This invention relates generally to a method for producing single-wall carbon nanotube (SWNT) catalyst supports and compositions thereof. In one embodiment, SWNTs or SWNT structures can be employed as the support material. A transition metal catalyst is added to the SWNT. In a preferred embodiment, the catalyst metal cluster is deposited on the open nanotube end by a docking process that insures optimum location for the subsequent growth reaction. The metal atoms may be subjected to reductive conditions.