阅读说明：本技术 氧化环酮的方法 (Process for oxidation of cyclic ketones ) 是由 史春风 王肖 黄慧 康振辉 刘阳 赵娟 于 2019-08-30 设计创作，主要内容包括：本公开涉及一种氧化环酮的方法,该方法包括：使环酮和含氧气体在催化剂的存在下进行接触反应,其中,所述催化剂为改性氮化碳。本公开采用改性氮化碳作为催化剂催化环酮的氧化反应,能够在温和的条件下实现对环酮的氧化,原料转化率和目标产物二元羧酸选择性较高,降低生产成本。(The present disclosure relates to a method of oxidizing cyclic ketones, the method comprising: the cyclic ketone and oxygen-containing gas are subjected to contact reaction in the presence of a catalyst, wherein the catalyst is modified carbon nitride. The method adopts the modified carbon nitride as the catalyst to catalyze the oxidation reaction of the cyclic ketone, can realize the oxidation of the cyclic ketone under mild conditions, has higher raw material conversion rate and higher selectivity of the target product dicarboxylic acid, and reduces the production cost.)

1. A method of oxidizing cyclic ketones, comprising: the method comprises the following steps of carrying out contact reaction on cyclic ketone and oxygen-containing gas in the presence of a catalyst, wherein the catalyst is modified carbon nitride, and the modified carbon nitride is prepared by a preparation method comprising the following steps:

a. adding urea into a quartz reactor, sealing, reacting at 400-800 ℃ for 1-12 h, and cooling to obtain carbon nitride;

b. and (b) carrying out hydrothermal treatment on the carbon nitride obtained in the step (a) in an ethylenediamine solution, and then drying to obtain the modified carbon nitride.

2. The method according to claim 1, wherein in step b, the hydrothermal treatment conditions are: the weight percentage concentration of the ethylenediamine is 0.1-20%, preferably 2-10%; the temperature is 120-300 ℃, and preferably 150-250 ℃; the time is 0.1 to 24 hours, preferably 3 to 18 hours.

3. The method of claim 1, wherein in step b, the drying conditions are: the temperature is 60-200 ℃, and preferably 80-180 ℃; the time is 1 to 12 hours, preferably 2 to 10 hours.

4. A process according to claim 1, wherein the carbon nitride has a particle size of 20 to 100nm in a proportion of 2 to 30% by weight, preferably 5 to 20% by weight, based on the total weight of the carbon nitride.

5. The process according to any one of claims 1 to 3, wherein the cyclic ketone is cyclohexanone, cyclopentanone, methylcyclopentanone, methylcyclohexanone, halogenated cyclopentanone, or halogenated cyclohexanone, or a mixture of two or three thereof;

the oxygen-containing gas is air or oxygen;

the molar ratio of the cyclic ketone to oxygen in the oxygen-containing gas is 1: (2-20), preferably 1: (4-10).

6. The process according to any one of claims 1 to 3, wherein the reaction is carried out in a slurry bed reactor, and the catalyst is used in an amount of 2 to 500mg, preferably 5 to 200mg, based on 10mL of the cyclic ketone.

7. The process according to any one of claims 1 to 3, wherein the reaction is carried out in a fixed bed reactor, and the weight hourly space velocity of the cyclic ketone is from 0.1 to 100h^-1Preferably 0.2 to 50 hours^-1。

8. The method of any one of claims 1 to 3, further comprising: the reaction is carried out in the presence of a solvent; the solvent is water, C1-C6 alcohol, C3-C8 ketone or C2-C6 nitrile, or the combination of two or three of the above;

the weight ratio of the cyclic ketone to the solvent is 1: (0.1-10).

9. The method of any one of claims 1 to 3, further comprising: the reaction is carried out in the presence of an initiator; the initiator is tert-butyl hydroperoxide, cumyl hydroperoxide, ethylbenzene hydroperoxide, peroxyacetic acid or peroxypropionic acid, or the combination of two or three of the above substances;

preferably, the dosage of the initiator is 0.05-0.3 mL based on 10mL of the cyclic ketone.

10. The method according to any one of claims 1 to 3, wherein the reaction conditions are as follows: the temperature is 60-150 ℃, and preferably 80-120 ℃; the pressure is 0.01 to 5MPa, preferably 0.2 to 2 MPa.

Technical Field

The present disclosure relates to a method of oxidizing cyclic ketones.

Background

Dicarboxylic acids are important organic chemical products, can perform salt forming reaction, esterification reaction, amidation reaction and the like, and can be polycondensed with diamine or dihydric alcohol to form high molecular polymers and the like. As dicarboxylic acid with important industrial significance, adipic acid plays an important role in the aspects of chemical production, organic synthesis industry, medicine, lubricant manufacturing and the like, and the yield is the second place in all dicarboxylic acids.

Adipic acid is generally produced by the oxidation of cyclohexanone, and generally includes the nitric acid oxidation, the peroxide oxidation, the ozone oxidation, the anodic oxidation and the nitrogen dioxide oxidation, depending on the oxidizing agent and the oxidation method used. The nitric acid oxidation method can cause equipment corrosion and is accompanied with the problem of environmental pollution; the oxidizing agents used in the peroxide oxidation method, the ozone oxidation method and the nitrogen dioxide oxidation method have high cost and are difficult to obtain; the anodic oxidation method has too low reaction rate and has no industrial prospect. Therefore, the method for preparing adipic acid by oxidizing cyclohexanone, which is environment-friendly and lower in cost, is a problem with practical significance.

Disclosure of Invention

The purpose of the present disclosure is to provide a method for oxidizing cyclic ketone, which can obtain higher raw material conversion rate and selectivity of target product dicarboxylic acid.

In order to achieve the above object, the present disclosure provides a method of oxidizing cyclic ketone, the method comprising: the method comprises the following steps of carrying out contact reaction on cyclic ketone and oxygen-containing gas in the presence of a catalyst, wherein the catalyst is modified carbon nitride, and the modified carbon nitride is prepared by a preparation method comprising the following steps:

a. adding urea into a quartz reactor, sealing, reacting at 400-800 ℃ for 1-12 h, and cooling to obtain carbon nitride;

b. and (b) carrying out hydrothermal treatment on the carbon nitride obtained in the step (a) in an ethylenediamine solution, and then drying to obtain the modified carbon nitride.

Optionally, in step b, the hydrothermal treatment conditions are as follows: the mass percentage concentration of the ethylenediamine is 0.1-20%, preferably 2-10%; the temperature is 120-300 ℃, and preferably 150-250 ℃; the time is 0.1 to 24 hours, preferably 3 to 18 hours.

Optionally, in step b, the drying conditions are: the temperature is 60-200 ℃, and preferably 80-180 ℃; the time is 1 to 12 hours, preferably 2 to 10 hours.

Optionally, the weight of the carbon nitride with the particle size of 20-100 nm accounts for 2-30%, preferably 5-20% of the total weight of the carbon nitride.

Optionally, the cyclic ketone is cyclohexanone, cyclopentanone, methylcyclopentanone, methylcyclohexanone, halogenated cyclopentanone, or halogenated cyclohexanone, or a mixture of two or three thereof; the oxygen-containing gas is air or oxygen; the molar ratio of the cyclic ketone to oxygen in the oxygen-containing gas is 1: (2-20), preferably 1: (4-10).

Optionally, the reaction is performed in a slurry bed reactor, and the amount of the catalyst is 2 to 500mg, preferably 5 to 200mg, based on 10mL of the cyclic ketone.

Optionally, the reaction is carried out in a fixed bed reactor, and the weight hourly space velocity of the cyclic ketone is 0.1-100 h^-1Preferably 0.2 to 50 hours^-1。

Optionally, the method further comprises: the reaction is carried out in the presence of a solvent; the solvent is water, C1-C6 alcohol, C3-C8 ketone or C2-C6 nitrile, or the combination of two or three of the above; the weight ratio of the cyclic ketone to the solvent is 1: (0.1-10).

Optionally, the method further comprises: the reaction is carried out in the presence of an initiator; the initiator is tert-butyl hydroperoxide, cumyl hydroperoxide, ethylbenzene hydroperoxide, peroxyacetic acid or peroxypropionic acid, or the combination of two or three of the above substances; preferably, the dosage of the initiator is 0.05-0.3 mL based on 10mL of the cyclic ketone.

Optionally, the reaction conditions are: the reaction conditions are as follows: the temperature is 60-150 ℃, and preferably 80-120 ℃; the pressure is 0.01 to 5MPa, preferably 0.2 to 2 MPa.

Through the technical scheme, the modified carbon nitride is used as the catalyst to catalyze the oxidation reaction of the cyclic ketone, the oxidation of the cyclic ketone can be realized under mild conditions, the conversion rate of raw materials and the selectivity of a target product, namely dicarboxylic acid are high, and the production cost is reduced.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Detailed Description

The following describes in detail specific embodiments of the present disclosure. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

The present disclosure provides a method of oxidizing cyclic ketones, the method comprising: the preparation method comprises the following steps of carrying out contact reaction on cyclic ketone and oxygen-containing gas in the presence of a catalyst, wherein the catalyst is modified carbon nitride, the modified carbon nitride is obtained by modifying the carbon nitride through a hydrothermal treatment of an ethylenediamine solution, and the preparation method specifically comprises the following steps:

a. adding urea into a quartz reactor, sealing, reacting at 400-800 ℃ for 1-12 h, and cooling to obtain carbon nitride;

b. and (b) carrying out hydrothermal treatment on the carbon nitride obtained in the step (a) in an ethylenediamine solution, and then drying to obtain the modified carbon nitride.

According to the present disclosure, in the step b, the ethylenediamine solution may be an ethylenediamine solution with any weight percentage concentration, and further, the weight percentage concentration of ethylenediamine is 0.1 to 20%, preferably 2 to 10%; the temperature is 120-300 ℃, and preferably 150-250 ℃; the time is 0.1 to 24 hours, preferably 3 to 18 hours.

According to the disclosure, drying is a common technical means in the field, and the carbon nitride material treated by ethylenediamine can be heated at 60-200 ℃, preferably 80-180 ℃; the drying is carried out for 1 to 12 hours, preferably 2 to 10 hours.

According to the present disclosure, the carbon nitride may have an average particle size of 10 to 1000nm, preferably 50 to 500 nm. In the present disclosure, the "particle size" refers to the maximum three-dimensional length of the particle, i.e., the distance between two points on the particle having the largest distance. The inventor also unexpectedly finds that the catalyst has better performance of catalyzing oxidation of cyclic ketone when the weight of carbon nitride with the particle size of 20-100 nm accounts for 2-30%, preferably 5-20% of the total weight of the carbon nitride. The modified nanocarbon-based material disclosed by the invention has a proper particle size and excellent catalytic performance, and is particularly suitable for catalytic oxidation of cyclic ketone and the like.

According to the present disclosure, the cyclic ketone may be cyclohexanone, cyclopentanone, methylcyclopentanone, methylcyclohexanone, halogenated cyclopentanone, or halogenated cyclohexanone; the oxygen-containing gas may be air or oxygen, in which case the molar ratio of the cyclic ketone to oxygen in the oxygen-containing gas is 1: (2-20), preferably 1: (4-10).

The cyclic ketone oxidation process of the present disclosure can be carried out in a variety of conventional catalytic reactors, such as can be carried out in a polytetrafluoroethylene reaction kettle or three-necked flask, or in suitable other reactors such as fixed beds, moving beds, suspended beds, and the like. Further, the pressure of the reaction process is not particularly limited, and may be the autogenous pressure of the system, or may be carried out under an additionally applied pressure condition, and preferably, the reaction process is carried out under the autogenous pressure (generally, in a closed vessel). The method of collecting the solid product after the reaction can be carried out by a conventional method such as filtration, centrifugation and the like.

In an alternative embodiment of the present disclosure, the reaction is carried out in a slurry bed reactor. In this case, the amount of the catalyst may be appropriately selected according to the amounts of the cyclic ketone and the oxygen-containing gas, and for example, the amount of the catalyst is 2 to 500mg, preferably 5 to 200mg, based on 10mL of the cyclic ketone.

In an alternative embodiment of the present disclosure, the reaction is carried out in a fixed bed reactor. At this time, the weight hourly space velocity of the cyclic ketone is 0.1-100 h^-1Preferably 0.2 to 50 hours^-1。

According to the present disclosure, to increase the degree of mixing between the reaction materials, the method may further comprise: the reaction is carried out in the presence of a solvent. The third solvent may be various liquid substances capable of dissolving the cyclic ketone and the peroxide or promoting the mixing of the two and promoting the dissolution of the target product. Typically, the solvent is water, a C1-C6 alcohol, a C3-C8 ketone, or a C2-C6 nitrile, or a combination of two or three thereof. Preferably, the solvent is selected from water and/or methanol. The amount of the solvent to be used may be appropriately selected depending on the amounts of the cyclic ketone and the oxygen-containing gas to be used, and for example, the weight ratio of the cyclic ketone to the solvent may be 1: (0.1-10).

According to the present disclosure, the method further comprises: the reaction is carried out in the presence of an initiator; the initiator is tert-butyl hydroperoxide, cumyl hydroperoxide, ethylbenzene hydroperoxide, peroxyacetic acid or peroxypropionic acid, or the combination of two or three of the above. The amount of the initiator may be appropriately selected according to the amounts of the cyclic olefin and the oxidant, for example, the amount of the initiator is 0.05 to 0.3mL based on 10mL of the cyclic ketone.

According to the present disclosure, the conditions of the reaction may be: the temperature is 60-150 ℃, and preferably 80-120 ℃; the pressure is 0.01 to 5MPa, preferably 0.2 to 2 MPa. In order to make the reaction more sufficient, it is preferable that the reaction is carried out under stirring.

The method takes the modified carbon nitride as the catalyst to catalyze the oxidation reaction of the cyclic ketone, can realize the oxidation of the cyclic ketone under mild conditions, has higher raw material conversion rate and target product selectivity, is easy to realize on the existing industrial equipment, and has industrialized prospect.

The present disclosure is described in detail below with reference to examples, but the scope of the present disclosure is not limited thereby.

All other reagents were commercially available analytical grade reagents, and the pressures were measured as gauge pressures.

Preparation examples 1 to 5 are provided to illustrate the preparation method of the modified carbon nitride employed in the present disclosure.

In the preparation examples, the average particle size (particle diameter) of carbon nitride was determined using TECNAIG (FEI corporation)²Model F20(200kv) transmission electron microscopeThe determination was carried out under the following test conditions: accelerating voltage of 20kV, preparing a sample by adopting a suspension method, putting the sample into a 2mL glass bottle, dispersing the sample by absolute ethyl alcohol, uniformly oscillating, taking one drop by using a dropper, dropping the drop on a sample net with the diameter of 3mm, putting the sample net into a sample injector after drying, inserting an electron microscope for observation, and randomly taking 100 carbon nitride particles for carrying out particle size statistics.

The carbon nitride is prepared by separating particles with a particle size of 3-20 nm by a membrane separation device (type BONA-GM-05) of Jinan Borna Biotechnology Limited to obtain particles with a particle size of 20-100 nm, and calculating the ratio of the particle weight with the particle size of 20-100 nm to the total mass of carbon oxide according to the weight of the particles with the particle size of 20-100 nm and the total mass of carbon nitride.

Preparation of example 1

50g of urea is placed in a crucible, covered and sealed, placed in a muffle furnace at 450 ℃ for roasting for 8h, cooled to obtain carbon nitride, then the carbon nitride is added into a sufficient amount of 2 weight percent ethylenediamine aqueous solution (the sufficient amount means that the ethylenediamine aqueous solution completely immerses the carbon nitride, the same is applied below), hydrothermal treatment is carried out for 12h at 200 ℃, and then drying is carried out for 6h at 120 ℃ to obtain the modified carbon nitride particles A1. The average particle size is 380nm, wherein the weight of the carbon nitride with the particle size of 20-100 nm accounts for 12% of the total weight of the carbon nitride.

Preparation of example 2

40g of urea is placed in a crucible, covered and sealed, and is placed in a muffle furnace at 550 ℃ for roasting for 5h, carbon nitride is obtained after cooling, then the carbon nitride is added into a sufficient amount of 10 weight percent ethylenediamine aqueous solution, hydrothermal treatment is carried out for 12h at 150 ℃, and then drying is carried out for 6h at 100 ℃ to obtain the modified carbon nitride particles A2. The average particle size is 190nm, wherein the weight of the carbon nitride with the particle size of 20-100 nm accounts for 19% of the total weight of the carbon nitride.

Preparation of example 3

60g of urea is placed in a crucible, covered and sealed, and is placed in a muffle furnace at 650 ℃ for roasting for 2h, carbon nitride is obtained after cooling, then the carbon nitride is added into a sufficient amount of 0.5 percent ethylene diamine aqueous solution by weight percentage, hydrothermal treatment is carried out for 6h at 280 ℃, and then drying is carried out for 6h at 150 ℃ to obtain modified carbon nitride particles A3. Detecting that the average particle size of the carbon nitride particles is 520nm, wherein the weight of the carbon nitride particles with the particle size of 20-100 nm accounts for 4% of the total weight of the carbon nitride.

Preparation of example 4

20g of urea is placed in a crucible, covered and sealed, and is placed in a muffle furnace at 400 ℃ for roasting for 6 hours, carbon nitride is obtained after cooling, then the carbon nitride is added into a sufficient amount of 8 percent by weight of ethylenediamine aqueous solution, hydrothermal treatment is carried out for 18 hours at 150 ℃, and then drying is carried out for 4 hours at 120 ℃ to obtain the modified carbon nitride particles A4. The average particle size is detected to be 90nm, wherein the weight of the carbon nitride with the particle size of 20-100 nm accounts for 25% of the total weight of the carbon nitride.

Preparation of example 5

100g of urea is placed in a crucible, covered and sealed, and is placed in a muffle furnace at the temperature of 420 ℃ for roasting for 4 hours, carbon nitride is obtained after cooling, then the carbon nitride is added into a sufficient amount of ethylenediamine aqueous solution with the weight percentage concentration of 5 percent, hydrothermal treatment is carried out for 24 hours at the temperature of 100 ℃, and then drying is carried out for 6 hours at the temperature of 120 ℃ to obtain the modified carbon nitride particles A5. The average particle size is 80nm, wherein the weight of the carbon nitride with the particle size of 20-100 nm accounts for 6% of the total weight of the carbon nitride.

Comparative example 1

50g of urea is placed in a crucible, covered and sealed, and placed in a muffle furnace at 450 ℃ for roasting for 8 hours to obtain carbon nitride particles A. The average particle size is 400nm, wherein the weight of the carbon nitride with the particle size of 20-100 nm accounts for 3% of the total weight of the carbon nitride.

Examples 1-11 are provided to illustrate the process of the present disclosure for the catalytic oxidation of cyclic ketones.

In the following examples and comparative examples, the oxidation products were analyzed by gas chromatography (GC: Agilent, 7890A) and gas chromatography-mass spectrometer (GC-MS: Thermo Fisher Trace ISQ). Conditions of gas chromatography: nitrogen carrier gas, temperature programmed at 140K: 60 ℃, 1 minute, 15 ℃/minute, 180 ℃, 15 minutes; split ratio, 10: 1; the injection port temperature is 300 ℃; detector temperature, 300 ℃. On the basis, the conversion rate of raw materials and the selectivity of target products are calculated by respectively adopting the following formulas:

percent cyclic ketone conversion ═ molar amount of cyclic ketone added before reaction-molar amount of cyclic ketone remaining after reaction)/molar amount of cyclic ketone added before reaction × 100%;

target product selectivity ═ molar amount of target product formed after the reaction)/molar amount of cyclic ketone added before the reaction × 100%.

The peroxide effective utilization ratio%.

Example 1

80ml of cyclohexanone and 0.25g of modified carbon nitride A1 were charged into a 250ml high-pressure reaction vessel to form a reaction mass, which was then sealed, and then oxygen (molar ratio of oxygen to cyclohexanone: 5: 1) was introduced, and the mixture was stirred at 120 ℃ and 2.0MPa for 4 hours, and then the catalyst was separated by centrifugation and filtration. The results of the oxidation product analysis are shown in Table 1.

Examples 2 to 5

Cyclohexanone was catalytically oxidized according to the procedure of example 1, except that modified carbon nitride A2-A5 was used in the same amount instead of A1, respectively. The results of the oxidation product analysis are shown in Table 1.

Example 6

80ml of cyclohexanone and 0.5g of modified carbon nitride A1 were added to a 250ml high-pressure reaction vessel to form a reaction mass, which was then sealed, and then oxygen (molar ratio of oxygen to cyclohexanone was 5: 1) was introduced, and the mixture was stirred at 70 ℃ and 0.1MPa for 6 hours, and then the catalyst was separated by centrifugation and filtration. The results of the oxidation product analysis are shown in Table 1.

Example 7

120ml of cyclohexanone and 0.25g of modified carbon nitride A1 were charged into a 250ml high-pressure reaction vessel to form a reaction mass, which was then sealed, and then oxygen (molar ratio of oxygen to cyclohexanone: 5: 1) was introduced, and the mixture was stirred at 130 ℃ and 3.0MPa for 2 hours, and then the catalyst was separated by centrifugation and filtration. The results of the oxidation product analysis are shown in Table 1.

Example 8

80ml of cyclohexanone and 1.5g of modified carbon nitride A1 were charged into a 250ml high-pressure reaction vessel to form a reaction mass, which was then sealed, and then oxygen (molar ratio of oxygen to cyclohexanone: 3: 1) was introduced, and the mixture was stirred at 120 ℃ and 2.0MPa for 4 hours, and then the catalyst was separated by centrifugation and filtration. The results of the oxidation product analysis are shown in Table 1.

Example 9

Feeding cyclohexanone into a reaction zone from a feed inlet at the top of a traditional fixed bed reactor, and feeding oxygen into the reaction zone from a feed inlet at the bottom of the fixed bed reactor to contact with modified carbon nitride A1 serving as a catalyst, wherein the molar ratio of the cyclohexanone to the oxygen is 1: 4, the reaction temperature is 90 ℃, the pressure is 0.8MPa, and the weight hourly space velocity of the cyclohexanone is 2.0h^-1. The reaction mixture obtained after the reaction was carried out for 2 hours was subjected to gas chromatography, and the results are shown in Table 1.

Example 10

Cyclohexanone and methanol as solvent are mixed to form a liquid mixture. Then, the liquid mixture is fed from a feed inlet at the top of the fixed bed reactor, oxygen is fed from a feed inlet at the bottom of the fixed bed reactor into a reaction zone to be contacted with modified carbon nitride A1 serving as a catalyst, wherein the molar ratio of cyclohexanone to oxygen is 1: 4, the weight ratio of cyclohexanone to methanol is 1: 4; the reaction temperature is 30 ℃, the pressure is 0.8MPa, and the weight hourly space velocity of the cyclohexanone is 2.0h^-1. The reaction mixture obtained after the reaction was carried out for 2 hours was subjected to gas chromatography, and the results are shown in Table 1.

Example 11

Feeding cyclohexanone into a reaction zone from a feed inlet at the top of a traditional fixed bed reactor, and feeding air into the reaction zone from a feed inlet at the bottom of the fixed bed reactor to contact with modified carbon nitride A1 serving as a catalyst, wherein the molar ratio of the cyclohexanone to oxygen in the air is 1: 3, the reaction temperature is 90 ℃, the pressure is 1.5MPa, and the weight hourly space velocity of the cyclohexanone is 1.0h^-1. The reaction mixture obtained after the reaction was carried out for 1 hour was subjected to gas chromatography, and the results are shown in Table 1.

Comparative example 1

Cyclohexanone was catalytically oxidized by the method of example 1, except that modified carbon nitride was not added as a catalyst. The results of the oxidation product analysis are shown in Table 1.

Comparative example 2

Cyclohexanone was catalytically oxidized by the method of example 1, except that unmodified carbon nitride a was added as a catalyst. The results of the oxidation product analysis are shown in Table 1.

TABLE 1

Sources of catalyst	Cyclic ketone conversion rate%	Target product selectivity,%
			Example 1	36	63
Example 2	34	67
			Example 3	29	62
Example 4	31	64
			Example 5	33	68
Example 6	29	57
			Example 7	47	51
Example 8	38	59
			Example 9	36	65
Example 10	21	63
			Example 11	20	56
Comparative example 1	3	19
			Comparative example 2	29	24

As can be seen from table 1, the oxidation of cyclic ketone can be achieved under mild conditions by using the method disclosed by the present disclosure, and the conversion rate of raw materials and the selectivity of the target product dicarboxylic acid are higher. Further comparison results show that the nano nitrogen-carbon material prepared by the method disclosed by the invention has a proper particle size, and the activity of the catalyst can be further improved, so that the cyclic ketone reaction is promoted to generate dicarboxylic acid.

The preferred embodiments of the present disclosure have been described in detail above, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.