The synthesis of carbon single-walled nanotubes of narrow diameter distribution

Methods and processes for the synthesis of single-walled carbon nanotubes is provided. Carbon precursor gas is contacted with a metal catalyst deposited on a support material. Metal catalyst is preferably a nanoparticle having a diameter of less than about 50nm. The reaction temperature is selected such that the eutectic point close to the mixture of the metal catalyst particles and the carbon.