Patent ID: 8287836

Claim:
A method for preparing single walled carbon nanotubes comprising the steps of: preparing a supported catalyst comprising a metal catalyst and a support material, said support material having at least one planar surface, calcining said supported catalyst at temperatures between 150 to 600Â° C., contacting said supported catalyst with a hydrocarbon and hydrogen at reaction conditions sufficient to produce at least 90% single walled carbon nanotubes in the amount greater than 1 gram single walled carbon nanotubes per gram metal catalyst, wherein the pressure in said reaction conditions is greater than about one and less than 10 atmospheres, the temperature is less than 800Â° C. and the partial pressure of hydrogen is maintained in excess of the stoichiometric level for the reaction taking place by selective control of the reaction feed, purge and recycle rates, and adjusting gas phase products of the reaction by separation steps to provide a recycle gas that is recycled to the contacting step.