Abstract Submitted to the    NANOTUBE'04 Conference:

Carbon nanotubes are produced by several methods: electric arc, laser ablation and heterogeneous catalysis. For carbon formation and hydrogen production via catalytic methods, the most used are: partial oxidation, reforming and methane cracking; and in comparison to those that produce a mixture of hydrogen, carbon oxides and water, methane cracking yields only carbon and hydrogen. In this work we have employed bimetallic Co and Mo supported on SiO2 to perform the cracking of methane to produce carbon nanotubes. The effects of Co:Mo ratio (1:2 and 2:1) and the reaction temperature (650^oC and 800^oC) on the conversion of methane, formation of nanotubes and hydrogen production, were observed. The methane conversion increases from 2.5% at 650^oC and a 5% methane feed concentration to 4.5% at 800^oC and 20% methane concentration. Using TEM carbon nanotubes were observed on both catalysts, being more defined for the Co:Mo 2:1 catalyst at both temperatures. This variable seems to affe ct the nanotube dimensions.