Growth of carbon nanotubes by fluidized bed catalytic chemical vapor deposition

Multi-walled carbon nanotubes have been produced from H$_2$/C$_2$H$_4$ mixtures on Fe/Si02 catalysts by a fluidized bed catalytic chemical vapor deposition process. Various parameters such as the duration of the experiments, the temperature, the H$_2$/C$_2$H$_4$ ratio or the amount of metal on the silica support have been examined. The influence of these parameters on both the carbon deposited yield and the morphology of the deposit have been examined. MWNT are preferably produced in the 550-750 °C temperature range on a 2%Fe/SiO$_2$ (w/w) catalyst in 30 min, with a H$_2$/C$_2$H$_4$ ratio of 3. The multi-walled carbon nanotubes remain attached on the silica support.