Catalytic decomposition of ethylene on iron -: the effect of process conditions on the yield and morphology of nanocarbon products

The catalytic decomposition of ethylene on nanocrystalline iron was investigated. The processes were carried out in a horizontal tube reactor under atmospheric pressure and in the temperature range of 500-800 degrees C. Various process parameters such as: reaction time, temperature, C2H4:H-2 ratio, C2H4:Ar ratio have been examined to determine the effect of these parameters on both the yield of carbon and the morphology of products. The quality of the products was characterized by means of transmission electron microscopy (TEM). According to the observed results, ethylene can be used as a very effective carbon source for growing multi-walled carbon nanotubes (MWCNTs). The mean diameter of the obtained MWCNTs was 20-30 nm. The length of carbon nanotubes increased with reaction time. The carbon nanotubes obtained in presence of hydrogen or argon in reaction mixture were straighter and less entangled than carbon nanotubes obtained through decomposition of pure ethylene.