Carbon formation on iron and nickel foils by hydrocarbon pyrolysis—reactions at 700°C

Abstract

Structural and morphological studies of carbons produced by pyrolysis of various hydrocarbons over iron and nickel foils have been carried out by high resolution electron microscopy. Kinetic and analytical measurements showed that the nature of the deposited carbon was a function of the rate of deposition rather than of the identity of the hydrocarbon gas phase. The carbon deposition rate was independent of pressure for methane and propane but dependent for propylene and butadiene above 1 Torr. The presence of residual metal in the deposited carbon in a finely dispersed form was established by oxidation. These results are compared with those of other workers and a carbon growth mechanism proposed that is consistent for both platelet and filamentary graphitic carbons.