Multiwalled carbon nanotubes and carbon nanorods were produced through a novel route in the presence of different metallic particle catalysts at the extremely low temperature of 200 degreesC. In this process, tetrachloroethylene (C2Cl4) was used as the carbon feedstock, which can be reduced by metallic potassium to free C-2 in benzene at the temperature of 200 degreesC. Then the freshly formed free C2 can assemble into the hexagonal carbon clusters, which can grow into nanotubes at the surface of the catalytic particles (Fe/Au). Transmission electron microscopy (TEM) images showed that the nanotubes had an average length of 1.8 mum, and the inner diameter of 60 nm, the outer diameter was 80 nm in average. The Y-junction carbon nanotubes were first observed in the solution reaction. In addition, the freshly reduced free C-2 can also form one-dimensional conjugate carbon chain clusters, and then they assemble into nanorods with the diameter of 70 nm and the length of 1000 nm in the presence of another catalytic particle (Ag). The catalyst and the reaction time play important roles in the nucleation and growth process of the nanotubes and nanorods.