High-efficiency adsorbent for purifying hexafluorobutadiene as well as preparation method and application of high-efficiency adsorbent

Abstract

The preparation method of the high-efficiency adsorbent for hexafluorobutadiene purification comprises the following steps: dispersing a fluorine-containing polymer, a metal precursor salt and a silicon-based template agent in a solvent, sequentially stirring and drying, and carrying out carbonization treatment in an N2 atmosphere for a period of time to obtain the high-efficiency adsorbent. The high-efficiency adsorbent is simple to prepare and easy to prepare in a large scale, and has an excellent industrial application prospect. The purity of hexafluorobutadiene purified by the high-efficiency adsorbent can reach 99.999% or above.

Description

Technical Field

[0001] The invention relates to a separation and purification technology for perfluorinated etching gas, in particular to a high-efficiency adsorbent for purifying hexafluorobutadiene and a preparation method and application thereof. Background Art

[0002] Today, the continuous commercialization of increasingly complex semiconductor integrated circuits requires the development of further manufacturing processes, and the etching process is one of the most critical processes in the manufacturing process. The etching process uses chemical solvents, corrosive gases or plasma to remove unwanted parts of the crystal or the surface layer of the crystal. The chemical solvent undergoes an isotropic etching reaction under the action of strong acid in wet etching, and can also etch the covered parts. Dry etching with corrosive gases or plasma ions can perform anisotropic etching in the vertical direction on the crystal surface. Therefore, dry etching is more suitable for high-precision and fine VLSI (very large-scale integrated circuit) etching processes.

[0003] Hexafluorobutadiene (also known as perfluorobutadiene) is a fully fluorinated compound with double bonds. Compared with traditional plasma etching gases CF4, C2F6, C3F8, c-C4F8 and NF3, hexafluorobutadiene has faster etching speed, high etching selectivity and high aspect ratio. These excellent properties are closely related to the molecular fragments generated during its cracking process. Hexafluorobutadiene decomposes into a variety of active free radicals, metastable particles and atoms, such as C*, F*, CF*, CF2* and CF3* in the plasma zone of the etching chamber. A large number of fluorine atoms react with silicon atoms in silicon materials to generate volatile gas SiF4. However, industrially synthesized hexafluorobutadiene generally contains impurities such as water, HF, butene dimer, fluorinated chlorides of butadiene, and alcohol. There are many synthetic processes for hexafluorobutadiene, and the composition and content of impurities produced by different processes are not the same.

[0004] The US invention patent with the announcement number US06544319B1 discloses the use of adsorption to remove impurities from hexafluorobutane, and studies the removal effects of adsorbents such as Al2O3, 5A molecular sieve, and zeolite on impurities. Among them, 5A molecular sieve has the best effect and can remove most impurities; when using Al2O3 adsorbent, heat release will cause hexafluorobutadiene to be lost due to disproportionation and decomposition reactions; cation-modified zeolite molecular sieves also have good adsorption and impurity removal effects. The Chinese invention patent with the announcement number CN106349008B proposes a method for purifying hexafluorobutadiene, in which resin, potassium borohydride, and graphene oxide aqueous solution are mixed in a certain proportion, and the product after reaction is filtered and dried, and then roasted in stages at different temperatures to obtain a high-efficiency adsorbent. The solvent is removed by extraction, and after the molecular sieve absorbs water, the high-efficiency adsorbent is used to remove most impurities, and then refined by distillation and other methods to obtain hexafluorobutadiene with high purity, and the final purity can reach 99.999%.

[0005] Therefore, it is feasible to purify hexafluorobutadiene by adsorption separation. However, the adsorbents currently used to purify hexafluorobutadiene have limited adsorption effects and are difficult to purify electronic grade hexafluorobutadiene. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a high-efficiency adsorbent for purifying hexafluorobutadiene and a preparation method and application thereof.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, comprising the following steps: dispersing a fluorine-containing polymer, a metal precursor salt and a silicon-based template in a solvent, and then stirring and drying them in sequence, and then carbonizing them in a N2 atmosphere for a period of time to obtain a high-efficiency adsorbent.

[0008] Another technical solution adopted by the present invention is: a high-efficiency adsorbent for purifying hexafluorobutadiene is prepared by adopting the preparation method of the high-efficiency adsorbent for purifying hexafluorobutadiene.

[0009] Another technical solution adopted by the present invention is: the use of the above-mentioned high-efficiency adsorbent for the purification of hexafluorobutadiene comprises the following steps: the crude hexafluorobutadiene is passed into an adsorption tower filled with the high-efficiency adsorbent for adsorption purification, and the hexafluorobutadiene after adsorption purification is subjected to multi-stage distillation to remove impurities to obtain high-purity hexafluorobutadiene.

[0010] The beneficial effects of the present invention are: the high-efficiency adsorbent of the present invention is simple to prepare, easy to scale up and prepare, and has excellent industrial application prospects. The purity of the hexafluorobutadiene obtained after purification by the high-efficiency adsorbent of the present invention can reach more than 99.999%. DETAILED DESCRIPTION

[0011] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes.

[0012] A method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene comprises the following steps: dispersing a fluorine-containing polymer, a metal precursor salt and a silicon-based template in a solvent, and then successively stirring and drying, and then carbonizing the mixture in a N2 atmosphere for a period of time to obtain a high-efficiency adsorbent.

[0013] From the above description, it can be seen that the beneficial effects of the present invention are: the present invention uses a fluorine-containing polymer as a carbon source precursor and obtains a fluorine-doped carbon material as the main body of the adsorbent after carbonization. Due to the extremely strong electronegativity of the F element, after being doped into the skeleton structure of the carbon material, the electronegativity of the carbon material can be effectively improved, thereby effectively adsorbing specific impurities. At the same time, by adding a silicon-based template agent to the fluorine-containing polymer gel, the fluorine-containing polymer releases an HF atmosphere during the carbonization process, and the silicon-based template is removed, thereby performing a pore-forming treatment on the carbon material, thereby greatly improving the specific surface area of ​​the carbon material, thereby increasing the adsorption and separation efficiency. The present invention also introduces metal ions into the fluorine-doped carbon material, and forms corresponding fluorides or fluorine oxides during the carbonization process, thereby adsorbing specific organic impurities, thereby achieving the purpose of efficient adsorption and separation. The high-efficiency adsorbent of the present invention is simple to prepare, easy to scale up, and has excellent industrial application prospects. The purity of hexafluorobutadiene obtained after purification by the high-efficiency adsorbent of the present invention can reach more than 99.999%.

[0014] Furthermore, the fluorine-containing polymer is any one of PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), PVF (polyvinyl fluoride) and PTrFE (polytrifluoroethylene).

[0015] Preferably, the fluoropolymer is PVDF or PTFE.

[0016] Furthermore, the metal in the metal precursor salt is any one of K, Na, Cu, Co, Ce and La.

[0017] Preferably, the metal in the metal precursor salt is any one of K, Cu, and La.

[0018] Furthermore, the metal precursor salt is a nitrate or a nitrate hydrate.

[0019] Furthermore, the silicon-based template is any one of nano-SiO2, SBA-15 molecular sieve and S-1 molecular sieve.

[0020] Preferably, the silicon-based template is nano-SiO2 or S-1 molecular sieve.

[0021] Furthermore, the solvent is a mixed solvent of N,N-dimethylformamide (DMF) and water, and the volume ratio of N,N-dimethylformamide to water is 4:1-10:1.

[0022] Preferably, the volume ratio of N,N-dimethylformamide to water is 7:1 to 10:1.

[0023] Furthermore, the mass ratio of the fluorine-containing polymer to the metal in the metal precursor salt is 4:1-20:1, and the mass ratio of the fluorine-containing polymer to the silicon-based template is 3:1-12:1.

[0024] Preferably, the mass ratio of the fluorine-containing polymer to the metal in the metal precursor salt is 8:1-15:1, and the mass ratio of the fluorine-containing polymer to the silicon-based template is 6:1-10:1.

[0025] Furthermore, the specific steps of stirring and drying are: after stirring at room temperature for 6 h, placing in a forced air drying oven and drying at 120 °C for 12 h.

[0026] Furthermore, the temperature of the carbonization treatment is 400~800 °C, and the time is 2~12 h.

[0027] Preferably, the carbonization treatment temperature is 500-700°C and the time is 4-8 h.

[0028] Another technical solution adopted by the present invention is: a high-efficiency adsorbent for purifying hexafluorobutadiene is prepared by adopting the preparation method of the high-efficiency adsorbent for purifying hexafluorobutadiene.

[0029] Another technical solution adopted by the present invention is: the use of the above-mentioned high-efficiency adsorbent for the purification of hexafluorobutadiene comprises the following steps: the crude hexafluorobutadiene is passed into an adsorption tower filled with the high-efficiency adsorbent for adsorption purification, and the hexafluorobutadiene after adsorption purification is subjected to multi-stage distillation to remove impurities to obtain high-purity hexafluorobutadiene.

[0030] Among them, multi-stage distillation is any multi-stage distillation technology for removing impurities known in the industry.

[0031] Furthermore, the feed flow rate of crude hexafluorobutadiene is 0.1~7 g / (g 吸附剂 •h).

[0032] Preferably, the feed flow rate of crude hexafluorobutadiene is 0.1-4 g / (g 吸附剂 •h).

[0033] Furthermore, the temperature of the adsorption purification is 20-80°C and the pressure is 0.1013-0.5 MPa.

[0034] Preferably, the temperature of the adsorption purification is 20-40° C. and the pressure is 0.1013-0.25 MPa.

[0035] Embodiment 1 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PVDF, 3.33 g of nano-SiO2 and 6.46 g of potassium nitrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 10: 1. The resulting solution was stirred at room temperature for 6 h, then placed in a forced air drying oven at 120 °C for 12 h, and then placed in a nitrogen atmosphere at 500 °C for 4 h for carbonization treatment to obtain a high-efficiency adsorbent.

[0036] The crude hexafluorobutadiene was introduced into an adsorption purification tower containing the high-efficiency adsorbent, and the temperature was 20 °C, the pressure was normal pressure, and the hexafluorobutadiene feed flow rate was 0.1 g / (g 吸附剂 •h) under the conditions of adsorption purification, the adsorbed hexafluorobutadiene is then subjected to a multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-1.

[0037] Embodiment 2 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PVF, 6.67 g of SBA-15 and 18.48 g of sodium nitrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 4: 1. The resulting solution was stirred at room temperature for 6 h, then placed in a forced air drying oven at 120 ° C for 12 h, and then placed in a nitrogen atmosphere at 400 ° C for 2 h for carbonization treatment to obtain a high-efficiency adsorbent.

[0038] The crude hexafluorobutadiene was introduced into an adsorption purification tower equipped with the high-efficiency adsorbent, and the temperature was 80 °C, the pressure was 0.5 MPa and the hexafluorobutadiene feed flow rate was 7 g / (g 吸附剂 •h) under the conditions of adsorption purification, the adsorbed hexafluorobutadiene is then subjected to a multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-2.

[0039] Embodiment 3 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PTrFE, 1.67 g of S-1 molecular sieve and 4.93 g of cobalt nitrate hexahydrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 9: 1. The resulting solution was stirred at room temperature for 6 h, dried in a forced air drying oven at 120 °C for 12 h, and then carbonized in a nitrogen atmosphere at 800 °C for 12 h to obtain a high-efficiency adsorbent.

[0040] The crude hexafluorobutadiene was introduced into an adsorption purification tower equipped with the high-efficiency adsorbent, and the temperature was 25 °C, the pressure was 0.15 MPa and the hexafluorobutadiene feed flow rate was 1 g / (g 吸附剂 •h) under the conditions of adsorption purification, the adsorbed hexafluorobutadiene is then subjected to a multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-3.

[0041] Embodiment 4 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PTFE, 2 g of nano-SiO2 and 4.13 g of cerium nitrate hexahydrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 8: 1. The resulting solution was stirred at room temperature for 6 h, then placed in a forced air drying oven at 120 °C for 12 h, and then placed in a nitrogen atmosphere at 600 °C for 6 h for carbonization treatment to obtain a high-efficiency adsorbent.

[0042] The crude hexafluorobutadiene was introduced into an adsorption purification tower equipped with the high-efficiency adsorbent, and the temperature was 30 °C, the pressure was 0.2 MPa and the hexafluorobutadiene feed flow rate was 1.5 g / (g 吸附剂 •h) under the conditions of adsorption purification, the hexafluorobutadiene after adsorption is then subjected to the multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-4.

[0043] Embodiment 5 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PVDF, 2.86 g of S-1 molecular sieve and 7.6 g of copper nitrate trihydrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 7: 1. The resulting solution was stirred at room temperature for 6 h, dried in a forced air drying oven at 120 °C for 12 h, and then carbonized at 700 °C in a nitrogen atmosphere for 8 h to obtain a high-efficiency adsorbent.

[0044] The crude hexafluorobutadiene was introduced into an adsorption purification tower equipped with the high-efficiency adsorbent, and the temperature was 40 °C, the pressure was 0.18 MPa and the hexafluorobutadiene feed flow rate was 2.5 g / (g 吸附剂 •h) under the conditions of adsorption purification, the adsorbed hexafluorobutadiene is then subjected to a multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-5.

[0045] Embodiment 6 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PTFE, 2.5 g of nano-SiO2 and 6.92 g of lanthanum nitrate hexahydrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 8: 1. The resulting solution was stirred at room temperature for 6 h, dried in a forced air drying oven at 120 °C for 12 h, and then carbonized at 650 °C in a nitrogen atmosphere for 7 h to obtain a high-efficiency adsorbent.

[0046] The crude hexafluorobutadiene was introduced into an adsorption purification tower equipped with the high-efficiency adsorbent, and the temperature was 35 °C, the pressure was 0.25 MPa and the hexafluorobutadiene feed flow rate was 4 g / (g 吸附剂 •h) under the conditions of adsorption purification, the adsorbed hexafluorobutadiene is then subjected to a multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-6.

[0047] Embodiment 7 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PTFE, 2.22 g of S-1 molecular sieve and 4.31 g of potassium nitrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 10: 1. The resulting solution was stirred at room temperature for 6 h, then placed in a forced air drying oven at 120 °C for 12 h, and then placed in a nitrogen atmosphere at 550 °C for 6 h for carbonization treatment to obtain a high-efficiency adsorbent.

[0048] The crude hexafluorobutadiene was introduced into an adsorption purification tower equipped with the high-efficiency adsorbent, and the temperature was 25 °C, the pressure was 0.2 MPa and the hexafluorobutadiene feed flow rate was 3 g / (g 吸附剂 •h) under the conditions of adsorption purification, the adsorbed hexafluorobutadiene is then subjected to a multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-7.

[0049] Embodiment 8 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PVDF, 2.5 g of nano-SiO2 and 4.15 g of lanthanum nitrate hexahydrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 8: 1. The resulting solution was stirred at room temperature for 6 h, then placed in a forced air drying oven at 120 °C for 12 h, and then placed in a nitrogen atmosphere at 700 °C for 4 h for carbonization treatment to obtain a high-efficiency adsorbent.

[0050] The crude hexafluorobutadiene was introduced into an adsorption purification tower equipped with the high-efficiency adsorbent, and the temperature was 40 °C, the pressure was 0.15 MPa and the hexafluorobutadiene feed flow rate was 3 g / (g 吸附剂 •h) under the conditions of adsorption purification, the adsorbed hexafluorobutadiene is then subjected to a multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-8.

[0051] Embodiment 9 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PVDF, 2 g of nano-SiO2 and 9.5 g of copper nitrate trihydrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 7: 1. The resulting solution was stirred at room temperature for 6 h, then placed in a forced air drying oven at 120 °C for 12 h, and then placed in a nitrogen atmosphere at 650 °C for 8 h for carbonization treatment to obtain a high-efficiency adsorbent.

[0052] The crude hexafluorobutadiene was introduced into an adsorption purification tower equipped with the high-efficiency adsorbent, and the temperature was 25 °C, the pressure was 0.2 MPa and the hexafluorobutadiene feed flow rate was 2.5 g / (g 吸附剂 •h) under the conditions of adsorption purification, the adsorbed hexafluorobutadiene is then subjected to a multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-9.

[0053] Embodiment 10 of the present invention is: a method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene, the steps are as follows: 20 g of PTFE, 3.3 g of S-1 molecular sieve and 5.17 g of potassium nitrate were weighed and dispersed in 400 mL of DMF / water mixed solvent, and the volume ratio of DMF to water was 8: 1. The resulting solution was stirred at room temperature for 6 h, dried in a forced air drying oven at 120 °C for 12 h, and then carbonized at 500 °C in a nitrogen atmosphere for 8 h to obtain a high-efficiency adsorbent.

[0054] The crude hexafluorobutadiene was introduced into an adsorption purification tower equipped with the high-efficiency adsorbent, and the temperature was 25 °C, the pressure was 0.18 MPa and the hexafluorobutadiene feed flow rate was 2 g / (g 吸附剂 •h) under the conditions of adsorption purification, the adsorbed hexafluorobutadiene is then subjected to a multi-stage distillation technology known in the industry to remove impurities, and finally high-purity hexafluorobutadiene is obtained, and the product number is recorded as S-10.

[0055] Comparative Example 1 of the present invention is: The only difference between Comparative Example 1 and Example 1 is that no silicon-based template is added when preparing the high-efficiency adsorption separation agent, and the product number is recorded as D-1.

[0056] Comparative Example 2 of the present invention: The only difference between Comparative Example 2 and Example 1 is that no fluorine-containing polymer is added when preparing the high-efficiency adsorption separation agent, and the product number is recorded as D-2.

[0057] Comparative Example 3 of the present invention: The only difference between Comparative Example 3 and Example 1 is that the high-efficiency adsorption separation agent is not added, and ZSM-5 molecular sieve is used instead of the high-efficiency adsorption separation agent, and the product number is recorded as D-3.

[0058] The product purity of Examples 1-10 and Comparative Examples 1-3, as well as the volume concentration of impurities, were tested. The test results are shown in Table 1 below.

[0059] Table 1

[0060] It can be seen from the results in Table 1 that the purity of hexafluorobutadiene obtained after purification by the high-efficiency adsorbent of the present invention can reach more than 99.999%, and the purification effect is better than that of ZSM-5 molecular sieve.

[0061] Embodiment 11 of the present invention is: a high-efficiency adsorbent prepared by the preparation method of embodiment 1.

[0062] Embodiment 12 of the present invention is: application of the high-efficiency adsorbent in Embodiment 11 in the purification of hexafluorobutadiene.

[0063] In summary, the high-efficiency adsorbent for purification of hexafluorobutadiene provided by the present invention and its preparation method and application have the following advantages: 1) The preparation method is simple and suitable for industrial production.

[0064] 2) The crude hexafluorobutadiene can be purified to above 99.999%.

[0065] 3) Using fluorine-containing polymers as carbon source precursors, so that fluorine-doped carbon materials are used as the main adsorbent. Fluorine doping can improve the electronegativity of carbon materials to adsorb specific impurities.

[0066] 4) Adding a silicon-based template to the fluorine-containing polymer gel to achieve pore-forming treatment of the carbon material and increase the adsorption and separation efficiency.

[0067] 5) Metal ions introduced into the fluorine-doped carbon material to adsorb specific organic impurities. The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformation made by using the content of the present invention specification, or directly or indirectly applied in related technical fields, is also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a highly efficient adsorbent for purifying hexafluorobutadiene, characterized in that: The method comprises the following steps: dispersing a fluorine-containing polymer, a metal precursor salt and a silicon-based template in a solvent, and then successively stirring and drying them, and then carbonizing them in a N2 atmosphere for a period of time to obtain a high-efficiency adsorbent.

2. The method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene according to claim 1, characterized in that: The fluorine-containing polymer is any one of PVDF, PTFE, PVF and PTrFE.

3. The method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene according to claim 1, characterized in that: The metal in the metal precursor salt is any one of K, Na, Cu, Co, Ce and La.

4. The method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene according to claim 1, characterized in that: The metal precursor salt is nitrate or nitrate hydrate.

5. The method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene according to claim 1, characterized in that: The silicon-based template agent is any one of nano-SiO2, SBA-15 molecular sieve and S-1 molecular sieve.

6. The method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene according to claim 1, characterized in that: The solvent is a mixed solvent of N,N-dimethylformamide and water, and the volume ratio of N,N-dimethylformamide to water is 4:1-10:

1.

7. The method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene according to claim 1, characterized in that: The mass ratio of the fluorine-containing polymer to the metal in the metal precursor salt is 4:1-20:1, and the mass ratio of the fluorine-containing polymer to the silicon-based template is 3:1-12:

1.

8. The method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene according to claim 1, characterized in that: The temperature of the carbonization treatment is 400-800°C and the time is 2-12 hours.

9. A highly efficient adsorbent for purification of hexafluorobutadiene, characterized in that: The adsorbent is prepared by the method for preparing a high-efficiency adsorbent for purifying hexafluorobutadiene according to any one of claims 1 to 8.

10. The use of the high-efficiency adsorbent for purification of hexafluorobutadiene as claimed in claim 9, characterized in that: The method comprises the following steps: introducing crude hexafluorobutadiene into an adsorption tower filled with a high-efficiency adsorbent for adsorption purification, and subjecting the adsorbed and purified hexafluorobutadiene to multi-stage distillation to remove impurities to obtain high-purity hexafluorobutadiene.

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