Efforts Toward Unraveling Plasma-Assisted Catalysis: Determination of Kinetics and Molecular Temperatures within N2O Discharges

Plasma-assisted catalysis represents an alternative solution to pollution abatement. To be viable, a thorough understanding of plasma-catalyst synergisms must be gained, specifically establishing links between the gas-phase, gas-surface interface, and resulting material properties. Optical emission spectroscopy provides insights into the impact of Pt and zeolite catalysts on plasma species densities, energetics, reaction kinetics, and plasma-catalyst configurations within N2O plasmas. The role of material structure on gas-phase chemistry is revealed through the use of Pt catalysts with two morphologies and size scaling. The concentration of excited-state NO substantially decreased at high powers with Pt nanopowder or microstructured zeolites. All catalytic materials significantly decreased N-2 vibrational temperatures, with little impact on rotational temperatures. Conversely, Pt materials had a limited effect on vibrational temperatures of NO; however, Pt powder enhanced NO decomposition within a two-stage system over the single-stage system. Material characterization revealed that the plasma effectively poisons Pt materials, resulting in poorer performance.