Nanostructured forms of carbon deposit obtained during cracking of methane reaction over nanocrystalline iron catalysts.

During catalytic cracking of methane reaction, different carbon nanostructures can be formed. This paper shows the results of a characteristic nanostructured carbon deposit obtained during cracking of methane reaction over nanocrystalline iron catalysts with or without cobalt addition. The properties of the carbon deposit were determined by X-ray diffraction, scanning electron microscope with energy dispersive spectrometer equipment, thermogravimetry-differential thermal analysis coupled with mass spectrometry, time-of-flight secondary ion mass spectrometry analysis and surface area analysis (Brunauer-Emmett-Teller isotherm [BET]). Significant differences in the morphology and properties of the obtained carbon were found. The mechanism of the formation of carbon nanostructures for both iron catalysts is proposed. [ABSTRACT FROM AUTHOR]