WO2016126133A1 - High-density bundle-type carbon nanotubes and preparation method therefor - Google Patents

High-density bundle-type carbon nanotubes and preparation method therefor Download PDF

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WO2016126133A1
WO2016126133A1 PCT/KR2016/001278 KR2016001278W WO2016126133A1 WO 2016126133 A1 WO2016126133 A1 WO 2016126133A1 KR 2016001278 W KR2016001278 W KR 2016001278W WO 2016126133 A1 WO2016126133 A1 WO 2016126133A1
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catalyst
carbon nanotubes
spherical
carbon
supported catalyst
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PCT/KR2016/001278
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French (fr)
Korean (ko)
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강경연
조동현
이승용
차진명
우지희
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주식회사 엘지화학
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Priority to CN201680000712.0A priority Critical patent/CN106103343B/en
Publication of WO2016126133A1 publication Critical patent/WO2016126133A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/745—Iron
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/75—Cobalt
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/755—Nickel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/84—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/85—Chromium, molybdenum or tungsten
    • B01J23/88—Molybdenum
    • B01J23/887—Molybdenum containing in addition other metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/8877—Vanadium, tantalum, niobium or polonium
    • B01J35/30—
    • B01J35/51—
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0201—Impregnation
    • B01J37/0207—Pretreatment of the support
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2202/00—Structure or properties of carbon nanotubes
    • C01B2202/20—Nanotubes characterized by their properties
    • C01B2202/32—Specific surface area
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2202/00—Structure or properties of carbon nanotubes
    • C01B2202/20—Nanotubes characterized by their properties
    • C01B2202/36—Diameter
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/03—Particle morphology depicted by an image obtained by SEM
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/10—Solid density

Definitions

  • the present invention relates to a high density bundled carbon nanotubes and a method of manufacturing the same.
  • carbon nanotubes are cylindrical carbon tubes having a diameter of about 3 to 150 nm, specifically about 3 to 100 nm, and having a length several times the diameter, for example, 100 times or more. Refers to. These CNTs consist of layers of aligned carbon atoms and have different types of cores. Such CNTs are also called carbon fibrils or hollow carbon fibers, for example.
  • CNTs are industrially important in the production of composites due to their size and specific properties, and have high utility in the field of electronic materials, energy materials and many other fields.
  • the CNT can be generally manufactured by an arc discharge method, a laser evaporation method, a chemical vapor deposition method, or the like.
  • the arc discharge method and the laser evaporation method is difficult to mass-produce, there is a problem that the economical efficiency is lowered due to excessive arc production cost or laser equipment purchase cost.
  • the catalyst used in the chemical vapor deposition method may be a carbon nanotube catalyst, a co-precipitation catalyst, etc., in which the catalytically active component has an oxide form, a partially or completely reduced form, or a hydroxide form, and can be generally used for preparing CNTs.
  • a double carbon nanotube catalyst which is because when the carbon nanotube catalyst is used, the bulk density of the catalyst itself is higher than that of the coprecipitation catalyst, and unlike the coprecipitation catalyst, the fineness of less than 10 microns is reduced, which may occur in the fluidization process. This is because the possibility of fine powder generation by attrition can be reduced, and the mechanical strength of the catalyst itself is also excellent, which can stabilize the reactor operation.
  • the prepared catalyst has a problem that the efficiency is low because a high metal loading amount compared to the amount produced during CNT synthesis.
  • the present invention to solve the above problems,
  • It provides a carbon nanotubes having a BET specific surface area of 1 to 50 m 2 / g and a bulk density of 60 to 250 kg / m 3 .
  • the carbon nanotubes may have a secondary structure in the form of a bundle.
  • the supported catalyst can be obtained by an impregnation method.
  • the total content of the catalyst component and the active ingredient may be 10 to 25 parts by weight based on 100 parts by weight of the spherical ⁇ -alumina.
  • the weight ratio of the catalyst component and the active ingredient may be 10 to 30: 1 to 14.
  • the catalyst component may be at least one of Fe, Co or Ni.
  • the ultrasonic fraction of the supported catalyst may be within 5%.
  • It provides a method for producing carbon nanotubes comprising the step of growing carbon nanotubes by decomposition of the carbon source injected on the catalyst surface.
  • the concentration of the aqueous metal solution may be 0.1 to 0.4 g / ml.
  • the aging impregnation process may be performed for 30 minutes to 15 hours at a temperature of 20 °C to 100 °C.
  • the firing temperature may be 550 °C to 800 °C.
  • after the vacuum drying process and before the firing process may further comprise the step of performing at least one preliminary baking at 250 to 400 °C.
  • the supported catalysts of the present invention can obtain CNT yields equal to or higher than those of low metals by using a spherical ⁇ -alumina support. Furthermore, the supported catalyst for synthesizing CNTs of the present invention can efficiently control CNT growth to synthesize bundle type high density CNTs.
  • FIG. 2 shows an SEM image of the supported catalyst obtained in Example 1.
  • FIG. 3 shows an SEM image of the support used in Comparative Example 1.
  • FIG. 4 shows an SEM image of the supported catalyst obtained in Comparative Example 1.
  • FIG. 5 shows a low magnification SEM image of CNTs obtained in Comparative Example 1.
  • FIG. 6 shows a high magnification SEM image of CNTs obtained in Comparative Example 1.
  • FIG. 7 shows a low magnification SEM image of the CNT obtained in Example 1.
  • FIG. 8 shows a high magnification SEM image of the CNT obtained in Example 1.
  • FIG. 9 shows a low magnification SEM image of CNTs obtained in Example 2.
  • FIG. 10 shows a high magnification SEM image of the CNT obtained in Example 2.
  • FIG. 11 shows a low magnification SEM image of CNTs obtained in Example 3.
  • FIG. 12 shows a high magnification SEM image of the CNT obtained in Example 3.
  • FIG. 13 shows a low magnification SEM image of CNTs obtained in Example 4.
  • FIG. 14 shows a high magnification SEM image of the CNT obtained in Example 4.
  • FIG. 15 shows an SEM image of the CNT obtained in Example 1.
  • FIG. 16 shows an SEM image of region A of FIG. 15.
  • FIG. 17 shows an SEM image of region B of FIG. 15.
  • the supported catalyst for synthesizing CNTs is supported on an Al-based support with a catalyst component and an active component
  • the Al-based support may include spherical ⁇ -alumina.
  • alumina having a chemical formula of Al 2 O 3 is present in several different phases, for example ⁇ -, ⁇ -, ⁇ -, ⁇ -, ⁇ - and ⁇ -alumina.
  • ⁇ -alumina corundum
  • the oxide ions form a hexagonally packed structure and the alumina ions are symmetrically distributed in the octahedral gap.
  • ⁇ -alumina has a "defective" spinel structure (the cation free spinel structure).
  • the support of the catalyst may comprise ⁇ -alumina.
  • ⁇ -alumina has high utility as a catalyst support due to its high porosity
  • ⁇ -alumina is known to have a very low utility as a catalyst support due to its very low porosity.
  • the CNT production method using the same as the catalyst support produces a high yield of CNTs even with a low metal loading when compared to a process using alumina having a different form and crystal structure as the catalyst support. It has been found that a bundle type spherical shape can be selectively obtained also in the shape of the resultant CNT.
  • the term "spherical" includes a case that is substantially spherical in addition to a perfect sphere, and may include a case having an elliptic cross section such as a potato shape.
  • the spherical ⁇ -alumina can be prepared by methods known in the art.
  • the Bayer method for producing alumina from bauxite is widely used industrially.
  • spherical ⁇ -alumina can be prepared by heating ⁇ -Al 2 O 3 or any hydrogen oxide above 1000 ° C.
  • the spherical ⁇ -alumina is dissolved in water-soluble precursors such as aluminum chloride or aluminum nitrate in water, and then the pH is about 8 or more, preferably about 9 or more, more preferably about 10 using an aqueous ammonia solution or a caustic soda solution.
  • the powder may be prepared by spray drying and then calcined at a temperature of about 1000 ° C. or higher, preferably 1100 to 1300 ° C., more preferably about 1200 ° C., but It is not limited.
  • the spherical ⁇ -alumina used as the support in the present invention may be of any suitable dimension.
  • a spherical ⁇ - alumina used in this invention as measured by the BET method may have a surface area of from about 1m 2 / g to about 50m 2 / g, for example, 1 to 30m 2 / g, for example 1 to 20 m 2 / g, for example 1 to 10 m 2 / g.
  • the spherical ⁇ - alumina used as the support has a very low porosity is smooth and even surface, unlike a conventional support, for example from 0.001 to 0.1cm 3 / g, for example from 0.005 to 0.05cm 3 / g It can have a pore volume of.
  • the spherical ⁇ -alumina which is a support, may be loaded with a relatively low content of metal, for example, about 10 to 25 parts by weight of the catalyst component and the active component based on 100 parts by weight of the spherical ⁇ -alumina, Or in an amount of about 15 to 20 parts by weight. Sufficient catalytic activity can be exhibited at such supported contents.
  • the catalyst component and the active component supported on the spherical ⁇ -alumina can be used in a weight ratio of 10 to 30: 1 to 14, and can exhibit better CNT production activity in this content range.
  • the catalyst component used in the present invention may be one or more selected from Fe, Co and Ni, for example Fe salt, Fe oxide, Fe compound, Co salt, Co oxide, Co compound, Ni salt, Ni oxide, Ni compound It may be one or more selected from the group consisting of, and as another example Fe (NO 3 ) 2 ⁇ 6H 2 O, Fe (NO 3 ) 2 ⁇ 9H 2 O, Ni (NO 3 ) 2 ⁇ 6H 2 O, Co (NO 3 ) a nitride such as 2 ⁇ 6H 2 O, or the like.
  • the active ingredient used in the present invention may be, for example, one or more of Mo and V, another example may be Mo salt, Mo oxide, Mo compound, V salt, V oxide, V compound, etc.
  • Mo salt Mo oxide
  • Mo compound Mo compound
  • V salt V oxide
  • V compound etc.
  • Nitrogen such as (NH 4 ) 6 Mo 7 O 24 4H 2 O and the like can be dissolved and used in distilled water.
  • the supported catalyst for synthesizing CNTs of the present invention as described above can be prepared by the impregnation method.
  • a method for preparing a supported catalyst for synthesizing CNTs wherein the Al-based support is spherical ⁇ -alumina.
  • the aqueous solution is formed by mixing the Al-based support in the aqueous metal solution containing the catalyst component precursor and the active component precursor, wherein the catalyst component, active Components and spherical ⁇ -alumina supports, which have already been described above.
  • the concentration of the metal aqueous solution is more efficient to use, for example, 0.1 to 0.4 g / ml, or 0.1 to 0.3 g / ml.
  • the content of the spherical ⁇ -alumina support mixed with the aqueous metal solution may be, for example, about 10 to 25 parts by weight based on 100 parts by weight of the spherical ⁇ -alumina, or It can be used to be supported in an amount of about 15 to 20 parts by weight.
  • step (2) of the preparation method Aging impregnation of the supported catalyst precursor solution in step (2) of the preparation method to obtain a mixture, wherein the impregnation is not limited to this, but 30 °C in the temperature range of 20 °C to 100 °C, or 60 to 100 °C It can be carried out for minutes to 15 hours, or 1 to 15 hours, it is possible to provide a high supporting efficiency in this range.
  • step (3) of the production method the mixture resulting from the aging impregnation obtained in step (2) is vacuum dried to coat the catalyst component and the active ingredient on the surface of the support.
  • the vacuum drying is to dry by rotary evaporation under vacuum, for example, can be carried out within 1 hour, or 1 minute to 1 hour under 45 to 80 °C, drying the excess metal salt remaining without impregnation in the support.
  • the process makes it possible to provide a coating impregnation of a uniform alumina surface.
  • vacuum in the vacuum drying described herein is not particularly limited as long as it corresponds to the vacuum range that is typically applied to vacuum drying.
  • step (4) of the production method the resultant obtained by vacuum drying in step (3) is fired to form a supported catalyst of the present invention, which is a final result, and such firing is about 550 to 800 ° C, or about 600 It may be carried out in the range of °C to 700 °C, it can be carried out in the air or under an inert atmosphere.
  • the firing time is not limited thereto, but may be performed within about 30 minutes to 5 hours.
  • the pre-baking may be carried out one or more times at about 250 to 400 °C, in this case immediately before the pre-firing Up to 50% of the supported catalyst precursor aqueous solution is impregnated with the spherical ⁇ -alumina support, and the remainder of the supported catalyst precursor aqueous solution is impregnated with the spherical ⁇ -alumina support immediately after or immediately before firing. It is desirable in terms of efficiency.
  • the bulk shape of the supported catalyst prepared as described above depends on the bulk shape of the spherical ⁇ -alumina support used. That is, the supported catalyst for synthesizing CNTs may have a spherical bulk shape and mainly have a structure in which a catalyst component is coated on one or multiple layers (two or three or more layers) on the surface of the support, and these may not have a continuous coating layer structure. It may be desirable to have a discontinuous coating structure in terms of CNT synthesis.
  • the supported catalyst for preparing CNTs provided by the present invention may have, for example, a particle size or an average particle diameter of about 30 to about 150 ⁇ m, and a surface particle size of SEM observation in a range of about 10 to 100 nm, in which CNT diameter Preferred in terms of control and catalytic activity.
  • the supported catalyst coated with the catalyst component and the active ingredient on the surface of the spherical ⁇ -alumina support is ultrasonic (ultrasonic) having a particle size of 32 ⁇ m or less based on the particle size measurement standard in consideration of the particle size or the average particle size range of the alumina support.
  • the number average particle size measurement may have a range of 5% or less, specifically 3% or less.
  • the fine powder is an aggregate of the catalyst material and the active material attached to the catalyst, and is not filtered out when sieved, but is different in particle size and catalyst activity from the catalyst-active material well coated on the support.
  • island-like aggregates attached to the catalyst significantly lower the yield of CNTs, and because the materials are rather weakly attached to the catalyst, they are separated at the time of ultrasonication to generate fine powder.
  • the ultrasonic differential amount refers to the number average particle diameter differential amount measured by the particle size analyzer after the ultrasonic treatment, wherein the support includes a multilayer support.
  • the supported catalyst for synthesizing CNTs obtained by the present invention is preferably spherical in consideration of specific surface area, and as shown in the SEM photograph of FIG. 1, the supported catalyst for synthesizing CNTs synthesized in the present invention is also spherical, almost spherical, Or substantially close to a sphere.
  • the process for preparing CNTs from the supported catalyst obtained by the above-described method includes, but is not limited to:
  • the reactor may be a fixed bed reactor or a fluidized bed reactor without limitation.
  • CNTs of the present invention obtained according to the production method is a potato or spherical bundle type having a bulk density of 60 to 250 kg / m 3 , flatness 0.9 to 1.0, particle size distribution (Dcnt) 0.5 to 1.0 (bundle type).
  • the term "bulk density” used in the present invention is defined by the following Equation 1, and because the amount of fine powder of the supported catalyst for synthesizing CNTs according to the present invention is small, the density distribution of CNTs grown therefrom may also have a specific range. .
  • the flatness and the bundle type can be obtained by a unique process prepared using the supported catalyst of the present invention described above.
  • the flatness ratio is defined by the following Equation 2.
  • Flatness shortest diameter through the center of CNT / maximum diameter through the center of CNT.
  • the particle size distribution value Dcnt may be defined by Equation 3 below.
  • Dn90 is the number average particle diameter measured under 90% in absorbing mode using Microtrac particle size analyzer after 3 hours of CNT in distilled water
  • Dn10 is the number average particle diameter measured under 10% reference
  • Dn50 is the number average particle diameter measured on a 50% basis.
  • the CNT obtained by the above production method may satisfy a particle diameter or an average particle diameter of 100 to 800 ⁇ m and a strand diameter of the CNTs of 10 to 50 nm.
  • the CNT of the present invention can be used as a raw material in the electric field, the electronic field, the energy field, etc., and can also be used as the reinforcing material in the plastic field.
  • Flask A was prepared completely dissolved in 15.0 ml.
  • Example 1 Spherical ⁇ -Al 2 O 3 680 0.01 4.9
  • Example 2 Spherical ⁇ -Al 2 O 3 660 0.01 4.9
  • Example 3 Spherical ⁇ -Al 2 O 3 620 0.01 4.9
  • Example 4 Spherical ⁇ -Al 2 O 3 600 0.01 4.9 Comparative Example 1 ⁇ -Al 2 O 3 680 0.55 185
  • FIG. 1 shows SEM images of the spherical ⁇ -alumina used as the support in Examples 1 to 4, and it can be seen that the support has a shape that is almost spherical.
  • FIG. 2 shows an SEM image of the supported catalyst obtained according to Example 1, and it can be seen that it has a substantially spherical shape similarly to the support.
  • Figure 3 shows an SEM image of the ⁇ -alumina used as the support in Comparative Example 1, it can be seen that the shape of the support has a rather irregular shape rather than spherical.
  • 4 shows an SEM image of the supported catalyst obtained according to Comparative Example 1, and it can be seen that the shape has a somewhat irregular shape similarly to the support.
  • Carbon nanotube synthesis was tested in a laboratory scale fixed bed reactor using the catalysts for synthesizing CNTs prepared in Examples 1 to 4 and Comparative Example 1. Specifically, the catalyst for synthesizing CNT prepared in the above process was mounted in the middle of a quartz tube having an inner diameter of 55 mm, and then heated up to 650 ° C. in a nitrogen atmosphere and maintained therein, and hydrogen gas was flowed at a flow rate of 60 sccm. Synthesizing for 3 hours while flowing to synthesize a predetermined amount of carbon nanotube aggregates. The CNT yield and bulk density at this time are described in Table 4 below.
  • Example 1 15.3 87 91.2
  • Example 2 15.3 60 102
  • Example 3 15.3 51 100
  • Example 4 15.3 27 60 Comparative Example 1 23.2 85 111.9
  • the supported catalysts obtained in Examples 1 to 4 showed better CNT yields even though the amount of metal supported was less than that of Comparative Example 1, and the bulk density was lower to obtain a larger diameter CNT. It can be seen that.
  • FIGS. 7 and 8 show low and high magnification SEM images of the CNT aggregates obtained in Example 1
  • FIGS. 9 and 10 show low and high magnification SEM images of the CNT aggregates obtained in Example 2
  • FIGS. 11 and FIG. 12 shows low and high magnification SEM images of the CNT aggregates obtained in Example 3
  • FIGS. 13 and 14 show low and high magnification SEM images of the CNT aggregates obtained in Example 14.
  • FIG. 7 to FIG. 14 when the CNT is prepared using the supported catalyst obtained according to the present invention, it can be confirmed that a large diameter CNT having a shape substantially close to a spherical shape and having a larger diameter is obtained. .
  • FIG. 15 is a SEM image of the CNT obtained in Example 1
  • FIG. 16 is an enlarged view of region A of FIG. 15
  • FIG. 17 is an enlarged view of region B of FIG. 15. It can be seen from FIGS. 16 and 17 that the CNTs obtained using the supported catalyst of the present invention have a secondary structure in the form of bundles.

Abstract

The present invention relates to: carbon nanotubes, which are grown on a supported catalyst having a catalyst component and an active component supported on a spherical α-alumina support, and have a BET specific surface area of 1-50 m2/g and a bulk density of 60-250 kg/m3; and a preparation method therefor.

Description

고밀도 번들형 카본나노튜브 및 그의 제조방법High Density Bundled Carbon Nanotubes and Manufacturing Method Thereof
본 출원은 2015.02.06.자 한국 특허출원 제10-2015-0018733호에 기초한 우선권의 이익을 주장하며, 해당 한국 특허 출원의 문헌에 개시된 모든 내용은 본 명세서의 일부로서 포함된다.This application claims the benefit of priority based on Korean Patent Application No. 10-2015-0018733 filed on February 6, 2015, and all contents disclosed in the literature of the Korean patent application are included as part of the present specification.
본 발명은 고밀도 번들형 카본나노튜브 및 그의 제조방법에 관한 것이다.The present invention relates to a high density bundled carbon nanotubes and a method of manufacturing the same.
일반적으로 카본나노튜브(이하, 'CNT'라 한다)란 대략 3 내지 150㎚, 구체적으로는 약 3 내지 100㎚의 직경을 갖고, 길이가 직경의 수배, 예를 들어 100배 이상인 원통형 탄소 튜브를 지칭한다. 이러한 CNT는 정렬된 탄소 원자의 층으로 이루어지고, 상이한 형태의 코어를 갖는다. 또한, 이러한 CNT는 예를 들면 탄소 피브릴 또는 중공 탄소 섬유라고도 불린다.Generally, carbon nanotubes (hereinafter referred to as 'CNT') are cylindrical carbon tubes having a diameter of about 3 to 150 nm, specifically about 3 to 100 nm, and having a length several times the diameter, for example, 100 times or more. Refers to. These CNTs consist of layers of aligned carbon atoms and have different types of cores. Such CNTs are also called carbon fibrils or hollow carbon fibers, for example.
한편, 이와 같은 CNT는 크기 및 특정 물성으로 인해 복합재의 제조에서 산업적으로 중요하고, 전자 소재 분야, 에너지 소재 분야 및 기타 여러 분야에서 높은 활용성을 갖고 있다.On the other hand, such CNTs are industrially important in the production of composites due to their size and specific properties, and have high utility in the field of electronic materials, energy materials and many other fields.
상기 CNT는 일반적으로 아크 방전법, 레이저 증발법, 화학 기상 증착법 등에 의하여 제조할 수 있다. 이들 중, 아크 방전법 및 레이저 증발법은 대량 생산이 어렵고, 과다한 아크 생산 비용 또는 레이저 장비 구입 비용으로 인해 경제성이 저하된다는 문제가 있다.The CNT can be generally manufactured by an arc discharge method, a laser evaporation method, a chemical vapor deposition method, or the like. Among these, the arc discharge method and the laser evaporation method is difficult to mass-produce, there is a problem that the economical efficiency is lowered due to excessive arc production cost or laser equipment purchase cost.
상기 화학 기상 증착법의 경우는, 기상 분산 촉매를 사용하는 방법인 경우 합성속도가 매우 더디고 합성되는 CNT의 입자가 너무 작은 문제가 있으며, 기판 담지 촉매를 사용하는 방법인 경우 반응기 내의 공간 이용 효율이 크게 떨어져 CNT의 대량 생산에 한계가 있다.In the case of the chemical vapor deposition method, there is a problem in that the synthesis rate is very slow in the case of using a gas phase dispersion catalyst, and the particles of CNTs synthesized are too small. There is a limit to the mass production of CNT off.
상기 화학기상 증착법에 사용되는 촉매는 촉매활성 성분이 산화물 형태, 부분 또는 완전 환원된 형태, 또는 수산화물 형태를 가지며, 통상적으로 CNT 제조에 사용될 수 있는 카본나노튜브 촉매, 공침촉매 등일 수 있다. 이중 카본나노튜브 촉매를 사용하는 것이 바람직한데, 이는 카본나노튜브 촉매가 사용되는 경우 촉매 자체의 벌크 밀도가 공침 촉매에 비해 높고 공침 촉매와 달리 10 마이크론 이하의 미분이 적어 유동화 과정에서 발생할 수 있는 마모(attrition)에 의한 미분발생 가능성을 줄일 수 있으며, 촉매 자체의 기계적 강도도 우수하여 반응기 운전을 안정하게 할 수 있는 효과를 갖기 때문이다.The catalyst used in the chemical vapor deposition method may be a carbon nanotube catalyst, a co-precipitation catalyst, etc., in which the catalytically active component has an oxide form, a partially or completely reduced form, or a hydroxide form, and can be generally used for preparing CNTs. It is preferable to use a double carbon nanotube catalyst, which is because when the carbon nanotube catalyst is used, the bulk density of the catalyst itself is higher than that of the coprecipitation catalyst, and unlike the coprecipitation catalyst, the fineness of less than 10 microns is reduced, which may occur in the fluidization process. This is because the possibility of fine powder generation by attrition can be reduced, and the mechanical strength of the catalyst itself is also excellent, which can stabilize the reactor operation.
또한, 이 같은 카본나노튜브 촉매의 제조 방법으로는 금속수용액과 지지체를 혼합한 다음 코팅-건조시켜 촉매를 제조하는 기술(함침법)이 제시되고 있으며, 이때 지지체로서는 다공성 구조체가 주로 사용되고 있다. 이 경우, 제조된 촉매는 CNT 합성시 생성량 대비 높은 금속 담지량이 요구되므로 효율성이 낮다는 문제가 있다.In addition, as a method of preparing such a carbon nanotube catalyst, a technique (impregnation method) of preparing a catalyst by mixing a metal aqueous solution and a support followed by coating-drying is proposed, and a porous structure is mainly used as a support. In this case, the prepared catalyst has a problem that the efficiency is low because a high metal loading amount compared to the amount produced during CNT synthesis.
본 발명이 해결하고자 하는 과제는,The problem to be solved by the present invention,
CNT 합성시 낮은 금속 담지량으로도 높은 수율을 얻을 수 있는 CNT 합성용 담지촉매를 제공하는 것이다.It is to provide a supported catalyst for CNT synthesis that can obtain a high yield even with a low metal loading in the synthesis of CNTs.
본 발명이 해결하고자 하는 다른 과제는,Another problem to be solved by the present invention,
상기 CNT 합성용 담지촉매의 제조방법을 제공하는 것이다.It is to provide a method for preparing the supported catalyst for CNT synthesis.
본 발명이 해결하고자 하는 또 다른 과제는,Another problem to be solved by the present invention,
상기 CNT 합성용 담지촉매를 사용하여 수득되는 CNT를 제공하는 것이다.It is to provide a CNT obtained by using the supported catalyst for CNT synthesis.
본 발명이 해결하고자 하는 또 다른 과제는,Another problem to be solved by the present invention,
상기 CNT 합성용 담지촉매를 사용하여 CNT를 합성하는 제조방법을 제공하는 것이다.It is to provide a method for synthesizing CNTs using the supported catalyst for synthesizing CNTs.
상기 과제를 해결하기 위하여 본 발명은,The present invention to solve the above problems,
구형상 α-알루미나 지지체에 촉매성분 및 활성성분이 지지되어 있는 담지촉매 상에 성장되어 있으며, It is grown on a supported catalyst on which a catalyst component and an active component are supported on a spherical α-alumina support.
BET 비표면적이 1 내지 50m2/g 이고, 벌크밀도가 60 내지 250kg/m3인 것인 카본나노튜브를 제공한다.It provides a carbon nanotubes having a BET specific surface area of 1 to 50 m 2 / g and a bulk density of 60 to 250 kg / m 3 .
상기 카본나노튜브는 번들 형태의 2차 구조를 갖는 것일 수 있다.The carbon nanotubes may have a secondary structure in the form of a bundle.
또한, 상기 담지촉매는 함침법에 의해 얻어질 수 있다.In addition, the supported catalyst can be obtained by an impregnation method.
일구현예에 따르면, 상기 촉매성분 및 활성성분의 합계 함량이 상기 구형상 α-알루미나 100중량부를 기준으로 10 내지 25중량부일 수 있다.According to one embodiment, the total content of the catalyst component and the active ingredient may be 10 to 25 parts by weight based on 100 parts by weight of the spherical α-alumina.
일구현예에 따르면, 상기 촉매성분 및 활성성분의 중량비가 10 내지 30 : 1 내지 14일 수 있다.According to one embodiment, the weight ratio of the catalyst component and the active ingredient may be 10 to 30: 1 to 14.
또한, 상기 촉매성분은 Fe, Co 또는 Ni 중 1종 이상일 수 있다.In addition, the catalyst component may be at least one of Fe, Co or Ni.
일구현예에 따르면, 상기 담지촉매의 울트라소닉 미분량이 5% 이내일 수 있다.According to one embodiment, the ultrasonic fraction of the supported catalyst may be within 5%.
또한, 상기 다른 과제를 해결하기 위하여 본 발명은,In addition, the present invention to solve the other problem,
촉매성분 전구체 및 활성성분 전구체를 포함하는 금속 수용액에 구형상 α-알루미나 지지체를 혼합하여 담지촉매 전구체 함유 수용액을 형성하는 단계;Forming a supported catalyst precursor-containing aqueous solution by mixing a spherical α-alumina support with an aqueous metal solution containing a catalyst component precursor and an active component precursor;
상기 담지촉매 전구체 함유 수용액을 숙성 함침시켜 혼합물을 수득하는 단계;Aging and impregnating the supported catalyst precursor-containing aqueous solution to obtain a mixture;
상기 혼합물을 진공건조하여 상기 지지체 표면에 상기 촉매성분 및 활성성분을 코팅하는 단계;Vacuum drying the mixture to coat the catalyst component and the active ingredient on the support surface;
상기 진공건조에 의해 얻어진 결과물을 소성하여 담지촉매를 형성하는 단계; Calcining the resultant obtained by vacuum drying to form a supported catalyst;
상기 담지촉매를 반응기 내부에 투입하고, 약 500 내지 900℃의 온도에서 반응기 내부로 탄소 공급원 또는 상기 탄소공급원과 수소가스, 질소가스 또는 이들의 혼합가스를 주입하는 단계; 및Injecting the supported catalyst into a reactor and injecting a carbon source or the carbon source and hydrogen gas, nitrogen gas, or a mixture thereof into the reactor at a temperature of about 500 to 900 ° C .; And
상기 촉매 표면 위에서 주입된 탄소 공급원의 분해를 통해 카본나노튜브를 성장시키는 단계;를 포함하는 카본나노튜브의 제조방법을 제공한다.It provides a method for producing carbon nanotubes comprising the step of growing carbon nanotubes by decomposition of the carbon source injected on the catalyst surface.
일구현예에 따르면, 상기 금속 수용액의 농도가 0.1 내지 0.4 g/ml일 수 있다.According to one embodiment, the concentration of the aqueous metal solution may be 0.1 to 0.4 g / ml.
일구현예에 따르면, 상기 숙성 함침 공정이 20℃ 내지 100℃의 온도에서 30분 내지 15시간 동안 수행될 수 있다.According to one embodiment, the aging impregnation process may be performed for 30 minutes to 15 hours at a temperature of 20 ℃ to 100 ℃.
또한, 상기 소성온도는 550℃ 내지 800℃일 수 있다.In addition, the firing temperature may be 550 ℃ to 800 ℃.
또한, 일구현예에 따르면, 상기 진공 건조 공정 이후 상기 소성 공정 이전에 250 내지 400℃ 하의 예비 소성을 1회 이상 수행하는 단계를 더 포함할 수 있다.In addition, according to one embodiment, after the vacuum drying process and before the firing process may further comprise the step of performing at least one preliminary baking at 250 to 400 ℃.
종래의 CNT 제조용 담지촉매가 생성량 대비 높은 금속 담지량이 요구되었던 것과 달리, 본 발명의 담지촉매는 구형상 α-알루미나 지지체를 사용함으로써 낮은 금속 담지량에서도 동등 수준 이상의 CNT 수율을 얻을 수 있다. 더욱이 본 발명의 CNT 합성용 담지촉매는 CNT 성장을 효율적으로 제어하여 번들 타입의 고밀도 CNT를 합성하는 것이 가능해진다.Unlike conventional supported catalysts for producing CNTs, which require a higher metal loading than the production amount, the supported catalysts of the present invention can obtain CNT yields equal to or higher than those of low metals by using a spherical α-alumina support. Furthermore, the supported catalyst for synthesizing CNTs of the present invention can efficiently control CNT growth to synthesize bundle type high density CNTs.
도 1은 실시예 1 내지 4에서 사용된 지지체의 SEM 화상을 나타낸다.1 shows SEM images of the supports used in Examples 1-4.
도 2는 실시예 1에서 얻어진 담지촉매의 SEM 화상을 나타낸다.2 shows an SEM image of the supported catalyst obtained in Example 1. FIG.
도 3은 비교예 1에서 사용된 지지체의 SEM 화상을 나타낸다.3 shows an SEM image of the support used in Comparative Example 1. FIG.
도 4는 비교예 1에서 얻어진 담지촉매의 SEM 화상을 나타낸다.4 shows an SEM image of the supported catalyst obtained in Comparative Example 1. FIG.
도 5는 비교예 1에서 얻어진 CNT의 저배율 SEM 화상을 나타낸다.5 shows a low magnification SEM image of CNTs obtained in Comparative Example 1. FIG.
도 6은 비교예 1에서 얻어진 CNT의 고배율 SEM 화상을 나타낸다.6 shows a high magnification SEM image of CNTs obtained in Comparative Example 1. FIG.
도 7은 실시예 1에서 얻어진 CNT의 저배율 SEM 화상을 나타낸다.7 shows a low magnification SEM image of the CNT obtained in Example 1. FIG.
도 8은 실시예 1에서 얻어진 CNT의 고배율 SEM 화상을 나타낸다.8 shows a high magnification SEM image of the CNT obtained in Example 1. FIG.
도 9는 실시예 2에서 얻어진 CNT의 저배율 SEM 화상을 나타낸다.9 shows a low magnification SEM image of CNTs obtained in Example 2. FIG.
도 10은 실시예 2에서 얻어진 CNT의 고배율 SEM 화상을 나타낸다.10 shows a high magnification SEM image of the CNT obtained in Example 2. FIG.
도 11은 실시예 3에서 얻어진 CNT의 저배율 SEM 화상을 나타낸다.11 shows a low magnification SEM image of CNTs obtained in Example 3. FIG.
도 12는 실시예 3에서 얻어진 CNT의 고배율 SEM 화상을 나타낸다.12 shows a high magnification SEM image of the CNT obtained in Example 3. FIG.
도 13은 실시예 4에서 얻어진 CNT의 저배율 SEM 화상을 나타낸다.FIG. 13 shows a low magnification SEM image of CNTs obtained in Example 4. FIG.
도 14는 실시예 4에서 얻어진 CNT의 고배율 SEM 화상을 나타낸다.14 shows a high magnification SEM image of the CNT obtained in Example 4. FIG.
도 15는 실시예 1에서 얻어진 CNT의 SEM 화상을 나타낸다.15 shows an SEM image of the CNT obtained in Example 1. FIG.
도 16은 도 15의 A 영역에 대한 SEM 화상을 나타낸다.FIG. 16 shows an SEM image of region A of FIG. 15.
도 17은 도 15의 B 영역에 대한 SEM 화상을 나타낸다.FIG. 17 shows an SEM image of region B of FIG. 15.
본 명세서 및 청구범위에 사용된 용어나 단어는 통상적이거나 사전적인 의미로 한정해서 해석되어서는 안되며, 발명자는 그 자신의 발명을 가장 최선의 방법으로 설명하기 위해 용어의 개념을 적절하게 정의할 수 있다는 원칙에 입각하여 본 발명의 기술적 사상에 부합하는 의미와 개념으로 해석되어야만 한다.The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best describe their invention. Based on the principle, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.
이하, 본 발명을 상세히 설명하기로 한다.Hereinafter, the present invention will be described in detail.
일태양에 따른 CNT 합성용 담지 촉매는 Al계 지지체에 촉매성분 및 활성성분이 지지되어 있으며, 상기 Al계 지지체는 구형상 α-알루미나를 포함할 수 있다.According to one embodiment, the supported catalyst for synthesizing CNTs is supported on an Al-based support with a catalyst component and an active component, and the Al-based support may include spherical α-alumina.
일반적으로, Al2O3의 화학식을 갖는 알루미나는 여러 개의 상이한 상, 예를 들어 α-, γ-, δ-, η-, θ- 및 Χ-알루미나로 존재한다. α-알루미나(코런덤)에서, 옥사이드 이온은 육면체의 밀집 패킹된 구조를 형성하고, 알루미나 이온이 팔면체 틈새 중에 대칭적으로 분포된다. 마찬가지로, γ-알루미나는 "결함 있는" 스피넬 구조 (양이온이 없는 스피넬 구조)를 갖는다.In general, alumina having a chemical formula of Al 2 O 3 is present in several different phases, for example α-, γ-, δ-, η-, θ- and Χ-alumina. In α-alumina (corundum), the oxide ions form a hexagonally packed structure and the alumina ions are symmetrically distributed in the octahedral gap. Likewise, γ-alumina has a "defective" spinel structure (the cation free spinel structure).
본 발명의 일구현예에서, 촉매의 지지체는 α-알루미나를 포함할 수 있다. γ-알루미나가 높은 다공성으로 인해 촉매 지지체로서 활용성이 높지만, α-알루미나는 다공성이 매우 낮아 촉매 지지체로서의 활용성이 매우 낮은 것으로 알려져 있다. 놀랍게도 상기 α-알루미나가 구형상인 경우, 이를 촉매 지지체로서 사용하는 CNT 제조방법이 다른 형태 및 결정 구조를 갖는 알루미나를 촉매 지지체로서 사용하는 공정과 비교 시, 낮은 금속 담지량으로도 높은 수율의 CNT를 생성할 수 있으며, 결과물 CNT의 형상에 있어서도 번들 타입의 구형상이 선택적으로 얻어질 수 있음을 발견하였다.In one embodiment of the invention, the support of the catalyst may comprise α-alumina. Although γ-alumina has high utility as a catalyst support due to its high porosity, α-alumina is known to have a very low utility as a catalyst support due to its very low porosity. Surprisingly, when the α-alumina is spherical, the CNT production method using the same as the catalyst support produces a high yield of CNTs even with a low metal loading when compared to a process using alumina having a different form and crystal structure as the catalyst support. It has been found that a bundle type spherical shape can be selectively obtained also in the shape of the resultant CNT.
본 발명에서 사용하는 구형상의 α-알루미나에서 "구형상"이라는 용어는 완전한 구형상 외에도 실질적으로 구형상인 경우를 포함하며, 포테이토 형상과 같이 단면이 타원 형상을 갖는 경우도 포함할 수 있다.In the spherical α-alumina used in the present invention, the term "spherical" includes a case that is substantially spherical in addition to a perfect sphere, and may include a case having an elliptic cross section such as a potato shape.
일구현예에 따르면, 상기 구형상 α-알루미나는 당업계에 공지된 방법으로 제조될 수 있다. 예를 들어, 보크사이트(bauxite)로부터 알루미나를 제조하기 위한 베이어(Bayer) 방법이 산업적으로 널리 사용된다. 마찬가지로, 구형상 α-알루미나는 γ-Al2O3 또는 임의의 수소함유(hydrous) 옥시드를 1000℃ 초과로 가열시켜서 제조할 수 있다. 상기 구형상 α-알루미나는 염화 알루미늄이나 질산 알루미늄 등의 수용성 전구체를 물에 녹인 후, 암모니아 수용액이나 가성소다 수용액을 이용하여 pH를 약 8 이상, 바람직하게는 약 9 이상, 더욱 바람직하게는 약 10 정도로 조절한 다음, 분무 건조(spray drying)를 통하여 파우더를 제조한 후, 이를 약 1000℃ 이상, 바람직하게는 1100 내지 1300℃, 더욱 바람직하게는 약 1200℃ 온도에서 소성하여 제조할 수 있으나, 이에 한정되는 것은 아니다.According to one embodiment, the spherical α-alumina can be prepared by methods known in the art. For example, the Bayer method for producing alumina from bauxite is widely used industrially. Likewise, spherical α-alumina can be prepared by heating γ-Al 2 O 3 or any hydrogen oxide above 1000 ° C. The spherical α-alumina is dissolved in water-soluble precursors such as aluminum chloride or aluminum nitrate in water, and then the pH is about 8 or more, preferably about 9 or more, more preferably about 10 using an aqueous ammonia solution or a caustic soda solution. After adjusting to a degree, the powder may be prepared by spray drying and then calcined at a temperature of about 1000 ° C. or higher, preferably 1100 to 1300 ° C., more preferably about 1200 ° C., but It is not limited.
본 발명에서 지지체로서 사용되는 구형상 α-알루미나는 임의의 적합한 치수로 된 것일 수 있다. 예를 들어, 본 발명에서 사용된 구형상 α-알루미나는 BET법으로 측정 시 예를 들어, 약 1m2/g 내지 약 50m2/g의 표면적을 가질 수 있고, 예를 들어, 1 내지 30m2/g, 예를 들어, 1 내지 20m2/g, 예를 들어, 1 내지 10 m2/g의 표면적을 가질 수 있다.The spherical α-alumina used as the support in the present invention may be of any suitable dimension. For example, a spherical α- alumina used in this invention as measured by the BET method, for example, may have a surface area of from about 1m 2 / g to about 50m 2 / g, for example, 1 to 30m 2 / g, for example 1 to 20 m 2 / g, for example 1 to 10 m 2 / g.
본 발명에서는 지지체로서 사용되는 구형상 α-알루미나는 종래의 지지체와 달리 표면이 매끄러워 매우 낮은 기공도를 가지며, 예를 들어 0.001 내지 0.1cm3/g, 예를 들어 0.005 내지 0.05cm3/g의 기공부피를 가질 수 있다.In the present invention, the spherical α- alumina used as the support has a very low porosity is smooth and even surface, unlike a conventional support, for example from 0.001 to 0.1cm 3 / g, for example from 0.005 to 0.05cm 3 / g It can have a pore volume of.
지지체인 상기 구형상 α-알루미나는 비교적 낮은 함량의 금속이 담지될 수 있으며, 상기 금속으로서 예를 들어 촉매성분 및 활성성분이 상기 구형상 α-알루미나 100중량부를 기준으로 약 10 내지 25중량부, 또는 약 15 내지 20중량부의 함량으로 담지될 수 있다. 이와 같은 담지 함량에서 충분한 촉매 활성을 나타낼 수 있다.The spherical α-alumina, which is a support, may be loaded with a relatively low content of metal, for example, about 10 to 25 parts by weight of the catalyst component and the active component based on 100 parts by weight of the spherical α-alumina, Or in an amount of about 15 to 20 parts by weight. Sufficient catalytic activity can be exhibited at such supported contents.
상기 구형상 α-알루미나에 담지되는 촉매성분 및 활성성분은 10 내지 30 : 1 내지 14의 중량비의 함량으로 사용할 수 있으며, 이러한 함량 범위에서 보다 나은 CNT 제조 활성을 나타낼 수 있게 된다.The catalyst component and the active component supported on the spherical α-alumina can be used in a weight ratio of 10 to 30: 1 to 14, and can exhibit better CNT production activity in this content range.
본 발명에서 사용되는 촉매성분은 Fe, Co 및 Ni로부터 선택된 1종 이상일 수 있으며, 일례로 Fe염, Fe산화물, Fe화합물, Co염, Co산화물, Co화합물, Ni염, Ni산화물, Ni화합물로 이루어진 군으로부터 선택된 1종 이상일 수 있고, 또 다른 일례로 Fe(NO3)2·6H2O, Fe(NO3)2·9H2O, Ni(NO3)2·6H2O, Co(NO3)2·6H2O 와 같은 질화물 등일 수 있다.The catalyst component used in the present invention may be one or more selected from Fe, Co and Ni, for example Fe salt, Fe oxide, Fe compound, Co salt, Co oxide, Co compound, Ni salt, Ni oxide, Ni compound It may be one or more selected from the group consisting of, and as another example Fe (NO 3 ) 2 · 6H 2 O, Fe (NO 3 ) 2 · 9H 2 O, Ni (NO 3 ) 2 · 6H 2 O, Co (NO 3 ) a nitride such as 2 · 6H 2 O, or the like.
또한, 본 발명에서 사용되는 활성성분은 일례로, Mo 및 V 중 1종 이상일 수 있고, 다른 일례로 Mo염, Mo산화물, Mo화합물, V염, V산화물, V화합물 등일 수 있으며, 또 다른 일례로 (NH4)6Mo7O24·4H2O와 같은 질화물 등을 증류수에 용해시켜 사용할 수 있다.In addition, the active ingredient used in the present invention may be, for example, one or more of Mo and V, another example may be Mo salt, Mo oxide, Mo compound, V salt, V oxide, V compound, etc. Another example Nitrogen such as (NH 4 ) 6 Mo 7 O 24 4H 2 O and the like can be dissolved and used in distilled water.
상술한 바와 같은 본 발명의 CNT 합성용 담지촉매는 함침법에 의해 제조할 수 있다.The supported catalyst for synthesizing CNTs of the present invention as described above can be prepared by the impregnation method.
일 구현예에 따르면,According to one embodiment,
(1) 촉매성분 전구체 및 활성성분 전구체를 포함하는 금속 수용액에 Al계 지지체를 혼합하여 담지촉매 전구체 함유 수용액을 형성하는 단계;(1) mixing an Al-based support with an aqueous metal solution containing a catalyst component precursor and an active component precursor to form a supported catalyst precursor-containing aqueous solution;
(2) 상기 담지촉매 전구체 함유 수용액을 숙성 함침시켜 혼합물을 수득하는 단계;(2) aging and impregnating the supported catalyst precursor-containing aqueous solution to obtain a mixture;
(3) 상기 혼합물을 진공건조하여 상기 지지체 표면에 상기 촉매성분 및 활성성분을 코팅하는 단계; 및(3) vacuum drying the mixture to coat the catalyst component and active ingredient on the support surface; And
(4) 상기 진공건조에 의해 얻어진 결과물을 소성하여 담지촉매를 형성하는 단계;를 포함하며,(4) baking the resultant obtained by the vacuum drying to form a supported catalyst;
상기 Al계 지지체가 구형상 α-알루미나인 CNT 합성용 담지촉매의 제조방법을 제공한다.Provided is a method for preparing a supported catalyst for synthesizing CNTs, wherein the Al-based support is spherical α-alumina.
상기 제조방법 중 (1) 단계에서 담지촉매 전구체 함유 수용액을 형성하게 되며, 이 수용액은 촉매성분 전구체 및 활성성분 전구체를 포함하는 금속 수용액에 Al계 지지체를 혼합하여 형성하게 되며, 이때 촉매성분, 활성성분 및 구형상 α-알루미나 지지체를 포함하며, 이들에 대해서는 이미 상술한 바와 같다.In the step (1) of the preparation method to form an aqueous solution containing the supported catalyst precursor, the aqueous solution is formed by mixing the Al-based support in the aqueous metal solution containing the catalyst component precursor and the active component precursor, wherein the catalyst component, active Components and spherical α-alumina supports, which have already been described above.
상기 금속 수용액의 농도는 함침 효율을 고려할 때, 예를 들어 0.1 내지 0.4 g/ml, 혹은 0.1 내지 0.3 g/ml의 범위를 사용하는 것이 보다 효율적이다. 이와 같은 금속 수용액에 혼합되는 구형상 α-알루미나 지지체의 함량은 이미 상술한 바와 같이, 예를 들어 촉매성분 및 활성성분이 상기 구형상 α-알루미나 100중량부를 기준으로 약 10 내지 25중량부, 또는 약 15 내지 20중량부의 함량으로 담지되도록 사용할 수 있다.In consideration of the impregnation efficiency, the concentration of the metal aqueous solution is more efficient to use, for example, 0.1 to 0.4 g / ml, or 0.1 to 0.3 g / ml. As described above, the content of the spherical α-alumina support mixed with the aqueous metal solution may be, for example, about 10 to 25 parts by weight based on 100 parts by weight of the spherical α-alumina, or It can be used to be supported in an amount of about 15 to 20 parts by weight.
상기 제조방법 중 (2) 단계에서 상기 담지촉매 전구체 용액을 숙성 함침하여 혼합물을 수득하게 되며, 이때 숙성 함침은 이에 한정하는 것은 아니나, 20℃ 내지 100℃, 혹은 60 내지 100℃의 온도범위에서 30분 내지 15시간, 혹은 1 내지 15시간 동안 수행할 수 있으며, 이와 같은 범위에서 높은 담지 효율을 제공할 수 있게 된다.Aging impregnation of the supported catalyst precursor solution in step (2) of the preparation method to obtain a mixture, wherein the impregnation is not limited to this, but 30 ℃ in the temperature range of 20 ℃ to 100 ℃, or 60 to 100 ℃ It can be carried out for minutes to 15 hours, or 1 to 15 hours, it is possible to provide a high supporting efficiency in this range.
상기 제조방법 중 (3) 단계에서는 상기 (2) 단계에서 얻어진 숙성 함침의 결과물인 혼합물을 진공건조하여 지지체 표면에 촉매성분 및 활성성분을 코팅하게 된다. 상기 진공 건조는 진공 하에 회전 증발시켜 건조시키는 것으로, 예를 들어 45 내지 80℃ 하에 1시간 이내, 혹은 1분 내지 1시간 범위에서 수행할 수 있으며, 지지체에 함침되지 않고 남아있는 여분의 금속염을 건조 공정을 통해 균일한 알루미나 표면의 코팅 함침을 제공할 수 있게 된다.In step (3) of the production method, the mixture resulting from the aging impregnation obtained in step (2) is vacuum dried to coat the catalyst component and the active ingredient on the surface of the support. The vacuum drying is to dry by rotary evaporation under vacuum, for example, can be carried out within 1 hour, or 1 minute to 1 hour under 45 to 80 ℃, drying the excess metal salt remaining without impregnation in the support The process makes it possible to provide a coating impregnation of a uniform alumina surface.
본 명세서에 기재된 진공 건조에서 "진공"의 의미는 통상적으로 진공 건조에 적용되는 진공 범위에 해당되는 경우 특별히 제한되지 않는다.The meaning of "vacuum" in the vacuum drying described herein is not particularly limited as long as it corresponds to the vacuum range that is typically applied to vacuum drying.
상기 제조방법 중 (4) 단계에서는 상기 (3) 단계의 진공건조에 의해 얻어진 결과물을 소성하여 최종 결과물인 본 발명의 담지촉매를 형성하게 되며, 이와 같은 소성은 약 550 내지 800℃, 또는 약 600℃ 내지 700℃의 범위에서 수행할 수 있으며, 공기 중에서 또는 불활성 대기 하에서 수행할 수 있다. 상기 소성 시간은 이에 한정하는 것은 아니나, 약 30분 내지 5시간 내에서 수행할 수 있다.In step (4) of the production method, the resultant obtained by vacuum drying in step (3) is fired to form a supported catalyst of the present invention, which is a final result, and such firing is about 550 to 800 ° C, or about 600 It may be carried out in the range of ℃ to 700 ℃, it can be carried out in the air or under an inert atmosphere. The firing time is not limited thereto, but may be performed within about 30 minutes to 5 hours.
일구현예에 따르면, 상기 (3) 단계의 진공 건조 후, 상기 (4) 단계의 소성 전, 약 250 내지 400℃ 하에 예비 소성을 1회 이상 수행할 수 있는데, 이 경우 상기 예비 소성 직전에 전체 담지촉매 전구체 수용액 중 최대 50%를 상기 구형상 α-알루미나 지지체에 함침시켜 사용하고, 상기 예비 소성 직후 또는 소성 직전에 담지촉매 전구체 수용액 잔부를 상기 구형상 α-알루미나 지지체에 함침시켜 사용하는 것이 반응의 효율성 측면에서 바람직하다.According to one embodiment, after the vacuum drying of the step (3), before the firing of the step (4), the pre-baking may be carried out one or more times at about 250 to 400 ℃, in this case immediately before the pre-firing Up to 50% of the supported catalyst precursor aqueous solution is impregnated with the spherical α-alumina support, and the remainder of the supported catalyst precursor aqueous solution is impregnated with the spherical α-alumina support immediately after or immediately before firing. It is desirable in terms of efficiency.
이에 한정하는 것은 아니나, 상기와 같이 제조된 담지촉매의 벌크 형상은 사용된 구형상 α-알루미나 지지체의 벌크 형태에 의존한다. 즉, 상기 CNT 합성용 담지 촉매는 벌크 형상이 구형상이고, 주로 지지체의 표면에 촉매 성분이 일층 혹은 다층(2층 또는 3층 이상) 코팅된 구조를 가질 수 있으며, 이들은 연속된 코팅층 구조를 가지기 보다는 불연속된 코팅 구조를 가지는 것이 CNT 합성 측면에서 바람직할 수 있다.Although not limited thereto, the bulk shape of the supported catalyst prepared as described above depends on the bulk shape of the spherical α-alumina support used. That is, the supported catalyst for synthesizing CNTs may have a spherical bulk shape and mainly have a structure in which a catalyst component is coated on one or multiple layers (two or three or more layers) on the surface of the support, and these may not have a continuous coating layer structure. It may be desirable to have a discontinuous coating structure in terms of CNT synthesis.
본 발명에서 제공되는 상기 CNT 제조용 담지촉매는, 일례로 입경 혹은 평균입경이 약 30 내지 약 150 ㎛이고, SEM 관찰시 표면 입도가 약 10 내지 100 ㎚의 범위를 가질 수 있으며, 이 범위에서 CNT 직경 조절 및 촉매 활성 측면에서 바람직하다.The supported catalyst for preparing CNTs provided by the present invention may have, for example, a particle size or an average particle diameter of about 30 to about 150 μm, and a surface particle size of SEM observation in a range of about 10 to 100 nm, in which CNT diameter Preferred in terms of control and catalytic activity.
한편, 상기 구형상 α-알루미나 지지체 표면에 촉매성분과 활성성분이 코팅된 담지 촉매는 상기 알루미나 지지체의 입경 혹은 평균 입경 범위를 고려하여 수 입경 측정 기준으로 32㎛ 이하의 입경을 울트라소닉(ultrasonic) 미분량으로 정의할 때, 개수 평균입경 측정치가 5% 이내, 구체적으로는 3% 이내의 범위를 가질 수 있다.On the other hand, the supported catalyst coated with the catalyst component and the active ingredient on the surface of the spherical α-alumina support is ultrasonic (ultrasonic) having a particle size of 32 μm or less based on the particle size measurement standard in consideration of the particle size or the average particle size range of the alumina support. When defined as a differential amount, the number average particle size measurement may have a range of 5% or less, specifically 3% or less.
참고로, 상기 울트라소닉 공정에서 미분은 촉매에 붙어있는 촉매물질과 활성 물질의 응집체로서, 체로 쳤을 때는 걸러져 나오지 않으나, 지지체에 잘 코팅된 촉매-활성 물질과는 입도가 다르고 촉매 활성 또한 상이한 것으로, 이와 같이 촉매에 붙어 있는 섬(island)형 응집체로 인해 CNT 수율이 현저히 떨어지며, 상기 물질들은 다소 약하게 촉매에 붙어 있기 때문에 울트라소닉시 분리되어 미분이 생성되는 것이다.For reference, in the ultrasonic process, the fine powder is an aggregate of the catalyst material and the active material attached to the catalyst, and is not filtered out when sieved, but is different in particle size and catalyst activity from the catalyst-active material well coated on the support. As such, island-like aggregates attached to the catalyst significantly lower the yield of CNTs, and because the materials are rather weakly attached to the catalyst, they are separated at the time of ultrasonication to generate fine powder.
본 발명에서 상기 울트라소닉 미분량은 울트라소닉 처리 후 입도 분석기를 통해 측정된 개수 평균입경 미분량을 의미하는 것으로, 이때 상기 담지란 다층 담지를 포함한다.In the present invention, the ultrasonic differential amount refers to the number average particle diameter differential amount measured by the particle size analyzer after the ultrasonic treatment, wherein the support includes a multilayer support.
특히 본 발명에 의해 수득된 CNT 합성용 담지 촉매는 비표면적을 고려할 때 구형인 것이 바람직하며, 도 1의 SEM 사진에서 보듯이, 실제 본 발명에서 제조한 CNT 합성용 담지촉매 또한 구형, 거의 구형, 또는 실질적으로 구형에 가까움을 규명하였다.In particular, the supported catalyst for synthesizing CNTs obtained by the present invention is preferably spherical in consideration of specific surface area, and as shown in the SEM photograph of FIG. 1, the supported catalyst for synthesizing CNTs synthesized in the present invention is also spherical, almost spherical, Or substantially close to a sphere.
상술한 방법으로 수득된 담지촉매로부터 CNT를 제조하는 공정은 다음과 같은 단계를 포함하나, 이에 한정되는 것은 아니다:The process for preparing CNTs from the supported catalyst obtained by the above-described method includes, but is not limited to:
상기 본 발명에 따른 담지촉매를 반응기 내부에 투입하고, 약 500 내지 900℃의 온도에서 반응기 내부로 탄소 공급원 또는 상기 탄소공급원과 수소가스, 질소가스 또는 이들의 혼합가스를 주입하는 단계; 및Injecting a supported catalyst according to the present invention into a reactor and injecting a carbon source or the carbon source and hydrogen gas, nitrogen gas, or a mixed gas thereof into the reactor at a temperature of about 500 to 900 ° C .; And
상기 촉매 표면 위에서 주입된 탄소 공급원의 분해를 통해 카본나노튜브를 성장시키는 단계.Growing carbon nanotubes through decomposition of the carbon source injected on the catalyst surface.
일구현예에 따르면, 상기 반응기로서는 고정층 반응기, 또는 유동층 반응기를 제한 없이 사용할 수 있다.According to one embodiment, the reactor may be a fixed bed reactor or a fluidized bed reactor without limitation.
본 발명의 제조방법에 따르면, 하기 실시예에서 규명된 바와 같이, 번들 형태의 2차 구조를 가지며, 구형의 벌크 형상을 갖는 CNT를, 상기 담지촉매의 금속 담지량 대비 높은 수율로 합성하는 것이 가능해진다.According to the production method of the present invention, as shown in the following examples, it is possible to synthesize CNTs having a secondary structure in the form of a bundle and having a spherical bulk shape at a higher yield than the amount of metal supported on the supported catalyst. .
상기 제조방법에 따라 얻어지는 본 발명의 CNT는 일례로 벌크 밀도(bulk density) 60 내지 250 kg/m3, 편평률 0.9 내지 1.0, 입도 분포값(Dcnt) 0.5 내지 1.0인 포테이토 또는 구 형상의 번들 타입(bundle type)일 수 있다.CNTs of the present invention obtained according to the production method is a potato or spherical bundle type having a bulk density of 60 to 250 kg / m 3 , flatness 0.9 to 1.0, particle size distribution (Dcnt) 0.5 to 1.0 (bundle type).
본 발명에서 사용되는 용어 "벌크 밀도"는 하기 식 1로 정의된 것으로, 본 발명에 따른 CNT 합성용 담지촉매의 미분량이 적으므로, 이로부터 성장된 CNT의 밀도 분포 또한 특정 범위를 가질 수 있다.The term "bulk density" used in the present invention is defined by the following Equation 1, and because the amount of fine powder of the supported catalyst for synthesizing CNTs according to the present invention is small, the density distribution of CNTs grown therefrom may also have a specific range. .
[식 1][Equation 1]
벌크 밀도= CNT 무게(kg) / CNT 부피 (m3)Bulk Density = CNT Weight (kg) / CNT Volume (m 3 )
또한, 편평률 및 번들 타입은 상술한 본 발명의 담지촉매를 사용하여 제조하는 독특한 공정에 의해 얻어질 수 있다. 이때 편평률은 하기 식 2로 정의된 것이다.In addition, the flatness and the bundle type can be obtained by a unique process prepared using the supported catalyst of the present invention described above. In this case, the flatness ratio is defined by the following Equation 2.
[식 2][Equation 2]
편평률 = CNT의 중심을 관통하는 최단 직경 / CNT의 중심을 관통하는 최대 직경.Flatness = shortest diameter through the center of CNT / maximum diameter through the center of CNT.
나아가, 상기 입도 분포값(Dcnt)는 하기 식 3으로 정의될 수 있다.Further, the particle size distribution value Dcnt may be defined by Equation 3 below.
[식 3][Equation 3]
Dcnt = [Dn90 - Dn10] / Dn50Dcnt = [Dn90-Dn10] / Dn50
식 중, Dn90은 CNT를 증류수에 넣고 3시간 방치 후 Microtrac 입도 분석기를 이용하여 흡수(absorbing) 모드에서 90% 기준하에 측정한 개수 평균 입경이고, Dn10은 10% 기준하에 측정한 개수 평균 입경, 그리고 Dn50은 50% 기준하에 측정한 개수 평균 입경이다.In the formula, Dn90 is the number average particle diameter measured under 90% in absorbing mode using Microtrac particle size analyzer after 3 hours of CNT in distilled water, and Dn10 is the number average particle diameter measured under 10% reference. Dn50 is the number average particle diameter measured on a 50% basis.
또한, 상기 제조방법에 의해 얻어지는 CNT는 입경 혹은 평균 입경 100 내지 800㎛ 및 그 CNT의 가닥 직경이 10 내지 50nm를 만족할 수 있다.In addition, the CNT obtained by the above production method may satisfy a particle diameter or an average particle diameter of 100 to 800 µm and a strand diameter of the CNTs of 10 to 50 nm.
본 발명의 CNT는 전기 분야, 전자 분야, 에너지 분야 등에서 원료로 사용될 수 있고, 또한 플라스틱 분야에서 보강재 등으로 사용될 수 있다. The CNT of the present invention can be used as a raw material in the electric field, the electronic field, the energy field, etc., and can also be used as the reinforcing material in the plastic field.
이하, 본 발명의 이해를 돕기 위하여 실시예를 제시하나, 하기 실시예는 본 발명을 예시하는 것일 뿐 본 발명의 범주 및 기술사상 범위 내에서 다양한 변경 및 수정이 가능함은 본 기술분야에서 통상의 지식을 가진 자에게 있어서 명백한 것이며, 이러한 변형 및 수정이, 첨부된 특허청구범위에 속하는 것도 당연한 것이다.Hereinafter, examples are provided to help the understanding of the present invention, but the following examples are only for exemplifying the present invention, and various changes and modifications can be made within the scope and spirit of the present invention. It will be apparent to those having the invention, and such variations and modifications are within the scope of the appended claims.
실시예 1 내지 4 및 비교예 1Examples 1 to 4 and Comparative Example 1
<CNT 촉매의 제조><Preparation of CNT Catalyst>
촉매금속 전구체로서 하기 표 1에 기재된 함량을 갖는 Fe(NO3)2·9H2O, Co(NO3)2·6H2O, (NH4)6Mo7O24 및 NH4VO3을 증류수 15.0 ml에 완전히 용해시킨 플라스크 A를 준비하였다. 지지체로서 구형상 α-Al2O3 (pore volume: 0.01 cm3/g, BET 비표면적: 4.9 m2/g, Saint Gobain사 제품) 12.5 mg (실시예 1 내지 4), 또는 γ-Al2O3 (pore volume: 0.55 cm3/g, BET 비표면적: 185 m2/g, Saint Gobain사 제품) 12.5 mg (비교예 1)이 담긴 플라스크 B에 상기 플라스크 A를 첨가시켜 촉매금속 전구체를 구형상 α-Al2O3에 담지시킨 후, 100℃ 환류조를 포함하는 항온 반응기에서 15시간 동안 교반하여 숙성시켰다. 이때 금속 수용액의 농도는 0.41g/ml이었고 침전이 관찰되지 않는 맑은 용액 상태이다.Fe (NO 3 ) 2 · 9H 2 O, Co (NO 3 ) 2 · 6H 2 O, (NH 4 ) 6 Mo 7 O 24 and NH 4 VO 3 having the contents shown in Table 1 as catalyst metal precursors were distilled water. Flask A was prepared completely dissolved in 15.0 ml. Spherical α-Al 2 O 3 (pore volume: 0.01 cm 3 / g, BET specific surface area: 4.9 m 2 / g, manufactured by Saint Gobain) as a support (Examples 1 to 4), or γ-Al 2 Flask A was added to Flask B containing O 3 (pore volume: 0.55 cm 3 / g, BET specific surface area: 185 m 2 / g, manufactured by Saint Gobain) (Comparative Example 1) to form a catalyst metal precursor. After being supported on the shape α-Al 2 O 3 , it was aged by stirring for 15 hours in a constant temperature reactor including a reflux tank at 100 ° C. At this time, the concentration of the aqueous metal solution was 0.41 g / ml and a clear solution state without precipitation is observed.
60℃ 항온조에서 100 rpm, 150 mbar의 회전 진공 장치에서 30분간 건조시킨 후, 에탄올 15ml를 추가하여 100 rpm에서 혼합 분산시킨 다음 건조시키는 공정을 총 2회 반복 수행하였다. 건조된 촉매를 350℃에서 중간 소성을 한 후, 하기 표 2의 소성 온도에서 3시간 소성시켜 균질(homogeneous)한 담지촉매를 제조하였다. 제조된 촉매는 건조시 구형상의 입상을 형성하였다.After drying for 30 minutes in a rotary vacuum apparatus of 100 rpm, 150 mbar in a 60 ℃ thermostat, 15 ml of ethanol was added, mixed and dispersed at 100 rpm and then dried twice in total. The dried catalyst was calcined at 350 ° C. and then calcined at the firing temperature of Table 2 for 3 hours to prepare a homogeneous supported catalyst. The prepared catalyst formed spherical granules upon drying.
구분division 지지체 (mg)Support (mg) 금속 전구체 함량 (mg)Metal precursor content (mg)
Fe(NO3)2·9H2OFe (NO 3 ) 2 9H 2 O Co(NO3)2·6H2OCo (NO 3 ) 2 6H 2 O (NH4)6Mo7O24 (NH 4 ) 6 Mo 7 O 24 NH4VO3 NH 4 VO 3
실시예 1 ~ 4Examples 1-4 12.5(구형상 α-Al2O3)12.5 (Spherical α-Al 2 O 3 ) 2.3912.391 7.3417.341 0.5520.552 0.3440.344
비교예 1Comparative Example 1 12.5(γ-Al2O3)12.5 (γ-Al 2 O 3 ) 3.9843.984 12.23412.234 0.9200.920 0.5740.574
상기 실시예 1 내지 4, 비교예 1에서 사용된 지지체의 종류, 소성 온도, 포어부피 및 비표면적은 하기 표 2와 같다.The types, firing temperature, pore volume, and specific surface area of the supports used in Examples 1 to 4 and Comparative Example 1 are shown in Table 2 below.
구분division 지지체 종류Support type 소성 온도(℃)Firing temperature (℃) 지지체 포어 부피(cm3/g)Support Pore Volume (cm 3 / g) 지지체 BET비표면적(m2/g)Support BET specific surface area (m 2 / g)
실시예 1Example 1 구형상 α-Al2O3 Spherical α-Al 2 O 3 680680 0.010.01 4.94.9
실시예 2Example 2 구형상 α-Al2O3 Spherical α-Al 2 O 3 660660 0.010.01 4.94.9
실시예 3Example 3 구형상 α-Al2O3 Spherical α-Al 2 O 3 620620 0.010.01 4.94.9
실시예 4Example 4 구형상 α-Al2O3 Spherical α-Al 2 O 3 600600 0.010.01 4.94.9
비교예 1Comparative Example 1 γ-Al2O3 γ-Al 2 O 3 680680 0.550.55 185185
상기 실시예 1 내지 4, 비교예 1에서 얻어진 담지촉매의 금속 함량은 하기 표 3과 같다.Metal contents of the supported catalysts obtained in Examples 1 to 4 and Comparative Example 1 are as shown in Table 3 below.
구분division 지지체 (중량부)Support (part by weight) 금속 함량 (중량부)Metal content (parts by weight) 총금속 함량Total metal content
FeFe CoCo MoMo VV 중량부Parts by weight 중량%weight%
실시예 1 ~ 4Examples 1-4 100100 2.62.6 11.911.9 2.42.4 1.21.2 18.118.1 15.315.3
비교예 1Comparative Example 1 100100 4.44.4 19.819.8 4.04.0 2.02.0 30.230.2 23.223.2
도 1은 상기 실시예 1 내지 4에서 지지체로 사용된 상기 구형상 α-알루미나의 SEM 화상을 나타내며, 상기 지지체가 거의 구형상에 가까운 형태를 갖고 있음을 알 수 있다. 도 2는 상기 실시예 1에 따라 얻어진 담지촉매의 SEM 화상을 나타내며, 상기 지지체와 마찬가지로 실질적으로 구형상의 형태를 갖고 있음을 알 수 있다.FIG. 1 shows SEM images of the spherical α-alumina used as the support in Examples 1 to 4, and it can be seen that the support has a shape that is almost spherical. FIG. 2 shows an SEM image of the supported catalyst obtained according to Example 1, and it can be seen that it has a substantially spherical shape similarly to the support.
도 3은 상기 비교예 1에서 지지체로서 사용된 상기 γ-알루미나의 SEM 화상을 나타내며, 상기 지지체의 형상이 구형이 아닌 다소 불규칙한 형상을 갖고 있음을 알 수 있다. 도 4는 상기 비교예 1에 따라 얻어진 담지촉매의 SEM 화상을 나타내며, 상기 지지체와 마찬가지로 그 형상이 다소 불규칙한 형상을 갖고 있음을 알 수 있다.Figure 3 shows an SEM image of the γ-alumina used as the support in Comparative Example 1, it can be seen that the shape of the support has a rather irregular shape rather than spherical. 4 shows an SEM image of the supported catalyst obtained according to Comparative Example 1, and it can be seen that the shape has a somewhat irregular shape similarly to the support.
< CNT 제조예 ><CNT production example>
상기 실시예 1 내지 4 및 비교예 1에서 제조된 CNT 합성용 촉매를 이용하여 실험실 규모의 고정층 반응장치에서 카본나노튜브 합성을 시험하였다. 구체적으로, 상기 공정에서 제조된 CNT 합성용 촉매를 직경 55 mm의 내경을 갖는 석영관의 중간부에 장착한 후, 질소 분위기에서 650℃까지 승온한 다음 유지시키고, 수소가스를 60 sccm의 유속으로 흘리면서 3시간 동안 합성하여 소정량의 카본나노튜브 응집체를 합성하였다. 이때의 CNT 수율 및 벌크밀도를 하기 표 4에 기재하였다.Carbon nanotube synthesis was tested in a laboratory scale fixed bed reactor using the catalysts for synthesizing CNTs prepared in Examples 1 to 4 and Comparative Example 1. Specifically, the catalyst for synthesizing CNT prepared in the above process was mounted in the middle of a quartz tube having an inner diameter of 55 mm, and then heated up to 650 ° C. in a nitrogen atmosphere and maintained therein, and hydrogen gas was flowed at a flow rate of 60 sccm. Synthesizing for 3 hours while flowing to synthesize a predetermined amount of carbon nanotube aggregates. The CNT yield and bulk density at this time are described in Table 4 below.
구분division 금속 담지량(중량%)Metal loading amount (% by weight) CNT 수율(CNT g/촉매 g)CNT yield (CNT g / catalyst g) CNT 벌크밀도(kg/m3)CNT bulk density (kg / m 3 )
실시예 1Example 1 15.315.3 8787 91.291.2
실시예 2Example 2 15.315.3 6060 102102
실시예 3Example 3 15.315.3 5151 100100
실시예 4Example 4 15.315.3 2727 6060
비교예 1Comparative Example 1 23.223.2 8585 111.9111.9
상기 표 4에 기재한 바와 같이, 실시예 1 내지 4에서 얻어진 담지촉매의 경우 금속 담지량이 비교예 1보다 적음에도 불구하고 보다 우수한 CNT 수율을 나타냈으며, 벌크밀도가 더 낮아 보다 대구경의 CNT가 얻어졌음을 알 수 있다. As shown in Table 4, the supported catalysts obtained in Examples 1 to 4 showed better CNT yields even though the amount of metal supported was less than that of Comparative Example 1, and the bulk density was lower to obtain a larger diameter CNT. It can be seen that.
도 5 및 도 6은 각각 상기 비교예 1에서 얻어진 CNT 응집체의 저배율 및 고배율 SEM 화상을 나타낸다. 도 5에서 확인할 수 있는 바와 같이 응집체 형상이 불규칙한 형상을 갖고 있으며, 도 6에 도시한 바와 같이 가닥 CNT의 직경이 다소 작음을 확인할 수 있다.5 and 6 show low and high magnification SEM images of the CNT aggregates obtained in Comparative Example 1, respectively. As can be seen in FIG. 5, the aggregate has an irregular shape, and as shown in FIG. 6, the diameter of the strand CNTs is somewhat small.
도 7 및 도 8은 상기 실시예 1에서 얻어진 CNT 응집체의 저배율 및 고배율 SEM 화상을 나타내며, 도 9 및 도 10은 상기 실시예 2에서 얻어진 CNT 응집체의 저배율 및 고배율 SEM 화상을 나타내고, 도 11 및 도 12는 상기 실시예 3에서 얻어진 CNT 응집체의 저배율 및 고배율 SEM 화상을 나타내며, 도 13 및 도 14는 상기 실시예 14에서 얻어진 CNT 응집체의 저배율 및 고배율 SEM 화상을 나타낸다. 상기 도 7 내지 도 14에서 알 수 있는 바와 같이, 본 발명에 따라 얻어진 담지촉매를 사용하여 CNT를 제조하는 경우 그 형상이 실질적으로 구형상에 가깝고, 직경이 보다 큰 대구경 CNT가 얻어짐을 확인할 수 있다.7 and 8 show low and high magnification SEM images of the CNT aggregates obtained in Example 1, and FIGS. 9 and 10 show low and high magnification SEM images of the CNT aggregates obtained in Example 2, and FIGS. 11 and FIG. 12 shows low and high magnification SEM images of the CNT aggregates obtained in Example 3, and FIGS. 13 and 14 show low and high magnification SEM images of the CNT aggregates obtained in Example 14. As can be seen from FIG. 7 to FIG. 14, when the CNT is prepared using the supported catalyst obtained according to the present invention, it can be confirmed that a large diameter CNT having a shape substantially close to a spherical shape and having a larger diameter is obtained. .
도 15는 상기 실시예 1에서 얻어진 CNT의 SEM 화상을 나타내며, 도 16은 도 15의 A 영역에 대한 확대도이며, 도 17은 도 15의 B 영역에 대한 확대도를 나타낸다. 도 16 및 도 17로부터 본 발명의 담지촉매를 사용하여 얻어진 CNT가 번들 형태의 2차 구조를 가짐을 알 수 있다.FIG. 15 is a SEM image of the CNT obtained in Example 1, FIG. 16 is an enlarged view of region A of FIG. 15, and FIG. 17 is an enlarged view of region B of FIG. 15. It can be seen from FIGS. 16 and 17 that the CNTs obtained using the supported catalyst of the present invention have a secondary structure in the form of bundles.

Claims (14)

  1. 구형상 α-알루미나 지지체에 촉매성분 및 활성성분이 지지되어 있는 담지촉매 상에 성장되어 있으며, It is grown on a supported catalyst on which a catalyst component and an active component are supported on a spherical α-alumina support.
    BET 비표면적이 1 내지 50m2/g 이고, 벌크밀도가 60 내지 250kg/m3인 것인 카본나노튜브.Carbon nanotubes having a BET specific surface area of 1 to 50 m 2 / g and a bulk density of 60 to 250 kg / m 3 .
  2. 제1항에 있어서,The method of claim 1,
    상기 카본나노튜브가 번들 형태의 2차 구조를 갖는 것인 카본나노튜브.Carbon nanotubes having a secondary structure in the form of a bundle carbon nanotubes.
  3. 제1항에 있어서,The method of claim 1,
    상기 담지촉매가 함침법에 의해 얻어진 것인 카본나노튜브.Carbon nanotubes wherein the supported catalyst is obtained by the impregnation method.
  4. 제1항에 있어서,The method of claim 1,
    상기 촉매성분 및 활성성분의 합계 함량이 상기 구형상 α-알루미나 100중량부를 기준으로 10 내지 25중량부인 것인 카본나노튜브.Carbon nanotubes of which the total content of the catalyst component and the active ingredient is 10 to 25 parts by weight based on 100 parts by weight of the spherical α-alumina.
  5. 제1항에 있어서,The method of claim 1,
    상기 촉매성분 및 활성성분의 중량비가 10 내지 30 : 1 내지 14인 것인 카본나노튜브.Carbon nanotubes of the weight ratio of the catalyst component and the active ingredient is 10 to 30: 1 to 14.
  6. 제1항에 있어서,The method of claim 1,
    상기 촉매성분이 Fe, Co 또는 Ni 중 1종 이상인 것인 카본나노튜브.Carbon nanotubes, wherein the catalyst component is at least one of Fe, Co or Ni.
  7. 제1항에 있어서,The method of claim 1,
    상기 활성성분이 Mo 및 V 중 1종 이상인 것인 카본나노튜브.Carbon nanotubes, wherein the active ingredient is at least one of Mo and V.
  8. 제1항에 있어서,The method of claim 1,
    상기 담지촉매의 울트라소닉 미분량이 5% 이내인 카본나노튜브.Ultrasonic fine fraction of the supported catalyst is less than 5% carbon nanotubes.
  9. 촉매성분 전구체 및 활성성분 전구체를 포함하는 금속 수용액에 구형상 α-알루미나 지지체를 혼합하여 담지촉매 전구체 함유 수용액을 형성하는 단계;Forming a supported catalyst precursor-containing aqueous solution by mixing a spherical α-alumina support with an aqueous metal solution containing a catalyst component precursor and an active component precursor;
    상기 담지촉매 전구체 함유 수용액을 숙성 함침시켜 혼합물을 수득하는 단계;Aging and impregnating the supported catalyst precursor-containing aqueous solution to obtain a mixture;
    상기 혼합물을 진공건조하여 상기 지지체 표면에 상기 촉매성분 및 활성성분을 코팅하는 단계;Vacuum drying the mixture to coat the catalyst component and the active ingredient on the support surface;
    상기 진공건조에 의해 얻어진 결과물을 소성하여 담지촉매를 형성하는 단계; Calcining the resultant obtained by vacuum drying to form a supported catalyst;
    상기 담지촉매를 반응기 내부에 투입하고, 약 500 내지 900℃의 온도에서 반응기 내부로 탄소 공급원 또는 상기 탄소공급원과 수소가스, 질소가스 또는 이들의 혼합가스를 주입하는 단계; 및Injecting the supported catalyst into a reactor and injecting a carbon source or the carbon source and hydrogen gas, nitrogen gas, or a mixture thereof into the reactor at a temperature of about 500 to 900 ° C .; And
    상기 촉매 표면 위에서 주입된 탄소 공급원의 분해를 통해 카본나노튜브를 성장시키는 단계;를 포함하는 카본나노튜브의 제조방법.And growing carbon nanotubes through decomposition of the carbon source injected on the catalyst surface.
  10. 제9항에 있어서,The method of claim 9,
    상기 금속 수용액의 농도가 0.1 내지 0.4 g/ml인 것인 카본나노튜브 제조방법.Carbon nanotube manufacturing method that the concentration of the aqueous metal solution is 0.1 to 0.4 g / ml.
  11. 제9항에 있어서,The method of claim 9,
    상기 숙성 함침 공정이 20℃ 내지 100℃의 온도에서 30분 내지 15시간 동안 수행되는 것인 카본나노튜브 제조방법.The aging impregnation process is carried out for 30 minutes to 15 hours at a temperature of 20 ℃ to 100 ℃ carbon nanotube manufacturing method.
  12. 제9항에 있어서,The method of claim 9,
    상기 소성온도가 550 내지 800℃인 것인 카본나노튜브 제조방법.Carbon firing method of the firing temperature is 550 to 800 ℃.
  13. 제9항에 있어서,The method of claim 9,
    상기 진공 건조 공정 이후 상기 소성 공정 이전에 250 내지 400℃ 하의 예비 소성을 1회 이상 수행하는 단계를 더 포함하는 것인 카본나노튜브 제조방법.After the vacuum drying process and before the firing step, the carbon nanotube manufacturing method further comprising the step of performing at least one pre-firing at 250 to 400 ℃.
  14. 제9항에 있어서,The method of claim 9,
    상기 코팅이 불연속 코팅인 것인 카본나노튜브 제조방법.Carbon coating method for manufacturing the coating is a discontinuous coating.
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