KR101340009B1 - Method for the synthesis of carbon materials using carbon dioxide - Google Patents

Abstract

A method of manufacturing carbon materials from carbon dioxides according to the present invention produces carbon materials from carbon dioxides in a high pressure condition without the existing high temperature/high pressure supercritical process which produces the carbon materials by using carbon dioxides as raw materials, thereby being economical as compared to the existing manufacture process. The carbon materials manufactured by using carbon dioxides of the present invention can be used as a catalyst in oxidation reduction reaction (ORR) generated in a positive electrode of a fuel cell and can be substituted for an expensive platinum catalyst. Additionally, the carbon materials manufactured by using carbon dioxides of the present invention can be applied to a supercapacitor which is a next generation energy storage medium and a gas separation media or a carrier of a catalyst. [Reference numerals] (AA) Furnace reactor;(BB) 25°C→500°C(5°C/min) 500°C : maintain for 2-3 hours;(CC) Wash 5M HCI;(DD) Hot water washing;(EE) Drying

Description

{Method for the Synthesis of Carbon Materials Using Carbon Dioxide}

The present invention relates to a method for preparing boron and / or nitrogen doped carbon material from carbon dioxide, and more particularly, to a method for synthesizing a carbon material from carbon dioxide under moderate conditions of normal pressure, not a high temperature / high pressure supercritical process. will be.

Carbon dioxide is the main culprit of greenhouse gases that have a significant impact on climate change, and occurs mostly in industries, cars, and homes that use fossil fuels. Recently, commercial researches to separate and capture carbon dioxide have been actively conducted as a realistic alternative to coping with climate change. However, separation and capture alone are currently difficult to handle more than 20 GT (gigaton) of carbon dioxide emitted annually from around the world. If carbon dioxide is collected in the ocean, there is a risk that the pH of the ocean may change and be destroyed in the marine ecosystem, and even if stored on the ocean floor, there is a risk that the carbon dioxide stored by the earthquake or tsunami is ejected. In addition, there is always a risk of leakage, even if stored in soil or tunnels. Therefore, a sustainable and most economical method for treating carbon dioxide is to develop a high value-added manufacturing process using carbon dioxide as a raw material, and at the same time, the production process using the carbon dioxide as a raw material generates carbon dioxide due to the use of energy compared to the existing process. It is essential that this less process be.

The process of producing high value-added carbon materials using carbon dioxide as a raw material generally uses high temperature / high pressure supercritical processes. A method of synthesizing porous carbon from carbon dioxide using a pure alkali metal (Li, Na) at a pressure of 500 ° C. or more and at least 300 atm has been reported (J. Am. Ceram. Soc., 94: 3078, 2011). In addition, a process for converting carbon dioxide to diamond at 440 ° C. and 800 atm using pure sodium has been published (J. Am. Chem. Soc., 125: 9302, 2003). However, the high temperature / high pressure supercritical process as described above has the disadvantage of high energy.

The carbon material synthesized through the carbon dioxide conversion process can be used as an electrode of a fuel cell or a supercapacitor. Carbon materials synthesized from carbon dioxide can be used in the electrodes of fuel cells, cathodes where most of the oxygen reduction reactions occur, and have the potential to replace expensive platinum catalysts. In addition, the synthesized porous carbon material may be used as an electrode of a supercapacitor, which is a next-generation energy storage medium, and may be used as a catalyst carrier or a gas separation medium.

Accordingly, the present inventors have made diligent efforts to synthesize high value-added carbon materials from boron hydride reducing agents from carbon dioxide under moderate conditions. It was confirmed that the synthesis of the carbon material, and also confirmed that it can be applied to the fuel cell electrode or the electrode of the supercapacitor by post-processing the synthesized carbon material, the present invention was completed.

It is an object of the present invention to provide a method for producing boron and / or nitrogen doped carbon materials from carbon dioxide using a boron hydride reducing agent under moderate conditions of normal pressure.

In order to achieve the above object, the present invention provides a method for producing a boron-doped carbon material from carbon dioxide comprising the step of converting carbon dioxide to a carbon material using a boron hydride reducing agent. In addition, the step of treating the boron-doped carbon material obtained with an acidic solution or hot water; And it provides a method for producing a boron-doped carbon material from carbon dioxide further comprising the step of drying the boron-doped carbon material treated with the acidic solution or hot water.

The present invention also comprises the steps of converting carbon dioxide to a carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And treating the boron-doped carbon material prepared by the method of any one of the steps of drying the boron-doped carbon material treated with the acidic solution or hot water with a boron-containing precursor material. And it provides a method for producing a boron-doped carbon material comprising the step of heat treatment, and provides a porous boron-doped carbon material prepared by the above method, the peak potential value is -0.35 V to -0.15 V.

The present invention also comprises the steps of converting carbon dioxide to a carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And treating the boron-doped carbon material prepared by the method of any one of the steps of drying the boron-doped carbon material treated with the acidic solution or hot water with a nitrogen-containing precursor material. And it provides a method for producing a boron and nitrogen doped carbon material comprising the step of heat treatment.

The present invention also comprises the steps of converting carbon dioxide to a carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And heat-treating the boron-doped carbon material prepared by the method of any one of the steps of drying the boron-doped carbon material treated with the acidic solution or hot water. The present invention provides a porous boron doped carbon material prepared by the above method and having a peak potential value of -0.35 V to -0.15 V.

The present invention also comprises the steps of converting carbon dioxide to a carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And treating the boron-doped carbon material prepared by the method of any one of the steps of drying the boron-doped carbon material treated with the acidic solution or hot water with a basic substance or carbon dioxide. And it provides a method for producing a boron-doped carbon material comprising the step of heat treatment, and provides a porous boron-doped carbon material prepared by the above method, Capacitance value is 50 F / g to 150 F / g.

The carbon material synthesized using carbon dioxide according to the present invention is not a high temperature / high pressure supercritical process for producing carbon material using carbon dioxide as a raw material, but by synthesizing a carbon material from carbon dioxide under moderate conditions of normal pressure. It is an economical process that saves energy than the manufacturing process. The carbon material synthesized using the carbon dioxide of the present invention can be used as a catalyst for oxygen reduction reaction (ORR) occurring at the anode of a fuel cell, and has the potential to replace expensive platinum catalysts. In addition, the carbon material synthesized using the carbon dioxide of the present invention can be applied to a supercapacitor, which is a next-generation energy storage medium, and can also be used as a catalyst carrier or a gas separation medium.

Figure 1 shows a method for producing a boron-doped porous carbon (BPC).
2 is a photograph of a BPC sample produced by the reaction of NaBH ₄ and CO ₂ .
Figure 3 shows the method of NaBH ₄ treatment of BPC.
4 shows a cyclic voltammetry measurement graph according to NaBH ₄ treatment.
Figure 5 shows the heat treatment method of the BPC.
Figure 6 shows a cyclic voltammetry measurement graph according to the heat treatment temperature.
Figure 7 shows the KOH treatment method of BPC.
8 shows a cyclic voltammetry measurement graph according to KOH treatment.
9 shows a graph of capacitance measurement according to KOH treatment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

In one aspect, the present invention relates to a method for producing a boron-doped carbon material from carbon dioxide comprising converting carbon dioxide to a carbon material using a boron hydride reducing agent. In addition, the step of treating the boron-doped carbon material obtained with an acidic solution or hot water; And it relates to a method for producing a boron-doped carbon material from carbon dioxide further comprising the step of drying the boron-doped carbon material treated with the acidic solution or hot water.

More specifically, the carbon dioxide used in the present invention may use pure carbon dioxide or carbon dioxide emitted from factories, power plants and automobiles, and the mixed gas containing carbon dioxide may be used without limitation.

The boron hydride reducing agent used in the present invention is lithium boron hydride (LiBH ₄ ), sodium boron hydride (NaBH ₄ ), potassium boron hydride (KBH ₄ ), magnesium boron hydride (Mg (BH ₄ ) ₂ ), Magnesium hydride (MgH ₂ ), calcium boron hydride (Ca (BH ₄ ) ₂ ), strontium boron hydride (Sr (BH ₄ ) ₂ ) and ammonia borane (NH ₃ BH ₃ ) It features.

The step of converting the carbon dioxide to the boron-doped carbon material is carried out at 1 to 100 atm, preferably at 100 to 1000 ℃, most preferably at a normal pressure of 500 ℃.

In addition, the step of treating the boron-doped carbon material obtained in the step of converting carbon dioxide to a boron-doped carbon material by using the boron hydride reducing agent of the present invention to remove the salt contained in the carbon material obtained This is for removing Na ₂ CO ₃ , NaBO ₂ and the like. The acidic solution is selected from the group consisting of HCl, H ₂ SO ₄ , HNO ₃ and HClO ₄ , it is most preferable to use HCl because Cl ions react with impurities of the carbon material to form salts and are easily removed by water. Do. In addition, the step of treating with hot water is preferably carried out at 40 ℃ to 90 ℃. The drying of the boron-doped carbon material treated with the acidic solution or hot water is preferably performed in an oven at 110 ° C. to 130 ° C. for 1 to 2 days.

In another aspect, the present invention comprises the steps of converting carbon dioxide to a boron doped carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And treating the boron-doped carbon material prepared by the method of any one of the steps of drying the boron-doped carbon material treated with the acidic solution or hot water with a boron-containing precursor material. And it relates to a method for producing a boron doped carbon material comprising the step of heat treatment.

Converting carbon dioxide to a boron doped carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And drying the boron-doped carbon material treated with the acidic solution or hot water is the same as described above.

More specifically, the boron-containing precursor material used in the present invention is boron oxide (B ₂ O ₃ ), boric acid (H ₂ BO ₃ ), lithium boron hydride (LiBH ₄ ), sodium boron hydride (NaBH ₄ ), Potassium boron hydride (KBH ₄ ), magnesium boron hydride (Mg (BH ₄ ) ₂ ), calcium boron hydride (Ca (BH ₄ ) ₂ ), strontium boron hydride (Sr (BH ₄ ) ₂ ) and ammonia bore It is characterized in that it is selected from the group consisting of phosphorus (NH ₃ BH ₃ ).

In the step of treating the boron-doped carbon material with a boron-containing precursor material and heat treatment, the heat treatment is performed at 700 ° C. to 1500 ° C. in an inert gas or mixed gas atmosphere, and more preferably at 850 ° C. to 1050 ° C. In addition, the inert gas is selected from the group consisting of nitrogen gas, argon gas and helium gas, the mixed gas is any one selected from the group consisting of nitrogen gas, argon gas and helium gas and carbon dioxide of 1 vol% to 30 vol% A mixture of these may be used.

In addition, the present invention relates to a porous boron doped carbon material prepared by the above production method, the peak potential value is -0.35 V to -0.15 V.

In order to analyze the electrochemical characteristics of the boron-doped carbon material prepared by the above method, cyclic voltammetry was performed, and glassy carbon was used as an automatic electrode, platinum wire as a counter electrode, and Ag / AgCl as a reference electrode. The activity of the catalyst for the oxygen reduction reaction was measured in an aqueous 1 M NaOH solution. In the cyclic voltammetry, when a voltage is applied between the electrode and the solution, an oxidation / reduction reaction proceeds, and when the reaction occurs, a peak for the reaction is observed. In order to measure the activity of the carbon material prepared in the present invention as an oxygen reduction catalyst, the potential starting value, which is the starting point of the reaction, and the potential peak value when the reaction occurs can be evaluated. Since it is not accurate to distinguish the double potential starting value, it is desirable to evaluate the activity for the reaction through the peak potential value. The faster the potential peak value, the faster the reaction proceeds. Thus, in the reduction reaction where the potential proceeds in the negative direction, the higher the potential peak value, the better the activity as a catalyst.

In another aspect, the present invention, the step of converting carbon dioxide to a boron doped carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And treating the boron-doped carbon material prepared by the method of any one of the steps of drying the boron-doped carbon material treated with the acidic solution or hot water with a nitrogen-containing precursor material. And it relates to a method for producing a boron and nitrogen doped carbon material comprising the step of heat treatment.

Converting carbon dioxide to a boron doped carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And drying the boron-doped carbon material treated with the acidic solution or hot water is the same as described above.

More specifically, the nitrogen-containing precursor material used in the present invention is polypyrrole ((C ₄ H ₂ NH) n), polyaniline (polyaniline), melamine (C ₃ H ₆ N ₆ ), PDI (N, N'- bis (2,6-diisopropyphenyl) -3,4,9,10-perylenetetracarboxylic diimide), Polyacrylonitrile (PAN), urea (CO (NH ₂ ) ₂ ), ammonia (NH ₃ ), hydrazine (N ₂ H ₄ ) and Ammonia borane (NH ₃ BH ₃ ) It is characterized in that it is selected from the group consisting of.

In the step of treating the boron doped carbon material with a nitrogen-containing precursor material and heat treatment, the heat treatment is performed at 700 ° C. to 1500 ° C. in an inert gas or mixed gas atmosphere, and more preferably at 850 ° C. to 1050 ° C. In addition, the inert gas is selected from the group consisting of nitrogen gas, argon gas and helium gas, the mixed gas is any one selected from the group consisting of nitrogen gas, argon gas and helium gas and carbon dioxide of 1 vol% to 30 vol% A mixture of these may be used.

In another aspect, the present invention comprises the steps of converting carbon dioxide to a boron doped carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And heat-treating the boron-doped carbon material prepared by the method of any one of the steps of drying the boron-doped carbon material treated with the acidic solution or hot water. It is about. In addition, the present invention relates to a porous boron doped carbon material prepared by the above method and having a peak potential value of -0.35 V to -0.15 V.

Converting carbon dioxide to a boron doped carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And drying the boron-doped carbon material treated with the acidic solution or hot water is the same as described above.

Further, the further heat treatment step after the drying step is carried out at 700 ℃ to 1500 ℃ in an inert gas or mixed gas atmosphere, it is more preferably carried out at 850 ℃ to 1050 ℃. In addition, the inert gas is selected from the group consisting of nitrogen gas, argon gas and helium gas, the mixed gas is any one selected from the group consisting of nitrogen gas, argon gas and helium gas and carbon dioxide of 1 vol% to 30 vol% A mixture of these may be used.

In another aspect, the present invention comprises the steps of converting carbon dioxide to a boron doped carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And treating the boron-doped carbon material prepared by the method of any one of the steps of drying the boron-doped carbon material treated with the acidic solution or hot water with a basic substance or carbon dioxide. And it relates to a method for producing a boron doped carbon material comprising the step of heat treatment.

Converting carbon dioxide to a boron doped carbon material using a boron hydride reducing agent; Treating the obtained boron-doped carbon material with an acidic solution or hot water; And drying the boron-doped carbon material treated with the acidic solution or hot water is the same as described above.

More specifically, the step of treating the boron-doped carbon material with a basic material is characterized by dissolving the basic material in distilled water or ethanol to treat the carbon material, or mechanically mixing the basic material and the carbon material. In addition, the basic material is selected from the group consisting of potassium hydroxide (KOH), sodium hydroxide (NaOH) and lithium hydroxide (LiOH). In addition, the carbon dioxide treatment of the boron doped carbon material is carried out in a CO ₂ gas or CO ₂ mixed gas atmosphere, the CO ₂ mixed gas and any one gas selected from the group consisting of nitrogen gas, argon gas and helium gas It is preferable that it is a mixed gas which mixed 5 vol%-100 vol% of carbon dioxide.

The boron-doped carbon material is treated with a basic material or carbon dioxide, and the heat treatment is performed at 700 ° C. to 1500 ° C. in an inert gas or mixed gas atmosphere, and more preferably at 850 ° C. to 1050 ° C. In addition, the inert gas is selected from the group consisting of nitrogen gas, argon gas and helium gas, the mixed gas is any one selected from the group consisting of nitrogen gas, argon gas and helium gas and carbon dioxide of 1 vol% to 30 vol% A mixture of these may be used.

In addition, the present invention relates to a porous boron doped carbon material prepared by the above method, and has a capacitance value of 50 F / g to 150 F / g. The carbon material produced through the present invention can be applied to a capacitor. A capacitor is a device that can store electricity. Capacitors are basically arranged so as to face two electrode plates in parallel and follow the formula q / E = C (q: charge of capacitor, E: voltage of capacitor, C: capacitance). In other words, when a DC voltage is applied, charges are accumulated on each electrode until this expression is satisfied. Capacitor performance is entirely dependent on capacitance, so the higher the value of capacitance, the higher the performance.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples.

Boron Doped  Porous carbon ( BPC Manufacturing method

A method of preparing boron-doped porous carbon using carbon dioxide will be described in detail with reference to FIG. 1. As the boron hydride reducing agent, sodium boron hydride (NaBH ₄ ) was used (> 99%, Fluka), and carbon dioxide (CO ₂ ) gas having a purity of 99.8% or more was used.

Put 4 g of NaBH _{4 in the} crucible into the Furnace reactor and flow 1 bar of CO ₂ gas at a flow rate of 76 cm ³ / min. At this time, the reaction temperature is raised to 500 ℃ at 5 ℃ / min and maintained at 500 ℃ for 2 to 3 hours. The carbon material thus produced is subjected to 5 M HCl treatment or hot water treatment. 5 M HCl treatment is as follows. 8 g of the resulting carbonaceous material is placed in a 250 ml beaker, poured 200 ml of 5 M HCl solution and removed after 24 hours along with the remaining solution on the soaked carbonaceous material. 200 ml of distilled water (DIW, DeIonized Water) is poured into the carbon material remaining in the beaker and the carbon material is settled, discarded along the solution, and the above distilled water washing process is repeated twice more. Finally, 200 ml of ethanol is poured into a beaker of the carbon material remaining as described above, and the carbon material is settled and then removed along the solution.

In addition, the hot water treatment process of the carbon material is as follows. 8 g of carbonaceous material is placed in a 250 ml beaker and 200 ml of distilled water is poured and stirred at 260 rpm for 4 hours at 85 ° C. If the carbon material sinks after stirring, the solution is discarded. The distilled water washing process of the HCl treatment is repeated five times. Finally, 200 ml of ethanol is poured and the carbon material is settled and then removed along the solution. The carbon material after 5 M HCl treatment or hot water treatment is dried in an oven at 120 ° C. for 24 hours to remove moisture remaining in the carbon material.

As described above, boron-doped porous carbon (BPC) may be finally manufactured by HCl or hot water treatment and drying on carbon material generated from carbon dioxide and sodium boron hydride (NaBH ₄ ). (FIG. 2).

BPC of NaBH ₄ process

Example 1 In addition to the manufacturing BPC from relates to a method for producing a carbon material which can be used in the electrode of the fuel cell to the sodium boron hydride (NaBH ₄₎ treatment, the sodium boron used in the experiment hydride (NaBH ₄ ) Is the same as that used in Example 1, and argon (Ar) gas having a purity of 99.9% or more was used.

Referring to Figure 3, the NaBH ₄ process will be described in more detail. 0.118 g of NaBH ₄ is dissolved in 6 cm ³ of ethanol, 1.5 cm ^{3 of which is} then pipetted and added to 0.1 g of BPC prepared in Example 1. Leave the vial lid at room temperature for 2-3 days to allow all of the ethanol to evaporate. As described above, 0.1663 g of BPC treated with NaBH ₄ was placed in a crucible and placed in a Furnace reactor to flow 1 bar of Ar gas at a flow rate of 50 cm ³ / min. At this time, the reaction temperature was raised to 25 ℃ 100 ℃ 20 minutes (3.75 ℃ / min), and maintained at 100 ℃ for 1 hour. Thereafter, the temperature was raised to 850 ° C. for 75 minutes (10 ° C./min), and maintained at 850 ° C. for 2 hours, followed by cooling to room temperature.

After the heat treatment, BPC is subjected to acid treatment or hot water treatment with 5 M HCl solution. For acid treatment, add 0.1151 g of BPC and 20 ml of 5 M HCl solution to the vial and seal for 5 days at room temperature. After 5 days, when the BPC has settled, remove the solution along the floating solution, pour 20 ml of distilled water back into the vial and remove the solution after 24 hours. Finally, 20 ml of ethanol is poured into the vial, and after 24 hours, the solution is repeated, the lid is opened at room temperature for 3 hours, and dried in an oven at 120 ° C. for 24 hours to remove water remaining in the BPC.

In addition, in the hot water treatment process, the BPC after the heat treatment is put 0.1151 g in a 250 ml beaker, 200 ml of distilled water is poured and stirred at 260 rpm for 4-5 hours at 85 ℃. When the BPC sinks after stirring, discard the solution, pour 200 ml of distilled water into the remaining BPC in the beaker, and after the BPC has settled, discard the solution along the solution, and repeat the above distilled water washing process five times. Finally, the ethanol washing process is performed in the same manner as the distilled water washing, and dried in an oven at 120 ° C. for 24 hours to remove all remaining water in the BPC.

As described above, after the BPC prepared in Example 1 was treated with NaBH ₄ (Sodium Borohydride) and subjected to heat treatment, the BPC which had undergone 5 M HCl or hot water treatment was named SB-BPC, and an oxygen reduction reaction occurred at the anode of the fuel cell. It can be used as a catalyst for (ORR, Oxidation Reduction Reaction). Using glassy carbon as an automatic electrode, a platinum wire as a counter electrode, and Ag / AgCl as a reference electrode, the activity of the catalyst for oxygen reduction reaction was measured in a basic electrolyte of 1 M NaOH solution (FIG. 4). The activity of the BPC prepared in Example 1, the SB-BPC prepared in Example 2, and the most commonly used commercial catalyst (Pt-AC) was compared. The commercial catalyst used in the experiment was activated carbon having 10 wt% of Pt (Platinum) supported (Sigma-Aldrich).

Figure 4 shows a cyclic voltammetry (CV) measurement graph, the maximum potential of the current was -0.31 V when using the BPC, -0.21 V when using the SB-BPC, respectively. As the peak of the oxygen reduction reaction shows a higher value, the higher activity of the oxygen reduction reaction shows that the SB-BPC has better activity than the BPC. NaBH ₄ treatment resulted in a wider C = C π bond, and B ₄ C, which is mainly present on the surface of BPC, was treated with NaBH ₄ to reduce the amount of B ₄ C and increase the BCO ₂ morphology. Eggplant property change is considered to be one of the factors that increased the activity of the fuel cell as a catalyst.

BPC Heat treatment

The present invention relates to a method of manufacturing a carbon material that can be used for an electrode of a fuel cell by further heat treating the BPC prepared in Example 1, and the heat treatment process will be described in more detail with reference to FIG. 5. The heat treatment temperature is 750 ° C, 850 ° C, 1050 ° C, 0.1 g of BPC prepared in Example 1 was placed in a crucible and placed in a Furnace reactor to flow 1 bar of Ar gas at a flow rate of 50 cm ³ / min. At this time, the reaction temperature was raised to 25 ℃ 100 ℃ 20 minutes (3.75 ℃ / min), and maintained at 100 ℃ for 1 hour. Thereafter, the temperature was raised to 750 ° C. (65 min), 850 ° C. (75 min), and 1050 ° C. (95 min) at a rate of 10 ° C./min, and maintained for 2 hours, followed by cooling to room temperature.

The BPC that has undergone heat treatment on the BPC prepared in Example 1 was named T-BPC, and according to the heat treatment temperature, it was named T-BPC (750), T-BPC (850), and T-BPC (1050). It was. The T-BPC prepared in Example 3 may be used as a catalyst for oxygen reduction reaction (ORR) occurring at the anode of a fuel cell, and glassy carbon is used as an automatic electrode, platinum wire as a counter electrode, and Ag / AgCl. Using the reference electrode, the activity of the catalyst for the oxygen reduction reaction in a 1 M NaOH aqueous solution of a basic electrolyte was measured (Fig. 6).

6 shows a cyclic voltammetry measurement graph according to the heat treatment temperature. As the heat treatment temperature increases, the peak potential at which the current is maximum increases. That is, the peak potential values of the T-BPC 750, the T-BPC 850, and the T-BPC 1050 are -0.233 V, -0.217 V, and -0.213 V, respectively. It can be seen that. In addition, the peak potential does not show a big difference when the T-BPC (850) and the T-BPC (1050) are compared, whereas the T-BPC (750) and the T-BPC (850) are compared to the oxygen reduction reaction. It was confirmed that the activity for the relatively large increase.

BPC of KOH process

The present invention relates to a method for producing a carbon material which can be used for the electrode of a fuel cell or the electrode of a supercapacitor by further treating potassium hydroxide (KOH) to the BPC prepared in Example 1, and having 99% pure potassium hydroxide (KOH). Used (Sigma-aldrich).

Referring to Figure 7, the KOH process will be described in more detail. An appropriate amount of KOH is dissolved in 6 cm ³ of ethanol, 1.5 cm ^{3 of which is} then pipetted and added to 0.1 g of BPC prepared in Example 1. KOH was used in 2.4 g, 1.2 g, 0.68 g, 0.4 g, respectively, the reaction proceeds independently. Keep each vial lid open at room temperature for a few days to allow the ethanol to evaporate. Furnace reactor containing 0.1 g, 0.0744 g, 0.2475 g, 0.44 g, 0.4912 g (0.0: 1, 0.1: 1, 1.0: 1, 1.7: 1, 3.0: 1) treated with KOH as above. 1 bar of Ar gas at a flow rate of 50 cm ³ / min. At this time, the reaction temperature was raised to 25 ℃ 100 ℃ 20 minutes (3.75 ℃ / min), and maintained at 100 ℃ for 1 hour. Thereafter, the temperature was raised to 850 ° C. for 75 minutes (10 ° C./min), and maintained at 850 ° C. for 2 hours, followed by cooling to room temperature.

After the heat treatment, BPC is subjected to acid treatment or hot water treatment with 5 M HCl solution. The acid treatment process contained BPC 0.0555 g, 0.0537 g, 0.1162 g, 0.1506 g, 0.0661 g (0.0: 1, 0.1: 1, 1.0: 1, 1.7: 1, 3.0: 1) after each heat treatment. 20 ml of 5 M HCl solution are added and sealed for 5 days and stored at room temperature. After 5 days, when the BPC has settled, remove the solution along the floating solution, pour 20 ml of distilled water back into the vial and remove the solution after 24 hours. Finally, 20 ml of ethanol is poured into the vial, and after 24 hours, the solution is repeated, the lid is opened at room temperature for 3 hours, and dried in an oven at 120 ° C. for 24 hours to remove water remaining in the BPC.

In addition, the hot water treatment process is the BPC after the heat treatment in a 250 ml beaker BPC 0.0555 g, 0.0537 g, 0.1162 g, 0.1506 g, 0.0661 g (0.0: 1, 0.1: 1, 1.0: 1, 1.7: 1, 3.0 : 1) Pour 200 ml of distilled water and stir at 260 rpm for 4-5 hours at 85 ℃. When the BPC sinks after stirring, discard the solution, pour 200 ml of distilled water into the remaining BPC in the beaker, and after the BPC has settled, discard the solution along the solution, and repeat the above distilled water washing process five times. Finally, the ethanol washing process is performed in the same manner as the distilled water washing, and dried in an oven at 120 ° C. for 24 hours to remove all remaining water in the BPC.

 KPC treated with BOH prepared in Example 1 BPC as described above was named KOH-BPC, KOH-BPC (0.0: 1), KOH- according to the weight ratio of KOH and BPC (Porous carbon) used in the reaction BPC (0.1: 1), KOH-BPC (1.0: 1), KOH-BPC (1.7: 1), KOH-BPC (3.0: 1). KOH-BPC (0.0: 1) is the same as pure BPC prepared in Example 1 with BPC without KOH treatment, and KOH-BPC (0.1: 1) is the final sample produced using 0.4 g of KOH. KOH-BPC (1.0: 1), KOH-BPC (1.7: 1), KOH-BPC (3.0: 1) are the final produced samples using 0.68 g, 1.2 g and 2.4 g KOH, respectively.

The KOH-BPC prepared in Example 4 may be used as a catalyst for Oxidation Reduction Reaction (ORR) occurring at the anode of a fuel cell. Using glassy carbon as an automatic electrode, a platinum wire as a counter electrode, and Ag / AgCl as a reference electrode, the activity of the catalyst for oxygen reduction reaction was measured in a basic electrolyte of 1 M NaOH solution (FIG. 8).

8 shows a cyclic voltammetry measurement graph according to the KOH treatment ratio, showing the highest activity in KOH-BPC (0.0: 1), KOH-BPC (0.1: 1), KOH-BPC (1.0: 1) ), KOH-BPC (1.7: 1), KOH-BPC (3.0: 1) in the order of higher KOH treatment rate was confirmed that the activity is reduced. The peak potential values for each sample were KOH-BPC (0.0: 1), KOH-BPC (0.1: 1), KOH-BPC (1.0: 1), KOH-BPC (1.7: 1) and KOH-BPC (3.0: The order of 1) is -0.213V, -0.221V, -0.236V, -0.242V, -0.232V. However, the capacitances corresponding to the area of the curve are KOH-BPC (3.0: 1), KOH-BPC (1.7: 1), BPC (1.0: 1), KOH-BPC (0.1: 1), and KOH-BPC (0.0: In the order of 1), KOH-BPC (3.0: 1) showed the highest KOH treatment ratio. Therefore, the treatment of KOH in the BPC is preferably applied to the supercapacitor rather than the oxygen reduction reaction of the fuel cell.

Figure 9 shows the results of Capacitance measurement according to the KOH treatment, KOH-BPC (1.7: 1) was prepared in Example 1 BPC and Meso-porous Carbon (MC, ordered mesoporous carbon CMK-3, Capacitance of ACS MATERIALS ^® The electrochemical performance was measured at a scan rate of 20 mV / s using a 3-electrode cell (Ag / AgCl-reference electrode) in an aqueous solution of Na ₂ SO ₄ at 1 M. KOH-treated KOH-BPC In the case of (1.7: 1), it can be confirmed that the shape of the rectangular shape is close to the shape of the ideal electric double layer capacitor (EDLC) .The area in the curve of the graph corresponds to the capacitance and KOH-BPC (1.7: 1). ) Showed a value of 133 F / g, which is a much better value compared to the area of the BPC CV curve shown in Figure 9, and even better compared to 120 F / g, the value of MC used for comparison. High value, therefore, KOH treatment greatly improves the performance of porous carbon materials Confirmed.

-

Claims (43)

Method of producing a boron doped carbon material from carbon dioxide comprising the step of converting carbon dioxide to a carbon material using a boron hydride reducing agent.
The method of claim 1,
Carbon dioxide is a method of producing a boron-doped carbon material from carbon dioxide, characterized in that using the exhaust gas containing carbon dioxide, or carbon dioxide emitted from the group selected from the group consisting of factories, power plants and automobiles, or a mixture thereof.
The method of claim 1,
Method of producing a boron-doped carbon material from carbon dioxide further comprising the step of treating the obtained boron-doped carbon material with an acidic solution or hot water.
The method of claim 3, wherein
Method of producing a boron-doped carbon material from carbon dioxide further comprising the step of drying the boron-doped carbon material treated with the acidic solution or hot water.
The method of claim 1,
The boron hydride is lithium boron hydride (LiBH ₄ ), sodium boron hydride (NaBH ₄ ), potassium boron hydride (KBH ₄ ), magnesium boron hydride (Mg (BH ₄ ) ₂ ), calcium boron hydride ( Ca (BH ₄ ) ₂ ), strontium boron hydride (Sr (BH ₄ ) ₂ ) and ammonia borane (NH ₃ BH ₃ ) A method for producing a boron doped carbon material from carbon dioxide, characterized in that selected from the group consisting of .
The method of claim 1,
Converting the carbon dioxide into the boron-doped carbon material is a method for producing a boron-doped carbon material from carbon dioxide, characterized in that carried out at 1 to 100 atm.
The method of claim 1,
Converting the carbon dioxide to a boron doped carbon material is a method for producing a boron doped carbon material from carbon dioxide, characterized in that carried out at 100 ℃ to 1000 ℃.
Treating the boron-doped carbon material prepared by the method of any one of claims 1 to 4 with a boron-containing precursor material; And a method for producing a boron doped carbon material comprising the step of heat treatment.
The method of claim 8,
Method for producing a boron-doped carbon material further comprising the step of treating the obtained boron-doped carbon material with an acidic solution or hot water.
The method of claim 9,
Method for producing a boron-doped carbon material further comprising the step of drying the boron-doped carbon material treated with the acidic solution or hot water.
The method of claim 8,
The boron-containing precursor material is boron oxide (B ₂ O ₃ ), boric acid (H ₂ BO ₃ ), lithium boron hydride (LiBH ₄ ), sodium boron hydride (NaBH ₄ ), potassium boron hydride (KBH ₄ ) , Magnesium boron hydride (Mg (BH ₄ ) ₂ ), calcium boron hydride (Ca (BH ₄ ) ₂ ), strontium boron hydride (Sr (BH ₄ ) ₂ ) and ammonia borane (NH ₃ BH ₃ ) Method for producing a boron doped carbon material, characterized in that selected from the group consisting of.
The method of claim 8,
The heat treatment is a method of producing a boron-doped carbon material, characterized in that carried out at 700 ℃ to 1500 ℃ in an inert gas or mixed gas atmosphere.
13. The method of claim 12,
The heat treatment is a method of producing a boron doped carbon material, characterized in that carried out at 850 ℃ to 1050 ℃.
13. The method of claim 12,
The inert gas is a method of producing a boron-doped carbon material, characterized in that selected from the group consisting of nitrogen gas, argon gas and helium gas.
13. The method of claim 12,
The mixed gas is a method for producing a boron-doped carbon material from carbon dioxide, characterized in that the mixed gas of any one selected from the group consisting of nitrogen gas, argon gas and helium gas and carbon dioxide.
delete Treating the boron doped carbon material prepared by the method of any one of claims 1 to 4 with a nitrogen-containing precursor material; And a heat treatment step of producing a boron and nitrogen doped carbon material.
18. The method of claim 17,
Method for producing a boron and nitrogen-doped carbon material further comprising the step of treating the obtained boron and nitrogen-doped carbon material with an acidic solution or hot water.
19. The method of claim 18,
Method for producing a boron and nitrogen-doped carbon material further comprising the step of drying the boron and nitrogen-doped carbon material treated with the acidic solution or hot water.
18. The method of claim 17,
The nitrogen-containing precursor material is polypyrrole ((C ₄ H ₂ NH) n), polyaniline (polyaniline), melamine (C ₃ H ₆ N ₆ ), PDI (N, N'-bis (2,6-diisopropyphenyl) -3,4,9,10-perylenetetracarboxylic diimide), Polyacrylonitrile (PAN), urea (CO (NH ₂ ) ₂ ), ammonia (NH ₃ ), hydrazine (N ₂ H ₄ ) and ammonia borane (NH ₃ BH ₃ Method for producing a boron and nitrogen doped carbon material, characterized in that selected from the group consisting of.
18. The method of claim 17,
The heat treatment is a method of producing a boron and nitrogen doped carbon material, characterized in that carried out at 700 ℃ to 1500 ℃ in an inert gas or mixed gas atmosphere.
22. The method of claim 21,
The heat treatment is a method for producing a boron and nitrogen doped carbon material, characterized in that carried out at 850 ℃ to 1050 ℃.
22. The method of claim 21,
The inert gas is a method of producing a boron and nitrogen doped carbon material, characterized in that selected from the group consisting of nitrogen gas, argon gas and helium gas.
22. The method of claim 21,
The mixed gas is a method of producing a boron and nitrogen-doped carbon material from carbon dioxide, characterized in that the mixed gas of any one selected from the group consisting of nitrogen gas, argon gas and helium gas and carbon dioxide.
A method of producing a boron-doped carbon material from carbon dioxide, further comprising the step of heat-treating the boron-doped carbon material prepared by the method of any one of claims 1 to 4.
26. The method of claim 25,
The heat treatment is a method for producing a boron-doped carbon material from carbon dioxide, characterized in that carried out at 700 ℃ to 1500 ℃ in an inert gas or mixed gas atmosphere.
27. The method of claim 26,
The heat treatment is a method for producing a boron doped carbon material from carbon dioxide, characterized in that performed at 850 ℃ to 1050 ℃.
27. The method of claim 26,
The inert gas is a method for producing a boron doped carbon material from carbon dioxide, characterized in that selected from the group consisting of nitrogen gas, argon gas and helium gas.
27. The method of claim 26,
The mixed gas is a method for producing a boron-doped carbon material from carbon dioxide, characterized in that the mixed gas of any one selected from the group consisting of nitrogen gas, argon gas and helium gas and carbon dioxide.
delete Treating the boron doped carbon material prepared by the method of any one of claims 1 to 4 with a basic material or carbon dioxide; And a method for producing a boron doped carbon material from carbon dioxide comprising the step of heat treatment.
32. The method of claim 31,
Method for producing a boron-doped carbon material further comprising the step of treating the obtained boron-doped carbon material with an acidic solution or hot water.
33. The method of claim 32,
Method for producing a boron-doped carbon material further comprising the step of drying the boron-doped carbon material treated with the acidic solution or hot water.
32. The method of claim 31,
The step of treating with a basic material is a method of producing a boron-doped carbon material, characterized in that to dissolve the basic material in distilled water or ethanol to treat the carbon material.
35. The method of claim 34,
The step of treating with a basic material is a method of producing a boron doped carbon material, characterized in that the mechanical mixing of the basic material and the carbon material.
36. The method of claim 35,
The basic material is a method of producing a boron-doped carbon material, characterized in that selected from the group consisting of potassium hydroxide (KOH), sodium hydroxide (NaOH) and lithium hydroxide (LiOH).
32. The method of claim 31,
The heat treatment is a method for producing a boron-doped carbon material from carbon dioxide, characterized in that carried out at 700 ℃ to 1500 ℃ in an inert gas or mixed gas atmosphere.
39. The method of claim 37,
The heat treatment is a method for producing a boron doped carbon material from carbon dioxide, characterized in that performed at 850 ℃ to 1050 ℃.
39. The method of claim 37,
The inert gas is a method for producing a boron doped carbon material from carbon dioxide, characterized in that selected from the group consisting of nitrogen gas, argon gas and helium gas.
39. The method of claim 37,
The mixed gas is a method for producing a boron-doped carbon material from carbon dioxide, characterized in that the mixed gas of any one selected from the group consisting of nitrogen gas, argon gas and helium gas and carbon dioxide.
delete 32. The method of claim 31,
Carbon dioxide treatment is a method for producing a boron doped carbon material from carbon dioxide, characterized in that performed in a CO ₂ gas or CO ₂ mixed gas atmosphere.
43. The method of claim 42,
CO ₂ mixed gas is a method for producing a boron-doped carbon material from carbon dioxide, characterized in that any one selected from the group consisting of 5 vol% to 100 vol% carbon dioxide and nitrogen gas, argon gas and helium gas.

Images