Catalyst For The Growth Of Carbon Single-Walled Nanotubes

Abstract

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.

1 .- 20 . (canceled) 
     
     
         21 . A chemical vapor deposition method for the preparation of single-wall carbon nanotubes (SWNT), the method comprising the steps of:
 providing supported catalyst nanoparticles, wherein the catalyst has a particle size between 1 nm and 10 nm;   heating the supported catalyst nanoparticles to a temperature below the melting point of the metal phase of the catalyst;   contacting the supported catalyst nanoparticles with a carbon precursor gas, wherein the carbon precursor gas comprises methane, an inert gas, and hydrogen;   forming SWNT by contacting the supported catalyst nanoparticles with the carbon precursor gas at a rate equivalent to the rate at which the carbon precursor gas reacts.   
     
     
         22 . The method of  claim 21 , wherein the inert gas is argon, helium, nitrogen, or combinations thereof. 
     
     
         23 . The method of  claim 21 , wherein the catalyst is iron, molybdenum, or combinations of iron and molybdenum. 
     
     
         24 . The method of  claim 21 , wherein the support is a powdered oxide. 
     
     
         25 . The method of  claim 24 , wherein the powdered oxide is selected from the group consisting of Al 2 O 3 , SiO 2 , MgO and zeolites. 
     
     
         26 . The method of  claim 25 , wherein the powdered oxide is Al 2 O 3 . 
     
     
         27 . The method of  claim 21 , wherein the catalyst and the support are in a ratio of about 1:1 to about 1:50.