Abstract: Magnesium and molybdenum oxide prepared by a sol-gel method was used to synthesize high quality multi-walled carbon nanotubes bundles by catalytic decomposition CH₄. The experiment reveals
that the prepared catalysts have high activity and high efficiency. After reacting for 2h, the quantity of synthesized MWNTs is over 30 times of the pristine
catalysts. Transmission electron microscopy, high-resolution transmission electron microscopy, thermal gravimetric analysis and laser Raman spectroscopy
were used to characterize the synthesized MWNTs bundles. The results show that the synthesized MWNTs bundles have a diameter distribution about
10～22nm. The longer the reaction time, the graphitization degree of the synthesized MWNTs bundles. After reacting for 1h, the MWNTs bundles
with a high purity of more than 95% can be obtained. The forming multilayers Mo particles on the surface of MgO support are the main cause of the nanotubes
bundles growth.

Key words: multi-walled carbon nanotubes bundles, chemical vapor deposition, magnesium and molybdenum oxide