WO2003018474A1 - Nanostructure synthesis - Google Patents

Nanostructure synthesis Download PDF

Info

Publication number
WO2003018474A1
WO2003018474A1 PCT/GB2002/003670 GB0203670W WO03018474A1 WO 2003018474 A1 WO2003018474 A1 WO 2003018474A1 GB 0203670 W GB0203670 W GB 0203670W WO 03018474 A1 WO03018474 A1 WO 03018474A1
Authority
WO
WIPO (PCT)
Prior art keywords
stainless steel
process according
catalyst
carbon
flake
Prior art date
Application number
PCT/GB2002/003670
Other languages
French (fr)
Inventor
Elodie Berangere Fourre
Virginie Ogrodnik
Allin Sidney Pratt
Original Assignee
Johnson Matthey Public Limited Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Johnson Matthey Public Limited Company filed Critical Johnson Matthey Public Limited Company
Publication of WO2003018474A1 publication Critical patent/WO2003018474A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/0005—Reversible uptake of hydrogen by an appropriate medium, i.e. based on physical or chemical sorption phenomena or on reversible chemical reactions, e.g. for hydrogen storage purposes ; Reversible gettering of hydrogen; Reversible uptake of hydrogen by electrodes
    • C01B3/001—Reversible uptake of hydrogen by an appropriate medium, i.e. based on physical or chemical sorption phenomena or on reversible chemical reactions, e.g. for hydrogen storage purposes ; Reversible gettering of hydrogen; Reversible uptake of hydrogen by electrodes characterised by the uptaking medium; Treatment thereof
    • C01B3/0021—Carbon, e.g. active carbon, carbon nanotubes, fullerenes; Treatment thereof
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/32—Hydrogen storage

Definitions

  • the present invention relates to processes for the synthesis of carbon nanostructures.
  • Carbon nanostructures are fullerene-type structures and typically have at least one dimension in the nanometre range. They may be, but are not limited to, tubular structures, fibres, powders or a mixture of these morphologies. In all these structures the basic building blocks of the structure are six and five-membered carbon rings, joined in various configurations. Carbon nanotubes were first reported by Iijima (Nature 354, (1991), 56). They have a tubular structure, and may be single- walled or multi- walled. Fibres may or may not be hollow, and the basal graphitic plane may be oriented along the length of the fibre or across the fibre, and even stacked conically. Many of the nanostructures and the factors controlling their formation and properties are discussed by Harris (Carbon Nanostructures and Related Structures, Cambridge 1999) and Dresselhaus et al (Science of Fullerenes and Carbon Nanotubes, Academic, 1996).
  • Carbon nanostructures can be synthesised by methods such as arc discharge, laser ablation and chemical vapour deposition (CVD). Many of the synthetic methods use a catalyst to promote the growth of the nanostructures. In CVD methods, a carbonaceous gas such as C H 2 , CH 4 , or CO is decomposed by a catalyst. The synthesis of nanostructures by CVD methods is a promising mass production method because the temperature required for nanostructure growth is around 700°C, which is much lower than in arc discharge or laser ablation. Takiwara et al (Jpn. J. appl. Phys. Vol. 39 (2000), 5177-5179) disclose a CVD method that uses nickel and zinc deposited on copper substrates to produce carbon "nanocoils".
  • Li et al. disclose a CVD method for the controlled growth of carbon nanotubes wherein the catalyst comprises graphite foil coated with a stainless steel film.
  • the film is applied using magnetron sputtering and is 2-lOOnm thick. Annealing in hydrogen converts the stainless steel film to stainless steel particles.
  • a process for the synthesis of carbon nanostructures comprises contacting a carbon source with a catalyst such that carbon nanostructures are grown on the catalyst, characterised in that the catalyst comprises stainless steel flake.
  • the term "catalyst” is used to describe a finely divided material on which reactions can take place and where nucleation and growth can proceed. It is not intended that the term 'catalyst' be solely used in the conventional sense, that is, there is no requirement in the present invention that the catalyst be unchanged during the process of the invention.
  • the term "stainless steel flake” is used to describe an iron alloy in particulate form where the particles have one physical dimension (minor dimension) which is substantially smaller than the other two physical dimensions.
  • the flake suitably has a minor dimension (or thickness) of 0.1 -1 ⁇ m, preferably about 0.6 ⁇ m.
  • stainless steels are those alloy steels which include appreciable amounts of chromium, for example 12% and above. Typically, the alloys may contain up to 25% chromium, up to 15% nickel, up to 1.5% carbon, and small amounts of other elements such as niobium, titanium, aluminium and copper, with the balance being iron.
  • a preferred composition the stainless steel flake is designated 316L, which is a common grade of stainless steel of low carbon content. Alternative designations of stainless steel may also be used as can mixtures of two or more types of stainless steel. Suitable 316L stainless steel can be purchased from Novamet Speciality Products Corporation in the form of flakes with a minor dimension of ca. 0.6 ⁇ m, the other two dimensions of the flake being in the range 10- 100 ⁇ m.
  • the carbon source comprises a carbonaceous gas, a carbonaceous liquid or any mixture thereof.
  • Some non-limiting examples include carbon monoxide, methane, natural gas and other gaseous or liquid hydrocarbons.
  • the carbon source may be provided substantially pure or be diluted or admixed with an inert or reactive carrier.
  • a first method a small quantity of stainless steel flake is placed in a tube, preferably a quartz tube. The tube is rotated to distribute the flake on the surface of the tube. The quantity of stainless steel flake used will depend on factors such as the size and shape of the tube and the gas flow rate.
  • a carbon source gas e.g., CO, CH 4 or similar hydrocarbon is passed over the flake at temperatures between 475°C and 1000°C and carbon nanostructures are grown on the flake.
  • the reaction time is dependant on gas flow rate and temperature.
  • the carbon source gas is diluted with hydrogen.
  • the stainless steel flake is fluidised in fluidised bed system.
  • a carbon source gas and optionally hydrogen are passed into the bed.
  • the carbon nanostructures grow on the flake. It is possible that some of the nanostructures may become detached from the flake during the reaction and be contained within the gas flow from the bed.
  • the stainless steel flake is admixed with a carbonaceous liquid and the mixture contacted with a heat source.
  • the flake may be blended into an organic liquid such as xylene, and sprayed into the hot zone of a furnace.
  • the organic liquid acts as a carbon source so it is not necessary to add a carbon source gas.
  • the process of the present invention may be carried out under substantially atmospheric pressure. This simplifies the process and leads to further cost reductions when compared to e.g. CVD methods for nano-structure synthesis. Although not as preferred, high and low pressures can also be used if desired.
  • the stainless steel flake is supported on a support.
  • the supported stainless steel catalyst as reported by Li et al is produced by sputtering commercial stainless steel onto a graphite foil substrate.
  • stainless steel flake can be deposited on a support by simply bringing the flake into contact with the support.
  • the support may be a heat resistant support such as a honeycomb support made of, for example, cordierite.
  • the heat resistant support may be a heat exchanger, which may be made of surface oxidised metal or high temperature plastic. If nanostructures are grown on the stainless steel flake deposited on the support, then the support may be a useful hydrogen storage device. Therefore the present invention also provides a process for producing a hydrogen storage device comprising the steps of depositing stainless steel flake on a support and synthesising carbon nanostructures on the flake.
  • Stainless steel is supplied to the process of the invention as stainless steel flake.
  • the form of the stainless steel will change during the process and the catalyst may not actually be stainless steel in the form of the original flakes, but may be stainless steel in a different form. Some change of shape is likely to occur particularly at more elevated temperatures during processing as the flake reduces its surface energy.
  • the carbon nanostructures grow on the surface of the stainless steel catalyst. Depending on the intended application of the carbon nanostructures, it may be necessary to remove the nanostructures from the catalyst.
  • One suitable method for the removal of the nanostructures from the catalyst is boiling in hydrochloric acid, although other methods will be apparent to those skilled in the art. For most applications however, it is unlikely to be necessary to remove the nanostructures from the catalyst.
  • Stainless steel is inert in many chemical environments, so the presence of stainless steel is unlikely to interfere with the functioning of the nanostructures.
  • the present invention provides carbon nanostructures as produced by the novel process according to the invention.
  • the present invention provides the use of carbon nanostructures as produced by the novel process according to the invention, as hydrogen storage media.
  • 0.020g of 316L stainless steel flake from Novamet Speciality Products Corporation (0.6 ⁇ m thick, other dimensions 40-100 ⁇ m) was placed in a quartz tube. The tube was rotated to distribute the flake on the surface of the tube. The tube was heated to a temperature of between 475°C and 800°C and a gas mixture of a carbon source and hydrogen was passed through the tube at a flow rate of approximately 600ml per hour for 24 hours (unless otherwise stated). At the end of this period the tube was cooled first under hydrogen and then under nitrogen.

Abstract

The present invention relates to a process for the synthesis of carbon nanostructures wherein a catalyst is used to promote the growth of the nanostructures from a carbon source, characterised in that stainless steel flake is used to provide the catalyst.

Description

NANOSTRUCTURE SYNTHESIS
The present invention relates to processes for the synthesis of carbon nanostructures.
Carbon nanostructures are fullerene-type structures and typically have at least one dimension in the nanometre range. They may be, but are not limited to, tubular structures, fibres, powders or a mixture of these morphologies. In all these structures the basic building blocks of the structure are six and five-membered carbon rings, joined in various configurations. Carbon nanotubes were first reported by Iijima (Nature 354, (1991), 56). They have a tubular structure, and may be single- walled or multi- walled. Fibres may or may not be hollow, and the basal graphitic plane may be oriented along the length of the fibre or across the fibre, and even stacked conically. Many of the nanostructures and the factors controlling their formation and properties are discussed by Harris (Carbon Nanostructures and Related Structures, Cambridge 1999) and Dresselhaus et al (Science of Fullerenes and Carbon Nanotubes, Academic, 1996).
Carbon nanostructures can be synthesised by methods such as arc discharge, laser ablation and chemical vapour deposition (CVD). Many of the synthetic methods use a catalyst to promote the growth of the nanostructures. In CVD methods, a carbonaceous gas such as C H2, CH4, or CO is decomposed by a catalyst. The synthesis of nanostructures by CVD methods is a promising mass production method because the temperature required for nanostructure growth is around 700°C, which is much lower than in arc discharge or laser ablation. Takiwara et al (Jpn. J. appl. Phys. Vol. 39 (2000), 5177-5179) disclose a CVD method that uses nickel and zinc deposited on copper substrates to produce carbon "nanocoils". Wei et al (J. Vac. Sci. Technol. B, 18(6), 3586-3589) disclose the growth of carbon nanotubes wherein the catalyst comprises a silica substrate, a thin (lOnm) titanium layer and iron particles deposited by electron-gun evaporation.
Li et al. (Chemical Physics Letters, 335, (2001), 141-149) disclose a CVD method for the controlled growth of carbon nanotubes wherein the catalyst comprises graphite foil coated with a stainless steel film. The film is applied using magnetron sputtering and is 2-lOOnm thick. Annealing in hydrogen converts the stainless steel film to stainless steel particles.
Dong et al. (Jn of Zhejiang Univ., 34, (2000) pp. 511-514, English abstract) describe the growth of carbon nanotubes on nano-metallic materials including stainless steel. Such materials are difficult to produce and expensive.
There are numerous potential applications of carbon nanostructures. They have considerable strength and flexibility and are potentially useful as reinforcing elements in composites. Additionally, they are electrically conductive and may be useful in nano-scale electronic circuits. Finally, they have interesting hydrogen storage properties, and may find application as hydrogen storage media (Seung Mi Lee et al, Synthesis Metals 113, (2000), 209-216). It is possible that an ideal structure for hydrogen storage has many basal plane edges at the surface because these may be suitable sites for attachment of hydrogen. Therefore a conically stacked nanofibre may be a suitable structure for hydrogen storage.
There is a need for processes for the synthesis of carbon nanostructures that can be applied on an industrial scale. The processes should produce large yields of nanostructures with reproducible properties. To be economically attractive, the processes should be simple and should not require extremes of pressure or temperature, or expensive reagents.
The present inventors have devised an improved process for the synthesis of carbon nanostructures. In accordance with the present invention, a process for the synthesis of carbon nanostructures comprises contacting a carbon source with a catalyst such that carbon nanostructures are grown on the catalyst, characterised in that the catalyst comprises stainless steel flake.
In the context of the present invention, the term "catalyst" is used to describe a finely divided material on which reactions can take place and where nucleation and growth can proceed. It is not intended that the term 'catalyst' be solely used in the conventional sense, that is, there is no requirement in the present invention that the catalyst be unchanged during the process of the invention. The term "stainless steel flake" is used to describe an iron alloy in particulate form where the particles have one physical dimension (minor dimension) which is substantially smaller than the other two physical dimensions. The flake suitably has a minor dimension (or thickness) of 0.1 -1 μm, preferably about 0.6 μm. As is known in the art, stainless steels are those alloy steels which include appreciable amounts of chromium, for example 12% and above. Typically, the alloys may contain up to 25% chromium, up to 15% nickel, up to 1.5% carbon, and small amounts of other elements such as niobium, titanium, aluminium and copper, with the balance being iron. A preferred composition the stainless steel flake is designated 316L, which is a common grade of stainless steel of low carbon content. Alternative designations of stainless steel may also be used as can mixtures of two or more types of stainless steel. Suitable 316L stainless steel can be purchased from Novamet Speciality Products Corporation in the form of flakes with a minor dimension of ca. 0.6 μm, the other two dimensions of the flake being in the range 10- 100 μm.
To form the supported stainless steel catalyst as reported by Li et al., it is necessary to sputter commercial stainless steel onto a graphite foil substrate. The sputtering is carried out in a vacuum chamber at 300°C. Following the sputtering step, the stainless steel film is reduced at 660°C in 50Torr of flowing hydrogen and nitrogen for two hours. It is stated that this step is needed to obtain catalyst particles and enhance the catalytic activity. This catalyst is unlikely to be used for mass production of carbon nanostructures due to the multiple steps and combination of low pressure and high temperature required to provide the catalyst. By contrast, the process of the present invention does not require multiple steps or careful pressure and temperature control to provide a catalyst that will promote nanostructure growth. Stainless steel flake is advantageously employed to provide the catalyst.
Preferably, the carbon source comprises a carbonaceous gas, a carbonaceous liquid or any mixture thereof. Some non-limiting examples include carbon monoxide, methane, natural gas and other gaseous or liquid hydrocarbons. The carbon source may be provided substantially pure or be diluted or admixed with an inert or reactive carrier. Several methods can be used to carry out the process of the present invention. In a first method, a small quantity of stainless steel flake is placed in a tube, preferably a quartz tube. The tube is rotated to distribute the flake on the surface of the tube. The quantity of stainless steel flake used will depend on factors such as the size and shape of the tube and the gas flow rate. A carbon source gas e.g., CO, CH4 or similar hydrocarbon is passed over the flake at temperatures between 475°C and 1000°C and carbon nanostructures are grown on the flake. The reaction time is dependant on gas flow rate and temperature. Preferably, the carbon source gas is diluted with hydrogen.
In a second method, the stainless steel flake is fluidised in fluidised bed system.
A carbon source gas and optionally hydrogen are passed into the bed. The carbon nanostructures grow on the flake. It is possible that some of the nanostructures may become detached from the flake during the reaction and be contained within the gas flow from the bed.
In a third method the stainless steel flake is admixed with a carbonaceous liquid and the mixture contacted with a heat source. For example, the flake may be blended into an organic liquid such as xylene, and sprayed into the hot zone of a furnace. The organic liquid acts as a carbon source so it is not necessary to add a carbon source gas.
Several factors will influence the nature of the carbon nanostructures produced, including the process method used, the selection of the carbon source and the temperature. Advantageously, the process of the present invention may be carried out under substantially atmospheric pressure. This simplifies the process and leads to further cost reductions when compared to e.g. CVD methods for nano-structure synthesis. Although not as preferred, high and low pressures can also be used if desired.
In an alternative embodiment of the invention the stainless steel flake is supported on a support. The supported stainless steel catalyst as reported by Li et al is produced by sputtering commercial stainless steel onto a graphite foil substrate. By contrast, stainless steel flake can be deposited on a support by simply bringing the flake into contact with the support. The support may be a heat resistant support such as a honeycomb support made of, for example, cordierite. Alternatively, the heat resistant support may be a heat exchanger, which may be made of surface oxidised metal or high temperature plastic. If nanostructures are grown on the stainless steel flake deposited on the support, then the support may be a useful hydrogen storage device. Therefore the present invention also provides a process for producing a hydrogen storage device comprising the steps of depositing stainless steel flake on a support and synthesising carbon nanostructures on the flake.
Stainless steel is supplied to the process of the invention as stainless steel flake. However, it is possible that the form of the stainless steel will change during the process and the catalyst may not actually be stainless steel in the form of the original flakes, but may be stainless steel in a different form. Some change of shape is likely to occur particularly at more elevated temperatures during processing as the flake reduces its surface energy.
The carbon nanostructures grow on the surface of the stainless steel catalyst. Depending on the intended application of the carbon nanostructures, it may be necessary to remove the nanostructures from the catalyst. One suitable method for the removal of the nanostructures from the catalyst is boiling in hydrochloric acid, although other methods will be apparent to those skilled in the art. For most applications however, it is unlikely to be necessary to remove the nanostructures from the catalyst. Stainless steel is inert in many chemical environments, so the presence of stainless steel is unlikely to interfere with the functioning of the nanostructures.
In a further aspect, the present invention provides carbon nanostructures as produced by the novel process according to the invention.
In a yet further aspect, the present invention provides the use of carbon nanostructures as produced by the novel process according to the invention, as hydrogen storage media.
The invention will now be described by way of example only, which is not intended to be limiting thereof. Example
0.020g of 316L stainless steel flake from Novamet Speciality Products Corporation (0.6 μm thick, other dimensions 40-100 μm) was placed in a quartz tube. The tube was rotated to distribute the flake on the surface of the tube. The tube was heated to a temperature of between 475°C and 800°C and a gas mixture of a carbon source and hydrogen was passed through the tube at a flow rate of approximately 600ml per hour for 24 hours (unless otherwise stated). At the end of this period the tube was cooled first under hydrogen and then under nitrogen.
Samples of carbon nanostructures were analysed by Transmission Electron Microscopy (TEM) using a Philips EM400T electron microscope operating at an accelerating voltage of lOOkV. Table 1 shows the results of several experiments using different gas mixtures and different temperatures.
Significant yields of carbon nanostructures can be produced by the method of the present invention, particularly when CO is used as the carbon source. The choice of conditions affects the size and morphology of the nanostructures that are produced.
Table 1
Figure imgf000008_0002
Figure imgf000008_0001

Claims

1. A process for the synthesis of carbon nanostructures, the process comprising contacting a carbon source with a catalyst such that carbon nanostructures are grown on the catalyst, characterised in that the catalyst comprises stainless steel flake.
2. A process according to claim 1, wherein the carbon source comprises a carbonaceous gas, a carbonaceous liquid or any mixture thereof.
3. A process according to claim 1 or claim 2, wherein the stainless steel flake has a minor dimension of between 0.1 and 1 μm.
4. A process according to any preceding claim, wherein the process is carried out at a temperature of between 475 and 1000°C.
5. A process according to any preceding claim, wherein the process is carried out at substantially atmospheric pressure.
6. A process according to any preceding claim, wherein the stainless steel flake is fluidised in fluidised bed system.
7. A process according to any of claims 1 to 6, wherein the stainless steel flake is admixed with a carbonaceous liquid and the mixture contacted with a heat source.
8. A process according to any of claims 1 to 7, wherein the stainless steel flake is supported on a support.
9. A process according to any preceding claim further comprising the step of removing the carbon nano-structures from the catalyst.
10. A process for producing a hydrogen storage device, the process comprising the steps of depositing stainless steel flake on a support and synthesising carbon nanostructures on the flake in a process according to any one of claims 1 to 7.
11. Carbon nanostructures produced by a process according to any one of claims 1 to 7.
12. The use of carbon nanostructures according to claim 11 as hydrogen storage media.
PCT/GB2002/003670 2001-08-22 2002-08-09 Nanostructure synthesis WO2003018474A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GBGB0120366.0A GB0120366D0 (en) 2001-08-22 2001-08-22 Nanostructure synthesis
GB0120366.0 2001-08-22

Publications (1)

Publication Number Publication Date
WO2003018474A1 true WO2003018474A1 (en) 2003-03-06

Family

ID=9920781

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2002/003670 WO2003018474A1 (en) 2001-08-22 2002-08-09 Nanostructure synthesis

Country Status (2)

Country Link
GB (1) GB0120366D0 (en)
WO (1) WO2003018474A1 (en)

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2399092A (en) * 2003-03-03 2004-09-08 Morgan Crucible Co Nanotube and/or nanofibre synthesis
WO2008128437A1 (en) * 2007-04-18 2008-10-30 Tsinghua University Multistage reactors for continuous production of carbon nanotubes
JP2015520717A (en) * 2012-04-16 2015-07-23 シーアストーン リミテッド ライアビリティ カンパニー Method for using a metal catalyst in a carbon oxide catalytic converter
US9090472B2 (en) 2012-04-16 2015-07-28 Seerstone Llc Methods for producing solid carbon by reducing carbon dioxide
US9221685B2 (en) 2012-04-16 2015-12-29 Seerstone Llc Methods of capturing and sequestering carbon
US9556031B2 (en) 2009-04-17 2017-01-31 Seerstone Llc Method for producing solid carbon by reducing carbon oxides
US9586823B2 (en) 2013-03-15 2017-03-07 Seerstone Llc Systems for producing solid carbon by reducing carbon oxides
US9598286B2 (en) 2012-07-13 2017-03-21 Seerstone Llc Methods and systems for forming ammonia and solid carbon products
US9604848B2 (en) 2012-07-12 2017-03-28 Seerstone Llc Solid carbon products comprising carbon nanotubes and methods of forming same
US9650251B2 (en) 2012-11-29 2017-05-16 Seerstone Llc Reactors and methods for producing solid carbon materials
US9731970B2 (en) 2012-04-16 2017-08-15 Seerstone Llc Methods and systems for thermal energy recovery from production of solid carbon materials by reducing carbon oxides
US9779845B2 (en) 2012-07-18 2017-10-03 Seerstone Llc Primary voltaic sources including nanofiber Schottky barrier arrays and methods of forming same
US9783416B2 (en) 2013-03-15 2017-10-10 Seerstone Llc Methods of producing hydrogen and solid carbon
US9796591B2 (en) 2012-04-16 2017-10-24 Seerstone Llc Methods for reducing carbon oxides with non ferrous catalysts and forming solid carbon products
US9896341B2 (en) 2012-04-23 2018-02-20 Seerstone Llc Methods of forming carbon nanotubes having a bimodal size distribution
US10086349B2 (en) 2013-03-15 2018-10-02 Seerstone Llc Reactors, systems, and methods for forming solid products
US10106416B2 (en) 2012-04-16 2018-10-23 Seerstone Llc Methods for treating an offgas containing carbon oxides
US10115844B2 (en) 2013-03-15 2018-10-30 Seerstone Llc Electrodes comprising nanostructured carbon
US10815124B2 (en) 2012-07-12 2020-10-27 Seerstone Llc Solid carbon products comprising carbon nanotubes and methods of forming same
WO2021168246A1 (en) * 2020-02-19 2021-08-26 Northeastern University Generation of high yields of carbon nanotubes (cnts) using recycled metal catalysts
US11752459B2 (en) 2016-07-28 2023-09-12 Seerstone Llc Solid carbon products comprising compressed carbon nanotubes in a container and methods of forming same

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
ARAKI H ET AL: "Effects of substrate materials on growth of carbon nanotubes by chemical vapor deposition using metal-phthalocyanines", JAPANESE JOURNAL OF APPLIED PHYSICS, PART 2 (LETTERS), 15 NOV. 1999, PUBLICATION OFFICE, JAPANESE JOURNAL APPL. PHYS, JAPAN, vol. 38, no. 11B, pages L1351 - L1353, XP001092760, ISSN: 0021-4922 *
LI W Z ET AL: "Controlled growth of carbon nanotubes on graphite foil by chemical vapor deposition", CHEMICAL PHYSICS LETTERS, 23 FEB. 2001, ELSEVIER, NETHERLANDS, vol. 335, no. 3-4, pages 141 - 149, XP002217825, ISSN: 0009-2614 *
LIMING YUAN ET AL: "Ethylene flame synthesis of well-aligned multi-walled carbon nanotubes", CHEMICAL PHYSICS LETTERS, 28 SEPT. 2001, ELSEVIER, NETHERLANDS, vol. 346, no. 1-2, pages 23 - 28, XP002219496, ISSN: 0009-2614 *
SONEDA Y ET AL: "Formation and texture of carbon nanofilaments by the catalytic decomposition of CO on stainless-steel plate", CARBON, ELSEVIER SCIENCE PUBLISHING, NEW YORK, NY, US, vol. 38, no. 3, 2000, pages 478 - 480, XP004186295, ISSN: 0008-6223 *

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2399092B (en) * 2003-03-03 2005-02-16 Morgan Crucible Co Nanotube and/or nanofibre synthesis
GB2399092A (en) * 2003-03-03 2004-09-08 Morgan Crucible Co Nanotube and/or nanofibre synthesis
WO2008128437A1 (en) * 2007-04-18 2008-10-30 Tsinghua University Multistage reactors for continuous production of carbon nanotubes
US9556031B2 (en) 2009-04-17 2017-01-31 Seerstone Llc Method for producing solid carbon by reducing carbon oxides
US9090472B2 (en) 2012-04-16 2015-07-28 Seerstone Llc Methods for producing solid carbon by reducing carbon dioxide
US9731970B2 (en) 2012-04-16 2017-08-15 Seerstone Llc Methods and systems for thermal energy recovery from production of solid carbon materials by reducing carbon oxides
US9221685B2 (en) 2012-04-16 2015-12-29 Seerstone Llc Methods of capturing and sequestering carbon
US10106416B2 (en) 2012-04-16 2018-10-23 Seerstone Llc Methods for treating an offgas containing carbon oxides
EP2838841A4 (en) * 2012-04-16 2015-12-23 Seerstone Llc Methods for using metal catalysts in carbon oxide catalytic converters
US9796591B2 (en) 2012-04-16 2017-10-24 Seerstone Llc Methods for reducing carbon oxides with non ferrous catalysts and forming solid carbon products
US9637382B2 (en) 2012-04-16 2017-05-02 Seerstone Llc Methods for producing solid carbon by reducing carbon dioxide
JP2015520717A (en) * 2012-04-16 2015-07-23 シーアストーン リミテッド ライアビリティ カンパニー Method for using a metal catalyst in a carbon oxide catalytic converter
US9896341B2 (en) 2012-04-23 2018-02-20 Seerstone Llc Methods of forming carbon nanotubes having a bimodal size distribution
US10815124B2 (en) 2012-07-12 2020-10-27 Seerstone Llc Solid carbon products comprising carbon nanotubes and methods of forming same
US9604848B2 (en) 2012-07-12 2017-03-28 Seerstone Llc Solid carbon products comprising carbon nanotubes and methods of forming same
US10358346B2 (en) 2012-07-13 2019-07-23 Seerstone Llc Methods and systems for forming ammonia and solid carbon products
US9598286B2 (en) 2012-07-13 2017-03-21 Seerstone Llc Methods and systems for forming ammonia and solid carbon products
US9779845B2 (en) 2012-07-18 2017-10-03 Seerstone Llc Primary voltaic sources including nanofiber Schottky barrier arrays and methods of forming same
US9650251B2 (en) 2012-11-29 2017-05-16 Seerstone Llc Reactors and methods for producing solid carbon materials
US10086349B2 (en) 2013-03-15 2018-10-02 Seerstone Llc Reactors, systems, and methods for forming solid products
US10115844B2 (en) 2013-03-15 2018-10-30 Seerstone Llc Electrodes comprising nanostructured carbon
US9783416B2 (en) 2013-03-15 2017-10-10 Seerstone Llc Methods of producing hydrogen and solid carbon
US9586823B2 (en) 2013-03-15 2017-03-07 Seerstone Llc Systems for producing solid carbon by reducing carbon oxides
US11752459B2 (en) 2016-07-28 2023-09-12 Seerstone Llc Solid carbon products comprising compressed carbon nanotubes in a container and methods of forming same
US11951428B2 (en) 2016-07-28 2024-04-09 Seerstone, Llc Solid carbon products comprising compressed carbon nanotubes in a container and methods of forming same
WO2021168246A1 (en) * 2020-02-19 2021-08-26 Northeastern University Generation of high yields of carbon nanotubes (cnts) using recycled metal catalysts

Also Published As

Publication number Publication date
GB0120366D0 (en) 2001-10-17

Similar Documents

Publication Publication Date Title
WO2003018474A1 (en) Nanostructure synthesis
Qin et al. Growing carbon nanotubes by microwave plasma-enhanced chemical vapor deposition
CN1290763C (en) Process for preparing nano-carbon tubes
US7687109B2 (en) Apparatus and method for making carbon nanotube array
CN1248959C (en) Carbon nano pipe array growth method
US7682658B2 (en) Method for making carbon nanotube array
JP3819382B2 (en) Carbon nanotube matrix and growth method thereof
Jung et al. Effect of NH3 environmental gas on the growth of aligned carbon nanotube in catalystically pyrolizing C2H2
US20050112052A1 (en) Methods for producing and using catalytic substrates for carbon nanotube growth
US7700048B2 (en) Apparatus for making carbon nanotube array
Rakov Materials made of carbon nanotubes. The carbon nanotube forest
US20050214197A1 (en) Methods for producing and using catalytic substrates for carbon nanotube growth
WO2009145959A1 (en) High throughput carbon nanotube growth system, and carbon nanotubes and carbon nanofibers formed thereby
Atthipalli et al. The effect of temperature on the growth of carbon nanotubes on copper foil using a nickel thin film as catalyst
Li et al. Synthesis of single-walled carbon nanotubes from heavy oil residue
JP3463091B2 (en) Method for producing carbon nanotube
Kim et al. Synthesis of high-density carbon nanotube films by microwave plasma chemical vapor deposition
Rajaura et al. Efficient chemical vapour deposition and arc discharge system for production of carbon nano-tubes on a gram scale
Yamamoto et al. Modification of surface energy, dry etching, and organic film removal using atmospheric-pressure pulsed-corona plasma
Chen et al. The formation conditions of carbon nanotubes array based on FeNi alloy island films
Liu et al. Effect of carbon deposits on the reactor wall during the growth of multi-walled carbon nanotube arrays
US7338554B2 (en) Method of synthesising and growing nanorods from a metal carbide on a substrate, substrates thus obtained and applications thereof
Wang et al. Different growth mechanisms of vertical carbon nanotubes by rf-or dc-plasma enhanced chemical vapor deposition at low temperature
US20050207964A1 (en) Method for synthesizing carbon nanotubes
CN1275851C (en) Preparation method of carbon nano-pipe

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SD SE SG SI SK SL TJ TM TN TR TT TZ UA UG US UZ VN YU ZA ZM ZW

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BY BZ CA CH CN CO CR CU CZ DE DM DZ EC EE ES FI GB GD GE GH HR HU ID IL IN IS JP KE KG KP KR LC LK LR LS LT LU LV MA MD MG MN MW MX MZ NO NZ OM PH PL PT RU SD SE SG SI SK SL TJ TM TN TR TZ UA UG US UZ VN YU ZA ZM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ UG ZM ZW AM AZ BY KG KZ RU TJ TM AT BE BG CH CY CZ DK EE ES FI FR GB GR IE IT LU MC PT SE SK TR BF BJ CF CG CI GA GN GQ GW ML MR NE SN TD TG

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LU MC NL PT SE SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP