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

• Published in: ACS catalysis Vol. 10; no. 11; pp. 6546 - 6560
• Main Authors: Hanna, Angela R, Fisher, Ellen R
• Format: Journal Article
• Language: English
• Published: American Chemical Society 05.06.2020
• Subjects: plasma kinetics; zeolites; nitrogen oxides; plasma-assisted catalysis; energy partitioning
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.0c00794

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 N2 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.