Metal Oxide Composite Carbon Nanotube Catalyst, Its Preparation Method and Its Application

Abstract

The present invention provides a metal oxide composite carbon nanotube catalyst, a preparation method thereof and an application thereof. In the catalyst, the proportion of metal oxides XO and YO is 13-88 wt%, and the balance is multi-walled carbon nanotubes; wherein, X is two or more of transition metal elements Cu, Zn, Mn, Co, and the two or more metals included in X are mixed in any proportion; Y is one of alkaline earth metals Ca, Mg and Sr; the molar ratio of X to Y is 1:0.05-0.5. The metal oxide composite carbon nanotube catalyst of the present invention has the advantages of wide raw material sources, high catalytic efficiency and low catalytic cost.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of organic compounds, and particularly relates to a multi-metal oxide composite carbon nanotube catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] Cumene hydroperoxide (CHP) is an important raw material for the production of phenol and acetone, and can also be used as an initiator for chain radical reactions and an arsenic remover for ethylene pyrolysis gasoline, etc., and occupies an extremely important position in the fields of polymer materials, fine chemicals, and organic synthesis. At present, the industrial production method of cumene hydroperoxide is to add a small amount of CHP as an initiator under the condition of no catalyst to oxidize cumene. Or, a method of using inorganic bases such as NaOH, KOH, and NaHCO3 as catalysts for oxidation. However, both of these methods have some problems. For example, in the method of direct oxidation without a catalyst, the reaction temperature is generally 110-115°C, and the reaction pressure is 0.4-0.6 MPa. Too high reaction temperature and reaction pressure will cause violent decomposition of CHP, and the increase of by-products such as phenol, acetone, and formic acid. If the operation is not careful, it may also cause an explosion. And as a catalyst, inorganic bases can neutralize the acid generated in the oxidation reaction process, thereby reducing the decomposition of CHP and the inhibition of the oxidation reaction by phenol. However, due to the influence of metal cations such as sodium and potassium ions introduced during the addition of inorganic bases on subsequent reactions, a large amount of water washing is required to remove them, resulting in the problem of sewage discharge. Therefore, finding a high-performance catalyst with mild reaction conditions and no influence on subsequent reactions has always been a research hotspot for the oxidation of cumene to CHP.

[0003] In recent years, carbon materials have received extensive attention due to their simple preparation, low price, environmental friendliness, and catalytic activity. Patent CN102911096B discloses a method for directly using carbon nanotubes as a solid catalyst to catalyze the oxidation of cumene to CHP. The reaction temperature is relatively low and it can be reused, but the selectivity of the product CHP is less than 90%, and there are many by-products. Patent CN114522680A discloses a preparation method of a MnO2 / CNTs catalyst for cumene oxidation. The reaction conditions are mild and the steps are simple, and the catalyst is easy to recover after the reaction, but the target product is 2-phenyl-2-propanol. In view of the deficiencies of existing catalysts, it is of great industrial application value to develop an environmentally friendly catalytic system that is easy to separate, highly active, has high yield and high stability, and enables the oxidation reaction to proceed at a lower reaction temperature. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-metal oxide composite carbon nanotube catalyst, a preparation method thereof, and an application thereof in view of the deficiencies of the prior art.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A metal oxide composite carbon nanotube catalyst, wherein the proportion of metal oxides XO and YO in the catalyst is 13-88 wt%, and the balance is multi-walled carbon nanotubes; wherein, X is two or more of transition metal elements Cu, Zn, Mn, and Co, and the two or more metals contained in X are mixed in any proportion; Y is one of alkaline earth metals Ca, Mg, and Sr; the molar ratio of X to Y is 1:0.05 to 0.5.

[0007] As a further improvement of the technical solution, in order to increase the loading amount of the metal oxide, the multi-walled carbon nanotubes have a diameter of 20-100 nm, a length of 5-15 μm, and a specific surface area of 40-300 m 2 / g.

[0008] The catalyst of the present invention can utilize the synergistic effect of transition metal oxides to improve the catalytic activity, and can use multi-walled carbon nanotubes as a carrier to increase the loading amount of active metals. Moreover, carbon nanotubes have a wide source and low cost. The catalyst of the present invention can be recycled, further reducing the cost.

[0009] The present invention also discloses a preparation method of the catalyst, including:

[0010] S1. Pretreat the carbon nanotubes. The carbon nanotubes are used as the carrier of the active component. During pretreatment, conventional acid treatment, alkali treatment, etc. in the art can be used to remove impurities on the surface of the carbon nanotubes and facilitate the loading of active metals.

[0011] S2. Dissolve the nitrates of X and Y in a mixed solution of water and an alcohol substance.

[0012] S3. Add the pretreated carbon nanotubes to the nitrate mixed solution prepared in step S2 to obtain a mixed solution of carbon nanotubes and metal ions. In order to make the carbon nanotubes and metal ions disperse evenly in the mixed solution, conventional dispersion means such as stirring and ultrasonic treatment can be used during the mixing process to enhance the mixing effect of the two.

[0013] S4. Under stirring conditions, add an alkaline solution dropwise to the mixed solution obtained in step S3 until the pH of the solution reaches 8-11. After the dropwise addition is completed, continue to stir and react. After the reaction is completed, stand for aging, filter, wash with water, dry, and calcine in sequence to obtain the catalyst.

[0014] The above preparation method has the advantages of simple steps, wide source of raw materials, and low cost.

[0015] As a further improvement of the technical solution, step S1 is to place the carbon nanotubes in a nitric acid solution to form a suspension, carry out a condensation reflux reaction at 110-120 °C, stand for precipitation and wash to neutrality after the reaction is completed, then carry out suction filtration, and then dry the filter cake for standby.

[0016] As a further improvement of the technical solution, in step S2, the alcohol substance is any one of ethanol, ethylene glycol and methanol, the volume ratio of water to alcohol is 1-4:1, and the total mass ratio of metal nitrate to the mixed solution is 0.01-2:1.

[0017] As a further improvement of the technical solution, in step S3, the mass ratio of carbon nanotubes to the total amount of nitrates in the nitrate mixed solution is 0.02-1:1. The mixed solution is obtained by ultrasonic wave and stirring simultaneously. The ultrasonic stirring time is 2-6 h, and the ultrasonic frequency is 20-40 kHz.

[0018] As a further improvement of the technical solution, in step S1, the mass fraction of nitric acid is 60-70%, the ratio of carbon nanotubes to nitric acid is 0.1-5 g / 100 ml, the condensation reflux time in the oil bath is 8-16 h, and the drying condition is to keep at 80-110 °C for 12-24 h; in step S2, the molar ratio of X to Y metal ions is 1:0.05-0.5, the alcohol substance is any one of ethanol, ethylene glycol and methanol, the volume ratio of water to alcohol is 1-4:1, the mass ratio of metal nitrate to the water and alcohol mixed solution is 0.01-2:1, the water bath temperature is 20-40 °C, and the stirring time is 0.5-2 h; in step S3, the total mass ratio of carbon nanotubes to nitrates in the nitrate mixed solution is 0.02-1:1, the ultrasonic stirring time is 2-6 h, and the ultrasonic frequency is 20-40 kHz; in step S4, the urea concentration is 0.05-2 mol / l, the dropping rate is 3-6 seconds / drop, the drying condition after standing and aging is to dry at 80-110 °C for 12-24 h, and the calcination condition is to calcine at 550-900 °C for 4-6 h in an argon or nitrogen atmosphere.

[0019] The present invention also discloses an application of the catalyst. Using cumene as a raw material and air as an oxidant, cumene hydroperoxide is synthesized under the action of the catalyst.

[0020] The catalyst separated by filtration after the reaction is successively stirred and washed with alcohol and deionized water, and then dried at 100-130 °C for 6-8 h for subsequent reuse.

[0021] This application uses a multi-metal oxide composite carbon nanotube as a catalyst, which can not only utilize the synergistic effect of transition metal oxides to improve the catalytic activity and the conversion rate of cumene (CM), but also utilize the strong interaction between alkaline earth metal oxides and cumene to improve the selectivity of CHP and reduce the generation of by-products such as acetophenone, α,α-dimethylbenzyl alcohol (DMBA), organic acids and phenol, thus simplifying the subsequent treatment process.

[0022] As a further improvement of the technical solution, in order to balance the catalytic effect and the reaction efficiency of side reactions, the mass ratio of the catalyst to cumene in the synthesis reaction is 0.002-0.02:1.

[0023] As a further improvement of the technical solution, in order to balance the reaction efficiency and equipment cost, the synthesis reaction temperature is 75-105 °C, and the reaction pressure is 0-0.5 MPa.

[0024] As a further improvement of the technical solution, in order to balance the reaction efficiency of the oxidation reaction and side reactions, the air inlet rate is 1-5 ml / min per milliliter of cumene.

[0025] The present invention has outstanding substantive features and remarkable progress compared with the prior art. Specifically, the catalyst of the present invention has the advantages of wide raw material sources and high catalytic efficiency. Further, the catalyst of the present invention can be recycled, reducing the catalytic reaction cost. Furthermore, the application of the catalyst of the present invention in the synthesis of cumene hydroperoxide improves the conversion rate of cumene (CM) and the selectivity of CHP. The catalyst of the present invention has the advantages of wide raw material sources, high catalytic efficiency and low catalytic cost. Specific embodiments

[0026] The technical solution of the present invention will be further described in detail below through specific embodiments, but the content of the present invention is not limited to the following embodiments.

[0027] Comparative Example 1 Oxidation of cumene to cumene hydroperoxide without catalyst

[0028] 100 g of cumene was added to a 250 ml three-necked flask. The reaction temperature was 85 °C, the flow rate of purified air (20.9 vol%) was 0.3 L / min, the rotation speed of the stirring paddle was 200 rpm, and the reaction was continuously carried out for 10 h under normal pressure. After the reaction, the components and pH of the oxidation solution were analyzed.

[0029] The organic components were determined by liquid chromatography. The conversion rate of cumene was 8.7%, the selectivity of CHP was 94.5%, the selectivity of the main by-product acetophenone was 1.4%, the selectivity of α,α-dimethylbenzyl alcohol was 3.6%, the phenol content was 423.3 ppm, and the pH value after the reaction was 3.65.

[0030] Comparative Example 2 Oxidation of cumene to cumene hydroperoxide with CuO-CaO catalyst

[0031] (1) Preparation of CuO-CaO catalyst

[0032] a. Dissolve Cu(NO3)2·2.5H2O and Ca(NO3)2·4H2O in a mixture of water and ethylene glycol at a molar ratio of metal elements of 3:1. The mass ratio of metal nitrate to the mixture of water and ethylene glycol is 1:1. Place it in a 25°C water bath and stir for 0.5 h to completely dissolve it in the mixture of water and ethylene glycol.

[0033] b. Under stirring conditions, slowly drip a 0.05 mol / l urea solution into the mixture of water and ethylene glycol at a dropping rate of 6 seconds per drop. Stop dripping after adjusting the solution pH to about 10. Continue stirring for 6 hours after the dripping is completed, then stand and age at 75°C in a water bath for 24 h. Filter, wash with water, dry at 80°C for 24 h, and then calcine at 800°C for 5 h in an argon atmosphere to obtain the CuO-CaO catalyst. After XRF analysis, the percentage contents of CuO and CaO in this composite system are 71.3% and 28.7% respectively.

[0034] (2) The catalyst catalyzes the oxidation of cumene to form CHP

[0035] Weigh 1.0 g of the above catalyst and 100 g of cumene and add them to a 250 ml three-necked flask. The reaction temperature is 85°C, the flow rate of purified air (20.9 vol%) is 0.3 L / min, the rotation speed of the stirring paddle is 200 r / min, and the reaction is continuously carried out at atmospheric pressure for 10 h. After the reaction is completed, filter and separate, and analyze the components and pH of the oxidation liquid.

[0036] The organic components are determined by liquid chromatography. The conversion rate of cumene is 28.6%, the selectivity of CHP is 94.1%, the selectivity of the main by-product acetophenone is 1.0%, the selectivity of α,α-dimethylbenzyl alcohol is 1.9%, the phenol content is 68.9 ppm, and the pH value after the reaction is 5.61.

[0037] Example 1 Preparation of CuO-ZnO-CaO-CNTs catalyst and catalytic oxidation of cumene

[0038] (1) Preparation of CuO-ZnO-CaO-CNTs catalyst

[0039] a. Pretreatment of carbon nanotubes: Place 15 g of commercially available carbon nanotubes with a diameter of 40 - 60 nm, a length of 5 - 15 μm, and a specific surface area of 40 - 70 m 2 2 / g into 1500 mL of 68% concentrated nitric acid solution, reflux and condense in an oil bath at 120°C for 12 h. After taking it out, let it stand and precipitate, pour out the supernatant and dilute it with water, let it stand, pour out the supernatant and dilute it with water, let it stand, and repeat this process until the supernatant is close to neutral, then filter to form a filter cake. Then wash it with deionized water until neutral and dry it at 100°C for 24 h for standby.

[0040] b. Dissolve Zn(NO3)2·6H2O, Cu(NO3)2·2.5H2O, and Ca(NO3)2·4H2O in a mixed solution of water and ethylene glycol with a volume ratio of 1:1 according to the molar ratio of metal elements 0.4:0.6:0.2. The mass ratio of metal nitrate to the mixed solution of water and ethylene glycol is 1:1. Place it in a 25°C water bath and stir for 0.5 h to completely dissolve it in the mixed solution of water and ethylene glycol.

[0041] c. Add the pretreated carbon nanotubes to the above nitrate mixed solution according to the mass ratio of 0.2:1 to the total amount of nitrates, and ultrasonically stir at a frequency of 40 kHz for 4 h to obtain a mixed solution of carbon nanotubes and metal ions.

[0042] d. Under stirring conditions, drop 0.05 mol / l urea solution into the mixed solution of carbon nanotubes and metal ions at a dropping rate of 6 seconds per drop. Stop dropping after adjusting the solution pH to about 10. Continue stirring for 6 hours after dropping. Then, stand and age at 75°C in a water bath for 24 h, filter, wash with water, dry at 80°C for 24 h, and then calcine in an argon atmosphere at 800°C for 5 h to obtain 24.9 g of CuO-ZnO-CaO-CNTs catalyst. After XRF analysis, the percentage contents of CuO, ZnO, and CaO in this composite system are 13.2%, 19.7%, and 6.2% respectively.

[0043] (2) The catalyst catalyzes the oxidation of cumene to form CHP

[0044] Weigh 1 g of the above catalyst and 100 g of cumene and add them to a 250 ml three-necked flask. The reaction temperature is 85°C, the air flow rate is 0.3 L / min, the stirring paddle speed is 200 r / min, and the reaction is carried out continuously for 10 h under normal pressure. After the reaction, filter and separate, and analyze the components and pH of the filtrate.

[0045] The organic components are determined by liquid chromatography. The conversion rate of cumene is 36.7%, the selectivity of CHP is 96.7%, the selectivity of the main by-product acetophenone is 0.8%, the selectivity of α,α-dimethylbenzyl alcohol is 2.1%, the phenol content is 60.1 ppm, and the pH value after the reaction is 4.86.

[0046] Comparing Example 1 with Comparative Examples 1 and 2, it is found that under the same oxidation conditions, adding the prepared CuO-ZnO-CaO-CNTs catalyst can not only increase the oxidation efficiency of CM from 8.7% to 36.7%, but also stabilize the selectivity of CHP above 95%, while reducing the formation of by-products acetophenone, α,α-dimethylbenzyl alcohol, and organic acids.

[0047] Example 2 The basic steps for preparing the CuO-MnO2-CaO-CNTs catalyst and catalyzing the oxidation of cumene are the same as those in Example 1, except that Cu(NO3)2·2.5H2O is replaced with Mn(NO3)2·4H2O, Zn 2+ , Mn 2+ and the molar ratio of Ca 2+ is still 0.4:0.6:0.2. Finally, 25.8 g of the catalyst is obtained. Through XRF analysis, the percentage contents of the three metal oxides, CuO, MnO2 and CaO, in this composite system are 13.4%, 21.1% and 7.2% respectively.

[0048] Determined by liquid chromatography, the conversion rate of cumene is 37.8%, the selectivity of CHP is 93.7%, the selectivity of the main by-product acetophenone is 1.5%, the selectivity of α,α-dimethylbenzyl alcohol is 3.8%, the phenol content is 82.3 ppm, and the pH value after the reaction is 4.39.

[0049] Example 3 Preparation of the CuO-ZnO-MgO-CNTs catalyst and catalyzing the oxidation of cumene

[0050] The basic steps are the same as those in Example 1, except that Ca(NO3)2·4H2O is replaced with Mg(NO3)2·6H2O, Zn 2+ , Cu 2+ and the molar ratio of Mg 2+ is still 0.4:0.6:0.2. Finally, 23.4 g of the catalyst is obtained. Through XRF analysis, the percentage contents of the three metal oxides, CuO, ZnO and MgO, in this composite system are 13.1%, 19.2% and 7.3% respectively.

[0051] Determined by liquid chromatography, the conversion rate of cumene is 33.2%, the selectivity of CHP is 95.6%, the selectivity of the main by-product acetophenone is 0.7%, the selectivity of α,α-dimethylbenzyl alcohol is 3.1%, the phenol content is 53.4 ppm, and the pH value after the reaction is 4.67.

[0052] Through Examples 1, 2 and 3, it is found that the CuO-ZnO-CaO-CNTs catalyst can ensure a high CM conversion rate (36.7%) while ensuring a high selectivity of CHP (96.7%), and the contents of the by-products acetophenone (selectivity 0.8%), α,α-dimethylbenzyl alcohol (selectivity 2.1%) and phenol (60.1 ppm) are relatively low, and the pH value after the reaction is relatively high, indicating that the amount of organic acid generated is also relatively small.

[0053] Example 4 Single-factor experiment on reaction temperature

[0054] Weigh 1 g of the catalyst prepared in Example 1 and 100 g of cumene and add them into a 250 ml three-necked flask. The air flow rate is 0.3 L / min, the rotation speed of the stirring paddle is 200 r / min, and the reaction is carried out continuously for 10 h under atmospheric pressure. Keeping other experimental conditions unchanged, the reaction temperatures of the four experiments are 75 °C, 85 °C, 95 °C and 105 °C respectively. After the reaction, filter and separate, and analyze the components and pH of the filtrate. The results are shown in Table 1 below

[0055] Table 1 shows the effect of temperature on the oxidation of cumene to CHP over the CuO-ZnO-CaO-CNTs catalyst

[0056]

[0057] It can be seen that as the reaction temperature increases continuously, the conversion rate of cumene increases continuously, but the selectivity of CHP decreases, the selectivity of by-products such as acetophenone and DMBA increases, the content of phenol increases, and the pH value decreases. This is because CHP itself is unstable, and decomposition will occur at too high a temperature. Therefore, too high a reaction temperature is not conducive to the formation of the target product

[0058] Single-factor experiment on reaction time in Example 5

[0059] Weigh 1 g of the catalyst prepared in Example 1 and 100 g of cumene and add them into a 250 ml three-necked flask. The reaction temperature is 80 °C, the air flow rate is 0.3 L / min, the rotation speed of the stirring paddle is 200 r / min. Samples are taken and analyzed at 4 h, 8 h, 12 h and 16 h respectively under atmospheric pressure. After the reaction, filter and separate, and analyze the components and pH of the filtrate. The results are shown in Table 2 below

[0060] Table 2 shows the effect of time on the oxidation of cumene to CHP over the CuO-ZnO-CaO-CNTs catalyst

[0061]

[0062]

[0063] According to Table 2, as the reaction time increases, the conversion rate of cumene increases continuously and the increasing rate becomes faster, but the selectivity of CHP gradually decreases, the selectivity of by-products increases, and the pH value decreases. Therefore, within the time range of Table 2, 8 - 12 h is the optimal time

[0064] Single-factor experiment on air flow rate in Example 6

[0065] Weigh 1 g of the catalyst prepared in Example 1 and 100 g of cumene and add them to a 250 ml three-necked flask. The reaction temperature is 80 °C, the rotation speed of the stirring paddle is 200 r / min, and the reactions are carried out continuously for 10 h under atmospheric pressure. With other conditions unchanged, the air flow rates in five experiments are 0.1, 0.2, 0.3, 0.4, and 0.5 L / min respectively. After the reaction ends, filter and separate, and analyze the components and pH of the filtrate. The results are shown in Table 3 below.

[0066] Table 3 shows the influence of air flow rate on the oxidation of cumene to CHP over the CuO-ZnO-CaO-CNTs catalyst

[0067]

[0068] It can be seen from Table 3 that when the flow rate is 0.1 - 0.5 L / min, the conversion rate of cumene increases with the increase of the input amount. However, when the flow rate is 0.4 - 0.5 L / min, the selectivity of CHP decreases to less than 95%, and side reactions increase.

[0069] Single-factor experiment on the catalyst dosage in Example 7

[0070] Weigh 0.0, 0.2, 0.5, 1.0, and 2.0 g of the catalyst prepared in Example 1, and add them to a 250 ml three-necked flask together with 100 g of cumene respectively. The reaction temperature is 80 °C, the air flow rate is 0.3 L / min, the rotation speed of the stirring paddle is 200 r / min, and the reactions are carried out continuously for 10 h under atmospheric pressure. After the reaction ends, filter and separate, and analyze the components and pH of the filtrate. The results are shown in Table 4 below.

[0071] Table 4 shows the influence of catalyst dosage on the oxidation of cumene to CHP over the CuO-ZnO-CaO-CNTs catalyst

[0072]

[0073] According to the above table, it can be clearly seen that the larger the dosage of the CuO-ZnO-CaO-CNTs catalyst, the better the cumene conversion. However, when the dosage exceeds 1.0 g, there is no obvious change in the CM conversion and CHP selectivity. Therefore, the optimal dosage is 0.5 - 1 g under these reaction conditions.

[0074] Stability experiment on the recycling of the catalyst in Example 8

[0075] (1) After filtering and separating the used catalyst in Example 1, wash it successively with alcohol and deionized water by stirring to remove the adhered organic substances, and then dry it at 105 °C for 8 h for repeated experiments.

[0076] (2) Use the recycled CuO-ZnO-CaO-CNTs catalyst to catalytically oxidize cumene with reference to the catalytic reaction steps in Example 1.

[0077] (3) Repeat the above catalytic reaction steps 4 times. The catalytic performance results in Example 1 and during the recycling process are shown in Table 5 below.

[0078] Table 5 shows the influence of the recycling of the CuO-ZnO-CaO-CNTs catalyst in the reaction of catalytically oxidizing cumene to produce CHP.

[0079]

[0080] It can be seen from the data in the table that there is no obvious change after the catalyst is reused 5 times, which indicates that the CuO-ZnO-CaO-CNTs catalyst can be recycled, thus reducing the cost of the catalyst.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered by the scope of the technical solutions claimed in the present invention.

Claims

1. Application of a metal oxide composite carbon nanotube catalyst, characterized in that, Using cumene as a raw material and air as an oxidant, cumene hydroperoxide is synthesized under the action of the catalyst; the proportion of metal oxides XO and YO in the catalyst is 13-88 wt%, and the balance is multi-walled carbon nanotubes; wherein, X is two or more of transition metal elements Cu, Zn, Mn, and Co, and the two or more metals contained in X are mixed in any proportion; Y is one of alkaline earth metals Ca, Mg, and Sr; the molar ratio of X to Y is 1:0.05-0.5; The multi-walled carbon nanotubes have a diameter of 20 to 100 nm, a length of 5 to 15 μm, and a specific surface area of 40 to 300 m 2 / g; The preparation method of the catalyst includes: S1. Pretreat the carbon nanotubes; S2. Dissolve the nitrates of X and Y in a mixed solution of water and an alcohol substance; S3. Add the pretreated carbon nanotubes into the nitrate mixed solution prepared in step S2 to obtain a mixed solution of carbon nanotubes and metal ions; S4. Under stirring conditions, dropwise add an alkaline solution to the mixed solution obtained in step S3 until the pH of the solution reaches 8-11. After the dropping is completed, continue stirring and reacting. After the reaction is completed, stand for aging, filter by suction, wash with water, dry, and calcine in sequence to obtain the catalyst; Step S1 is to place the carbon nanotubes in a nitric acid solution to form a suspension, carry out a condensation reflux reaction at 110-120 °C, stand for precipitation and wash to neutrality after the reaction is completed, then filter by suction, and then dry the filter cake for standby; In step S2, the alcohol substance is any one of ethanol, ethylene glycol, and methanol, the volume ratio of water to alcohol is 1-4:1, and the mass ratio of the total amount of metal nitrates to the mixed solution is 0.01-2:1; In step S3, the mass ratio of the carbon nanotubes to the total amount of nitrates in the nitrate mixed solution is 0.02-1:1, and the mixed solution is obtained by ultrasonic treatment and simultaneous stirring. The ultrasonic stirring time is 2-6 h, and the ultrasonic frequency is 20-40 kHz.

2. The application according to claim 1, characterized in that, In the synthesis reaction, the mass ratio of the catalyst to cumene is 0.002-0.02:

1.

3. The application according to claim 1, characterized in that, characterized in that, The synthesis reaction temperature is 75-105 °C, and the reaction pressure is 0-0.5 MPa.

4. The application according to claim 1, characterized in that Calculated by each milliliter of cumene, the feeding rate of air is 1-5 mL / min.

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