The catalytic decomposition of methane, as a potential alternative to steam reforming, may provide hydrogen without CO for niche applications, such as its use in fuel cells. The reaction was performed at the temperature range of 400-800 degrees C at the ambient pressure. The hydrogen concentration at the outlet of the reactor was analyzed by gas chromatography. Carbon nanomaterials were investigated by FE-SEM, TEM and Raman spectroscopy. This study has demonstrated the use of Co catalysts supported on ZSM-5 with two different molar ratios of SiO2: Al2O3 (25-30 and 300-350) for catalytic decomposition of methane to co-produce hydrogen and carbon nanomaterials, i.e. multi-walled carbon nanotubes, carbon nanocapsules filled with cobalt and carbon nanotubes filled with continuous cobalt nanowires. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.