Preparation, application and regeneration method of carbon-based catalyst

Abstract

The invention discloses a preparation method of a carbon-based catalyst and a regeneration method of an inactivated carbon-based catalyst, the preparation method comprises the following steps: (1) carrying out high-temperature treatment on an activated carbon carrier by using an aqueous solution containing a nitrogen compound, controlling the temperature to be 400-800 DEG C and the time to be 1-10 hours; the nitrogen-containing compound is selected from at least one of pyridine, C1-C3 aliphatic amine, pyrrole, piperidine, ammonia water and urea; and (2) taking out the activated carbon carrier subjected to high-temperature treatment, and soaking the activated carbon carrier in nitrogen-containing ionic liquid to obtain the carbon-based catalyst. When the carbon-based catalyst is used in a dehydrohalogenation reaction, the reaction temperature can be reduced, and the stability of the catalyst can be improved; and the inactivated carbon-based catalyst still has good catalytic activity and stability after regeneration, the production cost can be greatly reduced, and the method is very suitable for industrial application.

Description

Technical Field

[0001] The present invention relates to the preparation of fluoroolefins, in particular to the preparation of a carbon-based catalyst and its application in dehydrohalogenation reactions, as well as a regeneration method for the deactivated carbon-based catalyst. Background Art

[0002] Hydrofluoroolefins are an important class of fluorine-containing chemicals with wide applications. They can be used as monomers to prepare fluorine-containing polymers with excellent properties. Fluoroolefins have zero ozone-depleting substances (ODS) and extremely low global warming potential (GWP) values, making them ideal heat transfer fluids with potential application values in refrigeration, medical aerosols, polymers and other fields. 2,3,3,3-Tetrafluoropropene (abbreviated as "HFO-1234yf") is considered to be the most promising alternative refrigerant for automobiles at present. It has a very low global warming value (GWP < 4), excellent performance in various aspects, and shows significant environmental benefits. Vinylidene fluoride (VDF) is mainly used to prepare polyvinylidene fluoride (PVDF) materials with excellent heat resistance, chemical corrosion resistance and mechanical properties, which can be widely used in coatings, battery separators, electroacoustic devices, optoelectronic materials and other fields. In addition, vinylidene fluoride can also react and polymerize with other monomers to obtain copolymer materials with different properties and uses. Hexafluorobutyne is an important fluorine-containing fine chemical raw material, which has the potential to replace SF6 as an environmentally friendly insulating gas and also has high application value in the synthesis of fluorine-containing fine chemicals such as pharmaceuticals and pesticides.

[0003] Generally, the dehydrohalogenation reaction is a key step in the synthesis of fluoroolefins, and the catalyst is the core thereof.

[0004] Zheng Haifeng et al. (Chemical Reaction Engineering and Technology) used FeCl3 / C, CuCl2 / C and NiCl2 / C for the dehydrochlorination of R142b to synthesize VDF, but in the process of this reaction, the phenomenon of catalyst loss occurred, and the catalyst life was short.

[0005] Patent CN112194561A discloses a method for the dehydrochlorination of gaseous 1,1,1,4,4,4-hexafluoro-2-chlorobutene to prepare hexafluorobutyne. The reaction temperature is 100 - 400 °C, and the catalyst is an alkaline earth metal and a rare earth metal supported on a carbon carrier. The highest yield of hexafluorobutyne is 85%, with a large amount of rare earth elements loaded and a low yield.

[0006] The synthesis routes of HFO-1234yf mainly include fluorine-chlorine exchange reactions, dehydrohalogenation reactions and dehydrogenation reactions, etc., among which the dehydrohalogenation reaction is more common.

[0007] Patent CN1976885A discloses a method for preparing HFO-1234yf using CCl2=CClCH2Cl as a raw material. CCl2=CClCH2Cl first reacts with HF to form CF3CCl=CH2, and then undergoes an addition reaction with HF in the presence of a Cr2O3-FeCl3 / C catalyst to form CF3CFClCH3 (HCFC-244bb). Finally, HCFC-244bb eliminates one molecule of HCl to obtain HFO-1234yf. However, this method has a long reaction step, still requires highly corrosive HF, and the catalyst is loaded with heavy metals, which is prone to causing environmental pollution. More importantly, this type of catalyst loaded with active metals is not conducive to recycling, and the service life of the catalyst is not disclosed.

[0008] Patent US20070197842A discloses the use of Aldrich activated carbon, Calgon activated carbon, 0.5% Pd / C or 0.5% Pt / C catalysts in the reaction of dehydrochlorination of R244bb to prepare HFO-1234yf. When the reaction temperature is 400 °C, different catalysts all show high catalytic activity, and the conversion rate of HCFC-244bb can reach over 85%. However, the product selectivity varies significantly. Among them, Calgon activated carbon has the highest selectivity, and the selectivity of HFO-1234yf can reach 93%, while the selectivity of 0.5% Pd / C and 0.5% Pt / C is relatively poor, and the selectivity of HFO-1234yf is less than 60%.

[0009] Patent CN115215724A discloses a method for preparing HFO-1234yf from 3-chloro-1,1,1,2-tetrafluoropropane (HCFC-244eb) under the action of an activated carbon catalyst. When the reaction temperature is 350 °C, the raw material conversion rate is 99%. When the reaction temperature is 320 °C, the raw material conversion rate is 86.9%. When the reaction temperature is 300 °C, the raw material conversion rate is 75.8%. Under this catalyst, the reaction requires a relatively high reaction temperature for a high raw material conversion rate, and the catalyst efficiency is not disclosed.

[0010] In summary, in the process of dehydrohalogenation of chlorofluorocarbons to prepare fluorinated olefins, either heavy metal-supported catalysts are used, which are not only prone to causing environmental pollution but also have high catalyst costs; or activated carbon catalysts are directly used, which have low production costs but low catalytic efficiency and only have good catalytic activity at relatively high reaction temperatures, and the lifespan of the catalyst is unknown. Summary of the Invention

[0011] To solve the above technical problems, the present invention proposes a preparation method and application of a carbon-based catalyst with high catalytic activity, good catalyst stability, simple preparation, environmental friendliness, and simple catalyst regeneration.

[0012] The object of the present invention is achieved through the following technical solutions:

[0013] A preparation method of a carbon-based catalyst, the preparation method comprising:

[0014] (1) subjecting an activated carbon support to high-temperature treatment with an aqueous solution of a nitrogen-containing compound, controlling the temperature to be 400-800 °C and the time to be 1-10 h; the nitrogen-containing compound is selected from at least one of pyridine, C1-C3 aliphatic amines, pyrrole, piperidine, ammonia water, and urea; the C1-C3 aliphatic amine is preferably selected from at least one of n-propylamine or triethylamine;

[0015] (2) taking out the activated carbon support after high-temperature treatment and impregnating it in an ionic liquid to obtain the carbon-based catalyst, and the ionic liquid is a nitrogen-containing ionic liquid.

[0016] In step (1), the activated carbon support is selected from wood-based activated carbon, fruit shell-based activated carbon, coal-based activated carbon, regenerated carbon, or petroleum-based activated carbon. Preferably, the activated carbon is selected from fruit shell-based activated carbon, which has a rich pore structure and a large specific surface area, and can provide more adsorption sites.

[0017] The high-temperature treatment temperature is preferably 500-700 °C, and the treatment time is 2-5 h.

[0018] During the high-temperature treatment in step (1), first fill the activated carbon support in a reactor (such as a reaction tube), then heat it to 400-800 °C, and then continuously introduce the aqueous solution of the nitrogen-containing compound for high-temperature treatment.

[0019] In the aqueous solution of the nitrogen-containing compound, the mass concentration of the nitrogen-containing compound is 10-60%, preferably 20-50%, and this concentration can provide more active sites. The mass flow rate of the aqueous solution of the nitrogen-containing compound to the mass of the support is 0.1-10 h -1 , preferably 1-5 h -1 .

[0020] The nitrogen-containing compound is preferably at least one of ammonia water, pyridine, or urea. High-temperature water vapor acts on the surface of the support to produce a structure with developed micropores. The nitrogen-containing compound acts on the support at high temperature to form a C-N doped support, and more active sites are provided after doping.

[0021] In step (2), the ionic liquid is selected from at least one of 1-hexyl-3-methylimidazolium chloride, tetraalkylammonium salts, 1-alkyl-3-methylimidazolium nitrate, N-alkyl-pyridine sulfate, 1,2-dialkylpyrazolium chloride, and N-alkylthiazolium nitrate. Preferably, the ionic liquid is selected from 1-hexyl-3-methylimidazolium chloride, 1-alkyl-3-methylimidazolium nitrate, and N-alkyl-pyridine sulfate.

[0022] In step (2), the impregnation temperature in the ionic liquid can be arbitrary. For convenience of operation, it can be carried out at room temperature; the impregnation time is 6 to 24 h, preferably 8 to 16 h.

[0023] The loading amount of the ionic liquid on the activated carbon carrier is 0.1 to 10%, preferably 2 to 7%. The ionic liquid provides active sites. If the loading amount is too low, the activity of dehydrochlorination is low; if the loading amount is too high, it is easy to block the carrier pores and cause a decrease in the catalyst activity.

[0024] The present invention also provides the application of the carbon-based catalyst prepared by the above-mentioned preparation method in the dehydrohalogenation reaction. Specifically, the carbon-based catalyst is used for the dehydrochlorination reaction of at least one of R244eb, R244bb, R124, R133b or R1326.

[0025] The reaction temperature of the dehydrochlorination reaction is 150 to 400 °C, and the contact reaction time is 1 to 60 s. Preferably, the reaction temperature is 250 to 350 °C, and the contact reaction time is 5 to 30 s; the reaction pressure is atmospheric pressure. Compared with the conventional activated carbon catalyst, the carbon-based catalyst of the present invention can reduce the reaction temperature on the basis of ensuring the raw material conversion rate and selectivity, and significantly improve the stability and service life of the catalyst.

[0026] The carbonyl catalyst of the present invention also has the advantage of regeneration. Not only can the catalyst be regenerated and reused by a simple method, but the regenerated catalyst also has high catalytic activity and catalytic stability.

[0027] Therefore, the present invention also provides a regeneration method for the carbon-based catalyst. The regeneration method includes: dissolving the deactivated carbon-based catalyst used in the above-mentioned dehydrohalogenation reaction in a fluorinated organic solvent, and heating it under microwave with a heating power of 400 to 1500 W for 1 to 30 min; the fluorinated organic solvent is selected from at least one of trichlorotrifluoroethane, heptafluoropropane, pentafluorobutane or perfluorohexanone.

[0028] Preferably, the microwave heating power is 600 to 1000 W, and the heating time is 5 to 20 min; the fluorinated organic solvent is selected from at least one of trichlorotrifluoroethane and heptafluoropropane. Using a fluorinated organic solvent is more conducive to the elimination of carbon deposition and promotes the regeneration of the carbon-based catalyst.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. The preparation method of the carbon-based catalyst of the present invention is simple, has high universality, and good catalyst repeatability, which is conducive to large-scale production;

[0031] 2. The carbon-based catalyst of the present invention is used in the dehydrohalogenation reaction, especially in the reaction of preparing TrFE by dehydrochlorination of R133b. It can not only improve the catalytic activity, reduce the reaction temperature, but also significantly improve the stability and service life of the catalyst.

[0032] 3. The regeneration method of the carbon-based catalyst of the present invention is simple, which not only greatly reduces the production cost, can avoid the problem of difficult treatment of activated carbon solid waste, but also has good catalytic activity after regeneration, and the catalyst still has strong stability. Specific Embodiments

[0033] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to these specific embodiments. Those skilled in the art should recognize that the present invention covers all alternative, improved and equivalent solutions that may be included within the scope of the claims.

[0034] Example 1

[0035] Add 10 g of wood activated carbon (8-10 mesh) into the reaction tube, introduce 25% ammonia water solution with a mass flow rate of 10 g / h, carry out high-temperature pretreatment at 500 °C for 5 h. After cooling to room temperature, take it out and set aside. Weigh 5 g of the activated carbon carrier, prepare 20 mL of an ionic liquid containing 0.5 g of 1-hexyl-3-methylimidazolium chloride, add the carrier into the solution, impregnate for 8 h, and dry at 110 °C, denoted as Cat 1.

[0036] Example 2

[0037] The operation of this example is the same as that of Example 1, the only difference being that the mass concentration of the ammonia water solution is reduced to 10%, and other operations remain unchanged. The prepared carbon-based catalyst is denoted as Cat 2.

[0038] Example 3

[0039] The operation of this example is the same as that of Example 1, the only difference being that the high-temperature pretreatment time is reduced to 2 h, and other operations remain unchanged. The prepared carbon-based catalyst is denoted as Cat 3.

[0040] Example 4

[0041] The operation of this example is the same as that of Example 1, the only difference being that the mass concentration of the ammonia water solution is reduced to 20%, and the high-temperature pretreatment temperature is increased to 700 °C, and the pretreatment time is increased to 10 h, and other operations remain unchanged. The prepared carbon-based catalyst is denoted as Cat 4.

[0042] Example 5

[0043] The operation of this example is the same as that of Example 1, except that: the aqueous solution of the nitrogen-containing compound is replaced with a 60% by mass pyridine aqueous solution, and other operations remain unchanged. The prepared carbon-based catalyst is denoted as Cat 5.

[0044] Example 6

[0045] The operation of this example is the same as that of Example 1, except that: the aqueous solution of the nitrogen-containing compound is replaced with a 30% by mass urea aqueous solution, and the high-temperature pretreatment temperature is increased to 600 °C and the pretreatment time is reduced to 3 h, and other operations remain unchanged. The prepared carbon-based catalyst is denoted as Cat 6.

[0046] Example 7

[0047] The operation of this example is the same as that of Example 1, except that: the aqueous solution of the nitrogen-containing compound is replaced with a 30% by mass triethylamine aqueous solution, and other operations remain unchanged. The prepared carbon-based catalyst is denoted as Cat 7.

[0048] Example 8

[0049] The operation of this example is the same as that of Example 1, except that: a 20 mL solution containing 1 g of 1-methyl-3-methylimidazolium nitrate is prepared, and other operations remain unchanged. The prepared carbon-based catalyst is denoted as Cat 8.

[0050] Example 9

[0051] Add 10 g of shell-based activated carbon (8-10 mesh) to the reaction tube, introduce a 25% n-propylamine solution with a feeding rate of 10 g / h, and perform high-temperature pretreatment at 500 °C for 2 h. Cool to room temperature and take out for standby. Weigh 5 g of the activated carbon carrier, prepare a 20 mL solution containing 0.5 g of N-methyl-pyridine sulfate ionic liquid, add the carrier to the solution, impregnate for 8 h, and dry at 110 °C, denoted as Cat 9.

[0052] Example 10

[0053] Add coal-based activated carbon (8-10 mesh) to the reaction tube, introduce a 25% piperidine solution with a mass flow rate of 10 g / h, and perform high-temperature pretreatment at 500 °C for 5 h. Cool to room temperature and take out for standby. Weigh 5 g of the activated carbon carrier, prepare a 20 mL solution containing 0.5 g of N-ethyl thiazolium nitrate ionic liquid, add the carrier to the solution, impregnate for 8 h, and dry at 110 °C, denoted as Cat10.

[0054] Example 11

[0055] The operation of this example is the same as that of Example 1, except that: the aqueous solution of the nitrogen-containing compound is replaced with a 25% by mass pyrrole solution, and other operations remain unchanged. The prepared carbon-based catalyst is denoted as Cat 11.

[0056] Comparative Example 1

[0057] Wooden activated carbon (8 - 10 mesh) was dried at 110 °C for later use, denoted as CatB1.

[0058] Comparative Example 2

[0059] Weighed 5 g of wooden activated carbon (8 - 10 mesh) support, prepared 20 mL of ionic liquid containing 0.5 g of 1 - hexyl - 3 - methylimidazolium chloride, added the support into the solution, impregnated for 8 h, and dried at 110 °C, denoted as CatB2.

[0060] Comparative Example 3

[0061] Weighed 5 g of wooden activated carbon (8 - 10 mesh), passed 25% ammonia aqueous solution with a mass flow rate of 10 g / h, carried out high - temperature pretreatment at 500 °C for 5 h. Cooled to room temperature and taken out for later use, denoted as Cat B3.

[0062] Comparative Example 4

[0063] Added 10 g of wooden activated carbon (8 - 10 mesh) into the reaction tube, passed 25% ammonia aqueous solution with a mass flow rate of 10 g / h, carried out high - temperature pretreatment at 500 °C for 5 h. Cooled to room temperature and taken out for later use. Weighed 5 g of activated carbon support, prepared 20 mL of ionic liquid containing 0.5 g of dodecyltributylphosphonium bromide, added the support into the solution, impregnated for 8 h, and dried at 110 °C, denoted as CatB4.

[0064] Comparative Example 5

[0065] Added 10 g of wooden activated carbon (8 - 10 mesh) into the reaction tube, passed 25% ammonia aqueous solution with a feeding rate of 10 g / h, carried out high - temperature pretreatment at 300 °C for 5 h. Cooled to room temperature and taken out for later use. Weighed 5 g of activated carbon support, prepared 20 mL of ionic liquid containing 0.5 g of 1 - hexyl - 3 - methylimidazolium chloride, added the support into the solution, impregnated for 8 h, and dried at 110 °C, denoted as Cat B5.

[0066] Application Example 1

[0067] The application of the carbon - based catalysts prepared in the above examples and comparative examples in the synthesis of fluorinated olefins is as follows:

[0068] Took 2 g of catalyst (cat1) and loaded it into the reaction tube, respectively passed different fluorochloroalkanes for dehydrochlorination reaction, the reaction temperature was 300 °C, the contact time between the raw material and the catalyst was 10 - 30 s, and the reaction pressure was atmospheric pressure.

[0069] The end point of the reaction is that the conversion rate of the raw material is reduced to 80%. Catalyst efficiency = feed amount * average conversion rate * average selectivity / catalyst mass.

[0070] Collect the reaction gas for gas chromatography analysis, and the results are shown in Table 1 below:

[0071] Table 1 Dehydrochlorination reaction results of different fluorochlorohydrocarbons

[0072]

[0073]

[0074] Application Example 2

[0075] Apply the carbon-based catalysts obtained in the above examples and comparative examples in the synthesis of TrFE. The specific operation steps are as follows:

[0076] Take 2 g of different catalysts and load them into the reaction tube respectively. Introduce 1-chloro-1,1-difluoro-2-fluoroethane (R133b) for dehydrochlorination reaction. The reaction temperature is 300 °C, the contact time between the raw material and the catalyst is 10 - 30 s, and the reaction pressure is atmospheric pressure.

[0077] The end point of the reaction is that the conversion rate of the raw material is reduced to 80%. Catalyst efficiency = feed amount * average conversion rate * average selectivity / catalyst mass.

[0078] Collect the reaction gas for gas chromatography analysis, and the results are shown in Table 2 below:

[0079] Table 2 Reaction results of different catalysts

[0080]

[0081] Application Example 3

[0082] On the basis of Application Example 2, take Cat 1 as an example to investigate the influence of reaction temperature on the reaction results, as shown in Table 3 below:

[0083] Table 3 Reaction results at different reaction temperatures

[0084]

[0085] The catalyst of the present invention has good conversion rate and selectivity under low-temperature conditions, indicating better catalytic activity compared with commercial activated carbon catalysts; comparing the catalyst efficiency shows that the catalyst stability is significantly improved, the service life is increased, and the production cost is reduced.

[0086] Regeneration Example 1

[0087] Take 10 g of the deactivated Cat 1 and put it into a beaker. Add 30 mL of trifluorotrichloroethane, and then place it in a microwave oven for heating. The heating power is 400 W, and the heating time is 5 min. After heating, take it out, filter and dry it, and label it as Cat Z1.

[0088] Regeneration Example 2

[0089] The operation of this example is the same as that of Regeneration Example 1, except that: the microwave heating power is increased to 700 W, and other operations remain unchanged. The obtained regenerated catalyst is labeled as Cat Z2.

[0090] Regeneration Example 3

[0091] The operation of this example is the same as that of Regeneration Example 1, except that: the microwave heating power is increased to 1000 W, and other operations remain unchanged. The obtained regenerated catalyst is labeled as Cat Z3.

[0092] Regeneration Example 4

[0093] Take 10 g of the deactivated Cat 1 and put it into a beaker. Add 30 mL of perfluoroketone, and then place it in a microwave oven for heating. The heating power is 700 W, and the heating time is 20 min. After heating, take it out, filter and dry it, and label it as Cat Z4.

[0094] Regeneration Example 5

[0095] Take 10 g of the deactivated Cat1 and put it into a beaker. Add 30 mL of pentafluorobutane, and then place it in a microwave oven for heating. The heating power is 700 W, and the heating time is 20 min. After heating, take it out, filter and dry it, and label it as Cat Z5.

[0096] Regeneration Example 6

[0097] Subject Cat 1 to repeated use and regeneration. Take 10 g of the Cat 1 deactivated after the 5th use and put it into a beaker. Add 30 mL of pentafluorobutane, and then place it in a microwave oven for heating. The heating power is 700 W, and the heating time is 20 min. After heating, take it out, filter and dry it, and label it as Cat Z6.

[0098] Regeneration Comparative Example 1

[0099] Commercial activated carbon has hydrogen chloride deactivation activity. The deactivated catalyst is regenerated. Take 10 g of Cat B1 and put it into a beaker. Add 30 mL of ethanol, and then place it in a microwave oven for heating. The heating power is 700 W, and the heating time is 20 min. After heating, take it out, filter and dry it, and label it as Cat ZB1.

[0100] Regeneration Comparative Example 2

[0101] Use and regenerate Cat 1 repeatedly. Take 10 g of Cat 1 that has been deactivated after the fifth use and put it into a beaker. Add 30 mL of dichloromethane, and then place it in a microwave oven for heating. The heating power is 700 W and the heating time is 20 min. After heating, take it out, filter and dry it, and record it as Cat ZB2.

[0102] Application Example 4

[0103] The operation of this application example is the same as that of Application Example 2, except that: the reaction of dehydrochlorination of R133b to prepare TrFE is carried out using Cat Z1 - Cat Z6, Cat ZB1 - Cat ZB2. The reaction temperature is 300 °C and the contact time is 10 s. The reaction results are shown in Table 4 below:

[0104] Table 4 Reaction Results of Regenerated Catalysts

[0105]

[0106]

[0107] The present invention adopts the method of dissolving with a fluorinated organic solvent and microwave heating. The catalyst still has good catalyst efficiency after being regenerated five times, indicating that the regeneration method of the present invention is not only simple in operation but also can significantly improve the regeneration effect of the catalyst.

Claims

1. A method for preparing a carbon-based catalyst, characterized in that The preparation method includes: (1) The activated carbon support is subjected to high-temperature treatment with an aqueous solution of a nitrogen-containing compound, with the temperature controlled at 400 - 800 °C and the time being 1 - 10 h; the nitrogen-containing compound is selected from at least one of pyridine, C1-C3 aliphatic amines, pyrrole, piperidine, ammonia water, and urea; (2) The activated carbon support after high-temperature treatment is taken out and impregnated in an ionic liquid to obtain the carbon-based catalyst, and the ionic liquid is a nitrogen-containing ionic liquid.

2. The preparation method of the carbon-based catalyst according to claim 1, characterized in that: In an aqueous solution of a nitrogen-containing compound, the mass concentration of the nitrogen-containing compound is 10 to 60%, and the mass ratio of the mass flow rate of the aqueous solution of the nitrogen-containing compound to the carrier is 0.1 to 10 h -1 .

3. The preparation method of the carbon-based catalyst according to claim 1, wherein: In step (1), the high-temperature treatment temperature is 500 - 700 °C and the time is 2 - 5 h.

4. The preparation method of the carbon-based catalyst according to claim 1, characterized in that: In step (2), the ionic liquid is selected from at least one of 1-hexyl-3-methylimidazolium chloride, tetraalkylammonium salts, 1-alkyl-3-methylimidazolium nitrate, N-alkyl-pyridine sulfate, 1,2-dialkylpyrazolium chloride, and N-alkylthiazolium nitrate.

5. The preparation method of the carbon-based catalyst according to claim 4, characterized in that: In step (2), the loading amount of the ionic liquid on the activated carbon support is 0.1 - 10%.

6. The preparation method of the carbon-based catalyst according to claim 4, wherein: In step (2), the impregnation time is 4 - 24 h.

7. Use of the carbon-based catalyst prepared by the preparation method according to any one of claims 1-6 in the dehydrohalogenation reaction, characterized in that: The carbon-based catalyst is used for the dehydrochlorination reaction of at least one fluorochloroalkane selected from R244eb, R244bb, R124, R133b, or R1326.

8. Use of the carbon-based catalyst according to claim 7 in the dehydrohalogenation reaction, characterized in that: The reaction temperature of the dehydrochlorination reaction is 150 - 400 °C, and the contact reaction time is 1 - 60 s.

9. Use of the carbon-based catalyst according to claim 8 in the dehydrohalogenation reaction, characterized in that: The reaction temperature of the dehydrochlorination reaction is 250 - 350 °C, and the contact reaction time is 5 - 30 s.

10. A method for regenerating a carbon-based catalyst, characterized in that: The carbon-based catalyst deactivated after the dehydrohalogenation reaction in any one of claims 7 - 9 is dissolved in a fluorinated organic solvent and heated under microwave with a heating power of 400 - 1500 W for a heating time of 1 - 30 min.

11. The regeneration method of the carbon-based catalyst according to claim 10, wherein: The fluorinated organic solvent is selected from at least one of trichlorotrifluoroethane, heptafluoropropane, pentafluorobutane, or perfluorohexanone.

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