Thermocatalytic decomposition (TD) of natural gas (NG) is a promising CO2-free approach to hydrogen production, however, the practical realization of the sustainable TD process faces significant technical challenges due to rapid deactivation of existing catalysts by carbon deposits. In this work, the authors report on TD of NG and methane over a new type of carbon-based catalyst: plasma-generated carbon aerosols. The carbon aerosols were produced by non-thermal plasma-assisted decomposition of NG at near-ambient conditions. The plasma-generated carbons exhibit highest catalytic activity for methane (or NG) decomposition among known carbon-based catalysts with a comparable surface area. The nanostructure of the plasma-generated carbons was characterized and found to be consistent with highly disordered (amorphous) carbon. It is demonstrated that the combination of the carbon aerosol generator with the TD reactor provides a means for sustainable production of hydrogen and carbon from NG with a relatively high energy efficiency. (C) 2009 Elsevier B.V. All rights reserved.