2D-Imaging of Methyl in a HE/CH4 Nanosecond Pulsed Plasma Jet by Photo-Fragmentation Laser Induced Fluorescence

The coupling of methane to higher hydrocarbons is receiving increased interest for conversion of natural gas into value-added products. Conventional approaches such as oxidative coupling of methane (OCM) suffer from a tradeoff between selectivity and conversion because C 2 products are thermodynamically unfavorable at the high temperatures needed for significant conversion. A key step in the process is the extraction of a hydrogen atom from methane to form the methyl radical (CH 3 ). By coupling a plasma to OCM catalysts, the dehydrogenation step could be enhanced by the plasma, potentially enabling significant conversion at much lower temperatures while maintaining selectivity. To increase understanding of the kinetics of methyl production in the plasma and subsequent interaction with a catalyst, a spatially resolved and quantitative methyl diagnostic is needed.