Removal of NO by simultaneous action of dielectric-barrier discharge and TiO_2 photocatalyst

摘要

NO oxidation by simultaneous action of a dielectric barrier discharge and TiO_2 photocatalyst was investigated as a function of the inlet gas composition (NO, 0_2, N_2) and the input energy. Concentrations of various NO_x species and ozone in the outlet were detected by the optical absorption spectroscopy. Higher content of 0_2 (10% and higher) increased the removal of NO and resulted in a higher output of N_2O_5. TiO_2 coating on a reactor electrode resulted in the time-depending oxidation of NO. Initially the concentration of untreated NO fell below the level achieved without TiO_2 but after few minutes the positive effect of TiO_2 diminished. The initial decrease in NO level due to the presence of TiO_2 coating is explainable by surface reactions of NO species and absorbed oxygen. After few minutes, the surface states responsible for the initial removal of NO saturated and the effect of TiO_2 vanished.