Streamer dynamics and gas conversion in patterned dielectric barrier discharges

Packed bed volume and surface dielectric barrier discharges (DBDs) are frequently used for gas conversion, but suffer from various limitations. In volume DBDs the presence of beads in the volume at uncontrolled locations blocks the gas flow, leads to unstable discharge conditions, and limits diagnostic access. In surface DBDs, despite the presence of plasma induced vortex gas flows, plasma exposure of the gas stream is limited. We use an advanced plasma source, the patterned DBD, which combines volume and surface DBDs in a highly controlled way. Dielectric pellets are immersed into an electrode at fixed and controllable positions to enhance plasma stability and control. Based on experiments and simulations, we study the effects of catalytic coatings, deposition, floating dielectric rods placed in the plasma volume, and of the driving voltage waveform on the dynamics of volume and surface streamers, that determine the generation of reactive species, plasma-catalyst coupling, and conversion rates via electron heating. Based on these insights, we reveal the effects of such control parameters on the conversion of n-Butane as an example of a volatile organic compound.