A catalyst for the synthesis of chlorobenzene and its use
By supporting FeCl3/ZnCl2 catalyst on CeO2@volcanic rock composite material, the problem of low selectivity in the synthesis of chlorobenzene was solved, achieving efficient synthesis of chlorobenzene and reducing the generation of dichlorobenzene byproduct.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANHUI DONGZHI GUANGXIN AGROCHEMICAL CO LTD
- Filing Date
- 2026-03-30
- Publication Date
- 2026-06-30
AI Technical Summary
The catalysts used in the synthesis of chlorobenzene in the existing technology have low selectivity and are difficult to recover and process, resulting in the generation of a large amount of dichlorobenzene as a byproduct.
By using CeO2@volcanic rock composite material to support FeCl3/ZnCl2 catalyst, the acid strength of Lewis acid is adjusted, and chlorine is adsorbed by oxygen vacancies on the CeO2 surface, which promotes the breaking of Cl-Cl bonds in chlorine and improves catalyst selectivity.
It significantly improved the selectivity of chlorobenzene, reduced the formation of dichlorobenzene, and enhanced catalytic and synthesis efficiency.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalyst technology, specifically relating to a catalyst for the synthesis of chlorobenzene and its application. Background Technology
[0002] Chlorobenzene is an important raw material for chemical production. Its upstream raw materials are mainly benzene and chlorine. Benzene is mostly derived from petroleum refining byproducts. Downstream products cover pesticides, pharmaceutical intermediates, dyes, rubber, resins and other fields.
[0003] With the advancement of agricultural modernization and the development of industries such as pharmaceuticals and textiles, the demand for chlorobenzene is showing a steady growth trend. In the field of chlorobenzene production, new technologies are constantly emerging, bringing new opportunities to improve production efficiency, reduce costs, and enhance environmental performance.
[0004] Currently, the main method for preparing chlorobenzene is the chlorination process. Benzene and chlorine react in the presence of ferric chloride, resulting in the chlorination of benzene to form chlorobenzene. In addition to chlorobenzene, dichlorobenzene is also generated as a byproduct during the reaction. Post-processing is usually required to separate chlorobenzene and dichlorobenzene to obtain a chlorobenzene product with high purity. However, in the actual operation of traditional chlorobenzene synthesis, iron filings, iron rings, or anhydrous ferric chloride are placed in the reactor, and the ferric chloride generated from the reaction of benzene and chlorine catalyzes the reaction. This method suffers from low selectivity and difficulties in catalyst recovery and treatment. Therefore, developing a catalyst that can improve the selectivity of chlorobenzene synthesis is of great significance. Summary of the Invention
[0005] This invention provides a catalyst for synthesizing chlorobenzene and its application, which can solve the problem of low selectivity of catalysts for synthesizing chlorobenzene in the prior art.
[0006] The objective of this invention can be achieved through the following technical solutions: A catalyst for the synthesis of chlorobenzene, wherein the catalyst is FeCl3 / ZnCl2 supported on a CeO2@volcanic rock composite material.
[0007] This invention uses ferric chloride and zinc chloride, two Lewis acids, as the main catalytic active components. Ferric chloride is a traditional catalyst for the catalytic synthesis of chlorobenzene, but its strong acidity leads to further chlorination of the product, generating a large amount of dichlorobenzene byproduct. To improve selectivity and avoid over-chlorination, zinc chloride is added simultaneously. Compared with ferric chloride, zinc chloride has weaker acidity. By co-loading with ferric chloride, the acid strength of the Lewis acid is adjusted, so that it can meet the requirements for activating chlorine to generate chlorobenzene while avoiding secondary substitution, thus significantly improving the catalyst selectivity.
[0008] This invention uses CeO2@volcanic rock composite material as a carrier. Volcanic rock is a porous silicate material with abundant pores and a large specific surface area, which facilitates the diffusion of benzene and chlorine gas within the pores and avoids excessively high local chlorine concentrations that could generate byproducts. In-situ growth of CeO2 on the volcanic rock roughens the carrier surface and increases the pore size, allowing for better anchoring of ferric chloride and zinc chloride to the carrier surface. This results in high loading dispersion and avoids multiple substitutions. Furthermore, the oxygen vacancies on the CeO2 surface adsorb chlorine gas, promoting the breaking of Cl-Cl bonds in chlorine and improving catalytic efficiency.
[0009] Furthermore, the preparation steps of the catalyst are as follows: Weigh out ferric chloride hexahydrate and zinc chloride and dissolve them in anhydrous ethanol. Add CeO2@volcanic rock composite material, heat and soak for 5-8 hours, filter, wash, vacuum dry, transfer to muffle furnace and activate at 110-120℃ for 1-2 hours, and cool to room temperature to obtain catalyst.
[0010] FeCl3·6H2O and ZnCl2 were dissolved in anhydrous ethanol as a solvent and then CeO2@volcanic rock composite material was added. Due to capillary action, the solution entered the carrier pores, and the active components were adsorbed and dispersed on the carrier surface. After drying and activation, they were stably bound to the carrier surface.
[0011] Furthermore, the molar ratio of ferric chloride hexahydrate to zinc chloride is 4-6:1.
[0012] Furthermore, the ratio of the total mass of ferric chloride hexahydrate and zinc chloride to anhydrous ethanol is 10-20 g : 500 mL.
[0013] Furthermore, the CeO2@volcanic rock composite material is 3-4 times the total mass of ferric chloride hexahydrate and zinc chloride.
[0014] Furthermore, the preparation steps of the CeO2@volcanic rock composite material are as follows: S1. Weigh the volcanic rock, crush it, wash it to remove impurities, wash it with deionized water until neutral, and dry it to obtain pretreated volcanic rock. S2. Weigh out cerium nitrate and dissolve it in deionized water to obtain a cerium nitrate solution. Add citric acid and polyethylene glycol and stir until homogeneous. S3. Add pretreated volcanic rock, stir for 5-6 hours, then raise the temperature to 50-60℃ and continue stirring for 6-8 hours; S4. Place in an oven and dry at 110-120℃. After drying, calcine at 500-550℃ for 5-6 hours in air atmosphere, and grind to obtain CeO2@volcanic rock composite material.
[0015] In the above preparation method, CeO2 is generated and bound on the surface of volcanic rock via a sol-gel method. Cerium nitrate provides the cerium source, and citric acid acts as a complexing agent, reacting with cerium ions to form a uniform citric acid-cerium complex. This prevents metal ions from prematurely precipitating and separating due to solubility changes during subsequent drying. Polyethylene glycol is used as a dispersant to increase the viscosity of the solution and inhibit the aggregation of nanoparticles. The solution enters the pores of the volcanic rock, and after calcination, uniformly distributed nano-CeO2 crystals are generated on the volcanic rock surface.
[0016] Furthermore, the concentration of cerium nitrate in the cerium nitrate solution is 0.01-0.02 mol / L.
[0017] Furthermore, the molar ratio of citric acid to cerium ions is 1.5-2.0:1.
[0018] Furthermore, the mass ratio of polyethylene glycol to citric acid is 0.4-0.6:1.
[0019] Furthermore, the pretreated volcanic rock is 6-14 times the mass of cerium nitrate.
[0020] The present invention also provides an application of a catalyst for the synthesis of chlorobenzene, wherein the catalyst described above is used in the liquid-phase reaction of benzene and chlorine to synthesize chlorobenzene.
[0021] The beneficial effects of this invention are: (1) In this invention, two Lewis acids, ferric chloride and zinc chloride, are used as the main catalytic active components. Ferric chloride is a traditional catalyst for the catalytic synthesis of chlorobenzene, but its acidity is relatively strong, which leads to further chlorination of the product and the generation of more dichlorobenzene byproduct. In order to improve selectivity and avoid excessive chlorination, zinc chloride is added simultaneously in this invention. Compared with ferric chloride, zinc chloride has weaker acidity. By co-loading with ferric chloride, the acid strength of the Lewis acid is adjusted so that it can meet the requirements for activating chlorine to generate chlorobenzene and avoid secondary substitution, thus significantly improving the selectivity of the catalyst.
[0022] (2) This invention uses CeO2@volcanic rock composite material as a carrier. Volcanic rock is a porous silicate material with abundant pores and a large specific surface area, which facilitates the diffusion of benzene and chlorine in the pores and avoids excessive local chlorine concentrations that generate byproducts. In-situ growth of CeO2 on volcanic rock makes the carrier surface rougher, better anchoring ferric chloride and zinc chloride to the carrier surface, resulting in high loading dispersion and avoiding multiple substitutions. In addition, oxygen vacancies on the CeO2 surface adsorb chlorine, promoting the breaking of Cl-Cl bonds in chlorine and improving catalytic efficiency. Detailed Implementation
[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0024] Example 1
[0025] Preparation of CeO2@volcanic rock composite materials: S1. Weigh 1 kg of volcanic rock and crush it using a crusher. After crushing, the particle size is 2-3 mm. Add it to a 0.1 M hydrochloric acid solution and ultrasonically clean it for 20 min. After filtration, add it to a 0.1 M sodium hydroxide solution and ultrasonically clean it for 20 min to remove impurities. After filtration, wash it with deionized water until neutral and place it in an oven at 80℃ for 12 h to obtain pretreated volcanic rock.
[0026] S2. Weigh 13.0g of cerium nitrate (Ce(NO3)3·6H2O) and dissolve it in 2L of deionized water to obtain a 0.015mol / L cerium nitrate solution. Add 8.7g of citric acid and 4.4g of polyethylene glycol and stir for 30min. S3. Add 117.0g of pretreated volcanic rock, stir for 6 hours, then heat to 60℃ and continue stirring for 6 hours. S4. Place in an oven and dry at 120℃ for 5 hours. After drying, calcine at 550℃ for 5 hours in air atmosphere. Grind to obtain CeO2@volcanic rock composite material with a thickness of 2.0-3.0 mm.
[0027] Preparation of catalysts: Weigh 13.5 g (0.05 mol) ferric chloride hexahydrate and 1.4 g (0.01 mol) zinc chloride, dissolve them in 500 mL of anhydrous ethanol, add 52.2 g of the CeO2@volcanic rock composite material prepared above, heat to 50 °C and soak for 6 h, filter, wash repeatedly with anhydrous ethanol 5 times, vacuum dry at 60 °C for 5 h, transfer to a muffle furnace and activate at 120 °C for 2 h, cool to room temperature to obtain the catalyst.
[0028] Example 2
[0029] The only difference from Example 1 is that the concentration of cerium nitrate solution was adjusted to 0.02 mol / L when preparing CeO2@volcanic rock composite material.
[0030] Preparation of CeO2@volcanic rock composite materials: S1. Weigh 1 kg of volcanic rock and crush it using a crusher. After crushing, the particle size is 2-3 mm. Add it to a 0.1 M hydrochloric acid solution and ultrasonically clean it for 20 min. After filtration, add it to a 0.1 M sodium hydroxide solution and ultrasonically clean it for 20 min to remove impurities. After filtration, wash it with deionized water until neutral and place it in an oven at 80℃ for 12 h to obtain pretreated volcanic rock.
[0031] S2. Weigh 17.4g of cerium nitrate (Ce(NO3)3·6H2O) and dissolve it in 2L of deionized water to obtain a 0.02mol / L cerium nitrate solution. Add 11.5g of citric acid and 5.8g of polyethylene glycol and stir for 30min. S3. Add 117.0g of pretreated volcanic rock, stir for 6 hours, then heat to 60℃ and continue stirring for 6 hours. S4. Place in an oven and dry at 120℃ for 5 hours. After drying, calcine at 550℃ for 5 hours in air atmosphere. Grind to obtain CeO2@volcanic rock composite material with a thickness of 2.0-3.0 mm.
[0032] Preparation of catalysts: Weigh 13.5 g (0.05 mol) ferric chloride hexahydrate and 1.4 g (0.01 mol) zinc chloride, dissolve them in 500 mL of anhydrous ethanol, add 52.2 g of the CeO2@volcanic rock composite material prepared above, heat to 50 °C and soak for 6 h, filter, wash repeatedly with anhydrous ethanol 5 times, vacuum dry at 60 °C for 5 h, transfer to a muffle furnace and activate at 120 °C for 2 h, cool to room temperature to obtain the catalyst.
[0033] Example 3
[0034] The only difference from Example 1 is that the concentration of cerium nitrate solution was adjusted to 0.01 mol / L when preparing CeO2@volcanic rock composite material.
[0035] Preparation of CeO2@volcanic rock composite materials: S1. Weigh 1 kg of volcanic rock and crush it using a crusher. After crushing, the particle size is 2-3 mm. Add it to a 0.1 M hydrochloric acid solution and ultrasonically clean it for 20 min. After filtration, add it to a 0.1 M sodium hydroxide solution and ultrasonically clean it for 20 min to remove impurities. After filtration, wash it with deionized water until neutral and place it in an oven at 80℃ for 12 h to obtain pretreated volcanic rock.
[0036] S2. Weigh 8.7g of cerium nitrate (Ce(NO3)3·6H2O) and dissolve it in 2L of deionized water to obtain a 0.01mol / L cerium nitrate solution. Add 5.8g of citric acid and 2.9g of polyethylene glycol and stir for 30min. S3. Add 117.0g of pretreated volcanic rock, stir for 6 hours, then heat to 60℃ and continue stirring for 6 hours. S4. Place in an oven and dry at 120℃ for 5 hours. After drying, calcine at 550℃ for 5 hours in air atmosphere. Grind to obtain CeO2@volcanic rock composite material with a thickness of 2.0-3.0 mm.
[0037] Preparation of catalysts: Weigh 13.5 g (0.05 mol) ferric chloride hexahydrate and 1.4 g (0.01 mol) zinc chloride, dissolve them in 500 mL of anhydrous ethanol, add 52.2 g of the CeO2@volcanic rock composite material prepared above, heat to 50 °C and soak for 6 h, filter, wash repeatedly with anhydrous ethanol 5 times, vacuum dry at 60 °C for 5 h, transfer to a muffle furnace and activate at 120 °C for 2 h, cool to room temperature to obtain the catalyst.
[0038] Example 4
[0039] The only difference from Example 1 is that the amount of ferric chloride hexahydrate was adjusted to 16.2 g (0.06 mol) when preparing the catalyst, and the amount of CeO2@volcanic rock composite material was adjusted to 61.6 g accordingly.
[0040] Preparation of CeO2@volcanic rock composite materials: S1. Weigh 1 kg of volcanic rock and crush it using a crusher. After crushing, the particle size is 2-3 mm. Add it to a 0.1 M hydrochloric acid solution and ultrasonically clean it for 20 min. After filtration, add it to a 0.1 M sodium hydroxide solution and ultrasonically clean it for 20 min to remove impurities. After filtration, wash it with deionized water until neutral and place it in an oven at 80℃ for 12 h to obtain pretreated volcanic rock.
[0041] S2. Weigh 13.0g of cerium nitrate (Ce(NO3)3·6H2O) and dissolve it in 2L of deionized water to obtain a 0.015mol / L cerium nitrate solution. Add 8.7g of citric acid and 4.4g of polyethylene glycol and stir for 30min. S3. Add 117.0g of pretreated volcanic rock, stir for 6 hours, then heat to 60℃ and continue stirring for 6 hours. S4. Place in an oven and dry at 120℃ for 5 hours. After drying, calcine at 550℃ for 5 hours in air atmosphere. Grind to obtain CeO2@volcanic rock composite material with a thickness of 2.0-3.0 mm.
[0042] Preparation of catalysts: Weigh 16.2 g (0.06 mol) ferric chloride hexahydrate and 1.4 g (0.01 mol) zinc chloride, dissolve them in 500 mL of anhydrous ethanol, add 61.6 g of the CeO2@volcanic rock composite material prepared above, heat to 50 °C and soak for 6 h, filter, wash repeatedly with anhydrous ethanol 5 times, vacuum dry at 60 °C for 5 h, transfer to a muffle furnace and activate at 120 °C for 2 h, cool to room temperature to obtain the catalyst.
[0043] Example 5
[0044] The only difference from Example 1 is that the amount of ferric chloride hexahydrate was adjusted to 10.8 g (0.04 mol) when preparing the catalyst, and the amount of CeO2@volcanic rock composite material was adjusted to 42.7 g accordingly.
[0045] Example 6
[0046] The only difference from Example 1 is that the CeO2@volcanic rock composite material was adjusted to 59.6g when preparing the catalyst.
[0047] Preparation of CeO2@volcanic rock composite materials: S1. Weigh 1 kg of volcanic rock and crush it using a crusher. After crushing, the particle size is 2-3 mm. Add it to a 0.1 M hydrochloric acid solution and ultrasonically clean it for 20 min. After filtration, add it to a 0.1 M sodium hydroxide solution and ultrasonically clean it for 20 min to remove impurities. After filtration, wash it with deionized water until neutral and place it in an oven at 80℃ for 12 h to obtain pretreated volcanic rock.
[0048] S2. Weigh 13.0g of cerium nitrate (Ce(NO3)3·6H2O) and dissolve it in 2L of deionized water to obtain a 0.015mol / L cerium nitrate solution. Add 8.7g of citric acid and 4.4g of polyethylene glycol and stir for 30min. S3. Add 117.0g of pretreated volcanic rock, stir for 6 hours, then heat to 60℃ and continue stirring for 6 hours. S4. Place in an oven and dry at 120℃ for 5 hours. After drying, calcine at 550℃ for 5 hours in air atmosphere. Grind to obtain CeO2@volcanic rock composite material with a thickness of 2.0-3.0 mm.
[0049] Preparation of catalysts: Weigh 13.5 g (0.05 mol) ferric chloride hexahydrate and 1.4 g (0.01 mol) zinc chloride, dissolve them in 500 mL of anhydrous ethanol, add 59.6 g of the CeO2@volcanic rock composite material prepared above, heat to 50 °C and soak for 6 h, filter, wash repeatedly with anhydrous ethanol 5 times, vacuum dry at 60 °C for 5 h, transfer to a muffle furnace and activate at 120 °C for 2 h, cool to room temperature to obtain the catalyst.
[0050] Example 7
[0051] The only difference from Example 1 is that the CeO2@volcanic rock composite material was adjusted to 44.7g when preparing the catalyst.
[0052] Preparation of CeO2@volcanic rock composite materials: S1. Weigh 1 kg of volcanic rock and crush it using a crusher. After crushing, the particle size is 2-3 mm. Add it to a 0.1 M hydrochloric acid solution and ultrasonically clean it for 20 min. After filtration, add it to a 0.1 M sodium hydroxide solution and ultrasonically clean it for 20 min to remove impurities. After filtration, wash it with deionized water until neutral and place it in an oven at 80℃ for 12 h to obtain pretreated volcanic rock.
[0053] S2. Weigh 13.0g of cerium nitrate (Ce(NO3)3·6H2O) and dissolve it in 2L of deionized water to obtain a 0.015mol / L cerium nitrate solution. Add 8.7g of citric acid and 4.4g of polyethylene glycol and stir for 30min. S3. Add 117.0g of pretreated volcanic rock, stir for 6 hours, then heat to 60℃ and continue stirring for 6 hours. S4. Place in an oven and dry at 120℃ for 5 hours. After drying, calcine at 550℃ for 5 hours in air atmosphere. Grind to obtain CeO2@volcanic rock composite material with a thickness of 2.0-3.0 mm.
[0054] Preparation of catalysts: Weigh 13.5 g (0.05 mol) ferric chloride hexahydrate and 1.4 g (0.01 mol) zinc chloride, dissolve them in 500 mL of anhydrous ethanol, add 44.7 g of the CeO2@volcanic rock composite material prepared above, heat to 50 °C and soak for 6 h, filter, wash repeatedly with anhydrous ethanol 5 times, vacuum dry at 60 °C for 5 h, transfer to a muffle furnace and activate at 120 °C for 2 h, cool to room temperature to obtain the catalyst.
[0055] Comparative Example 1
[0056] The only difference from Example 1 is that pretreated volcanic rock is used instead of CeO2@volcanic rock composite material as the catalyst support material.
[0057] Preparation of pretreated volcanic rocks: Weigh 1 kg of volcanic rock and crush it using a crusher. After crushing, the particle size is 2-3 mm. Add it to a 0.1 M hydrochloric acid solution and ultrasonically clean it for 20 min. After filtration, add it to a 0.1 M sodium hydroxide solution and ultrasonically clean it for 20 min to remove impurities. After filtration, wash it with deionized water until neutral and place it in an oven at 80℃ for 12 h to obtain pretreated volcanic rock.
[0058] Preparation of catalysts: Weigh 13.5 g (0.05 mol) ferric chloride hexahydrate and 1.4 g (0.01 mol) zinc chloride, dissolve them in 500 mL of anhydrous ethanol, add 52.2 g of the CeO2@volcanic rock composite material prepared above, heat to 50 °C and soak for 6 h, filter, wash repeatedly with anhydrous ethanol 5 times, vacuum dry at 60 °C for 5 h, transfer to a muffle furnace and activate at 120 °C for 2 h, cool to room temperature to obtain the catalyst.
[0059] Comparative Example 2
[0060] The only difference from Example 1 is that zinc chloride is not loaded on the catalyst.
[0061] Preparation of CeO2@volcanic rock composite materials: S1. Weigh 1 kg of volcanic rock and crush it using a crusher. After crushing, the particle size is 2-3 mm. Add it to a 0.1 M hydrochloric acid solution and ultrasonically clean it for 20 min. After filtration, add it to a 0.1 M sodium hydroxide solution and ultrasonically clean it for 20 min to remove impurities. After filtration, wash it with deionized water until neutral and place it in an oven at 80℃ for 12 h to obtain pretreated volcanic rock.
[0062] S2. Weigh 13.0g of cerium nitrate (Ce(NO3)3·6H2O) and dissolve it in 2L of deionized water to obtain a 0.015mol / L cerium nitrate solution. Add 8.7g of citric acid and 4.4g of polyethylene glycol and stir for 30min. S3. Add 117.0g of pretreated volcanic rock, stir for 6 hours, then heat to 60℃ and continue stirring for 6 hours. S4. Place in an oven and dry at 120℃ for 5 hours. After drying, calcine at 550℃ for 5 hours in air atmosphere. Grind to obtain CeO2@volcanic rock composite material with a thickness of 2.0-3.0 mm.
[0063] Preparation of catalysts: Weigh 13.5 g (0.05 mol) of ferric chloride hexahydrate and dissolve it in 500 mL of anhydrous ethanol. Add 47.3 g of the CeO2@volcanic rock composite material prepared above, heat to 50 °C and soak for 6 h. Filter, wash 5 times with anhydrous ethanol, vacuum dry at 60 °C for 5 h, transfer to a muffle furnace and activate at 120 °C for 2 h, and cool to room temperature to obtain the catalyst.
[0064] Comparative Example 3
[0065] The only difference from Example 1 is that iron filings are used as the catalyst.
[0066] The catalysts prepared in Examples 1-7 and Comparative Examples 1-3 were used to react with chlorine gas in a liquid phase to synthesize chlorobenzene.
[0067] The catalyst was placed in a chlorinator, and 0.2 kg of dried benzene was added to the chlorinator. The dried chlorine gas was introduced into the chlorinator at a rate of 126.1 mL / min. The mass ratio of catalyst:benzene:chlorine gas was 1:100:90. The reaction temperature was controlled at 70-80℃, and the chlorination reaction was carried out for 4 hours to generate chlorinated liquid. The composition of the chlorinated liquid was detected to obtain the conversion rate of benzene and the mass fraction ratio of chlorobenzene to dichlorobenzene.
[0068] Table 1
[0069] As can be seen from Table 1, the catalyst prepared in this invention can improve the selectivity of the synthesis of chlorobenzene by liquid-phase chlorination of benzene and chlorine, reduce the generation of dichlorobenzene byproducts, and improve the synthesis efficiency.
[0070] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0071] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A catalyst for the synthesis of chlorobenzene, characterized in that, The catalyst is FeCl3 / ZnCl2 supported on CeO2@volcanic rock composite material.
2. The catalyst for synthesizing chlorobenzene according to claim 1, characterized in that, The catalyst is prepared in the following steps: Weigh out ferric chloride hexahydrate and zinc chloride and dissolve them in anhydrous ethanol. Add CeO2@volcanic rock composite material, heat and soak for 5-8 hours, filter, wash, vacuum dry, transfer to muffle furnace and activate at 110-120℃ for 1-2 hours, and cool to room temperature to obtain catalyst.
3. The catalyst for synthesizing chlorobenzene according to claim 2, characterized in that, The molar ratio of ferric chloride hexahydrate to zinc chloride is 4-6:
1.
4. The catalyst for synthesizing chlorobenzene according to claim 2, characterized in that, The ratio of the total mass of ferric chloride hexahydrate and zinc chloride to anhydrous ethanol is 10-20g: 500mL.
5. The catalyst for synthesizing chlorobenzene according to claim 2, characterized in that, The CeO2@volcanic rock composite material is 3-4 times the total mass of ferric chloride hexahydrate and zinc chloride.
6. The catalyst for synthesizing chlorobenzene according to claim 2, characterized in that, The preparation steps of the CeO2@volcanic rock composite material are as follows: S1. Weigh the volcanic rock, crush it, wash it to remove impurities, wash it with deionized water until neutral, and dry it to obtain pretreated volcanic rock. S2. Weigh out cerium nitrate and dissolve it in deionized water to obtain a cerium nitrate solution. Add citric acid and polyethylene glycol and stir until homogeneous. S3. Add pretreated volcanic rock, stir for 5-6 hours, then raise the temperature to 50-60℃ and continue stirring for 6-8 hours; S4. Place in an oven and dry at 110-120℃. After drying, calcine at 500-550℃ for 5-6 hours in air atmosphere, and grind to obtain CeO2@volcanic rock composite material.
7. The catalyst for synthesizing chlorobenzene according to claim 6, characterized in that, The concentration of cerium nitrate in the cerium nitrate solution is 0.01-0.02 mol / L.
8. The catalyst for synthesizing chlorobenzene according to claim 6, characterized in that, The molar ratio of citric acid to cerium ions is 1.5-2.0:1; The mass ratio of polyethylene glycol to citric acid is 0.4-0.6:
1.
9. The catalyst for synthesizing chlorobenzene according to claim 6, characterized in that, The pretreated volcanic rock was 6-14 times the mass of cerium nitrate.
10. The application of a catalyst for the synthesis of chlorobenzene, characterized in that, The catalyst according to any one of claims 1-9 is used for the synthesis of chlorobenzene by the liquid-phase reaction of benzene and chlorine.