Cathodic Contact Glow Discharge Electrolysis for the Degradation of Liquid Ammonia Solutions

The application of 50 VDC cathodic contact glow discharge electrolysis for six hours in 1.0 mol/L KOH + 0.8, 0.4 and 0.08 g/L ammonia results in the removal of 66, 71 and 77% of ammonia, respectively, following pseudo first-order kinetics at ca. 0.3 mol/kWh. The yields of dissolved NO2-N and NO3-N lie between 9 and 29% and are coupled with ammonia removal suggesting a nitrification process. Based on the near-cathode UV-Vis emissions and ionization products of H2O and NH3 molecules, a mechanism is proposed along with the charge/energy transfer reactions between the plasma-generated free radicals and ionic species. Joule heating and vaporization are also believed to physically remove ammonia.