0.316mol / L NaBH4 aqueous solution into the above solution and stir for 2h. During the whole process, nitrogen is passed and air is isolated to prevent nano zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven.

[0110] Example 4 Preparation of Catalyst

[0111] Add 5g of organic bentonite to 250mL of 0.162mol / L FeCl2·4H2O ethanol-water mixed solution (ethanol: water = 5:1) and stir for 6h; adjust pH to <3 with 1mol / L HCl; drop 250mL of 0.316mol / L NaBH4 aqueous solution into the above solution and stir for 2h. During the whole process, nitrogen is passed and air is isolated to prevent nano zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven.

[0112] Example 5 Preparation of Catalyst

[0113] Add 5g of organic bentonite to 250mL of 0.162mol / L FeCl2·4H2O ethanol-water mixed solution (ethanol: water = 5:1) and stir for 6h; adjust pH to <3 with 1mol / L HCl; drop 250mL of 0.316mol / L NaBH4 aqueous solution into the above solution, stir for 2h, then add 0.071g K2PdCl4 and continue stirring for 1h. The whole process is nitrogen-filled and air-isolated to prevent nano-zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven.

[0114] Example 6 Preparation of Catalyst

[0115] Add 5g of organic bentonite to 250mL of 0.03mol / L FeCl2·4H2O ethanol-water mixed solution (ethanol: water = 5:1), stir for 6h; adjust pH to <3 with 1mol / L HCl; drop 250mL of 0.06mol / L NaBH4 aqueous solution into the above solution, stir for 2h, and pass nitrogen throughout the process to isolate the air to prevent the nano zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven to obtain Fe / bentonite catalyst, recorded as catalyst #8. XRF determination of Fe loading in the catalyst: 5wt%.

[0116] Example 7 Preparation of Catalyst

[0117] Add 5g of organic bentonite to 250mL of 0.06mol / L FeCl2·4H2O ethanol-water mixed solution (ethanol: water = 5:1), stir for 6h; adjust pH to <3 with 1mol / L HCl; drop 250mL of 0.12mol / L NaBH4 aqueous solution into the above solution, stir for 2h, and pass nitrogen throughout the process to isolate the air to prevent the nano zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven to obtain Fe / bentonite catalyst, recorded as catalyst 9#. XRF determination of Fe loading in the catalyst: 13wt%.

[0118] Example 8 Preparation of Catalyst

[0119] Add 5g of organic bentonite to 250mL of 0.162mol / L FeCl2·4H2O ethanol-water mixed solution (ethanol: water = 5:1), stir for 6h; adjust pH to <3 with 1mol / L HCl; drop 250mL of 0.316mol / L NaBH4 aqueous solution into the above solution and stir for 2h. The whole process was ventilated with nitrogen and air was isolated to prevent the nano zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven to obtain Fe / bentonite catalyst, recorded as catalyst #1. XRF determination: Fe loading: 25wt%.

[0120] Example 9 Preparation of Catalyst

[0121] Add 5g of organic bentonite to 250mL of 0.06mol / L FeCl2·4H2O ethanol-water mixed solution (ethanol: water = 5:1), stir for 6h; adjust pH to <3 with 1mol / L HCl; drop 250mL of 0.12mol / L NaBH4 aqueous solution into the above solution, stir for 2h, then add 0.071g K2PdCl4, and continue stirring for 1h. The whole process is nitrogen-filled and air-isolated to prevent nano-zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water, and wash with alcohol. Dry in a vacuum oven to obtain Pd-Fe / bentonite catalyst, recorded as catalyst 2#. XRF determination: Pd loading: 0.04%; Fe loading: 13wt%.

[0122] Example 10 Preparation of Catalyst

[0123] 5g activated carbon (20% H3PO4 treated) was added to 250mL 0.06mol / L FeCl2·4H2O ethanol-water mixed solution (ethanol: water = 5:1), and stirred for 6h; 1mol / L HCl was used to adjust the pH to <3; 250mL 0.12mol / L NaBH4 aqueous solution was added dropwise to the above solution, and stirred for 2h. The whole process was nitrogen-filled and air-isolated to prevent the nano-zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water, and wash with alcohol. Dry in a vacuum oven to obtain Fe / activated carbon (20% H3PO4 treated), which was recorded as catalyst #3. XRF determined the Fe loading in the catalyst: 13wt%.

[0124] Example 11 Preparation of Catalyst

[0125] The preparation method of catalyst #4 is different from that of catalyst #3 in that the activated carbon treated with 20% H3PO4 is replaced with activated carbon treated with 20% HCl, and the other preparation conditions are the same.

[0126] Example 12 Preparation of Catalyst

[0127] The preparation method of catalyst #5 is different from that of catalyst #3 in that the activated carbon treated with 20% H3PO4 is replaced with activated carbon treated with 20% HNO3, and the other preparation conditions are the same.

[0128] Example 13 Preparation of Catalyst

[0129] 5g activated carbon (20% H3PO4 treated) was added to 250mL, 0.06mol / L FeCl2·4H2O and the same molar amount of copper chloride in ethanol-water mixed solution (ethanol: water = 5:1), stirred for 6h; 1mol / L HCl was used to adjust the pH to <3; 250mL, 0.25mol / L NaBH4 aqueous solution was added dropwise to the above solution, stirred for 2h, nitrogen was passed through the whole process, and the air was isolated to prevent the nano zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven to obtain Cu-Fe (Cu:Fe = 1:1) / activated carbon (20% H3PO4 treated) catalyst, recorded as catalyst 6#. XRF determined the Fe loading in the catalyst: 13wt%; Cu loading: 12.8wt%; about 1:1.

[0130] Example 14 Preparation of Catalyst

[0131] 5g activated carbon (20% H3PO4 treated) was added to 250mL, 0.06mol / L FeCl2·4H2O ethanol-water mixed solution (ethanol: water = 5:1), and stirred for 6h; 1mol / L HCl was used to adjust the pH to <3; 250mL, 0.12mol / L NaBH4 aqueous solution was added dropwise to the above solution, stirred for 2h, and then 0.019g K2PdCl4 was added and stirred for 1h. The whole process was ventilated with nitrogen and air was isolated to prevent the nano zero-valent iron from being oxidized by oxygen in the air. Filter, wash with deionized water and alcohol. Dry in a vacuum oven to obtain the Fe-Pd / activated carbon (20% H3PO4 treated) catalyst, which was recorded as catalyst #7. XRF determination: Fe loading: 13wt%; Pd loading: 0.1wt%.

[0132] In the preparation of the above 3# to 7# catalysts, the carrier activated carbon modification method is carried out according to the following steps: 20% HCl solution, 20% H3PO4 solution or 20% HNO3 solution are prepared respectively. 10g of activated carbon sample is placed in a 250mL round-bottom flask, and 100mL of the above solution is added respectively, and stirred and refluxed at 100°C for 5h. After cooling, the activated carbon sample is filtered, washed with deionized water until neutral, and filtered to obtain a filter cake. The treated activated carbon filter cake is placed in an oven and dried at 110°C for 10h.

[0133] Example 15 Preparation of 1,1,1,3-tetrachloropropane

[0134] Add 50g of carbon tetrachloride, 4g of 8# catalyst, and 1.3g of triethyl phosphite to a 100ml intermittent stainless steel autoclave with mechanical stirring; then pass ethylene to displace the remaining air in the autoclave twice, and after this step is completed, fill ethylene gas to 0.04MPa, heat to 60℃, and react for 3 hours; continue to pass ethylene until the reaction is completed, and after the reaction is completed, cool naturally and take the reaction liquid for gas chromatography analysis. The results show: carbon tetrachloride single-pass conversion rate: 63.5%; selectivity: 87.2%.

[0135] Example 16 Preparation of 1,1,1,3-tetrachloropropane

[0136] Add 50g of carbon tetrachloride, 3g of 9# catalyst, and 1.3g of triethyl phosphite to a 100ml intermittent stainless steel autoclave with mechanical stirring; then pass ethylene to displace the remaining air in the autoclave twice, and after this step is completed, fill ethylene gas to 0.08MPa, heat to 100℃, and react for 6 hours; continue to pass ethylene until the reaction is completed, and after the reaction is completed, cool naturally and take the reaction liquid for gas chromatography analysis. The results show: carbon tetrachloride single-pass conversion rate: 96.8%; selectivity: 98.7%

[0137] Example 17 Preparation of 1,1,1,3-tetrachloropropane

[0138] In a 100ml intermittent stainless steel high-pressure reactor with mechanical stirring, 50g of carbon tetrachloride, 6g of 1# catalyst and 1.3g of triethyl phosphite were added; then ethylene was passed through the reactor to replace the residual air twice. After this step was completed, ethylene gas was filled to 0.08MPa, and the temperature was heated to 140°C and reacted for 10 hours; ethylene was passed through the reactor until the reaction was completed. After the reaction was completed, the reactor was cooled naturally and the products were all coked and were black solids.

[0139] Examples 18 to 24, Comparative Example 1 Preparation of 1,1,1,3-tetrachloropropane

[0140] Experimental conditions: triethyl phosphite: 1.3 g, CCl4: 50 g, temperature: 100°C, pressure: 0.08 MPa, time: 3 h; catalyst addition amount: 3 g; the types of catalysts used and the reaction results are shown in Table 1.

[0141] Table 1 Catalyst types and reaction results used in 13-19

[0142]

[0143] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing 1,1,1,3-tetrachloropropane, characterized in that: The preparation method comprises: In the presence of a first catalyst and a second catalyst, reacting a raw material containing carbon tetrachloride and ethylene to obtain the 1,1,1,3-tetrachloropropane; The first catalyst comprises a carrier and an active component supported on the carrier; The active component is selected from nano zero-valent iron; The second catalyst is selected from at least one of phosphates and phosphites; The carrier is selected from at least one of porous materials; The porous material is selected from bentonite; The bentonite is obtained by modification with a surfactant; The surfactant is selected from at least one of quaternary ammonium salts; The reaction conditions include: temperature of 80-120° C.; time of 2-8 hours.

2. The preparation method according to claim 1, characterized in that: The active component also includes at least one of platinum and copper.

3. The preparation method according to claim 1, characterized in that: The active component is selected from any one of zero-valent iron nanoparticles, Pd-Fe bimetallic nanoparticles, and Cu-Fe bimetallic nanoparticles.

4. The preparation method according to claim 1, characterized in that: The quaternary ammonium salt is selected from hexadecyltrimethylammonium bromide.

5. The preparation method according to claim 1, characterized in that: In the first catalyst, the loading amount of the active component is 5.01-50.1 wt %.

6. The preparation method according to claim 3, characterized in that: In the Pd-Fe bimetallic nanoparticles, the mass ratio of the Fe to the Pd is 5-50:0.01-0.1; In the Cu-Fe bimetallic nanoparticles, the mass ratio of the Cu to the Fe is 0.5-1.5:0.5-1.

5.

7. The preparation method according to claim 1, characterized in that: The mass ratio of the carbon tetrachloride to the first catalyst is 50:1-10; The first catalyst is calculated based on the mass of the first catalyst itself.

8. The preparation method according to claim 1, characterized in that: The phosphate ester is selected from at least one of tributyl phosphate, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and dibutyl phosphate; The phosphite is selected from tributyl phosphite.

9. The preparation method according to claim 1, characterized in that: The mass ratio of the second catalyst to the first catalyst is 1.25-5:1-6; The second catalyst is measured by the mass of the second catalyst itself, and the first catalyst is measured by the mass of the first catalyst itself.

10. The preparation method according to claim 1, characterized in that: The preparation method comprises: placing the carbon tetrachloride, the first catalyst and the second catalyst into a reactor, introducing the ethylene, reacting, and obtaining the 1,1,1,3-tetrachloropropane.

11. The preparation method according to claim 1 or 10, characterized in that: The reaction conditions include: pressure 0.04-0.08 MPa.

12. The preparation method according to claim 1, characterized in that: The reaction conditions include: reacting under stirring, and the stirring speed is 800-2000 rpm.

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