Fossil fuel decarbonization is an emerging technological approach for significant reduction Of CO2 emissions into the atmosphere. CO2-free production of hydrogen via thermocatalytic decomposition of methane (natural gas) as a viable decarbonization strategy is discussed in this paper. The technical approach is based on a single-step decomposition (pyrolysis) of methane and other hydrocarbons over carbon-based catalysts in an air/water free environment. This approach eliminates the need for water-gas shift and CO2 removal stages, required by conventional processes (e.g. methane steam reforming), which significantly simplifies the process. Clean carbon is produced as a valuable byproduct of the process. The experimental data on the catalytic activity of different carbon-based catalysts in methane decomposition reaction are presented in this work. The paper also discusses various conceptual designs for the reactor suitable for decomposition of methane with production of hydrogen-rich gas and continuous withdrawal of elemental carbon.