In contrary to the conventional catalysis in the gas-solid reactions, ‍CCVD has a unique feature, i.e. the catalyst precursor enters in the same phase as the gaseous reactants. This feature leads to an axial gradient of catalyst precursor, which results in different carbon products along the reactor in the course of carbon nanotube synthesis. The reaction products collected from different parts of the reaction zone, were characterized by scanning electron microscopy (SEM). Further experiments in the presence of an packed bed of an inert material were carried out to see the quality variation of carbon products.

Keywords