Temperature-dependent behavior of nitrogen fixation in nanopulsed dielectric barrier discharge operated at different humidity levels and oxygen contents

• Published in: Journal of physics. D, Applied physics Applied physics, 2020-01, Vol.53 (11), p.114001
• Main Authors: Abdelaziz, Ayman A, Kim, Hyun-Ha
• Format: Article
• Language: English
• Subjects: dielectric barrier discharge (DBD); humidity effect; nitrogen fixation; oxygen content; temperature dependence
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/1361-6463/ab5c78

This study thoroughly analyzed the gas-temperature dependence of nitrogen fixation in a dielectric barrier discharge powered by a nanosecond pulsed high voltage. The correlation between temperature (in the range of 300-600 K) and the humidity effects (H2O  =  0.1% vol.-12.5% vol.) was systematically investigated at different oxygen contents (O2  =  5% vol.-40% vol.) in nitrogen. The nitrogen-content products were accurately evaluated by measuring them in the gas phase and that trapped in water, using Fourier transform infrared spectroscopy and ion chromatography, respectively. An examination of the current-voltage characteristics and optical emission spectroscopy indicated that temperature (within the tested range) had minor effects on the discharge characteristics, where the excitation processes slightly decreased while the dissociation and the ionization increased marginally. This eventually led to a constant amount of fixed nitrogen with temperature at a given gas mixture. However, a higher oxygen content promoted nitrogen fixation by increasing and accelerating the oxidation of fixed nitrogen to higher oxidation states. On the other hand, the temperature significantly affected the selectivity of the nitrogen-content products owing to its effect on the reaction rates of their formation and its significant influence on ozone decomposition. Operating the dielectric barrier discharge (DBD) at low temperatures favored the production of high-oxidation states of nitrogen that led to the formation of nitrate with free nitrite in water, which would be useful for agriculture. The results also indicated that operating the DBD at high temperatures is useful for obtaining high selectivity of NO, which can be useful for biological applications.