Patent ID: 7052668

Claim:
A method for producing single-wall carbon nanotubes, comprising: (a) providing a supercritical fluid catalyst stream comprising (i) a supercritical fluid, (ii) a catalyst precursor selected from the group consisting of multi-metallic catalyst precursors, mono-metallic catalyst precursors, and mixtures thereof that are dissolved, suspended, or both in the fluid, each multi-metallic catalyst precursor comprising at least two atoms, and each mono-metallic catalyst precursor comprising one atom, of at least one transition metal selected from the group consisting of Group VIb elements and Group VIIIb elements, and (iii) a plurality of seed molecules selected from the group consisting of fullerenes, derivatized fullerenes, polycyclic aromatic compounds, derivatized polycyclic aromatic compounds, and mixtures thereof, wherein the supercritical fluid catalyst stream is at a temperature below the decomposition temperature of the catalyst precursor, below the minimum single-wall carbon nanotube formation initiation temperature and below the polymerization temperature of the seed molecule; (b) providing a carbon feedstock gas stream at a temperature above the minimum single-wall carbon nanotube formation initiation temperature; and (c) mixing the carbon feedstock gas stream with the supercritical fluid catalyst stream to form a mixed gas stream, wherein (i) the catalyst precursor reaches a temperature above the decomposition temperature of the catalyst precursor, (ii) the temperature is sufficient to promote the initiation or growth of catalyst clusters, and (iii) the temperature is sufficient to promote the initiation and growth of single-wall carbon nanotubes on the catalyst clusters and on the seed molecules and to form the single-wall carbon nanotubes in the mixed gas stream.