Effect of inert gases on ozone generation using dielectric barrier discharge in oxygen

This paper reports the results of an experimental study of the effect of inert gases He, Ar and Kr on ozone generation in a Dielectric Barrier Discharge (DBD) fed by pure oxygen. The chemical reaction mechanisms related to the process of ozone generation are discussed. The experimental results show that ozone concentration decrease with decreasing oxygen content in all He+O 2, Ar+O 2 and Kr+O 2 mixtures mainly owing to the decrease of oxygen content. The conversion ratio of oxygen into ozone increases with increasing oxygen content in He+O 2 mixtures, but the addition of Ar and Kr can improve the conversion ratio due to the increase of free electrons density and excited oxygen molecules required for ozone formation through ionization and Penning effect. The effect of Kr is more significant for the lower first ionization energy of metastable state compared with other gases. It is probable that the ozone concentration, and ozone production efficiency increase with Kr addition when the reduced electric field and mean electron energy are high enough.