DECOMPOSITION OF NITRIC-OXIDE IN A SILENT DISCHARGE

The effect of some physical and chemical parameters on NO decomposition was determined at 25 °C in a laboratory silent discharge reactor on a gas containing 1 % NO in helium. Using a 3-mm electrode-gap reactor, the NO decomposition increased with increasing applied voltages in the range of 9 to 24 kV. The threshold value was estimated at about 3.3 kV. At 24 kV, over 98% of the NO was principally decomposed to its elements with gas residence times greater than 1.2 min. At shorter residence times, neither the N2 nor O2 formation yields were equivalent, the O2 being persistently lower than the N2. The disparity between N2 and O2 formation and NO decomposition became progressively less as the gas residence time increased. The formation of an intermediate dinitrogen trioxide, N2O3, can account for the observed results. The addition of H2O, CO2, and CO decreased the NO removal. When CO was added to NO or N2O, CO2 gas formed indicating that both nitrogen oxides were reduced. © 1979, American Chemical Society. All rights reserved.