Multi-walled carbon nanotubes (MWNTs) were synthesized by catalytic chemical vapor deposition (CCVD) using acetylene as the carbon source and Fe-supported zeolite (FAU) templates. The effect of the catalyst content and the reaction time on the synthesis of CNTs were investigated through transmission electron microscopy (TEM), thermogravimetic (TG) analysis, and Raman spectroscopy. A number of MWNTs synthesized for 1 h had inner and outer tube diameters in the range of 3.8-5.0 nm and 6.3-8.8 nm, respectively, which were smaller than those of conventional thick MWNTs. With increasing iron content in the zeolite, the carbon yield showed a monotonic increasing tendency, reaching 63.1% as the iron content was up to 0.12 mol%. With prolonged reaction times such as 30 minutes, 1 h, 2 h, and 3 h, the inner diameter of the CNTs remained constant while the outer diameter became larger and larger, with the carbon yield after the reaction of 3 h reaching 63.1%.

Keywords: Carbon nanotubes, Catalytic chemical vapor deposition, Zeolite, Template, Catalyst