Investigation of CoOx/AC catalysts in methane chemical vapour decomposition process for carbon nanotube (CNT) synthesis

The main purpose of this work is to investigate the CoO
_x
/AC catalyst in methane chemical vapour decomposition (m-CVD) for synthesizing CNTs. The effects of catalyst preparation conditions such as metal loading, calcination and reduction temperatures on the morphology and the quality of CNTs formed is investigated. CoO
_x
/AC catalyst samples are prepared with 5, 10, 15 and 20 wt% of cobalt oxide loadings by wetness impregnation method. The impregnated samples are dried at 105°C for 12 h and calcined in N
₂
at 350/450°C for 3 h. The calcined samples are further subjected to a reduction under H
₂
atmosphere in a tubular quartz reactor at two different temperatures of 450 and 550°C for 3 h.