KR102153241B1 - Hollow carbon black having micro-porosity and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a hollow carbon black having micro-pores, and to a manufacturing method thereof. The hollow carbon black is used as a carrier which can fill other materials inside, and is applicable to materials in various fields, such as an electrocatalyst carrier for a secondary cell or a fuel cell, a carbon support, a negative electrode material, a positive electrode material and the like.

Description

BACKGROUND OF THE INVENTION [0002] Hollow carbon black having micro-porosity and manufacturing method thereof

The present invention relates to a hollow carbon black having micro-porosity and a method of manufacturing the same, and can be used as a carrier capable of filling other materials therein, and a secondary battery or an electrocatalyst for a fuel cell It is an invention that can be applied to various fields such as support, carbon support, negative electrode material, and positive electrode material.

Carbon black is widely used as a black pigment and as a reinforcing agent and filler. Carbon blacks are produced with different properties by different methods. The most common method is a manufacturing method by oxidative pyrolysis of carbon-containing carbon black raw materials. In this case, the carbon black raw material is incompletely burned in the presence of oxygen at high temperature. Examples of methods for producing carbon black of this class include a furnace black method, a gas black method, and a lamp black method. Examples of other methods include an acetylene method, a thermal black method, and a plasma method.

In addition, carbon black is used as a conductive material such as manganese batteries, lithium batteries, and secondary batteries due to its high conductivity, and it is known that the more micropores in the aggregate of carbon black, the larger the capacity is known, and studies aimed at large-sized batteries are being conducted. , In fuel cells, it is used as a catalyst carrier in the catalyst layer, and studies are being conducted to control the specific surface area of carbon black in order to reduce the amount of expensive platinum catalyst added and increase the active area. As an example, there are various attempts such as increasing the amount of energy storage by maintaining conductivity by subjecting the surface of carbon black to a chemical activation treatment to form pores, or by introducing a mixed secondary structure between carbon blacks.

Korean Patent Application Publication No. 10-2014-0087393 (published date 2014.07.09)

As a result of repeatedly conducting studies for controlling the specific surface area of carbon black, the inventors of the present invention have completed the present invention by producing carbon black having significantly increased micropore volume and increased specific surface area of furnace carbon black among carbon blacks. .

As described above, the present invention is to provide a microporous hollow carbon black having a remarkably increased specific surface area and an increased micropore volume compared to the raw material carbon black, and a method of manufacturing the same.

The present invention for solving the above problems relates to a microporous hollow carbon black, as a furnace carbon black manufactured by performing a gas phase oxidation reaction using an oxidizing gas, which has a hollow structure, and has a microporous structure. Eggplant contains furnace carbon black.

As a preferred embodiment of the present invention, the microporous hollow carbon black of the present invention may have a micropore volume that satisfies Equation 1 below.

[Equation 1]

2.0 ≤ B/A ≤ 7.0

In Equation 1, A is the micropore volume of the furnace carbon black before gas phase oxidation reaction is performed, and B is the micropore volume of the furnace carbon black subjected to the gas phase oxidation reaction.

As a preferred embodiment of the present invention, the microporous hollow carbon black of the present invention may have a BET specific surface area of 180 to 1,200 m ² /g.

As a preferred embodiment of the present invention, the microporous hollow carbon black of the present invention may have a total pore volume of 0.190 to 1.200 cm ³ /g.

As a preferred embodiment of the present invention, the microporous hollow carbon black of the present invention may have an average particle diameter of micropores of 4.0 to 8.0 nm.

Another object of the present invention relates to a method for producing microporous hollow carbon black described above, comprising: a first step of preparing furnace carbon black; And a second step of performing a gas phase oxidation reaction using an oxidizing gas on the furnace carbon black.

As a preferred embodiment of the present invention, the micropore volume of the furnace carbon black subjected to the gas phase oxidation reaction of the second step may satisfy the following equation.

[Equation 1]

2.0 ≤ B/A ≤ 7.0

In Equation 1, A is the micropore volume of the furnace carbon black before gas phase oxidation reaction is performed, and B is the micropore volume of the furnace carbon black subjected to the gas phase oxidation reaction.

In a preferred embodiment of the present invention, the gas phase oxidation reaction is performed in an oxidation chamber, and the gas phase oxidation reaction can be performed for 30 minutes to 150 minutes while supplying an oxidizing gas in the oxidation chamber at 850°C to 1200°C. have.

As a preferred embodiment of the present invention, the oxidizing gas may include 99.000 to 99.999 vol% of CO ₂ .

In a preferred embodiment of the present invention, the gas phase oxidation reaction may be performed while supplying an oxidizing gas into the oxidation chamber at 50 to 200 mL/min.

In addition, another object of the present invention relates to an application product using the previously described microporous hollow carbon black, including the electrocatalyst carrier for a fuel cell including the microporous hollow carbon black, and the microporous hollow carbon black It is to provide a carbon support for secondary batteries and the like.

The carbon black produced by the manufacturing method of the present invention increases the micropore volume by about 2 times and up to 6 times less than that of the furnace carbon black before gas phase oxidation treatment, and thus, microporous pores having a high specific surface area and a high total pore volume. Hollow furnace carbon black can be produced. In addition, as shown in the schematic diagram in FIG. 1, unlike carbon black having a conventional porous structure, it has a hollow shape, and the microporous hollow furnace carbon black of the present invention can support various materials and has excellent electrical properties. , It can be used as a material in a wide variety of fields.

1 is a schematic diagram for explaining a structural difference between a porous carbon black before a gas phase oxidation reaction and a microporous hollow carbon black of the present invention subjected to an acid oxidation reaction.
2 is a schematic diagram of an oxidation chamber used in a gas phase oxidation reaction in the present invention.
3A to 3D are TEM photographs of microporous hollow furnace carbon black prepared by performing a gas phase oxidation reaction at 1,000°C with different reaction times.

Hereinafter, the present invention will be described in more detail through the method of manufacturing the microporous hollow carbon black of the present invention.

Step 1 of preparing the furnace carbon black of the present invention; And a second step of performing a gas phase oxidation reaction of the furnace carbon black using an oxidizing gas to produce microporous hollow carbon black.

The furnace carbon black of step 1 may be commercially sold and purchased furnace carbon black, preferably at least one selected from the brand name Super-p and the brand name C-NERGY. Included furnace carbon black can be used.

The gas phase oxidation reaction of the second step may be performed in the oxidation chamber shown schematically in FIG. 2, and after the furnace carbon black is introduced into the oxidation chamber, the gas phase oxidation reaction may be performed while supplying an oxidizing gas into the oxidation chamber.

The gas phase oxidation reaction can be carried out for 30 minutes to 150 minutes under 850 ℃ ~ 1200 ℃, while supplying the pyrophoric gas in the oxidation chamber, preferably for 40 minutes ~ 120 minutes under 900 ℃ ~ 1150 ℃, more preferably For example, it can be carried out for 45 minutes to 110 minutes under 950 ℃ ~ 1100 ℃. If the gas phase oxidation reaction temperature is less than 850°C or the gas phase oxidation reaction time is less than 30 minutes, there may be a problem in that the specific surface area, micropore volume, and total pore volume of the gas phase oxidation reaction furnace carbon black are low. In addition, when the gas phase oxidation reaction temperature exceeds 1200°C or the gas phase oxidation reaction time exceeds 150 minutes, physical properties such as the specific surface area and micropore volume of carbon black no longer increase, as well as pores (voids). Since the retaining wall becomes thin, the shape of the pores collapse, the mechanical strength of the carbon black is too low, it is easily broken, and the manufacturing yield may be significantly lowered. Therefore, it is recommended to perform it under the above temperature.

As the oxidizing gas, CO ₂ is used, preferably 99.000 to 99.999 vol%, preferably 99.500 to 99.999 vol%, more preferably 99.800 to 99.999 vol% CO ₂ is preferably used. In addition, the gas phase oxidation reaction can be performed while supplying the oxidizing gas into the oxidation chamber at a flow rate of 50 to 200 mL/min, preferably 80 to 150 mL/min, more preferably 85 to 120 mL/min.

In addition, the burn-off yield of the microporous hollow carbon black prepared by the above method may be 25.0% to 65.0%, preferably 30.0 to 63.0%, more preferably 35.0 to 55.0%.

The microporous hollow carbon black of the present invention prepared by this method has a hollow structure having microporous pores as shown in the schematic diagram in FIG. 1, and may have a micropore volume that satisfies Equation 1 below.

[Equation 1]

2.0 ≤ B/A ≤ 7.0, preferably 2.5 ≤ B/A ≤ 6.8, more preferably 3.0 ≤ B/A ≤ 6.5

In Equation 1, A is the micropore volume of the furnace carbon black before gas phase oxidation reaction is performed, and B is the micropore volume of the furnace carbon black subjected to the gas phase oxidation reaction.

In addition, the microporous hollow carbon black of the present invention has a BET specific surface area of 180 to 1,200 m ² /g, preferably a BET specific surface area of 320 to 1,150 m ² /g, more preferably 450 to 820 m ² /g. , And more preferably 490 to 750 m ² /g.

In addition, the microporous hollow carbon black of the present invention may have a total pore volume of 0.190 to 1.200 cm ³ /g, preferably, a total pore volume of 0.300 to 0.950 cm ³ /g, more preferably The total pore volume can satisfy 0.500 ~ 0.800 cm ³ /g.

In addition, the microporous hollow carbon black of the present invention may have an average particle diameter of micropores of 4.0 to 8.0 nm, preferably 4.0 to 6.5 nm, more preferably 4.2 to 6.0 nm.

And, the microporous hollow carbon black of the present invention may have a fraction (V _micro /V _total X 100%) of the micropore volume (V _micro ) to the _total pore volume (V _total ) from 4.0 to 13.6%, preferably It may be 5.0 to 13.6%.

Such, of the present invention Microporous hollow furnace carbon black can support a variety of materials and has excellent electrical properties, so it can be used as a material in a wide variety of fields, such as an electrocatalyst carrier for fuel cells and a carbon support for secondary batteries. .

Hereinafter, the present invention will be described in more detail based on examples. However, the scope of the present invention is limited by the following examples and should not be interpreted.

[Example]

Example 1: Preparation of microporous hollow furnace carbon black according to reaction time

Furnace carbon black (brand name: Super-P, manufacturer: IMERYS) was prepared as a raw material. The basic physical properties of the prepared furnace carbon black are shown in Table 1 below.

BET
Non-standard (m ² /g) Micro
Pore volume (cm ³ /g) Total pore volume
(cm ³ /g) Average pore size 61.4 0.01 0.165 10.8 nm

Next, after preheating the horizontal tube furnace (oxidation chamber) shown in FIG. 3 to 1000°C, the raw material was charged into the reaction tube of the oxidation chamber using a quartz boat, and then fixed at 1000°C. Gas phase oxidation reaction was carried out. An oxidizing gas containing CO ₂ having a concentration of 99.950 vol% as a reactor was used, and the flow rate of the oxidizing gas was maintained at 100 ml/min using a ball flow meter. In addition, the reaction times are shown in Table 2 below, and the yield (%), BET specific surface area (m ² /g), MV (micropore volume, cm ³ /) of the microporous hollow furnace carbon black prepared according to each reaction time g), the total pore volume (Total pore volume cm ³ /g) and the average pore size (nm) are shown in Table 2 below. In addition, a transmission electron microscope (TEM) measurement photograph of each of these is shown in FIGS. 3A and 3B.

Temperature
(℃) reaction
time
(minute) Burn-off
yield
(%) BET
Non-standard
(m ² /g) Micro
Pore volume
(cm ³ /g) Total pore
volume
(cm ³ /g) Average pore
size
(nm) 1,000 0 0 61.4 0.010 0.165 10.8 10 7.2 102.3 0.024 0.176 9.5 30 15.4 184.2 0.021 0.207 7.8 55 30.4 334.6 0.037 0.273 5.5 98 48.2 590.5 0.044 0.633 4.3 115 59.9 788.1 0.060 0.766 5.9 148 83.2 1,107.6 0.055 1.328 4.8

Referring to FIG. 3A, in the case of the furnace carbon black not subjected to gas phase oxidation treatment, pores were not observed inside, and pores were not developed inside, so it can be confirmed that the BET specific surface area is very small, 61.4 m ² /g. .

Referring to FIG. 3A, in the case of the furnace carbon black subjected to the gas phase oxidation treatment for 10 minutes, it was observed that the crystallites inside the furnace became cloudy, but it was confirmed that the micropore volume increased by about 2.4 times compared to the raw material furnace carbon black.

In addition, referring to FIGS. 3B and 3C, it can be seen that in the case of furnace carbon black in which gas phase oxidation treatment was performed for 30 minutes, 55 minutes, and 98 minutes, internal pores are developed and crystallinity of the walls surrounding the pores is increased. .

In addition, referring to FIG. 3C, in the case of the furnace carbon black subjected to the gas phase oxidation treatment for 115 minutes, the wall surrounding the inner pores became somewhat thinner and a little slippage occurred. In addition, referring to FIG. 3D, in the case of furnace carbon black subjected to gas phase oxidation treatment for 148 minutes, the BET specific surface area is increased by about 18 times compared to the raw material, and the pores are developed and grown (merged) to become the primary particles of carbon black. A phenomenon of collapse was observed. In addition, the furnace carbon black subjected to the gas phase oxidation treatment for 148 minutes had a burn-off yield of 83.2%, which was too high, so that the yield of the product was too low.

In addition, looking at Tables 2 and 3, as the gas phase oxidation reaction time increases, the BET specific surface area, micropore volume, and total pore volume tend to increase. However, if the gas phase oxidation reaction is performed for too long, the pores are crushed. , There was a phenomenon of coalescence between the furnace black, and the appropriate gas phase oxidation reaction time was 30 minutes to 150 minutes, preferably 40 minutes to 120 minutes, and more preferably about 45 minutes to 110 minutes to ensure proper physical properties and yield. Could be confirmed.

Example 2: Preparation of microporous hollow furnace carbon black according to reaction temperature

Gas-phase oxidation treatment of furnace carbon black (raw material) in the same manner as in Example 1, but the oxidation treatment temperature was varied as shown in Table 3 below to prepare microporous hollow furnace carbon black, respectively, and physical properties of the prepared furnace carbon black Was measured.

Temperature
(℃) reaction
time
(minute) Burn-off
yield
(%) BET
Non-standard
(m ² /g) Micro
Pore volume
(cm ³ /g) Total pore
volume
(cm ³ /g) Average pore
size
(nm) 800 98 23.8 217.2 0.027 0.249 6.9 880 32.3 360.6 0.039 0.298 5.1 950 43.3 500.1 0.041 0.591 4.8 1000 48.2 590.5 0.044 0.633 4.3 1150 61.8 790.8 0.063 0.798 5.7 1250 75.0 907.6 0.057 1.246 6.2

Looking at Table 3, it can be seen that as the reaction temperature increases, the burn-off yield increases, the BET specific surface area, the micropore volume, and the total pore volume increase, and the average pore size tends to decrease. In the case of 1250℃ exceeding 1200℃, when compared to 1150℃, the burn-off yield increased sharply, but rather the average pore size increased. This is because the micropores decreased and the macropores increased. This is because the total pore volume was greatly increased.

And, when the reaction temperature is less than 850 ℃ 800 ℃, there is a problem having too low physical properties in terms of specific surface area and micropore volume.

Example 3: Preparation of microporous hollow furnace carbon black according to oxidizing gas flow rate

Gas-phase oxidation treatment of furnace carbon black (raw material) in the same manner as in Example 1, but as a reactive body, CO ₂ (concentration of 99.950 vol%), an oxidizing gas, was changed as shown in Table 4 below to obtain microporous hollow furnace carbon black. Each was prepared, and the physical properties of the prepared furnace carbon black were measured.

CO ₂ flow
(ml/min) reaction
time/
reaction
Temperature Burn-off
yield
(%) BET
Non-standard
(m ² /g) Micro
Pore volume
(cm ³ /g) Total pore
volume
(cm ³ /g) Average pore
size
(nm) 45 98 minutes /
1000℃ 32.3 307.5 0.031 0.457 5.3 80 46.5 580.1 0.042 0.621 4.5 100 48.2 590.5 0.044 0.633 4.3 120 48.9 598.1 0.047 0.665 4.1 180 55.1 620.9 0.059 0.952 5.3 210 63.8 841.7 0.065 1.118 5.9

Referring to Table 3, as the CO ₂ flow rate increased, the burn-off yield increased, and the BET specific surface area, micropore volume, and total pore volume increased. However, when the CO ₂ flow rate was 45 ml/min, the yield was too low, and when the CO ₂ flow rate was 210 ml/min, the physical properties such as yield, specific surface area, micropore volume, and total pore volume were excellent, but the pores were too high. Since it is large and formed a lot, there is a problem that the strength is too weak and it is easily broken.

Through the above Examples and Experimental Examples, through the manufacturing method of the present invention, a hollow hollow furnace carbon black having a microporous structure having a micropore volume, a total pore volume and a BET specific surface area that is much higher than that of the raw material is obtained in a high yield. It was confirmed that it could be manufactured. As such, the microporous hollow furnace carbon black of the present invention can support various materials and has excellent electrical properties, and is expected to be used as a material in a wide variety of fields.

Claims (10)

1 step of preparing the furnace carbon black; And
A second step of performing a gas phase oxidation reaction of the furnace carbon black using an oxidizing gas in an oxidation chamber; includes,
The gas phase oxidation reaction is characterized in that it is carried out under the oxidizing gas atmosphere for 40 to 120 minutes under 850 to 1200°C while supplying an oxidizing gas containing 99.000 to 99.999 vol% of CO ₂ at 50 to 180 mL/min. Method for producing microporous hollow carbon black.
The method of claim 1, wherein the micropore volume of the furnace carbon black subjected to the gas phase oxidation reaction in the second step satisfies the following equation;
[Equation 1]
2.0 ≤ B/A ≤ 7.0
In Equation 1, A is the micropore volume of the furnace carbon black before the gas phase oxidation reaction is performed, and B is the micropore volume of the furnace carbon black on which the gas phase oxidation reaction is performed.
delete delete Furnace carbon black produced by gas-phase oxidation reaction using an oxidizing gas containing 99.000 to 99.999 vol% of CO ₂ , and has a hollow structure and has a number of micro-sized pores,
Microporous hollow carbon black, characterized in that it has a micropore volume that satisfies Equation 1 below, and has a BET specific surface area of 320 to 1,150 m ² /g;
[Equation 1]
2.0 ≤ B/A ≤ 7.0
In Equation 1, A is the micropore volume of the furnace carbon black before gas phase oxidation reaction is performed, and B is the micropore volume of the furnace carbon black subjected to the gas phase oxidation reaction.
delete The microporous hollow carbon black according to claim 5, wherein the total pore volume is 0.190 to 1.200 cm ³ /g.
The microporous hollow carbon black according to claim 5, wherein the average particle diameter of the micropores is 4.0 to 8.0 nm.
An electrocatalyst carrier for a fuel cell comprising the microporous hollow carbon black of claim 5, 7, or 8.
A carbon support for a secondary battery comprising the microporous hollow carbon black of claim 5, 7 or 8.

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