Methane Activation by Nonthermal Plasma Generated Carbon Aerosols

Abstract

Activation of methane is one of the most challenging problems in catalysis due to the refractory nature of methane. Of particular interest is catalytic dissociation of methane as an attractive CO2-free route to production of hydrogen from natural gas. Synthesis, characterization, and evaluation of catalytic activity of plasma-generated carbon aerosols for methane decomposition reaction are reported in this work. Carbon aerosols were produced by nonthermal plasma assisted decomposition of a carbon precursor gas (methane or propane) at near-ambient conditions. Plasma-generated carbons exhibited significantly higher catalytic activity for methane decomposition than known carbon-based catalysts with a comparable surface area. The mechanism of methane activation as well as the interrelation between the nanostructure of the plasma-generated carbons and their catalytic activity are discussed. The high catalytic activity of plasma-generated carbons for methane decomposition is attributed to the increased surface concentration of high-energy sites formed during nonequilibrium plasma assisted dissociation of a carbon precursor.