Effect of electrode structure on the packing material surface discharge characteristics in dielectric barrier discharge

In a single-particle packed bed dielectric barrier discharge reactor(SPR), the effect of high voltage electrode structure on the surface gas discharge characteristics of Al2 O3 ball with a diameter of 1mm was studied. The time-resolved images of the surface discharge of the ball under four electrodes were taken by ICCD camera. The high voltage electrode structures includes a single needle electrode, a hemispherical electrode, a hemispherical electrode with a convex top and a plate electrode. The results show that the surface electric field distortion is strongest at the contact point between the single needle electrode and the ball, and the surface ionization wave is most easily induced at the contact point with the ball. However, under the single needle electrode, the ionization wave can not propagate stably in a large area on the ball surface. The electric field distortion on the surface of the plate electrode is weak, and the voltage required to form the surface discharge is higher than that of the other three electrode structures. However, under the plate electrode, the ionization wave has the largest propagation area and the best stability on the spherical surface.

I. Introduction

In recent years, plasma catalysis has attracted more and more attention in the fields of carbon dioxide conversion, ozone generation, hydrogen production and gas pollutant removal ^{[1], [2]}. As one of the most commonly used structures in plasma catalysis, packed bed reactors can obtain ideal results. The presence of catalyst can cause plasma catalysis effect and change the discharge environment. Under the synergistic effect of catalytic effect and gas discharge enhancement, the efficiency of plasma catalytic reaction is significantly improved ^{[3], [4]}. However, the mechanism of catalytic surface discharge is not clear.