A method for preparing a porous carbon material based on ion catalytic induction phase separation

Abstract

The application relates to a preparation method of a porous carbon material based on an ion catalysis induced phase separation method. The preparation method of the porous carbon material based on the ion catalysis induced phase separation method comprises the following steps: a metal ion catalyst and a curing agent are added into a mixed solution of a thermosetting resin and an organic solvent by using an organic matter polymerization induced phase separation method, mixing, curing and debinding are performed, and the porous carbon material is obtained.

Description

Technical Field

[0001] This invention belongs to the field of carbon material preparation technology, and relates to a method for preparing porous carbon materials with adjustable pore size, specifically a method for preparing porous carbon materials based on ion catalytic induced phase separation. Background Technology

[0002] Porous carbon, as a functional carbon material with excellent pore structure, possesses superior properties such as high porosity, controllable pore size, high specific surface area, good electrical conductivity, and chemical stability. It is widely used in gas separation, water and air purification, adsorption materials, catalyst supports, chromatography, supercapacitors, and the preparation of structural carbide ceramics. The pore structure has a significant impact on the application of porous carbon materials. In the preparation of complex-shaped and difficult-to-process carbide ceramics using porous carbon as a preform, the pore structure has a substantial influence on the overall performance of the final ceramic component. Therefore, it is necessary to precisely control the pore structure and pore characteristic parameters of porous carbon.

[0003] Currently, common methods for preparing porous carbon materials include hard / soft template methods, catalytic activation methods, and polymerization-induced phase separation methods. Template methods are complex, requiring highly corrosive reagents such as hydrofluoric acid for template removal, posing safety hazards and increasing the risk of incomplete template removal. Activation methods typically use sodium hydroxide or potassium hydroxide as activating agents, causing environmental pollution. In contrast, polymerization-induced phase separation methods offer lower manufacturing costs, simpler processes, and are easier to industrialize. Most importantly, compared to other methods, organic polymerization-induced phase separation methods can more effectively control the pore structure of porous carbon.

[0004] Chinese patent (201810922755.5) employs a polymerization-induced phase separation method, using boric acid or borates as catalysts, introduced into a mixture of thermosetting phenolic resin, organic solvent, and curing agent. By controlling process parameters, porous carbon materials with tunable pore characteristics are prepared. The curing process involves initial holding at 80–100℃ for 4–8 hours, followed by raising the temperature to 160–200℃ and holding for 6–12 hours; this process is complex and time-consuming. Chinese patent (202211177982.2) also uses this method to uniformly mix phenolic resin, ethylene glycol, and curing agent. High-pressure assisted phase separation suppresses ethylene glycol boiling, promoting the participation of more active sites of the phenolic resin in the polymerization reaction, resulting in porous carbon materials with uniform nanoporous structures. However, the high-pressure assisted phase separation method employed here presents relatively difficult high-pressure conditions, requires sophisticated equipment, and is complex to operate. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, this invention provides a simple and efficient method for preparing porous carbon materials based on metal ion catalysis and organic polymerization-induced phase separation. This method introduces metal ions as a catalyst into the polymerization-induced phase separation method. Metal ions promote the polymerization of thermosetting phenolic resins with organic solvents, enabling better phase separation and thus reducing the conditions required for the curing process, shortening the preparation time and reducing the complexity of the porous carbon material preparation process. Furthermore, this invention can effectively control the pore characteristics of porous carbon materials by adjusting the content of metal ion salts, enabling the simple and efficient preparation of porous carbon materials with controllable pore size distribution.

[0006] On the one hand, the present invention provides a method for preparing porous carbon materials based on ion catalytic induced phase separation, comprising the following steps: using organic polymerization induced phase separation, adding metal ion catalyst and curing agent to a mixture of thermosetting resin and organic solvent, and obtaining porous carbon materials through mixing, curing and debinding.

[0007] Preferably, the thermosetting resin is at least one of phenolic resin, furfuryl alcohol resin, vinyl ester, and polyimide resin, and is preferably phenolic resin; the organic solvent is an alcohol, and the alcohol is at least one of ethylene glycol, polyethylene glycol, diethylene glycol, and triethylene glycol, and is preferably ethylene glycol; the mass ratio of the thermosetting phenolic resin to the organic solvent is (30-60):(40-70).

[0008] Preferably, the metal ion catalyst is at least one of zinc chloride, ferrous chloride, and copper chloride, and more preferably zinc chloride or ferrous chloride; the amount of the metal ion catalyst added is 0.1 to 10. wt% of the total mass of the thermosetting phenolic resin and the organic solvent, and more preferably 0.5 to 5. wt%.

[0009] Preferably, the curing agent is at least one of hexamethylenetetramine, benzenesulfonyl chloride, toluenesulfonyl chloride, and m-diphenylamine, and is more preferably hexamethylenetetramine; the amount of the curing agent added is 5 to 10 wt% of the total mass of the thermosetting phenolic resin and the organic solvent.

[0010] Preferably, the mixing method is magnetic stirring; the magnetic stirring speed is 100-400 r / min, and the magnetic stirring time is 1-2 h.

[0011] Preferably, the curing temperature is 80℃~130℃ and the time is 3~6h.

[0012] Preferably, the debonding process includes: a debonding temperature of 600–1200°C and a debonding time of 30–120 min; preferably, under vacuum conditions, the temperature is first increased to 25–200°C at a heating rate of 1–3°C / min, then increased to 200–600°C at a heating rate of 0.25–1°C / min, then increased to 600–1200°C at a heating rate of 1–2°C / min, and finally held at 600–1200°C for 30–120 min before being purged with argon or nitrogen and cooled to room temperature.

[0013] On the other hand, the present invention provides a porous carbon material prepared according to the above preparation method, wherein the average pore size of the porous carbon material is 10 nm to 1 μm.

[0014] This invention employs an organic polymerization-induced phase separation method, utilizing the complexation effect between metal ion salts (e.g., zinc chloride, ferrous chloride, copper chloride, etc.) and thermosetting phenolic resin. The introduction of metal ions promotes bond substitution of the benzene ring, facilitating the conjugation reaction between the carbonyl group and the benzene ring to construct a macrocyclic compound on the benzene ring. Simultaneously, it promotes the polymerization of thermosetting phenolic resin with organic solvents, increasing the degree of polymerization of the skeletal structure. Furthermore, under the action of metal ion salts, the resin mixture solution undergoes phase separation during curing, gradually forming a resin-rich phase and a solvent-rich phase. Subsequently, the solvent-rich phase volatilizes, forming a porous structure. By controlling the content of metal ion salts, the pore characteristics of the porous carbon material can be effectively controlled, providing a method for preparing porous carbon materials with controllable pore size distribution and a simple process flow. Compared to the metal ion soft template method for preparing porous carbon materials, the preparation method of this invention can form a porous structure in one step without acid washing or carbonization, making the preparation method simpler, faster, and more environmentally friendly.

[0015] Beneficial effects: Compared with the prior art, the above-mentioned technical solution of the present invention has the following main technical advantages: (1) Compared with the template method and the activation method, the polymerization-induced phase separation method for preparing porous carbon materials has a simple process and low manufacturing cost. (2) Compared with other types of catalysts (such as boric acid or borate), metal ion salts are more readily available, safer to use, and less polluting to the environment; (3) Compared with catalysts such as boric acid or borate, metal ion salts can better generate complexation effect with thermosetting phenolic resins, promote the bond substitution of benzene rings, facilitate the conjugation reaction between carbonyl groups and benzene rings, construct macrocyclic compounds on benzene rings, and form network structures; at the same time, they promote the polymerization of thermosetting phenolic resins with organic solvents and increase the degree of polymerization of the skeleton. (4) Using metal ion salts as catalysts can greatly reduce the conditions required for the curing process and shorten the preparation time and process difficulty of porous carbon materials. Attached Figure Description

[0016] Figure 1 The pore size distribution diagrams are shown for the porous carbon materials prepared in Examples 1-4 and Comparative Example 1. Figure 2 The microstructure diagrams are of the porous carbon materials prepared in Examples 1-3; Figure 3 This is a diagram showing the effect after curing in Example 2; Figure 4 This is a comparison image of the incompletely cured sample 2. Figure 5 Porosity diagrams of the porous carbon materials prepared in Examples 1-4 and Comparative Example 1; Figure 6 Shrinkage diagrams of the porous carbon materials prepared in Examples 1-4 and Comparative Example 1; Figure 7 The image shows the microstructure of the porous carbon material prepared in Comparative Example 3. Figure 8 This is a microstructure diagram of the porous carbon material prepared in Comparative Example 4. Detailed Implementation

[0017] To further illustrate the invention's content, features, and practical effects, the invention will be described in detail below with reference to embodiments. It should be noted that the modification methods of the invention are not limited to these specific implementation methods. Equivalent substitutions and modifications made by those skilled in the art based on their reading of the invention's content, without departing from the spirit and essence of the invention, are also within the scope of protection claimed by this invention.

[0018] This invention provides a method for preparing porous carbon materials based on ion-catalyzed induced phase separation. The method employs organic polymerization-induced phase separation, utilizing the complexation effect between metal ion salts (e.g., zinc chloride, ferrous chloride, copper chloride, etc.) and thermosetting phenolic resin. The introduction of metal ions promotes bond substitution of the benzene ring, facilitating the conjugation reaction between the carbonyl group and the benzene ring to construct macrocyclic compounds on the benzene ring. Simultaneously, it promotes the polymerization of thermosetting phenolic resin with organic solvents, increasing the degree of polymerization of the skeletal structure. By controlling the content of the metal ion salt, the pore characteristics of the porous carbon material can be effectively controlled. This provides a method for preparing porous carbon materials with controllable pore size distribution and a simple process flow. This method can better control the pore characteristics of porous carbon materials while reducing operational difficulty.

[0019] The following exemplarily illustrates the preparation method of porous carbon materials based on ion catalytic induced phase separation provided by the present invention.

[0020] An organic polymerization-induced phase separation method was used, in which metal ion catalysts and curing agents were added to a mixture of thermosetting resin and organic solvent, and the mixture was magnetically stirred to obtain a viscous resin mixture.

[0021] In an optional embodiment, the thermosetting resin is at least one of phenolic resin, furfuryl alcohol resin, vinyl ester, and polyimide resin, preferably phenolic resin; the organic solvent is an alcohol, preferably at least one of ethylene glycol, polyethylene glycol, diethylene glycol, and triethylene glycol, preferably ethylene glycol; the mass ratio of the thermosetting phenolic resin to the organic solvent is (30-60):(40-70). If the mass ratio of the thermosetting phenolic resin to the organic solvent is greater than 60:40, the solvent-rich phase cannot form a continuous phase, and the pore structure exists in isolation after volatilization, failing to form a three-dimensionally interconnected pore structure.

[0022] In an optional embodiment, the metal ion catalyst is at least one of zinc chloride, ferrous chloride, and copper chloride, preferably zinc chloride or ferrous chloride; the amount of the metal ion catalyst added is 0.1 to 10. wt% of the total mass of the thermosetting phenolic resin and the organic solvent, preferably 0.5 to 5. wt%. If the amount of the metal ion catalyst added is greater than 10. wt%, the degree of polymerization of the resin mixture is too high, which hinders the volatilization of the solvent-rich phase and easily forms closed pores.

[0023] In an optional embodiment, the curing agent is at least one of hexamethylenetetramine, benzenesulfonyl chloride, toluenesulfonyl chloride, and m-diphenylamine, preferably hexamethylenetetramine; the amount of the curing agent added is 5 to 10 wt% of the total mass of the thermosetting phenolic resin and the organic solvent.

[0024] In an optional embodiment, the magnetic stirring speed is 100-400 r / min, and the magnetic stirring time is 1-2 h.

[0025] The resulting viscous resin mixture was cured and debonded to obtain porous carbon material.

[0026] In an optional embodiment, the curing temperature is 80℃~130℃, and the time is 3~6 hours. If the curing time is too long, the resin-rich phase will partially volatilize, resulting in a deterioration of the carbon skeleton.

[0027] In an optional embodiment, the debinding process includes: a debinding temperature of 600–1200°C and a debinding time of 30–120 min; preferably, the temperature is first increased to 25–200°C at a heating rate of 1–3°C / min, then increased to 200–600°C at a heating rate of 0.25–1°C / min, then increased to 600–1200°C at a heating rate of 1–2°C / min, and finally held at 600–1200°C for 30–120 min before being cooled to room temperature by argon or nitrogen. The purpose of this special debinding process is to achieve more complete pyrolysis of the resin-rich phase and more complete evaporation of the residual solvent phase without damaging the pore structure.

[0028] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0029] Example 1 (Phenolic resin: ethylene glycol = 35:65, 0.5 wt% zinc chloride) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 35: 65) according to the mass percentage, and add 0.5.wt% zinc chloride and 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300 r / min for 1.5 h to mix evenly and obtain a viscous resin mixture. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Perform debonding treatment under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, and then filling with argon gas to cool to room temperature.

[0030] Example 2 (Phenolic resin: ethylene glycol = 35:65, 1.5 wt% zinc chloride) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 35: 65) according to the mass percentage, and add 1.5.wt% zinc chloride and 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300r / min for 1.5h until the mixture is homogeneous and a viscous resin mixture is obtained. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Perform debonding treatment under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, and then filling with argon gas to cool to room temperature.

[0031] Example 3 (Phenolic resin: ethylene glycol = 35:65, 2.5 wt% zinc chloride) (1) Weigh out phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 35: 65) according to the mass percentage, and add 2.5.wt% zinc chloride and 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300r / min for 1.5h until the mixture is homogeneous and a viscous resin mixture is obtained. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Debond it under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, and then cooling to room temperature by filling with argon gas.

[0032] Example 4 (Phenolic resin: ethylene glycol = 35:65, 5.wt% zinc chloride) (1) Weigh out phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 35: 65) according to the mass percentage, and add 5.wt% zinc chloride and 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300r / min for 1.5h until the mixture is homogeneous and a viscous resin mixture is obtained. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Perform debonding treatment under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, and then filling with argon gas to cool to room temperature.

[0033] Example 5 (Phenolic resin: ethylene glycol = 50:50, 1.5 wt% zinc chloride) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 50: 50) according to the mass percentage, and add 1.5.wt% zinc chloride and 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300r / min for 1.5h until the mixture is homogeneous and a viscous resin mixture is obtained. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Perform debonding treatment under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, and then filling with argon gas to cool to room temperature.

[0034] Example 6 (Phenolic resin: ethylene glycol = 35:65, 0.5 wt% ferrous chloride) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 35: 65) according to the mass percentage, and add 0.5.wt% ferrous chloride and 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300r / min for 1.5h until the mixture is homogeneous and a viscous resin mixture is obtained. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Perform debonding treatment under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, and then filling with argon gas to cool to room temperature.

[0035] Example 7 (Phenolic resin: ethylene glycol = 35:65, 1.5 wt% ferrous chloride) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 35: 65) according to the mass percentage, and add 1.5.wt% ferrous chloride and 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300 r / min for 1.5 h to mix evenly and obtain a viscous resin mixture. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Perform debonding treatment under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, and then filling with argon gas to cool to room temperature.

[0036] Example 8 (Phenolic resin: ethylene glycol = 35:65, 2.5 wt% ferrous chloride) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 35: 65) according to the mass percentage, and add 2.5.wt% ferrous chloride and 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300 r / min for 1.5 h to mix evenly and obtain a viscous resin mixture. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Perform debonding treatment under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, and then filling with argon gas to cool to room temperature.

[0037] Comparative Example 1 (Phenolic resin: ethylene glycol = 35:65, 0.wt% zinc chloride) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 35: 65) according to the mass percentage, and add 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300r / min for 1.5h to mix evenly and obtain a viscous resin mixture. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Perform debonding treatment under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, and then filling with argon gas to cool to room temperature.

[0038] Comparative Example 2 (Phenolic resin: ethylene glycol = 35:65, 1.5 wt% boric acid) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 35: 65) according to the mass percentage, and add 1.5.wt% boric acid and 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300r / min for 1.5h until the mixture is homogeneous and a viscous resin mixture is obtained. (2) Pour the obtained mixture into a mold and heat it to 90°C for 5 hours to cure. Then take out the sample. At this time, the sample has not been completely cured.

[0039] Comparative Example 3 (Phenolic resin: ethylene glycol = 20:80, 1.5wt% zinc chloride) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 20: 80) according to the mass percentage, and add 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300r / min for 1.5h until the mixture is homogeneous and a viscous resin mixture is obtained. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Debond it under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, filling with argon gas and cooling to room temperature to obtain porous carbon.

[0040] Comparative Example 4 (Phenolic resin: ethylene glycol = 65:35, 1.5wt% zinc chloride) (1) Weigh phenolic resin and ethylene glycol (phenolic resin: ethylene glycol = 20: 80) according to the mass percentage, and add 6.wt% hexamethylenetetraethylamine. Stir magnetically at 300r / min for 1.5h until the mixture is homogeneous and a viscous resin mixture is obtained. (2) Pour the obtained mixture into a mold and heat it to 90°C to solidify for 5 hours. Demold the solidified sample and place it in a graphite crucible. Debond it under vacuum and 900°C to obtain porous carbon material. The debonding process includes: heating to 200°C at a heating rate of 3°C / min, heating to 600°C at a heating rate of 1°C / min, heating to 900°C at a heating rate of 2°C / min, holding at 900°C for 30 minutes, filling with argon gas and cooling to room temperature to obtain porous carbon.

[0041] The pore sizes of the porous carbon materials in Examples 1-8 and Comparative Examples 1-2 are shown in Table 1.

[0042] Table 1:

[0043] Figure 1 The figures show the pore size distribution of the porous carbon materials prepared in Examples 1-4 and Comparative Example 1. As can be seen from the figures, the pore size first increases and then decreases with increasing zinc chloride content, reaching its maximum at 1.5 wt%.

[0044] Figure 2 The figures show the microstructure of the porous carbon materials prepared in Examples 1-3. As can be seen from the figures, the porous carbon exhibits good uniformity in its microstructure and forms a three-dimensional interconnected pore structure.

[0045] Figure 3The image shows the cured product of Example 2. As can be seen from the image, after curing and debonding treatment, the resin mixture in Example 2 cured well.

[0046] Figure 4 The image shows the effect of Comparative Example 2 before curing. As can be seen from the image, the resin mixture in Comparative Example 2 failed to cure completely after only 5 hours of curing.

[0047] Figure 5 The figures show the porosity of the porous carbon materials prepared in Examples 1-4 and Comparative Example 1. As can be seen from the figures, the porosity initially increases and then decreases with increasing zinc chloride content, reaching its maximum at 1.5 wt%.

[0048] Figure 6 The graph shows the shrinkage rate of the porous carbon materials prepared in Examples 1-4 and Comparative Example 1. As can be seen from the graph, the shrinkage rate first decreases and then increases with increasing zinc chloride content, reaching its minimum at 1.5 wt%.

[0049] Figure 7 The figure shows the microstructure of the porous carbon material prepared in Comparative Example 3. As can be seen from the figure, due to the low proportion of phenolic resin, the resin-rich phase cannot form a continuous phase during the phase separation process, and the complete carbon framework pore structure cannot be formed after the pyrolysis and carbonization of the resin mixture, and is thus destroyed.

[0050] Figure 8 The figure shows the microstructure of the porous carbon material prepared in Comparative Example 4. As can be seen from the figure, due to the excessively high proportion of phenolic resin, the solvent-rich phase cannot form a continuous phase during the phase separation process. After the resin mixture is pyrolyzed and carbonized, it cannot form a three-dimensional interconnected pore structure, and the pore structure tends to exist in isolation with a small pore size.

[0051] Combination Figure 1 , Figure 5 , Figure 6 Analysis showed that the porous carbon prepared in Example 2 exhibited the best performance. This is because when the catalyst content is below 1.5 wt%, Zn... 2+ The introduction of catalyst effectively promotes the complete volatilization of the enriched solvent phase, thereby improving the performance of porous carbon and increasing its porosity and pore size. When the catalyst content is higher than 1.5 wt%, the degree of polymerization of the resin system increases sharply, which leads to a significant inhibition of the phase separation process, resulting in a decrease in the performance of porous carbon and a reduction in porosity and pore size.

Claims

1. A method for preparing porous carbon materials based on ion-catalyzed induced phase separation, characterized in that, The process includes the following steps: using an organic polymerization-induced phase separation method, metal ion catalysts and curing agents are added to a mixture of thermosetting resin and organic solvent, and after mixing, curing, and debinding, porous carbon materials are obtained.

2. The preparation method according to claim 1, characterized in that, The thermosetting resin is at least one of phenolic resin, furfuryl alcohol resin, vinyl ester, and polyimide resin, preferably phenolic resin; the organic solvent is an alcohol, preferably ethylene glycol, polyethylene glycol, diethylene glycol, and triethylene glycol, preferably ethylene glycol; the mass ratio of the thermosetting phenolic resin to the organic solvent is (30-60):(40-70).

3. The preparation method according to claim 1 or 2, characterized in that, The metal ion catalyst is at least one of zinc chloride, ferrous chloride, and copper chloride, preferably zinc chloride or ferrous chloride; the amount of the metal ion catalyst added is 0.1 to 10. wt% of the total mass of the thermosetting phenolic resin and organic solvent, preferably 0.5 to 5. wt%.

4. The preparation method according to any one of claims 1-3, characterized in that, The curing agent is at least one of hexamethylenetetramine, benzenesulfonyl chloride, toluenesulfonyl chloride, and m-diphenylamine, preferably hexamethylenetetramine; the amount of the curing agent added is 5 to 10 wt% of the total mass of the thermosetting phenolic resin and the organic solvent.

5. The preparation method according to any one of claims 1-4, characterized in that, The mixing method is magnetic stirring; the magnetic stirring speed is 100-400 r / min, and the magnetic stirring time is 1-2 h.

6. The preparation method according to any one of claims 1-5, characterized in that, The curing temperature is 80℃~130℃, and the time is 3~6h.

7. The preparation method according to any one of claims 1-6, characterized in that, The debonding temperature is 600–1200℃, and the time is 30–120 min.

8. The preparation method according to claim 7, characterized in that, The debonding process includes: under vacuum conditions, first heating to 25-200°C at a heating rate of 1-3°C / min, then heating to 200-600°C at a heating rate of 0.25-1°C / min, then heating to 600-1200°C at a heating rate of 1-2°C / min, and finally holding at 600-1200°C for 30-120 minutes before purging with argon or nitrogen and cooling to room temperature.

9. A porous carbon material prepared by the preparation method according to any one of claims 1-8, characterized in that, The average pore size of the porous carbon material is 10 nm to 1 μm.

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