WO2015047050A1 - Catalyst for producing carbon nanotubes and carbon nanotubes produced using same - Google Patents

Catalyst for producing carbon nanotubes and carbon nanotubes produced using same Download PDF

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WO2015047050A1
WO2015047050A1 PCT/KR2014/009235 KR2014009235W WO2015047050A1 WO 2015047050 A1 WO2015047050 A1 WO 2015047050A1 KR 2014009235 W KR2014009235 W KR 2014009235W WO 2015047050 A1 WO2015047050 A1 WO 2015047050A1
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catalyst
carbon nanotubes
carbon nanotube
surface area
specific surface
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PCT/KR2014/009235
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French (fr)
Korean (ko)
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김성진
조동현
강경연
손승용
차진명
장형식
이승용
우지희
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주식회사 엘지화학
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Priority claimed from KR20140129449A external-priority patent/KR101508101B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to CN201480003906.7A priority Critical patent/CN104884384B/en
Priority to JP2015545399A priority patent/JP6131516B2/en
Priority to US14/439,168 priority patent/US9956546B2/en
Priority to EP14848695.4A priority patent/EP3053878A4/en
Publication of WO2015047050A1 publication Critical patent/WO2015047050A1/en

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    • B01J35/30—
    • 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
    • B01J23/847—Vanadium, niobium or tantalum or polonium
    • B01J23/8472—Vanadium
    • 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
    • B01J23/881—Molybdenum and 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
    • B01J23/76—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
    • B01J23/882—Molybdenum and cobalt
    • 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
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/16—Preparation
    • C01B32/162—Preparation characterised by catalysts

Definitions

  • the present invention relates to a catalyst for producing carbon nanotubes, particularly a catalyst capable of producing carbon nanotubes having a high specific surface area, and a carbon nanotube prepared using the same.
  • Carbon nanostructures refers to nanoscale carbon nanostructures having various shapes such as nanotubes, nanohairs, fullerenes, nanocones, nanohorns, and nanorods. High utilization in the technical field.
  • carbon nanotubes is a material in which the carbon atoms arranged in a hexagonal shape in the form of a tube, the diameter is approximately 1 to 100 nm.
  • CNTs carbon nanotubes
  • Such CNTs exhibit non-conductor, conductor or semiconducting properties depending on their unique chirality, and the carbon atoms are connected by strong covalent bonds, resulting in approximately 100 times greater tensile strength than steel, and excellent flexibility and elasticity. It is also chemically stable.
  • the type of CNT includes a single-walled carbon nanotube (SWCNT) composed of one layer and a diameter of about 1 nm, and a double-walled carbon composed of two layers and a diameter of about 1.4 to 3 nm.
  • nanotubes, DWCNTs) and multi-walled carbon nanotubes (MWCNTs) having a diameter of about 5 to 100 nm and consisting of three or more layers.
  • CNTs Due to characteristics such as chemical stability, excellent flexibility and elasticity, CNTs are being commercialized and applied in various fields, such as aerospace, fuel cells, composites, biotechnology, medicine, electrical and electronics, and semiconductors.
  • the primary structure of the CNT has a limit in directly adjusting its diameter or length to actual specifications for industrial applications, and thus, despite the excellent properties of the CNT, there are many limitations in industrial applications or applications.
  • the CNT is generally manufactured by arc discharge, laser ablation, chemical vapor deposition, or the like.
  • the arc discharge method and the laser evaporation method are difficult to mass-produce, and excessive arc production cost or laser equipment purchase cost is a problem.
  • the chemical vapor deposition method has a problem that the synthesis rate is very slow in the case of using a gas phase dispersion catalyst and the particles of the synthesized CNT are too small. There is a limit to mass production. Therefore, in order to increase the yield of CNT in chemical vapor deposition, studies on catalysts, reaction conditions, and the like are continuing.
  • CNTs having a small diameter and a form that can be well dispersed and mixed during compounding are required.
  • the problem to be solved by the present invention is to provide a catalyst having a small diameter and a high specific surface area, CNT having a bundle structure that can be dispersed and mixed well when compounding with a polymer in high yield. It is.
  • Another object of the present invention is to provide a CNT aggregate produced using the catalyst.
  • Another object of the present invention to provide a conductive polymer composite containing the CNT aggregate.
  • the support is supported by a graphitized metal catalyst and has a maximum diffraction peak at 2 ⁇ values of 35 to 38 ° in an XRD pattern in the range of 10 ° to 80 ° and at a value of 17 ° to 22 ° for the maximum diffraction peak size (a).
  • a catalyst for producing carbon nanotubes in which the ratio (b / a) of the size (b) of the diffraction peak of is 0.08 or more.
  • the XRD pattern of the catalyst may further have one or more diffraction peaks selected from 2 ⁇ values 30-33 °, 43-46 °, 57-60 ° and 63-67 °.
  • the catalyst may have a crystal size of 3 to 50 nm.
  • the catalyst is a supported catalyst obtained by calcining aluminum hydroxide at a first firing temperature of 100 to 500 ° C. to form a support, and carrying a catalyst metal precursor on the support and then firing at a second firing temperature of 100 to 800 ° C. Can be.
  • the catalyst may be selected to have a particle size of 30 to 150 ⁇ m and a number average particle size of 40 to 80 ⁇ m.
  • the graphitized metal catalyst is nickel (Ni), cobalt (Co), iron (Fe), platinum (Pt), gold (Au), aluminum (Al), chromium (Cr), copper (Cu), magnesium (Mg) , Manganese (Mn), molybdenum (Mo), rhodium (Rh), silicon (Si), tantalum (Ta), titanium (Ti), tungsten (W), uranium (U), vanadium (V) and zirconium (Zr) It may be one or more metals or alloys selected from the group consisting of.
  • the graphitized metal catalyst may be a plural-based metal catalyst including a main catalyst-catalyst.
  • the main catalyst may be at least one selected from Co and Fe, and the cocatalyst may be at least one selected from Mo and V.
  • the graphitized metal catalyst may be a binary metal catalyst selected from Co / Mo, Co / V, Fe / Mo, and Fe / V.
  • the graphitized metal catalyst may have a content of 0.5 to 5 mol of the cocatalyst with respect to 10 mol of the main catalyst.
  • the graphitized metal catalyst may be 5 to 40 parts by weight based on 100 parts by weight of the catalyst.
  • the present invention also provides a carbon nanotube aggregate comprising carbon nanotubes grown on the catalyst described above, wherein the BET specific surface area of the carbon nanotube aggregate is 200 m 2 / g or more, and the BET specific surface area and the crystal of the catalyst are determined.
  • carbon nanotube aggregates whose sizes satisfy the following relationship:
  • y is the BET specific surface area (m 2 / g) and x is the crystal size (nm) of the catalyst.
  • the specific surface area of the carbon nanotube aggregate and the crystal size of the catalyst may satisfy the following relationship.
  • the present invention also provides a method for producing a carbon nanotube aggregate comprising the step of contacting the catalyst described above with a gaseous carbon source to form carbon nanotubes (CNTs).
  • the gaseous carbon source may be at least one selected from the group consisting of carbon monoxide, methane, ethane, ethylene, ethanol, acetylene, propane, propylene, butane, butadiene, pentane, pentene, cyclopentadiene, hexane, cyclohexane, benzene and toluene have.
  • the reaction temperature may be 600 to 750 °C.
  • the present invention also provides a composite material comprising the carbon nanotube aggregate.
  • the composite material may have a conductivity that is inversely proportional to the crystal size of the catalyst.
  • the present invention since a carbon nanotube (CNT) having a large specific surface area and having a shape that can be well dispersed and mixed can be obtained, it is possible to improve physical properties of the composite material including the CNT. As a result, the CNTs according to the present invention can be usefully used in various fields such as energy materials, functional composites, medicines, batteries, semiconductors, and display devices.
  • CNT carbon nanotube
  • 1 is an XRD pattern of a catalyst prepared in an embodiment of the present invention.
  • Figure 2 is a graph showing the correlation between the crystal size of the catalyst prepared in the embodiment of the present invention and the BET specific surface area of the CNT aggregate prepared using the same.
  • FIG 3 is an SEM image of a CNT aggregate prepared according to an embodiment of the present invention.
  • FIG 4 is a graph showing the surface resistance of the polymer composite containing the CNT aggregate prepared according to the embodiment of the present invention as a correlation with the crystal size of the catalyst used to prepare the CNT aggregate.
  • the present invention obtains a supported catalyst having a controlled crystal size by optimizing a pretreatment step of a support and a formation step of a supported catalyst, and by using the same, a CNT aggregate having a low diameter and high specific surface area, and a polymer having conductivity controlled by containing such CNT aggregate It relates to manufacturing a composite material.
  • the catalyst according to the present invention has a graphitized metal catalyst on a support, has a maximum diffraction peak at a 2 ⁇ value of 35 to 38 ° in an XRD pattern in a range of 10 ° to 80 °, and has a maximum diffraction peak size (a).
  • the ratio (b / a) of the magnitude (b) of the diffraction peak at the 2 ⁇ value of 17 to 22 ° is characterized by being 0.08 or more.
  • the b / a may be 0.15 or less, 0.09 to 0.15, or 0.09 to 0.13.
  • the catalyst according to one embodiment may further have one or more diffraction peaks selected from 2 ⁇ values 30-33 °, 43-46 °, 57-60 ° and 63-67 ° of the XRD pattern. Can be.
  • the diffraction peak at 2 ⁇ values 30 to 33 ° may have a size of 0.3 to 0.5, or 0.35 to 0.45 relative to the maximum diffraction peak.
  • the diffraction peak at 2 ⁇ values 43 to 46 ° may have a size of 0.1 to 0.3, or 0.15 to 0.25 with respect to the maximum diffraction peak.
  • the diffraction peak at 2 ⁇ values 57 to 60 ° may have a size of 0.1 to 0.25, or 0.15 to 0.22 relative to the maximum diffraction peak.
  • the diffraction peak at the 2 ⁇ value of 63 to 67 ° may have a size of 0.3 to 0.5, or 0.35 to 0.45 relative to the maximum diffraction peak.
  • the catalyst can be controlled in the crystal size range of 3 to 50 nm, or 10nm to 50nm, the crystal size of the catalyst is the calcination conditions of the catalyst, that is, the type of catalyst metal, catalyst metal loading, calcining amount, firing time, firing temperature It can be controlled by adjusting various conditions.
  • the 'crystal size' of the catalyst is also referred to as 'crystallite size', and is calculated from the broadening of peaks appearing according to the XRD measurement. More specifically, the Bragg-Brentano method, a mode of incidence angle 1/2 of 2theta, is used, and the grain size formula is applied to the full pattern fitting method using the fundamental approach in the Bruker TOPAS program. Calculated by Therefore, it should be distinguished from the 'catalyst particle size' or the 'catalyst particle size' obtained from the SEM photograph. Since the grain size measurement and calculation method is in accordance with known standard methods, detailed description is omitted.
  • the catalyst according to the present invention exhibits a tendency to decrease the BET specific surface area of the resulting CNT aggregate as the crystal size of the catalyst increases.
  • the CNT aggregate produced using the catalyst according to the present invention has a BET specific surface area of 200 m 2 / g or more, and the BET specific surface area and crystal size of the catalyst satisfy the following relation:
  • y is the BET specific surface area (m 2 / g) and x is the crystal size (nm) of the catalyst.
  • the specific surface area of the carbon nanotube aggregate and the crystal size of the catalyst may satisfy one or more of the following relational expressions.
  • the specific surface area used in the present invention is measured by the BET method. Specifically, the specific surface area used is calculated by calculating the amount of nitrogen gas adsorption under liquid nitrogen temperature (77K) using BEL Japan's BELSORP-mini II. .
  • CNT aggregates according to the invention have a BET specific surface area of from 200 to 500 m 2 / g, or from 200 to 300 m 2 / g, or from 300 to 500 m 2 / g, or from 300 to 400 m 2 / g, or from 200 to 400 m 2 / g.
  • the electrical conductivity of the polymer compound containing the same tends to be improved.
  • the conductivity of the CNT-containing polymer compound is believed to be influenced by physical properties such as diameter and crystallinity of the CNT aggregate and dispersibility (associated with the CNT shape) during compounding.
  • the crystallite size of the catalyst according to the present invention and the surface resistance of the polymer compound containing the CNT aggregate prepared using the same have a relationship as shown in FIG. 4.
  • the crystal size of the catalyst is controlled to be small, a CNT aggregate having a high specific surface area (low diameter) can be produced, and as a result, a polymer compound having excellent conductivity can be prepared.
  • the support precursor obtained by first firing at a first firing temperature for example, at a temperature of 100 ° C. to 500 ° C. is loaded with a graphitization catalyst, and then, it is 100 ° C. to 800 ° C.
  • a supported catalyst prepared by second firing at a temperature is prepared.
  • the supported catalyst may be contacted with a gaseous carbon source to prepare a bundle of carbon nanotube aggregates having a BET specific surface area of preferably 200 m 2 / g or more (see FIG. 3).
  • 'bundle type' refers to a secondary shape in the form of a bundle or a rope, in which a plurality of CNTs are arranged or intertwined side by side, unless otherwise stated.
  • 'Non-bundle or entangled type' means a shape without a certain shape, such as a bundle or a rope shape.
  • the support precursor used in the production method serves to support the graphitization catalyst, it is possible to control the shape of the CNT according to the type.
  • an aluminum-based support precursor preferably aluminum hydroxide (aluminum-tri-hydroxide, ATH) can be used.
  • a support precursor can be used by drying for 1 hour to 24 hours at 50 °C to 150 °C.
  • the first firing temperature is preferably 500 ° C. or less, much lower than 700 ° C., which is known to convert aluminum hydroxide to alumina. That is, the first firing may include a heat treatment process performed at a temperature of about 100 ° C to about 500 ° C, or about 120 ° C to about 450 ° C, or 200 to 450 ° C, or 300 to 450 ° C, or 200 to 400 ° C. Can be.
  • the aluminum-based support formed by the above process preferably contains 30 wt% or more of AlO (OH) converted from Al (OH) 3 and does not include Al 2 O 3 .
  • the aluminum (Al) -based support may further include one or more selected from the group consisting of ZrO 2 , MgO and SiO 2 .
  • the aluminum (Al) -based support may have a spherical or potato shape, and may have a porous structure, a molecular sieve structure, a honeycomb structure, or another suitable structure to have a relatively high surface area per unit mass or volume.
  • the support precursor may have a primary particle size of about 20 to about 200 ⁇ m, porosity of about 0.1 to about 1.0 cm 3 / g, specific surface area of less than about 1 m 2 / g.
  • the first firing process may be performed for about 0.5 hours to about 10 hours, preferably about 1 hour to 5 hours, but is not limited thereto.
  • CNTs Contacting the graphitization catalyst used in the preparation method with a gaseous carbon source can form CNTs.
  • the growth process of CNTs is described above.
  • the carbonaceous material which is a gaseous carbon source
  • the graphite catalyst for example, a graphite metal catalyst
  • the carbonaceous material is thermally decomposed on the surface of the metal catalyst.
  • CNTs in which the carbon atom generated from the decomposed carbon-containing gas penetrates into the graphitized metal catalyst to be dissolved and then exceeds the solubility limit which is an inherent property of the graphitized metal catalyst.
  • the nucleation of the furnace occurs and grows into CNTs.
  • the graphitized metal catalyst serves to help the carbon components present in the carbonaceous material combine with each other to form a hexagonal ring structure, for example, to synthesize graphite, induce carbonization, or CNT It is possible to use the catalyst used to prepare the. More specifically, nickel (Ni), cobalt (Co), iron (Fe), platinum (Pt), gold (Au), aluminum (Al), chromium (Cr), copper (Cu), magnesium (Mg), With manganese (Mn), molybdenum (Mo), rhodium (Rh), silicon (Si), tantalum (Ta), titanium (Ti), tungsten (W), uranium (U), vanadium (V) and zirconium (Zr) One or more metals or alloys selected from the group consisting of can be used.
  • the graphitization catalyst may use a binary or ternary or higher polyvalent metal.
  • a binary or multi-part graphitization catalyst may be composed of a main catalyst and a promoter, Co, Fe, Ni, etc. may be used as the main catalyst, Mo, V, etc. may be used as the promoter.
  • Such binary or plural graphitization catalysts are Co / Mo, Co / V, Fe / Mo, Fe / V, Fe / Co, Fe / Co / V, Fe / Co / Mo, Co / Mo / V, Fe / Mo / V, Fe / Co / Mo / V, etc. are mentioned. Among these, it is more preferable that Co and V are included.
  • the component ratio thereof may be, for example, 0.1 to 10 moles or 0.5 to 5 moles of the cocatalyst based on 10 moles of the main catalyst.
  • the graphitization catalyst is supported on the support in the form of various precursors such as metal salts, metal oxides, or metal compounds.
  • various precursors such as metal salts, metal oxides, or metal compounds.
  • Fe salt, Fe oxide, Fe compound, Ni salt, Ni oxide, Ni compound, Co salt, Co oxide, Co compound, Mo oxide, Mo compound, Mo salt, V oxide, V compound, V salt, etc. can be illustrated.
  • Fe (NO 3 ) 2 ⁇ 6H 2 O, Fe (NO 3 ) 2 ⁇ 9H 2 O, Fe (NO 3 ) 3 , Fe (OAc) 2 , Ni (NO 3 ) 2 ⁇ 6H 2 O, Co (NO 3 ) 2 .6H 2 O, Co 2 (CO) 8 , [Co 2 (CO) 6 (t-BuC CH)], Co (OAc) 2 , (NH 4 ) 6 Mo 7 O 24 4H 2 O, Mo (CO) 6 , (NH 4 ) MoS 4 , NH 4 VO 3 , and the like can be used.
  • the precursor of the graphitization catalyst When the precursor of the graphitization catalyst is supported on the support in the form of a solution, and then undergoes a second firing process, it is mainly supported in the form of a metal oxide to form a supported catalyst.
  • a support for example a granular aluminum-based support in the precursor aqueous solution of the graphitization catalyst
  • the mixture is calcined at a first firing temperature of about 100 to 500 ° C. to form a support, and a catalyst metal precursor is supported on the support and then calcined at a second firing temperature of 100 to 800 ° C. to support CNT production catalyst.
  • It can be prepared by a method comprising; obtaining a.
  • the vacuum drying may be carried out by rotary evaporation in the range of about 30 minutes to about 12 hours under vacuum in the temperature range of about 40 to about 100 °C.
  • the method may include aging by rotation or stirring at about 45 to about 80 ° C. before the vacuum drying. For example, it may be performed for up to 5 hours, 20 minutes to 5 hours, or 1 to 4 hours.
  • the second firing process for forming the supported catalyst may be performed at a temperature of about 100 ° C to about 800 ° C, for example, about 200 ° C to about 800 ° C or 550 ° C to about 800 ° C. It is preferable that the temperature of a 2nd baking process is 200-400 degreeC higher than the temperature of a 1st baking process.
  • the particle size or average particle diameter measured before the second firing of the supported catalyst used in the preparation method is about 30 ⁇ m to about 150 ⁇ m, and the primary particle diameter of the granular support and the graphitization catalyst is about 10 nm to about 50 nm.
  • the spherical or potato shape refers to a three-dimensional shape such as a spherical and ellipsoidal shape having an aspect ratio of 1.2 or less.
  • the supported catalyst when preparing a CNT according to the present invention using a fluidized bed reactor, in particular, has a particle diameter of about 30 ⁇ m to about 150 ⁇ m, a number average particle diameter (Mn) of 40 to 80 ⁇ m, or It can be used selectively to be 50 to 70 ⁇ m, or 50 to 70 ⁇ m. This is because it is important to ensure that the catalyst fluidized bed flows well without catalyst aggregation in the reaction zone in the fluidized bed reactor.
  • Mn number average particle diameter
  • the supported catalyst may include about 5 to about 40 parts by weight of the graphitization catalyst based on 100 parts by weight of the supported catalyst, but is not limited thereto.
  • the supported catalyst includes a Co-based graphitization catalyst
  • the content of Co may be about 3 to about 100 moles based on 100 moles of the support.
  • the graphitization catalyst may have a structure in which one or more layers are coated on the surface and pores of the granular support, preferably the aluminum-based support.
  • a supported catalyst using an impregnation method, in which the bulk density of the catalyst itself is higher than that of the coprecipitation catalyst and less than 10 microns, unlike the coprecipitation catalyst, when the supported catalyst is used. It is possible to reduce the possibility of fine powder due to attrition, which can occur during fluidization process because of the small amount of fine powder. Also, the mechanical strength of the catalyst itself is excellent, which makes it possible to stabilize the reactor operation.
  • CNTs may be prepared by growing CNTs by chemical vapor phase synthesis through decomposition of a carbon source using the supported catalyst as described above.
  • the CNT in the method for producing CNTs according to the chemical vapor phase synthesis method, after charging the graphitization catalyst in the reactor, the CNT can be prepared by supplying a gaseous carbon source under conditions of normal pressure and high temperature.
  • the growth of the CNTs is carried out by the process of infiltrating and saturating the pyrolyzed hydrocarbons by applying high temperature heat to the graphitization catalyst, and depositing carbons from the saturated graphitization catalyst to form a hexagonal ring structure.
  • the chemical vapor phase synthesis method is to add the supported catalyst to a horizontal fixed bed reactor or fluidized bed reactor and about 500 °C to about 900 °C, or about 500 °C to 800 °C, or about 600 °C to 800 °C, about 600 °C
  • One or more carbon sources selected from saturated or unsaturated hydrocarbons having 1 to 6 carbon atoms at a temperature of from about 750 ° C., or about 650 ° C. to about 700 ° C., or the carbon source with a reducing gas (eg, hydrogen) and a carrier gas ( For example, it may be carried out by injecting a mixed gas of nitrogen). Injecting a carbon source into the supported catalyst to grow the CNTs may be performed for 30 minutes to 8 hours.
  • the supply gas may be a carbon source and a reducing gas or a carrier gas, respectively, or a mixture thereof.
  • induction heating radiant heat, laser, IR, microwave, plasma, UV, surface plasmon heating, etc. can be used without limitation.
  • the carbon source used in the chemical vapor phase synthesis method may supply carbon, and any material that may exist in the gas phase at a temperature of 300 ° C. or higher may be used without particular limitation.
  • a gaseous carbonaceous substance any compound containing carbon may be used, and a compound having 6 or less carbon atoms is preferable, and more preferably a compound having 4 or less carbon atoms.
  • one or more selected from the group consisting of carbon monoxide, methane, ethane, ethylene, ethanol, acetylene, propane, propylene, butane, butadiene, pentane, pentene, cyclopentadiene, hexane, cyclohexane, benzene and toluene can be used. It is not limited.
  • the mixed gas of hydrogen and nitrogen transports the carbon source, prevents CNTs from burning at high temperatures, and assists in the decomposition of the carbon source.
  • Such gaseous carbon source, hydrogen and nitrogen can be used in various volume ratios, for example, the volume ratio of nitrogen: gaseous carbon source: hydrogen is 1: 0.1 to 10: 0 to 10, or 1: 0.5 to 1.5: 0.5 to 1.5 Can be used in the range of.
  • the flow rate of the reaction gas can be suitably used in the range of about 100 sccm or more and about 10,000 sccm or less.
  • the CNTs are subjected to a cooling process.
  • the CNTs may be arranged more regularly by the cooling process.
  • Such cooling process may be natural cooling (removal of heat source), or cooling at a rate of about 5 ° C. to about 30 ° C. per minute.
  • a bundle type CNT having a BET specific surface area of about 200 m 2 / g or more, preferably about 200 m 2 / g to about 500 m 2 / g can be obtained.
  • the specific surface area can be measured by a conventional BET method.
  • the production method is capable of obtaining CNTs in high yield, for example, achieving a yield of about 5 to 50 times, or about 10 to 40 times.
  • the yield is obtained from the synthesized carbon nanotubes at room temperature and its content can be measured using an electronic balance.
  • the reaction yield can be calculated based on the weight of the supported catalyst used and the weight increase after the reaction based on the following formula.
  • the CNTs may be in a bundle having a flatness of about 0.9 to about 1, and as the BET specific surface area increases, each CNT strand diameter is about 2 nm to about 20 nm, preferably about 3 nm to about 8 nm. It may have a low diameter.
  • the flatness may be defined by the following equation.
  • CNTs have a large BET specific surface area, that is, a low diameter, and have a bundle shape, so that the CNTs are well dispersed and mixed in other materials, for example, polymers, thereby improving physical properties when forming a composite material.
  • Electrode structures such as solar cells, fuel cells, lithium batteries and supercapacitors; Functional composite materials; Energy material; medicine; It can be usefully used for semiconductors such as FETs.
  • Co-V metal catalyst was prepared as a graphitization catalyst.
  • Citric acid was added to Flask A in which NH 4 VO 3 was dissolved in 20 ml water as the precursor material of V.
  • Co (NO 3 ) 2 .6H 2 O was added as a precursor material of Co so that the molar ratio of Co: V was 10: 1.
  • the prepared aqueous metal solution was observed as a clear solution without precipitation.
  • the prepared catalyst was analyzed by XRD and the crystal size was measured.
  • the XRD analysis equipment used was as follows.
  • LynxEye position sensitive detector (3.7 ° slit)
  • the crystal size of the catalyst according to Co content and firing temperature is shown in Table 2. The crystal size was obtained by full pattern fitting.
  • CNT synthesis was tested in a laboratory scale fluidized bed reactor using each of the supported catalysts for synthesizing CNTs prepared above.
  • the catalyst for synthesizing CNT prepared in D was heated in a quartz tube reactor having an inner diameter of 58 mm and a length of 1200 mm, heated to 675 ° C. in a nitrogen atmosphere, and then maintained with a volume mixing ratio of nitrogen, hydrogen, and ethylene gas.
  • a predetermined amount of CNT aggregates were synthesized by synthesizing for 5.5 hours at 5.5: 1: 1 with a total of 4000 ml per minute.
  • the specific surface area and yield of the obtained CNT aggregate are shown in Table 3.
  • the specific surface area was measured by the BET method, and specifically, it calculated by calculating
  • FIG. 3 is an SEM image of a CNT aggregate. It can be seen from FIG. 3 that a bundled CNT aggregate is formed.
  • melt extrusion was carried out at 240 ⁇ 280 °C using a twin screw extruder to prepare a compound in the form of pellets.
  • the conductivity was measured using a conductivity meter (SRM-110, PINION). The relationship of the surface resistance of the polymer composite according to the catalyst crystal size is shown in FIG. 4.
  • the specific surface area of the CNT aggregate and the conductivity of the polymer composite including the CNT aggregate can be controlled by controlling the crystal size of the catalyst when preparing the supported catalyst.
  • the present invention since a carbon nanotube (CNT) having a large specific surface area and having a shape that can be well dispersed and mixed can be obtained, it is possible to improve physical properties of the composite material including the CNT. As a result, the CNTs according to the present invention can be usefully used in various fields such as energy materials, functional composites, medicines, batteries, semiconductors, and display devices.
  • CNT carbon nanotube

Abstract

Provided are a supported catalyst capable of producing carbon nanotubes having a high specific surface area, and carbon nanotubes obtained by using the supported catalyst. The CNTs can be produced at a high yield according to the present invention, and thus can be effectively utilized in a variety of fields.

Description

탄소나노튜브 제조용 촉매 및 이를 이용하여 제조된 탄소나노튜브Catalyst for preparing carbon nanotubes and carbon nanotubes manufactured using the same
본 발명은 탄소나노튜브 제조용 촉매, 특히 높은 비표면적의 탄소나노튜브를 제조할 수 있는 촉매 및 이를 이용하여 제조된 탄소나노튜브에 관한 것이다. The present invention relates to a catalyst for producing carbon nanotubes, particularly a catalyst capable of producing carbon nanotubes having a high specific surface area, and a carbon nanotube prepared using the same.
탄소나노구조체(carbon nanostructures, CNS)는 나노튜브, 나노헤어, 풀러렌, 나노콘, 나노호른, 나노로드 등 다양한 형상을 갖는 나노크기의 탄소나노구조체를 지칭하며, 여러 가지 우수한 성질을 보유하기 때문에 다양한 기술분야에서 활용도가 높다. Carbon nanostructures (CNS) refers to nanoscale carbon nanostructures having various shapes such as nanotubes, nanohairs, fullerenes, nanocones, nanohorns, and nanorods. High utilization in the technical field.
그 중에서도 특히 탄소나노튜브(carbon nanotube, CNT)는 6각형으로 배열된 탄소원자들이 튜브 형태를 이루고 있는 물질로, 직경이 대략 1 내지 100 nm로 이루어진다. 이와 같은 CNT는 특유의 나선성(chirality)에 따라 부도체, 전도체 또는 반도체 성질을 나타내며, 탄소 원자들이 강력한 공유결합으로 연결되어 있어 인장강도가 강철보다 대략 100 배 이상 크고, 유연성과 탄성 등이 뛰어나며, 화학적으로도 안정한 특성을 가진다.In particular, carbon nanotubes (carbon nanotubes, CNTs) is a material in which the carbon atoms arranged in a hexagonal shape in the form of a tube, the diameter is approximately 1 to 100 nm. Such CNTs exhibit non-conductor, conductor or semiconducting properties depending on their unique chirality, and the carbon atoms are connected by strong covalent bonds, resulting in approximately 100 times greater tensile strength than steel, and excellent flexibility and elasticity. It is also chemically stable.
상기 CNT의 종류에는, 한 겹으로 구성되고 직경이 약 1 nm인 단일벽 CNT (single-walled carbon nanotube, SWCNT), 두 겹으로 구성되고 직경이 약 1.4 내지 3 nm인 이중벽 CNT (double-walled carbon nanotube, DWCNT) 및 셋 이상의 복수의 겹으로 구성되고 직경이 약 5 내지 100 nm인 다중벽 CNT (multi-walled carbon nanotube, MWCNT)가 있다.The type of CNT includes a single-walled carbon nanotube (SWCNT) composed of one layer and a diameter of about 1 nm, and a double-walled carbon composed of two layers and a diameter of about 1.4 to 3 nm. nanotubes, DWCNTs) and multi-walled carbon nanotubes (MWCNTs) having a diameter of about 5 to 100 nm and consisting of three or more layers.
화학적 안정성, 우수한 유연성과 탄성 등과 같은 특징으로 인해, CNT는 다양한 분야, 예를 들어 우주항공, 연료전지, 복합재료, 생명공학, 의약, 전기전자, 반도체 등에서 그 제품화 및 응용 연구가 진행되고 있다. 하지만, CNT의 1차 구조는 그 직경이나 길이를 산업적인 응용이 가능한 실제의 규격에 이르도록 직접적으로 조절하는데 한계가 있어, CNT의 뛰어난 물성에도 불구하고 산업상 응용이나 적용에 많은 제약이 따른다.Due to characteristics such as chemical stability, excellent flexibility and elasticity, CNTs are being commercialized and applied in various fields, such as aerospace, fuel cells, composites, biotechnology, medicine, electrical and electronics, and semiconductors. However, the primary structure of the CNT has a limit in directly adjusting its diameter or length to actual specifications for industrial applications, and thus, despite the excellent properties of the CNT, there are many limitations in industrial applications or applications.
상기 CNT는 일반적으로 아크 방전법(arc discharge), 레이저 증발법(laser ablation), 화학 기상 증착법(chemical vapor deposition) 등에 의하여 제조된다. 그러나 상기 아크 방전법 및 레이저 증발법은 대량 생산이 어렵고, 과다한 아크 생산비용 또는 레이저 장비 구입비용이 문제된다. 또한 상기 화학 기상 증착법은 기상 분산 촉매를 사용하는 방법인 경우 합성속도가 매우 더디고 합성되는 CNT의 입자가 너무 작은 문제가 있으며, 담지 촉매를 사용하는 방법인 경우 반응기 내의 공간 이용 효율이 크게 떨어져 CNT의 대량 생산에 한계가 있다. 따라서, 화학 기상 증착법에 있어서 CNT의 수율을 높이기 위하여 촉매, 반응 조건 등에 대한 연구가 계속되고 있다.The CNT is generally manufactured by arc discharge, laser ablation, chemical vapor deposition, or the like. However, the arc discharge method and the laser evaporation method are difficult to mass-produce, and excessive arc production cost or laser equipment purchase cost is a problem. In addition, the chemical vapor deposition method has a problem that the synthesis rate is very slow in the case of using a gas phase dispersion catalyst and the particles of the synthesized CNT are too small. There is a limit to mass production. Therefore, in order to increase the yield of CNT in chemical vapor deposition, studies on catalysts, reaction conditions, and the like are continuing.
한편 CNT를 고분자와 컴파운딩하여 얻어지는 복합소재의 물성을 개선하기 위해서는 직경이 작고, 컴파운딩시 분산 및 혼합이 잘 될 수 있는 형태를 가진 CNT가 요구된다.Meanwhile, in order to improve the physical properties of the composite material obtained by compounding CNTs with polymers, CNTs having a small diameter and a form that can be well dispersed and mixed during compounding are required.
따라서 본 발명이 해결하고자 하는 과제는, 작은 직경과 높은 비표면적을 가지면서, 고분자와 컴파운딩시 분산 및 혼합이 잘 이루어질 수 있는 번들형 구조를 갖는 CNT를 높은 수율로 제공할 수 있는 촉매를 제공하는 것이다.Therefore, the problem to be solved by the present invention is to provide a catalyst having a small diameter and a high specific surface area, CNT having a bundle structure that can be dispersed and mixed well when compounding with a polymer in high yield. It is.
본 발명이 해결하고자 하는 다른 과제는 상기 촉매를 사용하여 제조된 CNT 집합체를 제공하는 것이다.Another object of the present invention is to provide a CNT aggregate produced using the catalyst.
본 발명의 또 다른 과제는 상기 CNT 집합체를 함유하는 전도성 고분자 복합재를 제공하는 것이다.Another object of the present invention to provide a conductive polymer composite containing the CNT aggregate.
상기 과제를 해결하기 위하여, 본 발명은,In order to solve the above problems, the present invention,
지지체에 그래파이트화 금속 촉매가 담지되어 있으며, 10°에서 80°범위의 XRD 패턴에서 2θ값 35~38°에서 최대 회절 피크를 가지며, 최대 회절 피크 크기(a)에 대한 2θ값 17~22°에서의 회절 피크의 크기(b)의 비(b/a)가 0.08 이상인 탄소나노튜브 제조용 촉매를 제공한다. The support is supported by a graphitized metal catalyst and has a maximum diffraction peak at 2θ values of 35 to 38 ° in an XRD pattern in the range of 10 ° to 80 ° and at a value of 17 ° to 22 ° for the maximum diffraction peak size (a). Provided is a catalyst for producing carbon nanotubes in which the ratio (b / a) of the size (b) of the diffraction peak of is 0.08 or more.
상기 촉매의 XRD 패턴은 2θ값 30~33°, 43~46°, 57~60° 및 63~67°에서 선택되는 하나 이상의 회절 피크를 추가로 가질 수 있다. The XRD pattern of the catalyst may further have one or more diffraction peaks selected from 2θ values 30-33 °, 43-46 °, 57-60 ° and 63-67 °.
상기 촉매는 결정크기가 3 내지 50 nm 일 수 있다. The catalyst may have a crystal size of 3 to 50 nm.
또, 상기 촉매는 수산화알루미늄을 100 내지 500℃의 제1 소성온도에서 소성하여 지지체를 형성하고, 상기 지지체에 촉매 금속 전구체를 담지시킨 후 100 내지 800℃의 제2 소성온도에서 소성하여 얻은 담지 촉매일 수 있다. The catalyst is a supported catalyst obtained by calcining aluminum hydroxide at a first firing temperature of 100 to 500 ° C. to form a support, and carrying a catalyst metal precursor on the support and then firing at a second firing temperature of 100 to 800 ° C. Can be.
또, 상기 촉매는 30 내지 150㎛의 입자 크기와 40 내지 80㎛의 수평균입경을 갖도록 선별된 것일 수 있다. In addition, the catalyst may be selected to have a particle size of 30 to 150㎛ and a number average particle size of 40 to 80㎛.
상기 그래파이트화 금속촉매는 니켈(Ni), 코발트(Co), 철(Fe), 백금(Pt), 금(Au), 알루미늄(Al), 크롬(Cr), 구리(Cu), 마그네슘(Mg), 망간(Mn), 몰리브덴(Mo), 로듐(Rh), 실리콘(Si), 탄탈륨(Ta), 티타늄(Ti), 텅스텐(W), 우라늄(U), 바나듐(V) 및 지르코늄(Zr)으로 이루어진 군으로부터 선택된 하나 이상의 금속 또는 합금일 수 있다. The graphitized metal catalyst is nickel (Ni), cobalt (Co), iron (Fe), platinum (Pt), gold (Au), aluminum (Al), chromium (Cr), copper (Cu), magnesium (Mg) , Manganese (Mn), molybdenum (Mo), rhodium (Rh), silicon (Si), tantalum (Ta), titanium (Ti), tungsten (W), uranium (U), vanadium (V) and zirconium (Zr) It may be one or more metals or alloys selected from the group consisting of.
상기 그래파이트화 금속촉매가 주촉매-조촉매를 포함하는 다원계 금속촉매일수 있다. The graphitized metal catalyst may be a plural-based metal catalyst including a main catalyst-catalyst.
상기 주촉매는 Co 및 Fe로부터 선택되는 하나 이상이고, 상기 조촉매는 Mo 및 V 으로부터 선택되는 하나 이상일 수 있다. The main catalyst may be at least one selected from Co and Fe, and the cocatalyst may be at least one selected from Mo and V.
상기 그래파이트화 금속촉매가 Co/Mo, Co/V, Fe/Mo 및 Fe/V 중에서 선택되는 2원계 금속촉매일 수 있다. The graphitized metal catalyst may be a binary metal catalyst selected from Co / Mo, Co / V, Fe / Mo, and Fe / V.
상기 그래파이트화 금속촉매는 상기 주촉매 10몰에 대하여 조촉매의 함량이 0.5몰 내지 5몰인 것일 수 있다. The graphitized metal catalyst may have a content of 0.5 to 5 mol of the cocatalyst with respect to 10 mol of the main catalyst.
또, 상기 촉매 총중량 100중량부를 기준으로 상기 그래파이트화 금속 촉매가 5 내지 40 중량부 담지된 것일 수 있다. In addition, the graphitized metal catalyst may be 5 to 40 parts by weight based on 100 parts by weight of the catalyst.
본 발명은 또한, 전술한 촉매 상에 성장된 탄소나노튜브를 포함하는 탄소나노튜브 집합체로서, 탄소나노튜브 집합체의 BET 비표면적이 200 m2/g 이상이며, 상기 BET 비표면적과 상기 촉매의 결정크기가 하기 관계식을 만족하는 것인 탄소나노튜브 집합체를 제공한다: The present invention also provides a carbon nanotube aggregate comprising carbon nanotubes grown on the catalyst described above, wherein the BET specific surface area of the carbon nanotube aggregate is 200 m 2 / g or more, and the BET specific surface area and the crystal of the catalyst are determined. Provided are carbon nanotube aggregates whose sizes satisfy the following relationship:
y ≤ -2.1 x + 400y ≤ -2.1 x + 400
상기 식에서, y 는 BET 비표면적(m2/g), x는 촉매의 결정크기(nm)임. Wherein y is the BET specific surface area (m 2 / g) and x is the crystal size (nm) of the catalyst.
또, 상기 탄소나노튜브 집합체의 비표면적과 촉매의 결정크기가 하기 관계식을 만족하는 것일 수 있다. In addition, the specific surface area of the carbon nanotube aggregate and the crystal size of the catalyst may satisfy the following relationship.
-2.1 x + 200 ≤ y ≤ -2.1 x + 400-2.1 x + 200 ≤ y ≤ -2.1 x + 400
본 발명은 또한 전술한 촉매를 기상 탄소공급원과 접촉 반응시켜 탄소나노튜브(CNT)를 형성하는 단계를 포함하는 탄소나노튜브 집합체 제조방법을 제공한다. The present invention also provides a method for producing a carbon nanotube aggregate comprising the step of contacting the catalyst described above with a gaseous carbon source to form carbon nanotubes (CNTs).
상기 기상 탄소공급원이 일산화탄소, 메탄, 에탄, 에틸렌, 에탄올, 아세틸렌, 프로판, 프로필렌, 부탄, 부타디엔, 펜탄, 펜텐, 사이클로펜타디엔, 헥산, 사이클로헥산, 벤젠 및 톨루엔으로 이루어진 군으로부터 선택된 하나 이상인 것일 수 있다. The gaseous carbon source may be at least one selected from the group consisting of carbon monoxide, methane, ethane, ethylene, ethanol, acetylene, propane, propylene, butane, butadiene, pentane, pentene, cyclopentadiene, hexane, cyclohexane, benzene and toluene have.
상기 반응 온도는 600 내지 750℃ 일 수 있다. The reaction temperature may be 600 to 750 ℃.
본 발명은 또한 상기 탄소나노튜브 집합체를 포함하는 복합소재를 제공한다. The present invention also provides a composite material comprising the carbon nanotube aggregate.
상기 복합소재는 촉매의 결정크기에 반비례 하는 전도도를 가질 수 있다. The composite material may have a conductivity that is inversely proportional to the crystal size of the catalyst.
본 발명에 따르면 비표면적이 크고, 분산 및 혼합이 잘 될 수 있는 형태를 가진 탄소나노튜브(CNT)가 얻어질 수 있으므로, 상기 CNT를 포함하는 복합소재의 물성을 개선하는 것이 가능해진다. 그 결과 본 발명에 따른 CNT는 에너지 소재, 기능성 복합재, 의약, 전지, 반도체, 표시소자 등 다양한 분야에 유용하게 사용할 수 있다.According to the present invention, since a carbon nanotube (CNT) having a large specific surface area and having a shape that can be well dispersed and mixed can be obtained, it is possible to improve physical properties of the composite material including the CNT. As a result, the CNTs according to the present invention can be usefully used in various fields such as energy materials, functional composites, medicines, batteries, semiconductors, and display devices.
도 1은 본 발명의 실시예에서 제조된 촉매의 XRD 패턴이다. 1 is an XRD pattern of a catalyst prepared in an embodiment of the present invention.
도 2는 본 발명의 실시예에서 제조된 촉매의 결정크기와 이를 이용하여 제조된 CNT 집합체의 BET 비표면적의 상관관계를 나타내는 그래프이다. Figure 2 is a graph showing the correlation between the crystal size of the catalyst prepared in the embodiment of the present invention and the BET specific surface area of the CNT aggregate prepared using the same.
도 3은 본 발명의 실시예에 따라 제조된 CNT 집합체의 SEM 이미지이다. 3 is an SEM image of a CNT aggregate prepared according to an embodiment of the present invention.
도 4는 본 발명의 실시예에 따라 제조된 CNT 집합체를 함유하는 고분자 복합재의 표면저항을 CNT 집합체 제조에 사용된 촉매의 결정크기와의 상관관계로 나타낸 그래프이다.4 is a graph showing the surface resistance of the polymer composite containing the CNT aggregate prepared according to the embodiment of the present invention as a correlation with the crystal size of the catalyst used to prepare the CNT aggregate.
이하 본 발명을 보다 상세히 설명한다.Hereinafter, the present invention will be described in more detail.
본 발명은 지지체의 전처리 단계 및 담지 촉매의 형성 단계를 최적화함으로써 결정크기가 제어된 담지 촉매를 얻고, 이를 이용하여 저직경 높은 비표면적의 CNT 집합체, 그리고 이러한 CNT 집합체를 함유하여 전도도가 제어된 고분자 복합재를 제조하는 것에 관한 것이다. The present invention obtains a supported catalyst having a controlled crystal size by optimizing a pretreatment step of a support and a formation step of a supported catalyst, and by using the same, a CNT aggregate having a low diameter and high specific surface area, and a polymer having conductivity controlled by containing such CNT aggregate It relates to manufacturing a composite material.
본 발명에 따른 촉매는, 지지체에 그래파이트화 금속 촉매가 담지되어 있으며, 10°에서 80°범위의 XRD 패턴에서 2θ값 35~38°에서 최대 회절 피크를 가지며, 최대 회절 피크 크기(a)에 대한 2θ값 17~22°에서의 회절 피크의 크기(b)의 비(b/a)가 0.08 이상 인 것을 특징으로 한다. The catalyst according to the present invention has a graphitized metal catalyst on a support, has a maximum diffraction peak at a 2θ value of 35 to 38 ° in an XRD pattern in a range of 10 ° to 80 °, and has a maximum diffraction peak size (a). The ratio (b / a) of the magnitude (b) of the diffraction peak at the 2θ value of 17 to 22 ° is characterized by being 0.08 or more.
일 구현예에 따르면, 상기 b/a 는 0.15 이하 일 수 있으며, 0.09 내지 0.15, 또는 0.09 내지 0.13 일 수 있다. According to an embodiment, the b / a may be 0.15 or less, 0.09 to 0.15, or 0.09 to 0.13.
도 1 에 도시된 바와 같이, 일 구현예에 따른 촉매는 XRD 패턴의 2θ값 30~33°, 43~46°, 57~60° 및 63~67°에서 선택되는 하나 이상의 회절 피크를 추가로 가질 수 있다.As shown in FIG. 1, the catalyst according to one embodiment may further have one or more diffraction peaks selected from 2θ values 30-33 °, 43-46 °, 57-60 ° and 63-67 ° of the XRD pattern. Can be.
일 구현예에 따르면, 2θ값 30~33°에서의 회절 피크는 최대 회절 피크 대비 0.3 내지 0.5, 또는 0.35 내지 0.45의 크기를 가질 수 있다. According to one embodiment, the diffraction peak at 2θ values 30 to 33 ° may have a size of 0.3 to 0.5, or 0.35 to 0.45 relative to the maximum diffraction peak.
또, 2θ값 43~46°에서의 회절 피크는 최대 회절 피크 대비 0.1 내지 0.3, 또는 0.15 내지 0.25의 크기를 가질 수 있다. In addition, the diffraction peak at 2θ values 43 to 46 ° may have a size of 0.1 to 0.3, or 0.15 to 0.25 with respect to the maximum diffraction peak.
또, 2θ값 57~60°에서의 회절 피크는 최대 회절 피크 대비 0.1 내지 0.25, 또는 0.15 내지 0.22의 크기를 가질 수 있다. In addition, the diffraction peak at 2θ values 57 to 60 ° may have a size of 0.1 to 0.25, or 0.15 to 0.22 relative to the maximum diffraction peak.
또, 2θ값 63~67°에서의 회절 피크는 최대 회절 피크 대비 0.3 내지 0.5, 또는 0.35 내지 0.45의 크기를 가질 수 있다. In addition, the diffraction peak at the 2θ value of 63 to 67 ° may have a size of 0.3 to 0.5, or 0.35 to 0.45 relative to the maximum diffraction peak.
상기 촉매는 결정크기가 3 내지 50 nm 범위, 또는 10nm 내지 50nm에서 제어될 수 있는데, 촉매의 결정 크기는 촉매의 소성조건, 즉 촉매 금속의 종류, 촉매 금속 담지량, 소성량, 소성시간, 소성온도 등 다양한 조건을 조절하여 제어할 수 있다. The catalyst can be controlled in the crystal size range of 3 to 50 nm, or 10nm to 50nm, the crystal size of the catalyst is the calcination conditions of the catalyst, that is, the type of catalyst metal, catalyst metal loading, calcining amount, firing time, firing temperature It can be controlled by adjusting various conditions.
여기서, 촉매의 '결정 크기'란 '결정립 크기(crystallite size)'라고도 하며, XRD 측정에 따라 나타나는 피크(peak)들의 폭(broadening)으로부터 계산된 크기이다. 보다 구체적으로 Bragg-Brentano 방식, 입사각이 2theta의 1/2인 모드(mode)를 사용하고, 결정립 크기 공식은 Bruker TOPAS program 내 기초접근법(Fundamental approach)을 이용한 풀 패턴 피팅법(full pattern fitting)에 의해 계산된 값이다. 따라서 SEM 사진에 의해 입자 크기를 구하는 '촉매 입경' 또는 '촉매 입자 크기' 와는 구별되어야 한다. 결정립 크기 측정 및 계산 방법은 알려진 표준 방법에 따르므로, 구체적인 설명은 생략한다. Here, the 'crystal size' of the catalyst is also referred to as 'crystallite size', and is calculated from the broadening of peaks appearing according to the XRD measurement. More specifically, the Bragg-Brentano method, a mode of incidence angle 1/2 of 2theta, is used, and the grain size formula is applied to the full pattern fitting method using the fundamental approach in the Bruker TOPAS program. Calculated by Therefore, it should be distinguished from the 'catalyst particle size' or the 'catalyst particle size' obtained from the SEM photograph. Since the grain size measurement and calculation method is in accordance with known standard methods, detailed description is omitted.
도 2에 도시된 바와 같이, 본 발명에 따른 촉매는 촉매의 결정 크기가 증가할수록 결과적으로 제조되는 CNT 집합체의 BET 비표면적이 감소하는 경향을 나타낸다. As shown in FIG. 2, the catalyst according to the present invention exhibits a tendency to decrease the BET specific surface area of the resulting CNT aggregate as the crystal size of the catalyst increases.
구체적으로, 본 발명에 따른 촉매를 사용하여 제조된 CNT 집합체는 BET 비표면적이 200 m2/g 이상이며, 상기 BET 비표면적과 상기 촉매의 결정크기가 하기 관계식을 만족한다: Specifically, the CNT aggregate produced using the catalyst according to the present invention has a BET specific surface area of 200 m 2 / g or more, and the BET specific surface area and crystal size of the catalyst satisfy the following relation:
y ≤ -2.1 x + 400y ≤ -2.1 x + 400
상기 식에서, y 는 BET 비표면적(m2/g), x는 촉매의 결정크기(nm)임. Wherein y is the BET specific surface area (m 2 / g) and x is the crystal size (nm) of the catalyst.
더욱 바람직하게는, 상기 탄소나노튜브 집합체의 비표면적과 촉매의 결정크기가 하기 관계식 중 하나 이상을 만족하는 것일 수 있다. More preferably, the specific surface area of the carbon nanotube aggregate and the crystal size of the catalyst may satisfy one or more of the following relational expressions.
-2.1 x + 200 ≤ y ≤ -2.1 x + 400-2.1 x + 200 ≤ y ≤ -2.1 x + 400
-2.1 x + 250 ≤ y ≤ -2.1 x + 350-2.1 x + 250 ≤ y ≤ -2.1 x + 350
-2.1 x + 250 ≤ y ≤ -2.1 x + 300-2.1 x + 250 ≤ y ≤ -2.1 x + 300
-2.1 x + 270 ≤ y ≤ -2.1 x + 320-2.1 x + 270 ≤ y ≤ -2.1 x + 320
-2.1 x + 270 ≤ y ≤ -2.1 x + 300-2.1 x + 270 ≤ y ≤ -2.1 x + 300
본 발명에서 사용하는 비표면적은 BET법에 의해 측정한 것으로서, 구체적으로는 BEL Japan사 BELSORP-mini II를 이용하여 액체 질소 온도 하(77K)에 있어서의 질소가스 흡착량을 구하여 산출한 것이 바람직하다. The specific surface area used in the present invention is measured by the BET method. Specifically, the specific surface area used is calculated by calculating the amount of nitrogen gas adsorption under liquid nitrogen temperature (77K) using BEL Japan's BELSORP-mini II. .
본 발명에 따른 CNT 집합체는 BET 비표면적이 200 내지 500 m2/g, 또는 200 내지 300 m2/g, 또는 300 내지 500 m2/g, 또는 300 내지 400 m2/g, 또는 200 내지 400 m2/g 일 수 있다. CNT aggregates according to the invention have a BET specific surface area of from 200 to 500 m 2 / g, or from 200 to 300 m 2 / g, or from 300 to 500 m 2 / g, or from 300 to 400 m 2 / g, or from 200 to 400 m 2 / g.
BET 비표면적이 커질수록 CNT 집합체의 직경이 작은 것을 의미한다. The larger the BET specific surface area, the smaller the diameter of the CNT aggregate.
본 발명에 따르면, CNT 집합체의 비표면적이 커질수록 이를 함유하는 고분자 컴파운드의 전기전도성이 향상되는 경향을 나타낸다. CNT 함유 고분자 컴파운드의 전도도는 CNT 집합체의 직경, 결정성과 같은 물리적 특성과 컴파운딩시 분산성(CNT 형상과 연관됨)에 의해 영향을 받는 것으로 파악된다. According to the present invention, as the specific surface area of the CNT aggregate increases, the electrical conductivity of the polymer compound containing the same tends to be improved. The conductivity of the CNT-containing polymer compound is believed to be influenced by physical properties such as diameter and crystallinity of the CNT aggregate and dispersibility (associated with the CNT shape) during compounding.
본 발명에 따른 촉매의 결정 크기와 이를 이용하여 제조된 CNT 집합체를 함유하는 고분자 컴파운드의 표면저항은 도 4에 나타낸 바와 같은 관계를 갖는다. The crystallite size of the catalyst according to the present invention and the surface resistance of the polymer compound containing the CNT aggregate prepared using the same have a relationship as shown in FIG. 4.
결국, 본 발명에 따르면, 촉매의 결정 크기를 작게 조절하면 높은 비표면적(저직경)을 갖는 CNT 집합체를 제조할 수 있고, 그 결과 전도성이 우수한 고분자 컴파운드를 제조할 수 있다. As a result, according to the present invention, if the crystal size of the catalyst is controlled to be small, a CNT aggregate having a high specific surface area (low diameter) can be produced, and as a result, a polymer compound having excellent conductivity can be prepared.
본 발명의 일구현예에 따르면, 지지체 전구체를 제 1 소성온도, 예를 들어 100℃ 내지 500℃의 온도에서 제1 소성하여 얻어진 지지체에 그래파이트화 촉매를 담지시킨 후, 이를 100℃ 내지 800℃의 온도에서 제2 소성하여 제조된 담지 촉매를 제조한다. According to one embodiment of the present invention, the support precursor obtained by first firing at a first firing temperature, for example, at a temperature of 100 ° C. to 500 ° C. is loaded with a graphitization catalyst, and then, it is 100 ° C. to 800 ° C. A supported catalyst prepared by second firing at a temperature is prepared.
상기 담지 촉매를 기상 탄소공급원과 접촉시켜 바람직하게는 BET 비표면적이 200 m2/g 이상인 번들형 탄소나노튜브 집합체를 제조할 수 있다(도 3 참조). The supported catalyst may be contacted with a gaseous carbon source to prepare a bundle of carbon nanotube aggregates having a BET specific surface area of preferably 200 m 2 / g or more (see FIG. 3).
본 발명에서 사용하는 용어 '번들형 (bundle type)'이란 달리 언급되지 않는 한, 복수개의 CNT가 나란하게 배열 또는 뒤엉켜있는, 다발(bundle) 혹은 로프(rope) 형태의 2차 형상을 지칭한다. '비번들형(non-bundle 또는 entangled type)'이란 다발 혹은 로프 형태와 같은 일정한 형상이 없는 형태를 의미한다.As used herein, the term 'bundle type' refers to a secondary shape in the form of a bundle or a rope, in which a plurality of CNTs are arranged or intertwined side by side, unless otherwise stated. 'Non-bundle or entangled type' means a shape without a certain shape, such as a bundle or a rope shape.
상기 제조방법에 사용되는 지지체 전구체는 그래파이트화 촉매를 담지하는 역할을 수행하며, 그 종류에 따라 CNT의 형상을 제어할 수 있다. The support precursor used in the production method serves to support the graphitization catalyst, it is possible to control the shape of the CNT according to the type.
이와 같은 지지체 전구체로서는 예를 들어 알루미늄계 지지체 전구체, 바람직하게는 수산화알루미늄 (aluminum-tri-hydroxide, ATH)을 사용할 수 있다. 이와 같은 지지체 전구체는 50℃ 내지 150℃에서 1 시간 내지 24 시간 동안 건조시켜 사용할 수 있다.As such a support precursor, for example, an aluminum-based support precursor, preferably aluminum hydroxide (aluminum-tri-hydroxide, ATH) can be used. Such a support precursor can be used by drying for 1 hour to 24 hours at 50 ℃ to 150 ℃.
상기 지지체 전구체를 제1 소성하여 지지체를 형성하게 되는 바, 제1 소성 온도는 수산화알루미늄이 알루미나로 전환되는 것으로 알려진 700℃ 보다 훨씬 낮은 500℃ 이하인 것이 바람직하다. 즉, 제1 소성은 약 100℃ 내지 약 500℃, 또는 약 120℃ 내지 약 450℃, 또는 200 내지 450℃, 또는 300 내지 450℃, 또는 200 내지 400℃ 의 온도에서 수행하는 열처리 공정을 포함할 수 있다. Since the support precursor is first calcined to form a support, the first firing temperature is preferably 500 ° C. or less, much lower than 700 ° C., which is known to convert aluminum hydroxide to alumina. That is, the first firing may include a heat treatment process performed at a temperature of about 100 ° C to about 500 ° C, or about 120 ° C to about 450 ° C, or 200 to 450 ° C, or 300 to 450 ° C, or 200 to 400 ° C. Can be.
상기와 같은 공정에 의해 형성되는 알루미늄계 지지체는 Al(OH)3에서 전환된 AlO(OH)를 30 중량% 이상 포함하고 Al2O3는 포함하지 않는 것이 바람직하다. The aluminum-based support formed by the above process preferably contains 30 wt% or more of AlO (OH) converted from Al (OH) 3 and does not include Al 2 O 3 .
또한 상기 알루미늄(Al)계 지지체에 ZrO2, MgO 및 SiO2로 이루어지는 그룹에서 선택되는 하나 이상을 추가로 포함할 수 있다. 상기 알루미늄(Al)계 지지체는 구형 또는 포테이토형의 형상을 가지고, 단위 질량 또는 부피당 비교적 높은 표면적을 갖도록 다공성 구조, 분자체 구조, 벌집 구조, 또 다른 적합한 구조를 가질 수 있다. In addition, the aluminum (Al) -based support may further include one or more selected from the group consisting of ZrO 2 , MgO and SiO 2 . The aluminum (Al) -based support may have a spherical or potato shape, and may have a porous structure, a molecular sieve structure, a honeycomb structure, or another suitable structure to have a relatively high surface area per unit mass or volume.
일 구현예에 따르면, 상기 지지체 전구체는 일차 입경 약 20 내지 약 200 ㎛, 기공율 약 0.1 내지 약 1.0 cm3/g, 비표면적 약 1 m2/g 미만인 것일 수 있다.According to one embodiment, the support precursor may have a primary particle size of about 20 to about 200 ㎛, porosity of about 0.1 to about 1.0 cm 3 / g, specific surface area of less than about 1 m 2 / g.
상기 제1 소성 공정은 약 0.5 시간 내지 약 10 시간, 바람직하게는 약 1시간 내지 5시간 동안 수행할 수 있으나, 이에 한정되는 것은 아니다.The first firing process may be performed for about 0.5 hours to about 10 hours, preferably about 1 hour to 5 hours, but is not limited thereto.
상기 제조방법에 사용되는 그래파이트화 촉매를 기상 탄소공급원과 접촉시키면 CNT를 형성할 수 있다. 이와 같은 CNT의 성장 과정을 보다 구체적으로 설명하면, 기상 탄소공급원인 탄소계 물질을 상기 그래파이트화 촉매, 예를 들어 그래파이트화 금속 촉매와 접촉시킨 후 이를 열처리하면 상기 탄소계 물질이 금속 촉매 표면에서 열분해되며, 분해된 탄소 함유 가스로부터 생성되는 탄소원자가 상기 그래파이트화 금속 촉매 내부로 침투하여 고용된 후, 그 침투 함량이 상기 그래파이트화 금속 촉매의 고유 특성인 고용 한계(solubility limit)를 초과하는 경우, CNT로의 핵생성이 일어나 CNT로 성장하게 된다.Contacting the graphitization catalyst used in the preparation method with a gaseous carbon source can form CNTs. In more detail, the growth process of CNTs is described above. When the carbonaceous material, which is a gaseous carbon source, is contacted with the graphite catalyst, for example, a graphite metal catalyst, and then heat treated, the carbonaceous material is thermally decomposed on the surface of the metal catalyst. And CNTs in which the carbon atom generated from the decomposed carbon-containing gas penetrates into the graphitized metal catalyst to be dissolved and then exceeds the solubility limit which is an inherent property of the graphitized metal catalyst. The nucleation of the furnace occurs and grows into CNTs.
상기 그래파이트화 금속 촉매는 상기 탄소계 물질에 존재하는 탄소성분들이 서로 결합하여 6각형의 고리 구조를 형성하도록 도와주는 역할을 수행하는 바, 그 예로서는 그래파이트를 합성하거나, 탄화반응을 유도하거나, 또는 CNT를 제조하는데 사용되는 촉매를 사용할 수 있다. 보다 구체적으로는, 니켈(Ni), 코발트(Co), 철(Fe), 백금(Pt), 금(Au), 알루미늄(Al), 크롬(Cr), 구리(Cu), 마그네슘(Mg), 망간(Mn), 몰리브덴(Mo), 로듐(Rh), 실리콘(Si), 탄탈륨(Ta), 티타늄(Ti), 텅스텐(W), 우라늄(U), 바나듐(V) 및 지르코늄(Zr)으로 이루어진 군으로부터 선택된 하나 이상의 금속 또는 합금을 사용할 수 있다.The graphitized metal catalyst serves to help the carbon components present in the carbonaceous material combine with each other to form a hexagonal ring structure, for example, to synthesize graphite, induce carbonization, or CNT It is possible to use the catalyst used to prepare the. More specifically, nickel (Ni), cobalt (Co), iron (Fe), platinum (Pt), gold (Au), aluminum (Al), chromium (Cr), copper (Cu), magnesium (Mg), With manganese (Mn), molybdenum (Mo), rhodium (Rh), silicon (Si), tantalum (Ta), titanium (Ti), tungsten (W), uranium (U), vanadium (V) and zirconium (Zr) One or more metals or alloys selected from the group consisting of can be used.
상기 그래파이트화 촉매는 2원계 또는 3원계 이상의 다원계 금속을 사용할 수 있다. 이와 같은 2원계 또는 다원계 그래파이트화 촉매는 주촉매 및 조촉매로 구성될 수 있으며, 상기 주촉매로서는 Co, Fe, Ni 등을 사용할 수 있고, 상기 조촉매로서는 Mo, V 등을 사용할 수 있다. 이와 같은 2원계 또는 다원계 그래파이트화 촉매는 Co/Mo, Co/V, Fe/Mo, Fe/V, Fe/Co, Fe/Co/V, Fe/Co/Mo, Co/Mo/V, Fe/Mo/V, Fe/Co/Mo/V 등을 들 수 있다. 이 중에서도 Co와 V 을 포함하는 것이 더욱 바람직하다. The graphitization catalyst may use a binary or ternary or higher polyvalent metal. Such a binary or multi-part graphitization catalyst may be composed of a main catalyst and a promoter, Co, Fe, Ni, etc. may be used as the main catalyst, Mo, V, etc. may be used as the promoter. Such binary or plural graphitization catalysts are Co / Mo, Co / V, Fe / Mo, Fe / V, Fe / Co, Fe / Co / V, Fe / Co / Mo, Co / Mo / V, Fe / Mo / V, Fe / Co / Mo / V, etc. are mentioned. Among these, it is more preferable that Co and V are included.
주촉매 및 조촉매를 포함하는 상기 2원계 그래파이트화 촉매에서 이들의 성분비로서는 예를 들어 주촉매 10몰을 기준으로 조촉매 0.1몰 내지 10몰, 또는 0.5 몰 내지 5몰을 사용할 수 있다.In the binary graphitization catalyst including the main catalyst and the cocatalyst, the component ratio thereof may be, for example, 0.1 to 10 moles or 0.5 to 5 moles of the cocatalyst based on 10 moles of the main catalyst.
상기 그래파이트화 촉매는 금속염, 금속산화물, 또는 금속화합물 등의 다양한 전구체 형태로 상기 지지체에 담지된다. 예를 들어, 상기 그래파이트화 촉매의 전구체로서는 물에 용해될 수 있는 Fe염, Fe산화물, Fe화합물, Ni염, Ni산화물, Ni화합물, Co염, Co산화물, Co화합물, Mo산화물, Mo화합물, Mo염, V산화물, V화합물, V염 등을 예시할 수 있다. 또 다른 일례로 Fe(NO3)2·6H2O, Fe(NO3)2·9H2O, Fe(NO3)3, Fe(OAc)2, Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Co2(CO)8, [Co2(CO)6(t-BuC=CH)], Co(OAc)2, (NH4)6Mo7O24·4H2O, Mo(CO)6, (NH4)MoS4, NH4VO3 등을 사용할 수 있다.The graphitization catalyst is supported on the support in the form of various precursors such as metal salts, metal oxides, or metal compounds. For example, as the precursor of the graphitization catalyst, Fe salt, Fe oxide, Fe compound, Ni salt, Ni oxide, Ni compound, Co salt, Co oxide, Co compound, Mo oxide, Mo compound, Mo salt, V oxide, V compound, V salt, etc. can be illustrated. Another example is Fe (NO 3 ) 2 · 6H 2 O, Fe (NO 3 ) 2 · 9H 2 O, Fe (NO 3 ) 3 , Fe (OAc) 2 , Ni (NO 3 ) 2 · 6H 2 O, Co (NO 3 ) 2 .6H 2 O, Co 2 (CO) 8 , [Co 2 (CO) 6 (t-BuC = CH)], Co (OAc) 2 , (NH 4 ) 6 Mo 7 O 24 4H 2 O, Mo (CO) 6 , (NH 4 ) MoS 4 , NH 4 VO 3 , and the like can be used.
상기 그래파이트화 촉매의 전구체가 용액의 형태로 상기 지지체에 담지된 후, 제2 소성 공정을 거치게 되면, 주로 금속 산화물의 형태로 담지되어 담지 촉매를 형성할 수 있게 된다.When the precursor of the graphitization catalyst is supported on the support in the form of a solution, and then undergoes a second firing process, it is mainly supported in the form of a metal oxide to form a supported catalyst.
보다 구체적으로, 그래파이트화 촉매의 전구체 수용액에 지지체, 예를 들어 입상의 알루미늄계 지지체를 혼합하는 단계; 및More specifically, mixing a support, for example a granular aluminum-based support in the precursor aqueous solution of the graphitization catalyst; And
상기 혼합물을 진공건조 후 약 100 내지 500℃의 제1 소성온도에서 소성하여 지지체를 형성하고, 상기 지지체에 촉매 금속 전구체를 담지시킨 후 100 내지 800℃의 제2 소성온도에서 소성하여 CNT 제조용 담지 촉매를 수득하는 단계;를 포함하는 방법에 의해 제조될 수 있다. After the vacuum drying, the mixture is calcined at a first firing temperature of about 100 to 500 ° C. to form a support, and a catalyst metal precursor is supported on the support and then calcined at a second firing temperature of 100 to 800 ° C. to support CNT production catalyst. It can be prepared by a method comprising; obtaining a.
일 구현예에 따르면, 상기 진공 건조는 약 40 내지 약 100℃ 온도 범위의 진공 하에 약 30분 내지 약 12시간 범위 내에서 회전 증발시켜 수행될 수 있다.According to one embodiment, the vacuum drying may be carried out by rotary evaporation in the range of about 30 minutes to about 12 hours under vacuum in the temperature range of about 40 to about 100 ℃.
일 구현예에 따르면, 상기 진공 건조 전 약 45 내지 약 80℃ 하에 회전 또는 교반에 의해 숙성시키는 단계를 포함할 수 있다. 일례로 최대 5시간, 20분 내지 5시간, 혹은 1 내지 4시간 동안 수행할 수 있다. According to one embodiment, the method may include aging by rotation or stirring at about 45 to about 80 ° C. before the vacuum drying. For example, it may be performed for up to 5 hours, 20 minutes to 5 hours, or 1 to 4 hours.
상기 담지 촉매를 형성하는 제2 소성 공정은 약 100℃ 내지 약 800℃, 예를 들어 약 200℃ 내지 약 800℃ 또는 550℃ 내지 약 800℃의 온도에서 수행될 수 있다. 제2 소성 공정의 온도는 제1 소성공정의 온도보다 200 내지 400℃ 높은 것이 바람직하다. The second firing process for forming the supported catalyst may be performed at a temperature of about 100 ° C to about 800 ° C, for example, about 200 ° C to about 800 ° C or 550 ° C to about 800 ° C. It is preferable that the temperature of a 2nd baking process is 200-400 degreeC higher than the temperature of a 1st baking process.
상기 제조방법에서 사용되는 담지 촉매의 제2 소성 전 측정한 입경 혹은 평균입경은 약 30㎛ 내지 약 150㎛이고, 상기 입상 지지체 및 그래파이트화 촉매의 일차 입경은 약 10nm 내지 약 50nm인 구형 또는 포테이토형일 수 있다. 여기서 구형 또는 포테이토 형상이란 종횡비(aspect ratio) 1.2 이하의 구형, 타원체형과 같은 3차원 형상을 지칭한다. The particle size or average particle diameter measured before the second firing of the supported catalyst used in the preparation method is about 30 μm to about 150 μm, and the primary particle diameter of the granular support and the graphitization catalyst is about 10 nm to about 50 nm. Can be. Here, the spherical or potato shape refers to a three-dimensional shape such as a spherical and ellipsoidal shape having an aspect ratio of 1.2 or less.
일 구현예에 따라, 유동층 반응기를 이용하여 본 발명에 따른 CNT를 제조하는 경우에는 특히, 담지 촉매의 입경이 약 30㎛ 내지 약 150㎛이고, 수평균입경(Mn)이 40 내지 80㎛, 또는 50 내지 70㎛, 또는 50 내지 70㎛ 이 되도록 선별하여 사용할 수 있다. 유동층 반응기 내 반응영역에서 촉매 유동층이 촉매 응집없이 잘 유동되도록 하는 것이 중요하기 때문이다. According to one embodiment, when preparing a CNT according to the present invention using a fluidized bed reactor, in particular, the supported catalyst has a particle diameter of about 30 μm to about 150 μm, a number average particle diameter (Mn) of 40 to 80 μm, or It can be used selectively to be 50 to 70㎛, or 50 to 70㎛. This is because it is important to ensure that the catalyst fluidized bed flows well without catalyst aggregation in the reaction zone in the fluidized bed reactor.
일 구현예에 따르면, 상기 담지 촉매는 상기 담지촉매 100 중량부를 기준으로 상기 그래파이트화 촉매를 약 5 내지 약 40 중량부의 범위로 포함할 수 있으나, 이에 한정되는 것은 아니다.According to one embodiment, the supported catalyst may include about 5 to about 40 parts by weight of the graphitization catalyst based on 100 parts by weight of the supported catalyst, but is not limited thereto.
예를 들어, 상기 담지촉매가 Co계 그래파이트화 촉매를 포함하는 경우, 상기 Co의 함량은 상기 지지체 100몰을 기준으로 약 3몰 내지 약 100몰의 함량이 될 수 있다.For example, when the supported catalyst includes a Co-based graphitization catalyst, the content of Co may be about 3 to about 100 moles based on 100 moles of the support.
일 구현예에 따르면, 상기 그래파이트화 촉매는 입상 지지체, 바람직하게는 알루미늄계 지지체 표면 및 세공에 일층 혹은 다층 코팅된 구조를 가질 수 있다.According to one embodiment, the graphitization catalyst may have a structure in which one or more layers are coated on the surface and pores of the granular support, preferably the aluminum-based support.
상기 담지 촉매 제조과정에 있어서, 함침법을 이용한 담지 촉매를 사용하는 것이 바람직한데, 이는 담지 촉매가 사용되는 경우 촉매 자체의 벌크 밀도(bulk density)가 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.In the process of preparing the supported catalyst, it is preferable to use a supported catalyst using an impregnation method, in which the bulk density of the catalyst itself is higher than that of the coprecipitation catalyst and less than 10 microns, unlike the coprecipitation catalyst, when the supported catalyst is used. It is possible to reduce the possibility of fine powder due to attrition, which can occur during fluidization process because of the small amount of fine powder. Also, the mechanical strength of the catalyst itself is excellent, which makes it possible to stabilize the reactor operation.
상술한 바와 같은 담지 촉매를 이용하여 탄소공급원의 분해를 통한 화학적 기상 합성법으로 CNT를 성장시켜 CNT를 제조할 수 있다. CNTs may be prepared by growing CNTs by chemical vapor phase synthesis through decomposition of a carbon source using the supported catalyst as described above.
상기 화학적 기상 합성법에 따른 CNT 제조방법에 있어서, 그래파이트화 촉매를 반응기 내에 장입시킨 후, 상압 및 고온의 조건하에서 기상 탄소공급원을 공급하여 CNT를 제조할 수 있다. CNT의 성장은 상술한 바와 같이 고온의 열이 가해져 열분해된 탄화수소가 그래파이트화 촉매 내로 침투, 포화되는 과정을 거치고, 포화된 그래파이트화 촉매로부터 탄소들이 석출되며 6각형의 고리 구조를 형성하며 수행된다.In the method for producing CNTs according to the chemical vapor phase synthesis method, after charging the graphitization catalyst in the reactor, the CNT can be prepared by supplying a gaseous carbon source under conditions of normal pressure and high temperature. As described above, the growth of the CNTs is carried out by the process of infiltrating and saturating the pyrolyzed hydrocarbons by applying high temperature heat to the graphitization catalyst, and depositing carbons from the saturated graphitization catalyst to form a hexagonal ring structure.
본 발명에 있어서, 상기 화학적 기상 합성법은 상기 담지 촉매를 수평 고정층 반응기 또는 유동층 반응기에 투입하고 약 500℃ 내지 약 900℃, 또는 약 500℃ 내지 800℃, 또는 약 600℃ 내지 800℃, 약 600℃ 내지 약 750℃, 또는 약 650℃ 내지 약 700℃의 온도에서 탄소수 1 내지 6의 포화 또는 불포화 탄화수소에서 선택된 하나 이상의 탄소 공급원, 또는 상기 탄소공급원과 환원가스(예를 들어, 수소) 및 운반가스(예를 들어, 질소)의 혼합가스를 주입하여 실시될 수 있다. 상기 담지 촉매에 탄소공급원을 주입하여 CNT를 성장시키는 단계는 30분 내지 8시간 동안 수행될 수 있다.In the present invention, the chemical vapor phase synthesis method is to add the supported catalyst to a horizontal fixed bed reactor or fluidized bed reactor and about 500 ℃ to about 900 ℃, or about 500 ℃ to 800 ℃, or about 600 ℃ to 800 ℃, about 600 ℃ One or more carbon sources selected from saturated or unsaturated hydrocarbons having 1 to 6 carbon atoms at a temperature of from about 750 ° C., or about 650 ° C. to about 700 ° C., or the carbon source with a reducing gas (eg, hydrogen) and a carrier gas ( For example, it may be carried out by injecting a mixed gas of nitrogen). Injecting a carbon source into the supported catalyst to grow the CNTs may be performed for 30 minutes to 8 hours.
일 구현예에 따라 유동층 반응기를 사용하여 본 발명에 따른 CNT를 제조하는 경우에는 유동층 반응기 하단에 가스 공급구를 구비하여 가스 유동에 의해 촉매입자가 응집되지 않도록 하거나 뭉쳐진 촉매 입자들을 개별 입자로 분리해주는 것이 바람직하다. 이때 공급가스는 탄소공급원과 환원가스 또는 운반가스를 각각 또는 이들의 혼합가스를 사용하는 것이 가능하다. When manufacturing a CNT according to the present invention by using a fluidized bed reactor according to an embodiment provided with a gas supply port at the bottom of the fluidized bed reactor to prevent the agglomerated catalyst particles by the gas flow or to separate the agglomerated catalyst particles into individual particles It is preferable. In this case, the supply gas may be a carbon source and a reducing gas or a carrier gas, respectively, or a mixture thereof.
상기 제조방법 중 소성 공정이나 열처리 공정을 위한 열원으로서는 유도가열(induction heating), 복사열, 레이져, IR, 마이크로파, 플라즈마, UV, 표면 플라즈몬 가열 등을 제한 없이 사용할 수 있다.As the heat source for the firing process or the heat treatment process of the manufacturing method, induction heating, radiant heat, laser, IR, microwave, plasma, UV, surface plasmon heating, etc. can be used without limitation.
상기 화학적 기상 합성법에 사용되는 탄소공급원은 탄소를 공급할 수 있으며, 300℃ 이상의 온도에서 기상으로 존재할 수 있는 물질이라면 특별한 제한 없이 사용할 수 있다. 이와 같은 기상 탄소계 물질로서는 탄소를 함유하는 화합물이면 가능하며, 탄소수 6개 이하의 화합물이 바람직하고, 더욱 바람직하게는 탄소수 4개 이하의 화합물이다. 그러한 예로서는 일산화탄소, 메탄, 에탄, 에틸렌, 에탄올, 아세틸렌, 프로판, 프로필렌, 부탄, 부타디엔, 펜탄, 펜텐, 사이클로펜타디엔, 헥산, 사이클로헥산, 벤젠 및 톨루엔으로 이루어진 군으로부터 선택된 하나 이상을 사용할 수 있으나 이에 한정되는 것은 아니다. 또한, 수소 및 질소의 혼합가스는 탄소공급원을 운송하며, CNT가 고온에서 연소되는 것을 방지하고, 탄소공급원의 분해를 돕는다.The carbon source used in the chemical vapor phase synthesis method may supply carbon, and any material that may exist in the gas phase at a temperature of 300 ° C. or higher may be used without particular limitation. As such a gaseous carbonaceous substance, any compound containing carbon may be used, and a compound having 6 or less carbon atoms is preferable, and more preferably a compound having 4 or less carbon atoms. As such an example, one or more selected from the group consisting of carbon monoxide, methane, ethane, ethylene, ethanol, acetylene, propane, propylene, butane, butadiene, pentane, pentene, cyclopentadiene, hexane, cyclohexane, benzene and toluene can be used. It is not limited. In addition, the mixed gas of hydrogen and nitrogen transports the carbon source, prevents CNTs from burning at high temperatures, and assists in the decomposition of the carbon source.
이와 같은 기상 탄소공급원, 수소 및 질소는 다양한 부피비로 사용될 수 있으며, 예를 들어 질소 : 기상 탄소공급원 : 수소의 부피비는 1 : 0.1 ~ 10 : 0 ~ 10, 또는 1 : 0.5 ~ 1.5 : 0.5 ~ 1.5의 범위에서 사용할 수 있다. 이 때 반응가스의 유량은 약 100 sccm 이상 약 10,000sccm 이하의 범위에서 적절히 사용할 수 있다.Such gaseous carbon source, hydrogen and nitrogen can be used in various volume ratios, for example, the volume ratio of nitrogen: gaseous carbon source: hydrogen is 1: 0.1 to 10: 0 to 10, or 1: 0.5 to 1.5: 0.5 to 1.5 Can be used in the range of. At this time, the flow rate of the reaction gas can be suitably used in the range of about 100 sccm or more and about 10,000 sccm or less.
상기와 같이 고온의 열처리 공정에 의해 CNT를 성장시킨 후, 냉각 공정을 거치게 되는 바, 이와 같은 냉각 공정에 의해 상기 CNT는 보다 규칙적으로 배열될 수 있다. 이와 같은 냉각 공정은 자연 냉각(열원의 제거), 또는 분당 약 5℃ 내지 약 30℃의 속도로 냉각할 수 있다.After the CNTs are grown by a high temperature heat treatment process as described above, the CNTs are subjected to a cooling process. The CNTs may be arranged more regularly by the cooling process. Such cooling process may be natural cooling (removal of heat source), or cooling at a rate of about 5 ° C. to about 30 ° C. per minute.
상기와 같은 제조공정을 거치게 되면 BET 비표면적이 약 200 m2/g 이상, 바람직하게는 약 200 m2/g 내지 약 500 m2/g인 번들형 CNT가 얻어질 수 있게 된다. 상기 비표면적은 통상의 BET법을 통해 측정할 수 있다.Through such a manufacturing process, a bundle type CNT having a BET specific surface area of about 200 m 2 / g or more, preferably about 200 m 2 / g to about 500 m 2 / g can be obtained. The specific surface area can be measured by a conventional BET method.
특히 상기 제조방법은 높은 수율로 CNT를 수득할 수 있게 되는 바, 예를 들어 약 5배 내지 50배, 또는 약 10배 내지 40배의 수율을 달성할 수 있게 된다. 상기 수율은 합성된 탄소나노튜브를 상온에서 수득하여 그 함량을 전자저울을 이용하여 측정할 수 있다. 이때 반응 수율은 사용한 담지 촉매의 중량과 반응 후 중량 증가량을 기준으로 하기 식에 의거하여 계산할 수 있다.In particular, the production method is capable of obtaining CNTs in high yield, for example, achieving a yield of about 5 to 50 times, or about 10 to 40 times. The yield is obtained from the synthesized carbon nanotubes at room temperature and its content can be measured using an electronic balance. The reaction yield can be calculated based on the weight of the supported catalyst used and the weight increase after the reaction based on the following formula.
CNT 수율(배)=(반응 후 총 중량g - 사용한 담지 촉매의 중량g)/사용한 담지 촉매 중량gCNT yield (times) = (total weight after reaction g-weight of supported catalyst used) / g of supported catalyst used
본 발명에 있어서, 상기 CNT는 편평률이 약 0.9 내지 약 1인 번들형일 수 있으며, 또한 BET 비표면적이 증가함에 따라 CNT 각 가닥 직경은 약 2nm 내지 약 20nm, 바람직하게는 약 3nm 내지 약 8nm의 저직경을 가질 수 있다. In the present invention, the CNTs may be in a bundle having a flatness of about 0.9 to about 1, and as the BET specific surface area increases, each CNT strand diameter is about 2 nm to about 20 nm, preferably about 3 nm to about 8 nm. It may have a low diameter.
상기 편평률은 하기 식으로 정의될 수 있다. The flatness may be defined by the following equation.
편평률 = CNT의 중심을 관통하는 최단 직경 / CNT의 중심을 관통하는 최대 직경Flatness = shortest diameter through the center of CNT / maximum diameter through the center of CNT
상술한 바와 같은 CNT는 BET 비표면적이 크고, 즉 저직경이며, 번들 형태를 가짐에 따라 다른 소재, 예를 들어 고분자에 분산 및 혼합이 잘 되므로 복합소재의 형성시 물성을 개선할 수 있게 된다.As described above, CNTs have a large BET specific surface area, that is, a low diameter, and have a bundle shape, so that the CNTs are well dispersed and mixed in other materials, for example, polymers, thereby improving physical properties when forming a composite material.
따라서 다양한 LCD, OLED, PDP, e-paper와 같은 표시소자; 태양전지, 연료전지, 리튬전지, 슈퍼 커패시터 등의 전극 구조체; 기능성 복합소재; 에너지 소재; 의약; FET 등의 반도체 등에 유용하게 사용할 수 있다.Therefore, various display devices such as LCD, OLED, PDP, e-paper; Electrode structures such as solar cells, fuel cells, lithium batteries and supercapacitors; Functional composite materials; Energy material; medicine; It can be usefully used for semiconductors such as FETs.
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 same, and it is natural that such variations and modifications belong to the appended claims.
실시예 1Example 1
A. 그래파이트화 금속촉매 전구체 수용액 제조A. Preparation of Graphitized Metal Catalyst Precursor Aqueous Solution
그래파이트화 촉매로서 Co-V 금속촉매를 준비하였다. Co-V metal catalyst was prepared as a graphitization catalyst.
V의 전구체 물질로서 NH4VO3를 20ml 물에 용해시킨 플라스크 A에 시트르산을 투입하였다. Co:V의 몰비가 10:1이 되도록 Co의 전구체 물질로서 Co(NO3)2·6H2O 를 투입하였다. 제조된 금속 수용액은 침전 없이 맑은 용액 상태로 관찰되었다.Citric acid was added to Flask A in which NH 4 VO 3 was dissolved in 20 ml water as the precursor material of V. Co (NO 3 ) 2 .6H 2 O was added as a precursor material of Co so that the molar ratio of Co: V was 10: 1. The prepared aqueous metal solution was observed as a clear solution without precipitation.
B. 지지체 준비B. Support Preparation
알루미늄계 지지체로서 수산화알루미늄(Aluminum-tri-hydroxide, Al(OH)3)을 250 내지 500℃에서 4시간 소성하여 얻어진 지지체 20g을 플라스크 B에 준비하였다. XRD 분석에 의하면 소성 후 지지체는 AlO(OH)를 40 중량% 이상 함유하는 것으로 나타났다. 20 g of the support obtained by calcining aluminum hydroxide (Aluminum-tri-hydroxide, Al (OH) 3 ) at 250 to 500 ° C. for 4 hours was prepared in Flask B. XRD analysis showed that after firing the support contained at least 40% by weight of AlO (OH).
C. 담지촉매 제조C. Supported Catalyst Manufacturing
ATH400 20g을 mol 기준 100으로 환산하면, Co 30몰 및 V 3몰이 되도록 플라스크 B에 상기 플라스크 A 용액 40g을 첨가하였다. 그래파이트화 촉매 금속 전구체를 충분히 ATH400에 담지시킨 후, 60℃ 항온조에서 5분간 교반하여 숙성시켰다. 이를 상기 온도를 유지하면서 80 rpm으로 회전시키며, 진공 건조하에 60 분간 건조시켰다. 건조된 촉매를 675℃에서 4시간 동안 제 2 소성시켜 담지 촉매를 제조하였다. When 20 g of ATH400 was converted to 100 mol basis, 40 g of the Flask A solution was added to Flask B such that 30 mol of Co and 3 mol of V were added. The graphitized catalyst metal precursor was sufficiently supported on ATH400, and then aged by stirring for 5 minutes in a 60 ° C thermostat. It was spun at 80 rpm while maintaining the temperature and dried for 60 minutes under vacuum drying. The dried catalyst was second calcined at 675 ° C. for 4 hours to prepare a supported catalyst.
제조된 촉매를 XRD로 상분석하고 결정크기를 측정하였다. 사용한 XRD 분석 장비는 다음과 같다. The prepared catalyst was analyzed by XRD and the crystal size was measured. The XRD analysis equipment used was as follows.
Bruker AXS D4 Endeavor XRD (전압: 40 kV, 전류: 40 mA)Bruker AXS D4 Endeavor XRD (Voltage: 40 kV, Current: 40 mA)
Cu Kα radiation (파장: 1.54 Å)Cu Kα radiation (wavelength: 1.54 Å)
LynxEye position sensitive detector (3.7° slit)LynxEye position sensitive detector (3.7 ° slit)
측정한 XRD 패턴은 도 1 및 표 1과 같다. 시료 1 내지 5가 결정 크기와 상관없이 거의 유사한 패턴을 나타냄을 확인할 수 있다. Measured XRD pattern is shown in Figure 1 and Table 1. It can be seen that Samples 1 to 5 exhibit almost similar patterns regardless of the crystal size.
표 1
2θ(Cu Kα) 시료 1 시료2 시료 3 시료 4 시료 5
19.0 11 10 11 11 12
31.2 41 39 41 40 39
36.8 100 100 100 100 100
44.8 23 20 20 17 17
55.6 8 9 9 10 10
59.3 18 18 18 19 19
65.2 40 40 41 42 43
Table 1
2θ (Cu Kα) Sample 1 Sample 2 Sample 3 Sample 4 Sample 5
19.0 11 10 11 11 12
31.2 41 39 41 40 39
36.8 100 100 100 100 100
44.8 23 20 20 17 17
55.6 8 9 9 10 10
59.3 18 18 18 19 19
65.2 40 40 41 42 43
Co 함량 및 소성온도에 따른 촉매의 결정크기를 표 2에 나타내었다. 결정크는 풀패턴피팅법(full pattern fitting)에 의해 구하였다.The crystal size of the catalyst according to Co content and firing temperature is shown in Table 2. The crystal size was obtained by full pattern fitting.
표 2
시료 촉매/소성온도 Co 함량(wt%) 결정크기(nm)
1 CoV/400-675 10 14
2 CoV/400-675 12.7 18
3 CoV/400-675 15 24
4 CoV/500-675 15 28
5 CoV/250-675 15 46
TABLE 2
sample Catalyst / Firing Temperature Co content (wt%) Crystal size (nm)
One CoV / 400-675 10 14
2 CoV / 400-675 12.7 18
3 CoV / 400-675 15 24
4 CoV / 500-675 15 28
5 CoV / 250-675 15 46
D. CNT 합성D. CNT Synthesis
상기에서 제조된 CNT 합성용 담지 촉매를 각각 이용하여 실험실 규모의 유동층 반응장치에서 CNT 합성을 시험하였다. 구체적으로 상기 D에서 제조된 CNT 합성용 촉매를 직경 58 mm의 내경과 길이 1200 mm의 석영관 반응기에서, 질소 분위기에서 675℃까지 승온한 다음 유지시키고, 질소와 수소, 그리고 에틸렌 가스의 부피 혼합비를 5.5:1:1로 총 분당 4000 ml 흘리면서 2시간 동안 합성하여 소정량의 CNT 집합체를 합성하였다.CNT synthesis was tested in a laboratory scale fluidized bed reactor using each of the supported catalysts for synthesizing CNTs prepared above. Specifically, the catalyst for synthesizing CNT prepared in D was heated in a quartz tube reactor having an inner diameter of 58 mm and a length of 1200 mm, heated to 675 ° C. in a nitrogen atmosphere, and then maintained with a volume mixing ratio of nitrogen, hydrogen, and ethylene gas. A predetermined amount of CNT aggregates were synthesized by synthesizing for 5.5 hours at 5.5: 1: 1 with a total of 4000 ml per minute.
얻어진 CNT 집합체의 비표면적 및 수율은 표 3과 같다. 비표면적은 BET법에 의해 측정한 것으로서, 구체적으로는 BEL Japan사 BELSORP-mini II를 이용하여 액체 질소 온도 하(77K)에 있어서의 질소가스 흡착량을 구하여 산출하였다.The specific surface area and yield of the obtained CNT aggregate are shown in Table 3. The specific surface area was measured by the BET method, and specifically, it calculated by calculating | requiring nitrogen gas adsorption amount under liquid nitrogen temperature (77K) using BELSORP-mini II by BEL Japan.
표 3
시료 결정크기(nm) BET 비표면적(m2/g) 수율(배)
1 14 257 14
2 18 247 16.4
3 24 242 22
4 28 224 22.7
5 46 190 14
TABLE 3
sample Crystal size (nm) BET specific surface area (m 2 / g) Yield (times)
One 14 257 14
2 18 247 16.4
3 24 242 22
4 28 224 22.7
5 46 190 14
촉매의 결정크기에 따른 CNT 집합체의 비표면적의 관계를 도 2에 나타내었다. The relationship between the specific surface area of the CNT aggregate and the crystal size of the catalyst is shown in FIG. 2.
도 2에 도시된 바와 같이 촉매의 결정크기와 CNT 집합체의 비표면적은 상호 반비례, 즉 촉매의 결정크기가 작아질수록 CNT 집합체의 비표면적이 증가하는 것을 알 수 있다. As shown in FIG. 2, it can be seen that the specific surface area of the catalyst and the CNT aggregate are in inverse proportion to each other, that is, as the crystal size of the catalyst decreases, the specific surface area of the CNT aggregate increases.
도 3은 CNT 집합체의 SEM 이미지이다. 도 3으로부터 번들형 CNT 집합체가 형성되었음을 확인할 수 있다. 3 is an SEM image of a CNT aggregate. It can be seen from FIG. 3 that a bundled CNT aggregate is formed.
고분자 복합재 전도도 측정Polymer composite conductivity measurement
실시예에 따른 촉매로 제조된 CNT 집합체 함량이 3 중량%가 되도록 폴리카보네이트(MI 22) 와 혼합한 후 이축스크류압출기를 이용하여 240~280℃로 용융압출하여 펠렛 형태의 컴파운드를 제조하였다. 상기 컴파운드를 사용하여 전도도 측정용 시편을 제작한 후 전도도측정기(SRM-110, PINION사)를 사용하여 전도도를 측정하였다. 촉매 결정크기에 따른 고분자 복합재의 표면저항의 관계를 도 4에 나타내었다. After mixing with a polycarbonate (MI 22) so that the content of the CNT aggregate prepared by the catalyst according to the embodiment is 3% by weight, melt extrusion was carried out at 240 ~ 280 ℃ using a twin screw extruder to prepare a compound in the form of pellets. After preparing a test piece for measuring the conductivity using the compound, the conductivity was measured using a conductivity meter (SRM-110, PINION). The relationship of the surface resistance of the polymer composite according to the catalyst crystal size is shown in FIG. 4.
도 4로부터, 촉매 결정크기가 작아질수록 표면저항이 감소, 즉 전도도는 증가하는 것을 확인할 수 있다. 이는 촉매 결정크기가 작아질수록 제조되는 CNT 집합체의 비표면적이 증가하는 것과 관련이 있다고 볼 수 있다. 4, it can be seen that as the catalyst crystal size decreases, the surface resistance decreases, that is, the conductivity increases. This may be related to the increase in specific surface area of the prepared CNT aggregates as the catalyst crystal size decreases.
따라서 담지촉매 제조시 촉매의 결정크기를 조절함으로써 CNT 집합체의 비표면적, 나아가 CNT 집합체를 포함하는 고분자 복합재의 전도도를 조절할 수 있음을 알 수 있다. Therefore, it can be seen that the specific surface area of the CNT aggregate and the conductivity of the polymer composite including the CNT aggregate can be controlled by controlling the crystal size of the catalyst when preparing the supported catalyst.
본 발명에 따르면 비표면적이 크고, 분산 및 혼합이 잘 될 수 있는 형태를 가진 탄소나노튜브(CNT)가 얻어질 수 있으므로, 상기 CNT를 포함하는 복합소재의 물성을 개선하는 것이 가능해진다. 그 결과 본 발명에 따른 CNT는 에너지 소재, 기능성 복합재, 의약, 전지, 반도체, 표시소자 등 다양한 분야에 유용하게 사용할 수 있다.According to the present invention, since a carbon nanotube (CNT) having a large specific surface area and having a shape that can be well dispersed and mixed can be obtained, it is possible to improve physical properties of the composite material including the CNT. As a result, the CNTs according to the present invention can be usefully used in various fields such as energy materials, functional composites, medicines, batteries, semiconductors, and display devices.

Claims (18)

  1. 지지체에 그래파이트화 금속 촉매가 담지되어 있으며, 10°에서 80°범위의 XRD 패턴에서 2θ값 35~38°에서 최대 회절 피크를 가지며, 최대 회절 피크 크기(a)에 대한 2θ값 17~22°에서의 회절 피크의 크기(b)의 비(b/a)가 0.08 이상인 탄소나노튜브 제조용 촉매. The support is supported by a graphitized metal catalyst and has a maximum diffraction peak at 2θ values of 35 to 38 ° in an XRD pattern in the range of 10 ° to 80 ° and at a value of 17 ° to 22 ° for the maximum diffraction peak size (a). A catalyst for producing carbon nanotubes, wherein a ratio (b / a) of the size (b) of the diffraction peak of is 0.08 or more.
  2. 제1항에 있어서, The method of claim 1,
    2θ값 30~33°, 43~46°, 57~60° 및 63~67°에서 선택되는 하나 이상의 회절 피크를 추가로 갖는 것인 탄소나노튜브 제조용 촉매. A catalyst for producing carbon nanotubes further having one or more diffraction peaks selected from 2θ values of 30 to 33 °, 43 to 46 °, 57 to 60 ° and 63 to 67 °.
  3. 제1항에 있어서, The method of claim 1,
    결정크기가 3 내지 50 nm인 것인 탄소나노튜브 제조용 촉매. A catalyst for producing carbon nanotubes having a crystal size of 3 to 50 nm.
  4. 제1항에 있어서, The method of claim 1,
    상기 촉매는 수산화알루미늄을 100 내지 500℃의 제1 소성온도에서 소성하여 지지체를 형성하고, 상기 지지체에 촉매 금속 전구체를 담지시킨 후 100 내지 800℃의 제2 소성온도에서 소성하여 얻은 담지 촉매인 것인, 탄소나노튜브 제조용 촉매. The catalyst is a supported catalyst obtained by calcining aluminum hydroxide at a first firing temperature of 100 to 500 ° C. to form a support, and supporting the catalyst metal precursor on the support and then calcining at a second firing temperature of 100 to 800 ° C. Phosphorus, catalyst for producing carbon nanotubes.
  5. 제1항에 있어서, The method of claim 1,
    상기 촉매는 30 내지 150㎛의 입자 크기와 40 내지 80㎛의 수평균입경을 갖도록 선별된 것인, 탄소나노튜브 제조용 촉매.The catalyst is selected to have a particle size of 30 to 150㎛ and a number average particle size of 40 to 80㎛, the catalyst for producing carbon nanotubes.
  6. 제1항에 있어서,The method of claim 1,
    상기 그래파이트화 금속촉매가 니켈(Ni), 코발트(Co), 철(Fe), 백금(Pt), 금(Au), 알루미늄(Al), 크롬(Cr), 구리(Cu), 마그네슘(Mg), 망간(Mn), 몰리브덴(Mo), 로듐(Rh), 실리콘(Si), 탄탈륨(Ta), 티타늄(Ti), 텅스텐(W), 우라늄(U), 바나듐(V) 및 지르코늄(Zr)으로 이루어진 군으로부터 선택된 하나 이상의 금속 또는 합금인 것인, 탄소나노튜브 제조용 촉매. The graphite metal catalyst is nickel (Ni), cobalt (Co), iron (Fe), platinum (Pt), gold (Au), aluminum (Al), chromium (Cr), copper (Cu), magnesium (Mg) , Manganese (Mn), molybdenum (Mo), rhodium (Rh), silicon (Si), tantalum (Ta), titanium (Ti), tungsten (W), uranium (U), vanadium (V) and zirconium (Zr) It is one or more metals or alloys selected from the group consisting of, the catalyst for producing carbon nanotubes.
  7. 제1항에 있어서,The method of claim 1,
    상기 그래파이트화 금속촉매가 주촉매-조촉매를 포함하는 다원계 금속촉매인 것인, 탄소나노튜브 제조용 촉매. Wherein the graphitized metal catalyst is a multi-metal catalyst containing a main catalyst-catalyst, carbon nanotube catalyst for producing.
  8. 제7항에 있어서,The method of claim 7, wherein
    상기 주촉매는 Co 및 Fe로부터 선택되는 하나 이상이고, 상기 조촉매는 Mo 및 V 으로부터 선택되는 하나 이상인 것인, 탄소나노튜브 제조용 촉매. The main catalyst is at least one selected from Co and Fe, and the cocatalyst is at least one selected from Mo and V, the catalyst for producing carbon nanotubes.
  9. 제1항에 있어서,The method of claim 1,
    상기 그래파이트화 금속촉매가 Co/Mo, Co/V, Fe/Mo 및 Fe/V 중에서 선택되는 2원계 금속촉매인 것인, 탄소나노튜브 제조용 촉매. Wherein the graphitized metal catalyst is a binary metal catalyst selected from Co / Mo, Co / V, Fe / Mo and Fe / V, carbon nanotube production catalyst.
  10. 제7항에 있어서,The method of claim 7, wherein
    상기 그래파이트화 금속촉매는 상기 주촉매 10몰에 대하여 조촉매의 함량이 0.1몰 내지 10몰인 것인, 탄소나노튜브 제조용 촉매. The graphitized metal catalyst is a carbon nanotube production catalyst, the content of the promoter is 0.1 mol to 10 mol relative to 10 mol of the main catalyst.
  11. 제1항에 있어서,The method of claim 1,
    상기 촉매 총중량 100중량부를 기준으로 상기 그래파이트화 금속 촉매가 5 내지 40 중량부 담지된 것인, 탄소나노튜브 제조용 촉매. A catalyst for preparing carbon nanotubes, wherein the graphitized metal catalyst is supported by 5 to 40 parts by weight based on 100 parts by weight of the catalyst.
  12. 제1항 내지 제11항 중 어느 한 항에 따른 촉매 상에 성장된 탄소나노튜브를 포함하는 탄소나노튜브 집합체로서,A carbon nanotube assembly comprising carbon nanotubes grown on a catalyst according to any one of claims 1 to 11,
    탄소나노튜브 집합체의 BET 비표면적이 200 m2/g 이상이며, 상기 BET 비표면적과 상기 촉매의 결정크기가 하기 관계식을 만족하는 것인 탄소나노튜브 집합체: A carbon nanotube aggregate having a BET specific surface area of at least 200 m 2 / g and a crystal size of the BET specific surface area satisfying the following relationship:
    y ≤ -2.1 x + 400y ≤ -2.1 x + 400
    상기 식에서, y 는 BET 비표면적(m2/g), x는 촉매의 결정크기(nm)임. Wherein y is the BET specific surface area (m 2 / g) and x is the crystal size (nm) of the catalyst.
  13. 제12항에 있어서, The method of claim 12,
    상기 탄소나노튜브 집합체의 비표면적과 촉매의 결정크기가 하기 관계식을 만족하는 것인 탄소나노튜브 집합체:A carbon nanotube assembly in which the specific surface area of the carbon nanotube aggregate and the crystal size of the catalyst satisfy the following relationship:
    -2.1 x + 200 ≤ y ≤ -2.85 x + 400-2.1 x + 200 ≤ y ≤ -2.85 x + 400
    상기 식에서, y 는 BET 비표면적(m2/g), x는 촉매의 결정크기(nm)임. Wherein y is the BET specific surface area (m 2 / g) and x is the crystal size (nm) of the catalyst.
  14. 제1항 내지 제11항 중 어느 한 항의 촉매를 기상 탄소공급원과 접촉 시켜 탄소나노튜브(CNT)를 형성하는 단계를 포함하는 탄소나노튜브 집합체 제조방법. 12. A method of producing a carbon nanotube aggregate comprising the step of contacting the catalyst of any one of claims 1 to 11 with a gaseous carbon source to form carbon nanotubes (CNTs).
  15. 제14항에 있어서,The method of claim 14,
    상기 기상 탄소공급원이 일산화탄소, 메탄, 에탄, 에틸렌, 에탄올, 아세틸렌, 프로판, 프로필렌, 부탄, 부타디엔, 펜탄, 펜텐, 사이클로펜타디엔, 헥산, 사이클로헥산, 벤젠 및 톨루엔으로 이루어진 군으로부터 선택된 하나 이상인 것인 탄소나노튜브 집합체 제조방법.The gaseous carbon source is at least one selected from the group consisting of carbon monoxide, methane, ethane, ethylene, ethanol, acetylene, propane, propylene, butane, butadiene, pentane, pentene, cyclopentadiene, hexane, cyclohexane, benzene and toluene Carbon nanotube aggregate manufacturing method.
  16. 제14항에 있어서,The method of claim 14,
    상기 반응 온도가 600℃ 내지 750℃인 것인 탄소나노튜브 집합체 제조방법.The reaction temperature is 600 to 750 ℃ carbon nanotube assembly manufacturing method.
  17. 제12항에 따른 탄소나노튜브 집합체를 포함하는 복합소재.A composite material comprising the carbon nanotube aggregate according to claim 12.
  18. 제17항에 있어서,The method of claim 17,
    상기 복합소재는 촉매의 결정크기에 반비례 하는 전도도를 갖는 것인 복합소재.The composite material having a conductivity inversely proportional to the crystal size of the catalyst.
PCT/KR2014/009235 2013-09-30 2014-09-30 Catalyst for producing carbon nanotubes and carbon nanotubes produced using same WO2015047050A1 (en)

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