Synthesis of Carbon Nanoparticles in a Compression Reactor in Atmosphere of Buffer Gases

Physicochemical aspects of the gas-phase synthesis of nanopowders using a cyclic compression reactor are considered. Precursors (methane, ethylene, and acetylene) are compressed under conditions close to adiabatic ones in atmosphere of buffer monatomic gases (argon, helium, and neon). The effect of the pressure in the reactor and precursor/buffer gas volumetric ratio on the composition, morphology, and structure of carbon-containing particles (pyrolysis products) is studied. Complete pyrolysis is observed for all precursors but under different conditions. Thermal decomposition of methane, having the minimum enthalpy of formation, is observed in atmosphere with an argon content of 97.5% at a peak pressure of greater than 10 MPa. Helium shows limited possibilities for thermal relaxation under the conditions for fast reactions (