CN114618544A - Synthetic method of lamellar structure catalyst - Google Patents
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Abstract
The invention belongs to the technical field of catalysts, and relates to a method for synthesizing a lamellar structure catalyst, which comprises the following steps: stirring 1.7-2 g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6-10 g of aluminum nitrate nonahydrate, 85-97 g of urea and 470g of water to fully dissolve solids, adding into a high-pressure reaction kettle, stirring and reacting at 120 ℃ for 8 hours, stopping stirring, keeping the temperature and standing for 12 hours, cooling to room temperature, taking out the material, and washing with water until the pH value is neutral; and (4) centrifugally dewatering, drying the solid, grinding and crushing to obtain the lamellar structure catalyst. The catalyst prepared by the method is used for preparing the carbon nano tube, the yield of the carbon nano tube per unit weight of the catalyst is not lower than 17%, the mixture ratio of slurry prepared by the collected carbon nano tube product is 97.5% of NMP, 2% of CNT, 0.25% of dispersing agent and 0.5% of PVP, the test coating mixture ratio is 7.5g of slurry, 50g of HSV, 15.6g of LCO, the addition amount of the CNT is 0.3%, and the measured coating resistivity is not higher than 13.26m omega cm.
Description
Technical Field
The invention relates to a synthesis method of a lamellar structure catalyst, belonging to the technical field of catalysts.
Background
In recent years, carbon nanotubes have been widely used as an excellent conductive agent in the lithium battery industry of new energy automobiles. Because of the ultrahigh length-diameter ratio and high conductivity, compared with the traditional conductive agent graphite and super P, the conductive agent graphite and super P can build a high-efficiency three-dimensional conductive network structure in the electrode with very low addition amount, has extremely high conductive efficiency, and can improve key indexes such as energy density, service life and the like of the battery. Therefore, it has been a trend to synthesize a novel carbon nanotube conductive agent instead of the conventional conductive agent.
In the synthesis process of carbon nanotubes, catalysts are essential, and the structure and the shape of the catalyst affect the structure and the properties of the carbon nanotubes. At present, the catalyst for synthesizing the carbon nano tube is mainly in a disordered piled powder state or a granular state, the synthesized carbon nano tube is mutually agglomerated and wound, the defects are obvious, the subsequent dispersion and processing become difficult, and the performance of the carbon nano tube is not favorably exerted. By adjusting the microstructure of the catalyst, the carbon nano-tubes with the same orientation and parallel arrangement can be synthesized under certain conditions. Compared with wound carbon nanotubes, the carbon nanotube array has consistent length-diameter ratio, better orientation and higher purity, and is beneficial to exerting the excellent performance of the carbon nanotubes.
In the synthesis process of the array carbon nano tube, the winding problem of the carbon nano tube is improved along with the application of the catalyst with a layered structure. However, the catalyst with a layered structure generally takes natural vermiculite as a main raw material, and more impurity ions such as iron and chromium are introduced in the process of synthesizing the carbon nanotube, so that the subsequent purification treatment process and cost are increased.
Patent CN111495380A provides a method for preparing carbon nanotube catalyst, which comprises respectively preparing a catalyst containing Mg2+、Al3+、Co2+And a mixed solution A and a weak base solution B of the catalyst promoter containing metal ions, dripping the weak base solution B into the mixed solution A in the process of heating, and then standing, filtering, washing and calcining to obtain the catalyst. The method is characterized in that urea and a plurality of weak bases are added as a precipitating agent to prepare the carbon nano tube catalyst under normal pressure. But the yield and conductivity of the carbon nanotubes prepared by the catalyst are still to be improved.
Patent CN109665512a provides a synthesis method of multi-walled carbon nanotubes, which specifically comprises blending a mixed salt solution containing active components and carrier phase components with an alkaline solution containing an alkaline precipitant under stirring, standing at 80-105 ℃ to obtain a suspension, and standing, filtering, washing, and freeze-drying to obtain a sheet catalyst. However, the carbon nanotubes prepared by the catalyst have no array orientation as seen from SEM characterization, and the yield and the conductivity of the prepared carbon nanotubes are still to be improved.
Disclosure of Invention
[ problem ] to
The catalyst prepared by the method is used for preparing the carbon nano tube, the yield of the carbon nano tube per unit weight of the catalyst is not lower than 1700%, the mixture ratio of slurry prepared by the collected carbon nano tube product is 97.5% of NMP + 2% of CNT + 0.25% of dispersing agent + 0.5% of PVP, the test coating mixture ratio is 7.5g of slurry +50g of HSV +15.6g of LCO, the addition amount of the CNT is 0.3%, and the measured coating resistivity is not higher than 13.26m omega.
[ solution ]
The method is carried out in a high-pressure reaction kettle in the process of synthesizing MgAl hydrotalcite layered double-metal hydroxide LDH, urea is used as a precipitator, and one or more active metals such as iron, cobalt, nickel and the like are loaded to an LDH laminate by utilizing the adjustability of LDH laminate elements, so that the catalyst with the catalytic activity of catalyzing the growth of carbon nano tubes is obtained. The synthesized catalyst is of a lamellar structure, and the carbon nano tube synthesized by the catalyst has array orientation and good conductivity.
The first purpose of the invention is to provide a synthesis method of a lamellar structure catalyst, which comprises the following steps:
stirring 1.7-2 g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6-10 g of aluminum nitrate nonahydrate, 85-97 g of urea and 470g of water to fully dissolve solids, adding into a high-pressure reaction kettle, stirring and reacting at 120 ℃ for 8 hours, stopping stirring, keeping the temperature and standing for 12 hours, cooling to room temperature, taking out the material, and washing with water until the pH value is neutral; and (4) centrifugally dewatering, drying the solid, grinding and crushing to obtain the lamellar structure catalyst.
A second object of the present invention is to provide a method for synthesizing a lamellar structure catalyst, comprising the steps of:
stirring 1.7g of cobalt nitrate hexahydrate, 2g of ferric nitrate nonahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 97g of urea and 470g of water to fully dissolve solids, adding the mixture into a high-pressure reaction kettle, stirring and reacting for 8 hours at 120 ℃, stopping stirring, keeping the temperature and standing for 12 hours, cooling to room temperature, taking out the material, and washing with water until the pH value is neutral; and (4) centrifugally dewatering, drying the solid, grinding and crushing to obtain the lamellar structure catalyst.
As a preferred embodiment, the method for synthesizing the lamellar structure catalyst comprises the following steps:
stirring 1.7g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 97g of urea and 470g of water to fully dissolve solids, adding the mixture into a high-pressure reaction kettle, stirring and reacting for 8 hours at 120 ℃, stopping stirring, keeping the temperature and standing for 12 hours, cooling to room temperature, taking out materials, and washing with water until the pH value is neutral; and (4) centrifugally dewatering, drying the solid, grinding and crushing to obtain the lamellar structure catalyst.
As a preferred embodiment, the method for synthesizing the lamellar structure catalyst comprises the following steps:
1.7g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 85.9g of urea and 470g of water are stirred to fully dissolve solids, the mixture is added into a high-pressure reaction kettle, stirred and reacted for 8 hours at 120 ℃, then the stirring is stopped, the mixture is kept at the temperature and kept stand for 12 hours, then the mixture is taken out after being cooled to the room temperature, and the mixture is washed by water until the pH value is neutral; and (4) centrifugally dewatering, drying the solid, grinding and crushing to obtain the lamellar structure catalyst.
As a preferred embodiment, the rotating speed of the stirring blade in the high-pressure reaction kettle is set to be 80-120 r/min.
As a preferred embodiment, the conditions of drying: the solid was dried in an air-blast drying oven at 60 ℃.
A third object of the present invention is to provide a lamellar structure catalyst for carbon nanotube production, which is characterized by being produced by the aforementioned method.
The fourth purpose of the invention is to provide the application of the lamellar structure catalyst in the preparation of carbon nanotubes.
The fifth purpose of the invention is to provide a method for preparing carbon nano tubes, which comprises the steps of putting a certain weight of the lamellar structure catalyst into a quartz tube furnace, introducing nitrogen with the flow rate of 200ml/min, and heating to 300 ℃ at the temperature of 15 ℃/min; keeping the nitrogen flow rate unchanged after the temperature reaches 300 ℃, introducing hydrogen with the flow rate of 200ml/min, and continuously heating to 660 ℃ at the speed of 15 ℃/min; stopping introducing hydrogen when the temperature reaches 660 ℃, introducing propylene with the flow rate of 100ml/min while keeping introducing nitrogen to synthesize the carbon nano tube, wherein the reaction time is 40 min; after the reaction is finished, cooling under the protection of nitrogen; after cooling, collecting the products in the tube furnace, weighing the weight of the products, and calculating the yield by dividing the weight of the products by the weight of the lamellar structure catalyst; the yield of the carbon nano tube is not lower than 1700%.
A sixth object of the present invention is to provide the carbon nanotubes prepared by the above method, wherein the carbon nanotubes have array orientation and good electrical conductivity.
In the preparation process of the catalyst, in order to obtain a better LDH structure, the dosage of the cobalt nitrate hexahydrate, the magnesium nitrate hexahydrate, the aluminum nitrate nonahydrate and the urea is optimized. In the reaction process, urea is selected as a precipitator, and slowly decomposes to release ammonia at the temperature higher than 60 ℃, so that the pH value in the solution is kept constant, and simultaneously the released carbon dioxide enters the LDH intercalation in the form of carbonate ions. The reaction condition is a high-pressure reaction kettle, relatively high pressure is obtained at high temperature, and compared with LDH synthesized under normal pressure, hydrotalcite compounds with good dispersity and high crystallinity are obtained. The high dispersibility of the catalytic active elements in the catalyst ensures the high activity of the surface of the lamellar catalyst, thereby preparing the carbon nano tube with orientation.
[ advantageous effects ]:
the invention takes urea as a precipitator, and synthesizes the high-purity lamellar catalyst under high pressure by optimizing the dosage of cobalt nitrate hexahydrate, magnesium nitrate hexahydrate, aluminum nitrate nonahydrate and urea (see figure 1); the carbon nano tube prepared by the synthesized catalyst has array orientation (see figure 2) and good electrical conductivity; in the process of synthesizing the catalyst, the introduction of impurities is avoided by selecting catalyst elements, and a complex purification process is not needed in the later period, so that the cost is reduced; the catalyst prepared by the method is used for preparing the carbon nano tube, the yield of the carbon nano tube per unit weight of the catalyst is not lower than 1700%, the mixture ratio of slurry prepared from the collected carbon nano tube product is 97.5% of NMP + 2% of CNT + 0.25% of dispersant + 0.5% of PVP, the test coating mixture ratio is 7.5g of slurry +50g of HSV +15.6g of LCO, the addition amount of the CNT is 0.3%, and the measured coating resistivity is not higher than 13.26m omega cm.
Drawings
FIG. 1 is a scanning electron micrograph of a catalyst prepared in examples 1 to 5 of the present invention magnified 10000 times.
FIG. 2 is a scanning electron micrograph of carbon nanotubes prepared from the catalysts of examples 1 to 5 of the present invention magnified 10000 times.
Detailed Description
Example 1
Weighing 1.7g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 85.9g of urea and 470g of pure water, stirring for dissolving, adding into an autoclave, setting the rotating speed of a stirring paddle at 100r/min, electrically heating to 120 ℃, and reacting at constant temperature for 8 hours. After the reaction, the stirring was stopped, and the mixture was allowed to stand for 12 hours while maintaining the temperature. Then cooling to room temperature, taking out the material, and washing with water until the pH value is neutral. And then centrifugally dewatering, placing the obtained product into an air drying oven, drying at 60 ℃, grinding and crushing to obtain the lamellar catalyst.
Example 2
With reference to example 1, the only difference is that 1.7g of cobalt nitrate hexahydrate was replaced by 2g of iron nitrate nonahydrate, specifically:
2g of ferric nitrate nonahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 85.9g of urea and 470g of pure water are weighed and stirred for dissolution. Adding the mixture into a high-pressure kettle, setting the rotating speed of a stirring paddle to be 100r/min, electrically heating the mixture to 120 ℃, and reacting the mixture for 8 hours at constant temperature. After the reaction, the stirring was stopped, and the mixture was allowed to stand for 12 hours while maintaining the temperature. Then cooling to room temperature, taking out the materials, and washing with water until the pH value is neutral. And then centrifugally dewatering, drying in an air-blast drying oven at 60 ℃, and grinding and crushing to obtain the lamellar catalyst.
Example 3
Referring to example 1, the only difference was that 1.7g of cobalt nitrate hexahydrate was replaced with 1.7g of cobalt nitrate hexahydrate and 2g of iron nitrate nonahydrate, and the amount of urea used was adjusted to 97g, specifically:
1.7g of cobalt nitrate hexahydrate, 2g of iron nitrate nonahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 97g of urea and 470g of pure water are weighed and stirred for dissolution. Adding the mixture into a high-pressure kettle, setting the rotating speed of a stirring paddle to be 100r/min, electrically heating the mixture to 120 ℃, and reacting the mixture for 8 hours at constant temperature. After the reaction, the stirring was stopped, and the mixture was allowed to stand for 12 hours while maintaining the temperature. Then cooling to room temperature, taking out the material, and washing with water until the pH value is neutral. And then centrifugally dewatering, drying in an air-blast drying oven at 60 ℃, and grinding and crushing to obtain the lamellar catalyst.
Example 4
With reference to example 1, the only difference is that the amount of urea used is adjusted to 97g, specifically:
1.7g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 97g of urea and 470g of pure water are weighed and stirred for dissolution. Adding the mixture into a high-pressure kettle, setting the rotating speed of a stirring paddle to be 100r/min, electrically heating the mixture to 120 ℃, and reacting the mixture for 8 hours at constant temperature. After the reaction, the stirring was stopped, and the mixture was allowed to stand for 12 hours while maintaining the temperature. Then cooling to room temperature, taking out the materials, and washing with water until the pH value is neutral. And then centrifugally dewatering, drying in an air-blast drying oven at 60 ℃, and grinding and crushing to obtain the lamellar catalyst.
Example 5
With reference to example 4, the only difference is that the amount of aluminium nitrate nonahydrate was adjusted to 10g, specifically:
1.7g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 10g of aluminum nitrate nonahydrate, 97g of urea and 470g of pure water are weighed and stirred for dissolution. Adding the mixture into a high-pressure kettle, setting the rotating speed of a stirring paddle to be 100r/min, electrically heating the mixture to 120 ℃, and reacting the mixture for 8 hours at constant temperature. After the reaction, the stirring was stopped, and the mixture was allowed to stand for 12 hours while maintaining the temperature. Then cooling to room temperature, taking out the materials, and washing with water until the pH value is neutral. And then centrifugally dewatering, drying in an air-blast drying oven at 60 ℃, and grinding and crushing to obtain the lamellar catalyst.
Comparative example 1:
according to the preparation method provided by patent CN111495380A, the catalyst was prepared: 9.60 grams of cobalt nitrate hexahydrate, 25.38 grams of magnesium nitrate hexahydrate, 24.76 grams of aluminum nitrate nonahydrate, and 1.26 grams of yttrium nitrate hexahydrate were weighed into 400 grams of purified water and identified as solution A. 20.73 grams of potassium carbonate and 42 grams of sodium bicarbonate were weighed into 600 grams of water and recorded as solution B. Slowly dripping the solution B into the salt solution A at the temperature of 100 ℃, and finishing dripping for 10 hours to obtain the final pH value of 9.5. And keeping the temperature at 95 ℃ for 10h, carrying out suction filtration and washing until the pH value of the washing liquid is less than 8, and preparing the catalyst precursor. Drying the prepared catalyst precursor at 200 ℃, putting the dried catalyst precursor into a high-temperature furnace, raising the temperature to 900 ℃ at the speed of 15 ℃/min, and then preserving the temperature for 1 hour to obtain the catalyst.
Comparative example 2:
according to the preparation method provided by patent CN109665512A, the catalyst was prepared: 0.84 g of cobalt nitrate hexahydrate, 10.11 g of magnesium nitrate hexahydrate, 29.59 g of aluminum nitrate nonahydrate and 11.63 g of iron nitrate nonahydrate were weighed out and added to 500 g of pure water to obtain solution A. Weighing 135 g of urea, dissolving the urea into 225mL of water to obtain a solution B, mixing the A, B solutions at room temperature, slowly heating to 103 ℃ at the speed of 3 ℃/min under the stirring state, keeping the temperature and stirring for 12h, and then stopping the reaction. And (3) placing the obtained suspension in an oven at 95 ℃ for 12h, then cooling, filtering, washing 3 times with deionized water, and freeze-drying to obtain the catalyst.
Comparative example 3:
on the basis of example 1, only the amount of magnesium nitrate hexahydrate is changed, specifically as follows:
weighing 1.7g of cobalt nitrate hexahydrate, 25g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 85.9g of urea and 470g of pure water, stirring for dissolving, adding into an autoclave, setting the rotating speed of a stirring blade to be 100r/min, electrically heating to 120 ℃, and reacting at constant temperature for 8 hours. After the reaction, the stirring was stopped, and the mixture was allowed to stand for 12 hours while maintaining the temperature. Then cooling to room temperature, taking out the materials, and washing with water until the pH value is neutral. And then centrifugally dewatering, drying in an air-blast drying oven at 60 ℃, and grinding and crushing to obtain the lamellar catalyst.
Comparative example 4:
on the basis of example 1, only the reaction temperature was varied, specifically as follows:
weighing 1.7g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 85.9g of urea and 470g of pure water, stirring for dissolving, adding into an autoclave, setting the rotating speed of a stirring paddle at 100r/min, electrically heating to 90 ℃, and reacting at constant temperature for 8 hours. After the reaction, the stirring was stopped, and the mixture was allowed to stand for 12 hours while maintaining the temperature. Then cooling to room temperature, taking out the materials, and washing with water until the pH value is neutral. And then centrifugally dewatering, drying in an air-blast drying oven at 60 ℃, and grinding and crushing to obtain the lamellar catalyst.
Application of catalyst in preparation of carbon nano tube
0.4g of each of the catalysts of examples 1 to 5 and comparative examples 1 to 4 was charged into a quartz tube furnace having a diameter of 60mm, nitrogen gas was introduced at a flow rate of 200ml/min, and the temperature was raised to 300 ℃ at 15 ℃/min. Keeping the nitrogen flow rate unchanged after the temperature reaches 300 ℃, introducing hydrogen with the flow rate of 200ml/min, and continuously heating to 660 ℃ at the speed of 15 ℃/min; stopping introducing the hydrogen, introducing the propylene at the flow rate of 100ml/min while keeping introducing the nitrogen, and growing the carbon nano tube for 40 min. After the reaction is finished, cooling under the protection of nitrogen, cooling, collecting the products in the tube furnace, weighing, and calculating the yield by dividing the weight of the products by the weight of the catalyst.
The slurry ratio of the collected carbon nanotube product prepared into slurry is 97.5% of NMP + 2% of CNT + 0.25% of dispersant + 0.5% of PVP, the coating ratio is tested to be 7.5g of slurry +50g of HSV +15.6g of LCO, the CNT addition is 0.3%, and the test results of the measured coating resistivity are as follows:
TABLE 1 yield and coating resistivity of carbon nanotubes prepared by the catalysts of examples 1-4 and comparative examples 1-4
| Catalyst and process for preparing same | Yield/%) | Coating resistivity/m omega cm |
| Practice ofExample 1 | 2025 | 13.05 |
| Example 2 | 1821 | 13.26 |
| Example 3 | 1700 | 12.11 |
| Example 4 | 1867 | 9.68 |
| Example 5 | 1800 | 13.25 |
| Comparative example 1 | 1350 | 22.23 |
| Comparative example 2 | 1120 | 28.16 |
| Comparative example 3 | 1070 | 18.22 |
| Comparative example 4 | 963 | 21.30 |
In the carbon tubes prepared in comparative example 1 (catalyst prepared according to the method disclosed in patent CN 111495380A), it can be seen that the yield of the prepared carbon tubes is lower than in examples 1 to 5, and the conductivity is worse (coating resistivity is high).
The carbon tubes prepared in comparative example 2 (catalyst prepared according to the method disclosed in CN 109665512A) had lower yield and poorer conductivity than those prepared in example 2.
Comparative example 3, on the basis of example 1, the amount of magnesium nitrate hexahydrate was changed, and compared with example 1, the yield decreased and the resistivity increased after the change.
Comparative example 4, on the basis of example 1, the reaction temperature was changed, and compared with example 1, the yield decreased and the resistivity increased after the change.
Claims (10)
1. The method for synthesizing the lamellar structure catalyst is characterized by comprising the following steps of:
stirring 1.7-2 g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6-10 g of aluminum nitrate nonahydrate, 85-97 g of urea and 470g of water to fully dissolve solids, adding into a high-pressure reaction kettle, stirring and reacting at 120 ℃ for 8 hours, stopping stirring, keeping the temperature and standing for 12 hours, cooling to room temperature, taking out the material, and washing with water until the pH value is neutral; and (4) centrifugally dewatering, drying the solid, grinding and crushing to obtain the lamellar structure catalyst.
2. A synthetic method of a lamellar structure catalyst is characterized by comprising the following steps:
stirring 1.7g of cobalt nitrate hexahydrate, 2g of ferric nitrate nonahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 97g of urea and 470g of water to fully dissolve solids, adding the mixture into a high-pressure reaction kettle, stirring and reacting for 8 hours at 120 ℃, stopping stirring, keeping the temperature and standing for 12 hours, cooling to room temperature, taking out the material, and washing with water until the pH value is neutral; and (4) centrifugally dewatering, drying the solid, grinding and crushing to obtain the lamellar structure catalyst.
3. The method of claim 1, comprising the steps of:
stirring 1.7g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 97g of urea and 470g of water to fully dissolve solids, adding into a high-pressure reaction kettle, stirring at 120 ℃ for reaction for 8 hours, stopping stirring, keeping the temperature, standing for 12 hours, cooling to room temperature, taking out materials, and washing with water until the pH value is neutral; and (4) centrifugally dewatering, drying the solid, grinding and crushing to obtain the lamellar structure catalyst.
4. The method of claim 1, comprising the steps of:
stirring 1.7g of cobalt nitrate hexahydrate, 15.4g of magnesium nitrate hexahydrate, 5.6g of aluminum nitrate nonahydrate, 85.9g of urea and 470g of water to fully dissolve solids, adding the solid into a high-pressure reaction kettle, stirring and reacting for 8 hours at 120 ℃, stopping stirring, keeping the temperature and standing for 12 hours, cooling to room temperature, taking out the material, and washing with water until the pH value is neutral; and (4) centrifugally dewatering, drying the solid, grinding and crushing to obtain the lamellar structure catalyst.
5. The method according to any one of claims 1 to 4, wherein the rotation speed of the stirring blade is set to 80 to 120r/min in the autoclave.
6. A method according to any one of claims 1 to 4, characterized in that the conditions of drying are: the solid was dried in an air-blast drying oven at 60 ℃.
7. A lamellar structure catalyst for the production of carbon nanotubes, characterized in that it is produced by the process according to any one of claims 1 to 6.
8. Use of the lamellar structure catalyst according to claim 7 for the preparation of carbon nanotubes.
9. A method for preparing carbon nanotubes, characterized in that, a certain weight of the lamellar structure catalyst according to claim 7 is taken and placed in a quartz tube furnace, nitrogen with the flow rate of 200ml/min is introduced, and the temperature is raised to 300 ℃ at 15 ℃/min; keeping the nitrogen flow rate unchanged after the temperature reaches 300 ℃, introducing hydrogen with the flow rate of 200ml/min, and continuously heating to 660 ℃ at the speed of 15 ℃/min; stopping introducing hydrogen when the temperature reaches 660 ℃, introducing propylene with the flow rate of 100ml/min while keeping introducing nitrogen to synthesize the carbon nano tube, wherein the reaction time is 40 min; after the reaction is finished, cooling under the protection of nitrogen; after cooling, collecting the products in the tube furnace, weighing the weight of the products, and calculating the yield by dividing the weight of the products by the weight of the lamellar structure catalyst; the yield of the carbon nano tube is not lower than 1700%.
10. The carbon nanotubes prepared by the method of claim 9, wherein the carbon nanotubes have an array orientation and good electrical conductivity.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150321168A1 (en) * | 2014-05-09 | 2015-11-12 | University Of Notre Dame Du Lac | Carbon nanotube ponytails |
| CN109626357A (en) * | 2019-01-31 | 2019-04-16 | 新奥石墨烯技术有限公司 | A kind of ultra-fine carbon nanotube and preparation method thereof |
| CN111495381A (en) * | 2019-01-31 | 2020-08-07 | 新奥石墨烯技术有限公司 | Preparation method of flaky catalyst, flaky catalyst and application of flaky catalyst in preparation of superfine carbon nano tube |
| CN111495380A (en) * | 2019-01-31 | 2020-08-07 | 江苏天奈科技股份有限公司 | Preparation method of carbon nanotube catalyst and carbon nanotube |
| CN114029047A (en) * | 2021-12-22 | 2022-02-11 | 长沙晟天新材料有限公司 | Preparation method of array carbon nanotube supported catalyst |
-
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150321168A1 (en) * | 2014-05-09 | 2015-11-12 | University Of Notre Dame Du Lac | Carbon nanotube ponytails |
| CN109626357A (en) * | 2019-01-31 | 2019-04-16 | 新奥石墨烯技术有限公司 | A kind of ultra-fine carbon nanotube and preparation method thereof |
| CN111495381A (en) * | 2019-01-31 | 2020-08-07 | 新奥石墨烯技术有限公司 | Preparation method of flaky catalyst, flaky catalyst and application of flaky catalyst in preparation of superfine carbon nano tube |
| CN111495380A (en) * | 2019-01-31 | 2020-08-07 | 江苏天奈科技股份有限公司 | Preparation method of carbon nanotube catalyst and carbon nanotube |
| CN114029047A (en) * | 2021-12-22 | 2022-02-11 | 长沙晟天新材料有限公司 | Preparation method of array carbon nanotube supported catalyst |
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