Selective formation of carbon nanotubes over Co-modified beta zeolite by CCVD

Multiwall carbon nanotubes containing carbon–zeolite composite materials have been obtained by ethylene catalytic chemical vapor deposition (CCVD) on Co-modified beta zeolite powder. High carbon selectivity to nanotubes was achieved. The combined physical characterisation through several techniques, such as TEM, HRTEM, SEM, XRD, N2 adsorption–desorption, allows to determine the geometric characteristics of nanotubes and their dependence of catalyst and synthesis conditions.