A modified high boron-nitrogen phenolic resin-based material, a preparation method and application thereof

Abstract

The present application relates to the field of carbon materials, in particular to a modified high boron and nitrogen phenolic resin-based material, a preparation method and application thereof. The preparation method is to prepare the modified high boron and nitrogen phenolic resin-based material by co-condensation reaction of a modifier, 3-hydroxyphenylboronic acid and formaldehyde and carbonization. The modifier is selected from one of melamine, melamine OAT waste residue and urea. The present application introduces nitrogen-containing groups into the molecular chain segments of phenolic resin to prepare carbon materials with high boron and nitrogen content and high specific surface area. The preparation method is simple and easy to operate, and the carbon material product shows good electrochemical performance. The modified high boron and nitrogen phenolic resin-based material prepared by the present application can be applied to the field of electrode materials or catalytic materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of carbon materials, in particular to a modified high boron-nitrogen phenolic resin-based material and a preparation method and application thereof. BACKGROUND

[0002] Developing green economy and protecting ecological environment are important directions for current development, which has significant supporting significance for solving global problems such as resource consumption and environmental pollution. Energy storage and catalysis technology are representatives in this field. Through advanced energy storage systems, efficient use of green energy can be achieved, such as supercapacitors, lithium ion batteries, etc., which have been widely used and are an important part of the future green economic system. Through efficient catalytic systems, the effective conversion of substances can be achieved, energy consumption can be reduced, and resource utilization can be improved.

[0003] Carbon materials are widely used in the fields of energy storage and catalysis, which can be used as electrode materials for supercapacitors or new energy power batteries, or as support materials for catalysts. The most widely used carbon materials at present include graphite, graphene, carbon nanotubes, and porous carbon, etc. as disclosed in CN102651476B. Carbon microspheres, as a special structure of carbon materials, have the advantages of large specific surface area, stable structure, and light weight, etc. As electrode materials or catalyst materials, they can significantly improve the electrochemical performance and catalytic performance. The structure of carbon materials can be further improved by doping, such as boron, nitrogen, phosphorus, and sulfur doping, etc. In the prior art, boron-doped carbon microspheres can be prepared by using triphenyl borate, but the boron content is low. Although high boron content carbon microspheres can be prepared by using 3-hydroxyphenyl boronic acid, the specific surface area is very low, and the performance of single-doped modified carbon microspheres also needs to be improved. SUMMARY

[0004] In order to overcome the defects of the prior art, the technical problem to be solved by the present application is to provide a preparation method of a modified high boron-nitrogen phenolic resin-based material which can improve the specific surface area of boron-doped carbon materials and the boron and nitrogen content, the modified high boron-nitrogen phenolic resin-based material prepared by the aforementioned preparation method, and the application of the aforementioned modified high boron-nitrogen phenolic resin-based material.

[0005] In order to solve the above technical problems, the present application provides a preparation method of a modified high boron-nitrogen phenolic resin-based material, which is prepared by co-condensation reaction of a modifier and 3-hydroxyphenyl boronic acid with formaldehyde and carbonization.

[0006] The modifier is selected from one of melamine, melamine OAT waste residue, and urea.

[0007] Further provided is a modified high boron-nitrogen phenolic resin-based material prepared by the aforementioned preparation method.

[0008] Further, the application provides a use of the modified high-boron and nitrogen-containing phenolic resin-based material in preparing an electrode material or a catalytic material.

[0009] The application has the advantages that the application introduces nitrogen-containing groups into the molecular chain segments of the phenolic resin to prepare a carbon material with high boron and nitrogen contents and high specific surface area, the preparation method is simple and easy to implement, and the prepared carbon material product exhibits good electrochemical performance. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 The SEM image of the modified high-boron and nitrogen-containing phenolic resin-based material prepared in Example 1 of the application is shown. DETAILED DESCRIPTION

[0011] To make the technical content of the application, the achieved purposes and effects clear, the following describes the application in combination with the embodiments and the accompanying drawings.

[0012] In this context, the melamine OAT waste residue is a kind of waste generated in the production of melamine, and the main components are melamine, cyanuric acid, monoamide cyanuric acid, diamide cyanuric acid, etc. (as shown below).

[0013]

[0014] The prior art generally uses 3-hydroxyphenylboronic acid to perform polycondensation with formaldehyde under the action of an alkaline catalyst (for example, ammonia) to prepare a crosslinked phenolic resin, and the reaction formula is as shown below.

[0015]

[0016] Although the phenolic resin prepared directly from 3-hydroxyphenylboronic acid and formaldehyde has a high boron content and a high crosslinking degree, the groups are prone to stacking and difficult to crack during carbonization, resulting in a small number of pores and a low specific surface area of the prepared carbon material. At the same time, the extremely high boron content in the resin will produce a large amount of boron trioxide during cracking, causing the pores to be blocked and the resin cracking to be inhibited, which is directly reflected in the decrease of the specific surface area of the carbon material (generally, the specific surface area of the carbon material is less than 50 m 2 / g), which greatly affects the use of the material in the downstream. At the same time, although the carbon material has a high boron content, the boron element mainly exists in the form of boron trioxide, which is difficult to achieve the purpose of improving the performance of the carbon material.

[0017] To solve the foregoing problems, the application provides a preparation method of a modified high-boron and nitrogen-containing phenolic resin-based material, and the modified high-boron and nitrogen-containing phenolic resin-based material prepared by the preparation method has high boron and nitrogen contents and a high specific surface area.

[0018] Specifically, the present application provides a preparation method of a high boron-nitrogen phenolic resin-based material, which comprises a modification agent and 3-hydroxyphenylboronic acid and formaldehyde through a co-condensation reaction and carbonization to prepare a modified high boron-nitrogen phenolic resin-based material; wherein the modification agent is selected from one of melamine, melamine OAT waste residue and urea.

[0019] Taking the modification agent as melamine OAT waste residue as an example, the reaction formula is as follows:

[0020]

[0021] In this reaction, since the melamine OAT waste residue component contains amides, cyanic acids and hydroxyl groups, carboxyl groups and amide groups in the structure which have poor reactivity and can terminate the reaction, the crosslinking degree of the phenolic resin can be effectively reduced, so that it is easy to crack at high temperature. At the same time, since other groups are introduced into the crosslinking structure, the regularity of the carbon material is destroyed, so that the groups are more easily broken in the cracking process, thereby improving the specific surface area of the material. In addition, due to the introduction of nitrogen-containing groups in the structure, a large number of electron-rich nitrogen atoms can attract electron-deficient boron to form B-N covalent bonds during high-temperature carbonization, thereby significantly reducing the probability of the formation of boron trioxide to avoid its blockage of the pores, further improving the specific surface area of the carbon material, and the formed B-N covalent groups can significantly improve the application performance of the carbon material, such as electrochemical performance and catalytic activity. Since the melamine OAT waste residue is a waste residue generated in the production process of melamine, the introduction of the melamine OAT waste residue as a modification agent into the structure of the phenolic resin can realize the high-value utilization of waste resources, and has good economic and social benefits.

[0022] In this reaction, the melamine OAT waste residue can be replaced by urea or melamine, and its function is basically the same. On the one hand, since urea has a straight chain structure and does not contain aromatic rings, the introduction of urea can further reduce the crosslinking degree of the phenolic resin, improve the flexibility of the molecular structure and improve the cracking effect of the resin. On the other hand, high nitrogen content can inhibit the conversion of boron elements into oxides, thereby improving the porosity and boron-nitrogen content of the carbon material. Melamine has a similar structure to melamine OAT waste residue, i.e. a triazine ring structure, so it can have similar effects and results.

[0023] In a preferred embodiment, the amount of the modification agent is 5-50% of the amount of 3-hydroxyphenylboronic acid. In this embodiment, by adjusting the ratio of the amount of the modification agent to the amount of 3-hydroxyphenylboronic acid, the boron and nitrogen content of the carbon material can be accurately controlled to meet specific needs.

[0024] In one embodiment, the co-condensation reaction is: the reaction of the modifier, 3-hydroxyphenylboronic acid and formaldehyde in a solvent under the action of a basic catalyst at 90-200°C for 1-48h.

[0025] Preferably, the basic catalyst is selected from one of ammonia, ethylenediamine, sodium hydroxide, potassium hydroxide. The solvent is selected from at least one of water, ethanol, methanol, acetone, tetrahydrofuran, methane, chloroform.

[0026] In one embodiment, the carbonization is: carbonization at 600-1000°C for 1-6h under an inert atmosphere.

[0027] In one embodiment, during the co-condensation reaction and carbonization process, the step of separating, washing and drying the precipitated product of the co-condensation reaction is further included. In an alternative embodiment, after centrifugation of the precipitated product by a high-speed centrifuge, the supernatant is removed, the bottom precipitate is washed with water, centrifuged and separated, and the solid product is vacuum dried.

[0028] A modified high-boron-nitrogen phenolic aldehyde resin-based material prepared by the aforementioned preparation method, wherein the modified high-boron-nitrogen phenolic aldehyde resin-based material is in a spherical shape.

[0029] In one embodiment, the boron content of the modified high-boron-nitrogen phenolic aldehyde resin-based material is ≥4%, and the nitrogen content is ≥4%. In this embodiment, melamine OAT waste residue, urea or melamine and 3-hydroxyphenylboronic acid are used as raw materials. Since the raw material structure contains abundant boron and nitrogen elements, the boron and nitrogen elements are directly retained in the molecular structure of the phenolic aldehyde resin during the reaction process. And in the carbonization process, due to the formation of a large amount of B-N covalent bond structure, the volatilization of boron and nitrogen can be effectively inhibited, and the generation of boron trioxide can be effectively avoided, thereby obtaining a carbon material with high boron and nitrogen content.

[0030] In one embodiment, the BET specific surface area of the modified high-boron-nitrogen phenolic aldehyde resin-based material is ≥400m 2 / g. In this embodiment, the introduction of melamine OAT waste residue, melamine, linear amide and other structures into the boron phenolic aldehyde resin can effectively promote the breaking of the molecular chain and inhibit the plugging of the pores, thereby increasing the specific surface area of the carbon material. At the same time, in this embodiment, the specific surface area of the carbon material can be adjusted by changing the amount of melamine OAT waste residue, melamine and urea.

[0031] In one embodiment, the modified high boron-nitrogen phenolic resin-based material has a particle size of < 1000 nm. In this embodiment, the nanoscale spherical structure carbon material is prepared by controlling the amount of melamine OAT waste residue, melamine or urea, and 3-hydroxyphenylboronic acid and formaldehyde to form a dilute solution system, thereby facilitating the preparation of nanoscale spherical structure carbon material. The reduction of the particle size of the carbon material can effectively increase the specific surface area of the material, further improving the performance of the carbon material. In a preferred embodiment, the modified high boron-nitrogen phenolic resin-based material has a particle size of < 600 nm. In this embodiment, the particle size of the modified high boron-nitrogen phenolic resin-based material can be easily adjusted by changing the concentration of monomers and catalysts.

[0032] The use of the modified high boron-nitrogen phenolic resin-based material as described above in the preparation of electrode materials or catalytic materials. The modified high boron-nitrogen phenolic resin-based material prepared by the preparation method described above has a high specific surface area, thus providing more contact area and enrichment space. The rich boron-nitrogen content and B-N arch structure in the structure can play a role in regulating electron movement, improving the electrochemical performance of the carbon material. The rich nitrogen content can improve the wettability of the material, improve the surface contact of the material with the base solvent, and further improve the performance of the material.

[0033] Example 1

[0034] A method for preparing a modified high boron-nitrogen phenolic resin-based material: melamine OAT waste residue 10 mg and 3-hydroxyphenylboronic acid 90 mg, 37% formaldehyde 150 mg, and 25% ammonia water 280 mg are added to 20 mL of a solvent composed of water / ethanol (volume ratio 18:2), and reacted at 130°C for 24 h. The obtained precipitate is separated, washed and dried to obtain a modified phenolic resin. The modified phenolic resin is carbonized at 800°C for 4 h under nitrogen protection to obtain a high boron-nitrogen phenolic resin-based spherical material BNC1. The boron content of the obtained boron-nitrogen phenolic resin-based spherical material is 7.2%, the nitrogen content is 4.7%, the BET specific surface area is equal to 567 m 2 / g, and the average particle size is about 565 nm, and the SEM image is shown in Figure 1

[0035] Example 2

[0036] ​A preparation method of a modified high boron-nitrogen phenolic resin-based material: melamine OAT waste residue 20 mg and 3-hydroxyphenylboronic acid 80 mg, 37% formaldehyde 150 mg and 25% ammonia water 280 mg are added into a solvent composed of 20 mL water / ethanol (volume ratio 18:2), and reacted at 130°C for 24 h; the obtained precipitate is separated, washed and dried to obtain a modified phenolic resin; the modified phenolic resin is carbonized at 800°C for 4 h under nitrogen protection to obtain a high boron-nitrogen phenolic resin-based spherical material BNC2. The boron content of the obtained boron-nitrogen phenolic resin-based spherical material is 6.1%, the nitrogen content is 5.6%, the BET specific surface area is equal to 626 m 2 / g, and the average particle size is about 453 nm.

[0037] Example 3

[0038] A preparation method of a modified high boron-nitrogen phenolic resin-based material: melamine OAT waste residue 20 mg and 3-hydroxyphenylboronic acid 80 mg, 37% formaldehyde 150 mg and 25% ammonia water 280 mg are added into a solvent composed of 20 mL water / ethanol (volume ratio 18:2), and reacted at 130°C for 24 h; the obtained precipitate is separated, washed and dried to obtain a modified phenolic resin; the modified phenolic resin is carbonized at 800°C for 4 h under nitrogen protection to obtain a high boron-nitrogen phenolic resin-based spherical material BNC2. The boron content of the obtained boron-nitrogen phenolic resin-based spherical material is 6.1%, the nitrogen content is 5.6%, the BET specific surface area is equal to 626 m 2 / g, and the average particle size is about 453 nm.

[0039] Example 4

[0040] A preparation method of a modified high boron-nitrogen phenolic resin-based material: melamine OAT waste residue 20 mg and 3-hydroxyphenylboronic acid 80 mg, 37% formaldehyde 150 mg and 25% ammonia water 280 mg are added into a solvent composed of 20 mL water / ethanol (volume ratio 18:2), and reacted at 130°C for 24 h; the obtained precipitate is separated, washed and dried to obtain a modified phenolic resin; the modified phenolic resin is carbonized at 800°C for 4 h under nitrogen protection to obtain a high boron-nitrogen phenolic resin-based spherical material BNC2. The boron content of the obtained boron-nitrogen phenolic resin-based spherical material is 6.1%, the nitrogen content is 5.6%, the BET specific surface area is equal to 626 m 2 / g, and the average particle size is about 453 nm.

[0041] Example 5

[0042] A preparation method of a modified high boron-nitrogen phenolic resin-based material: urea 10 mg and 3-hydroxyphenylboronic acid 90 mg, 37% formaldehyde 150 mg and 25% ammonia water 280 mg are added into a solvent composed of 20 mL of water / ethanol (volume ratio 18:2), and reacted at 130°C for 24 h. The obtained precipitate is separated, washed and dried to obtain a modified phenolic resin. The modified phenolic resin is carbonized at 800°C for 4 h under nitrogen protection to obtain a high boron-nitrogen phenolic resin-based spherical material BNC5. The boron content of the obtained boron-nitrogen phenolic resin-based spherical material is 6.5%, the nitrogen content is 4.1%, the BET specific surface area is equal to 692 m 2 / g, and the average particle size is about 510 nm.

[0043] Comparative Example 1

[0044] A modified phenolic resin is prepared by using 3-hydroxyphenylboronic acid and formaldehyde to condense, and then a phenolic resin-based material is obtained after carbonization. The preparation method is as follows: 3-hydroxyphenylboronic acid 90 mg, 37% formaldehyde 150 mg and 25% ammonia water 280 mg are added into a solvent composed of 20 mL of water / ethanol (volume ratio 18:2), and reacted at 130°C for 24 h. The obtained precipitate is separated, washed and dried to obtain a modified phenolic resin. The modified phenolic resin is carbonized at 800°C for 4 h under nitrogen protection to obtain a phenolic resin-based spherical material BNC6. The boron content of the obtained phenolic resin-based spherical material is 8.0%, the nitrogen content is 1.9%, the BET specific surface area is equal to 42 m 2 / g, and the average particle size is about 512 nm.

[0045] Detection Example

[0046] The phenolic resin-based spherical materials obtained in Examples 1, 2 and 5 and Comparative Example 1 are used as electrode materials.

[0047] The performance test method of the supercapacitor is as follows: carbon material, binder and carbon black are mixed uniformly at a mass ratio of 8:1:1, coated on an electrode sheet to prepare a working electrode. Constant current charge and discharge test is carried out on a CHI760E electrochemical workstation using 6M KOH electrolyte and a three-electrode system. The electrodes of the three-electrode system include a reference electrode (Hg / HgO), a counter electrode (Pt sheet) and a working electrode (self-made). The electrical performance test results are as shown in Table 1.

[0048] Table 1

[0049]

[0050] As can be seen from Table 1, the electrode prepared from the modified high boron-nitrogen phenolic resin-based material obtained in Examples 1, 2 and 5 has higher capacity and capacity retention rate than the phenolic resin-based material prepared in Comparative Example 1.

[0051] The above merely illustrates the embodiments of the present application, and is not intended to limit the patent scope of the present application. Any equivalent transformation or direct or indirect application in the related technical field based on the content of the present application specification and drawings is also included in the patent protection scope of the present application.

Claims

1. A method for producing a modified high boron-nitrogen phenolic resin-based material, characterized by, The modified high boron-nitrogen phenolic aldehyde resin-based material is prepared by reacting a modifier, 3-hydroxyphenylboronic acid and formaldehyde in a solvent under the action of an alkaline catalyst at 90-200 DEG C for 1-48 h, and then carbonizing. The modifier is selected from one of melamine, melamine OAT waste residue and urea. The amount of the modifier is 5-50% of the amount of 3-hydroxyphenylboronic acid.

2. The preparation method according to claim 1, characterized in that, The alkaline catalyst is selected from one of ammonia, ethylenediamine, sodium hydroxide and potassium hydroxide.

3. The preparation method according to claim 1, characterized in that, The carbonization is carbonization at 600-1000 DEG C for 1-6 h under an inert atmosphere. 4.A modified high boron-nitrogen phenolic aldehyde resin-based material prepared by the preparation method in any one of claims 1 to 3.

5. The modified high boron-nitrogen phenolic resin-based material of claim 4, wherein, The boron content of the modified high boron-nitrogen phenolic aldehyde resin-based material is ≥4%, and the nitrogen content is ≥4%.

6. The modified high boron-nitrogen phenolic resin-based material of claim 4, wherein, The modified high boron-nitrogen phenolic resin-based material has a BET specific surface area ≥ 400 m 2 / g.

7. The modified high boron-nitrogen phenolic resin-based material of claim 4, wherein The particle size of the modified high boron-nitrogen phenolic aldehyde resin-based material is ≤1000 nm. 8.The use of the modified high boron-nitrogen phenolic aldehyde resin-based material in any one of claims 4 to 7 in the preparation of electrode materials or catalytic materials.

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