Eur. Phys. J. Appl. Phys. (2013) 61: 24305
https://doi.org/10.1051/epjap/2012120421

Oxidation of nitrogen oxide in hybrid plasma-catalytic reactors based on DBD and Fe₂O₃^*

Institute of Physics, University of Tartu, Tähe 4, 51010 Tartu, Estonia

^a e-mail: indrek.jogi@ut.ee

Received: 30 September 2012
Revised: 30 October 2012
Accepted: 5 December 2012
Published online: 15 February 2013

Abstract

In the present study, Fe₂O₃ was used as catalyst for the removal of NO in a hybrid plasma- catalytic reactor. The catalyst was located either directly inside the hybrid plasma-catalytic reactor or in a separate catalytic reactor, which followed ozone producing and injecting plasma reactor. Ozone production in such a reactor was dependent on the state of the electrode surface. The fresh catalyst ensured an order of magnitude smaller ozone concentration in the outlet of the hybrid reactor. After a short treatment of the catalyst with NO₂, its ability to destroy ozone diminished but was regained after heating of the reactor up to 100 °C. Similarly to earlier results obtained with TiO₂, the removal of NO in the hybrid reactor with Fe₂O₃ was enhanced compared to that in an ordinary plasma reactor. In the ozone injection reactor, oxidation of NO to NO₂ took place with considerably higher efficiency compared to the hybrid reactor. The use of catalyst in the ozonation stage further improved the oxidation of NO₂ to N₂O₅. The time-dependence effects of NO removal during plasma and ozone oxidation were explained by reactions between NO₂ adsorbed on surface, with surface-bound NO₃ and gas phase NO as the reaction product.