Catalytic growth of single-wall carbon nanotubes from metal particles
First Claim
1. A method of making single wall carbon nanotubes comprising:
- a. providing metal particles on a support in a reaction zone;
b. supplying a first carbon-containing gas to the reaction zone, under first conditions such that the metal particles which are large enough to primarily produce multiwall carbon nanotubes are deactivated; and
c. supplying a second carbon-containing gas, which can be the same or different than the first carbon containing gas, to the reaction zone, under second conditions that are different from the first conditions and wherein single wall carbon nanotubes primarily are formed.
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Abstract
Single-walled carbon nanotubes have been synthesized by the catalytic decomposition of both carbon monoxide and ethylene over a supported metal catalyst known to produce larger multi-walled nanotubes. Under certain conditions, there is no termination of nanotube growth, and production appears to be limited only by the diffusion of reactant gas through the product nanotube mat that covers the catalyst The present invention concerns a catalyst-substrate system which promotes the growth of nanotubes that are predominantly single-walled tubes in a specific size range, rather than the large irregular-sized multi-walled carbon fibrils that are known to grow from supported catalysts. With development of the supported catalyst system to provide an effective means for production of single-wall nanotubes, and further development of the catalyst geometry to overcome the diffusion limitation, the present invention will allow bulk catalytic production of predominantly single-wall carbon nanotubes from metal catalysts located on a catalyst supporting surface.
233 Citations
105 Claims
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1. A method of making single wall carbon nanotubes comprising:
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a. providing metal particles on a support in a reaction zone;
b. supplying a first carbon-containing gas to the reaction zone, under first conditions such that the metal particles which are large enough to primarily produce multiwall carbon nanotubes are deactivated; and
c. supplying a second carbon-containing gas, which can be the same or different than the first carbon containing gas, to the reaction zone, under second conditions that are different from the first conditions and wherein single wall carbon nanotubes primarily are formed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 50)
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41. A method of making single wall carbon nanotubes comprising
a. providing a supported metal particle catalyst in a reaction zone; - and
b. contacting the supported metal particle catalyst with a carbon-containing gas in a reaction zone, under first conditions that result in the deactivation of larger metal particles which primarily produce multiwall carbon nanotubes;
c. changing the first conditions to second conditions in the reaction zone to produce single wall carbon nanotubes on smaller particles; and
d. producing a product which is predominantly comprised of single wall carbon nanotubes. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67)
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68. A method of making single wall carbon nanotubes comprising:
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a. providing metal particles selected from the group consisting of Fe, Ni, Co, and combinations comprising any of these on a support in a reaction zone;
b. supplying CO to the reaction zone, under first conditions such that the metal particles having diameters greater than about 3 nm are deactivated; and
c. supplying a second carbon-containing gas, which can be the same or different than CO, to the reaction zone, under second conditions that are different from the first conditions and wherein single wall carbon nanotubes primarily are formed. - View Dependent Claims (69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 101)
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87. A method of making single wall carbon nanotubes comprising:
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a. providing in a reaction zone metal particles selected from the group consisting of Fe, Ni, Co, and combinations comprising any of these, on a support, selected from the group consisting of alumina, carbon, quartz, silicates, mullite, and aluminosilicates;
b. supplying a first carbon-containing gas, under first conditions such that the metal particles greater than about 3 nm are deactivated by encapsulation;
c. supplying a second carbon-containing gas, which can be the same or different than the first carbon containing gas, to the reaction zone, under second conditions that are different from the first conditions and wherein single wall carbon nanotubes primarily are formed. - View Dependent Claims (88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 102, 103, 104, 105)
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Specification