摘要:
Methods are provided for the preparation of single-walled carbon nanotubes using chemical vapor deposition processes. In some aspects, single-walled carbon nanotubes having narrow distribution of diameters are formed by contacting a carbon precursor gas with a catalyst on a support, wherein the catalyst has an average diameter of less than about 2 nm.
摘要:
Methods and processes for synthesizing single-wall carbon nanotubes are provided. A carbon precursor gas is contacted with metal catalysts deposited on a support material. The metal catalysts are preferably nanoparticles having diameters less than about 3 nm. The reaction temperature is selected such that it is near the eutectic point of the mixture of metal catalyst particles and carbon. Further, the rate at which hydrocarbons are fed into the reactor is equivalent to the rate at which the hydrocarbons react for given synthesis temperature. The methods produce carbon single-walled nanotubes having longer lengths.
摘要:
The present teachings are directed toward a matrix containing nanosized metal components and carbon nanotubes, with the carbon nanotubes being produced in situ by the nanosized metal components upon the contacting of the nanosized metal components with a carbon source under conditions sufficient to produce the carbon nanotubes. Also disclosed are methods of producing the matrix containing the nanosized metal components and carbon nanotubes.
摘要:
Methods are provided for the preparation of single-walled carbon nanotubes using chemical vapor deposition processes. In some aspects, single-walled carbon nanotubes having narrow distribution of diameters are formed by contacting a carbon precursor gas with a catalyst on a support, wherein the catalyst has an average diameter of less than about 2 nm.
摘要:
Methods and processes for determining the particle size distribution of metal catalysts are provides. Superconducting Quantum Interference Device (SQUID) magnetometer is used to evaluate the magnetic catalyst particle sizes dispersed in the support material. Dependence on variation of the metal/support material ratio, which defines the metal particle sizes, the catalyst can show paramagnetic, superparamagnetic, and ferromagnetic behaviors.
摘要:
The present teachings are directed toward a matrix containing nanosized metal components and carbon nanotubes, with the carbon nanotubes being produced in situ by the nanosized metal components upon the contacting of the nanosized metal components with a carbon source under conditions sufficient to produce the carbon nanotubes. Also disclosed are methods of producing the matrix containing the nanosized metal components and carbon nanotubes.
摘要:
The present teachings are directed toward methods of determining the lifetime of a catalyst for producing carbon nanotubes. The methods include providing different isotopically-labeled reaction components, primarily hydrocarbon sources containing different carbon isotopes, to the catalyst and measuring the Raman spectra of the carbon nanotubes produced with the different hydrocarbon sources.
摘要:
The present teachings are directed toward methods of determining the lifetime of a catalyst for producing carbon nanotubes. The methods include providing different isotopically-labeled reaction components, primarily hydrocarbon sources containing different carbon isotopes, to the catalyst and measuring the Raman spectra of the carbon nanotubes produced with the different hydrocarbon sources.
摘要:
Methods and processes for synthesizing single-wall carbon nanotubes are provided. A carbon precursor gas is contacted with metal catalysts deposited on a support material. The metal catalysts are preferably nanoparticles having diameters less than about 3 nm. The reaction temperature is selected such that it is near the eutectic point of the mixture of metal catalyst particles and carbon. Further, the rate at which hydrocarbons are fed into the reactor is equivalent to the rate of formation of carbon SWNTs for given synthesis temperature. The methods produce carbon single-walled nanotubes having longer lengths.
摘要:
Methods and processes for preparing supported metal catalysts are provided, where the supported metal catalysts can be used for the bulk synthesis of carbon nanotubes. The salts of the metal and the support are selected such that they are soluble in the same solvent. The catalyst can be prepared from the liquid phase through joint precipitation of the metal and the support material. The methods can be used to increase the metal load on the support. Use of the catalysts increases the yield of the carbon nanotubes.