Natural gas partial oxidation process as a way to synthesize onion-like carbon

Onion-like carbon (OLC) particles were produced as a byproduct of thermal partial oxidation of methane under different O2/Natural Gas (NG) ratio. It was established that the particles have quasi-spherical morphology and concentric shell structure. The particles have an outer diameter of 20–60 nm while the inner cage is rather typical for onions and has a diameter below 1 nm. The concentric graphitic structure and spherical symmetry along with the absence of amorphous carbon were confirmed by transmission electron microscopy, electron diffraction, EDX spectroscopy and Raman investigation. Variation of O2/NG ratio was proved a powerful tool for controlling OLC particles yield and structure. The formation of single-core or multicore OLC can be controlled by thermal partial oxidation process.