NO removal is studied in N2/NO and in N2/NO/C2H4 mixtures through time-resolved laser-induced fluorescence in the afterglow of a pulsed homogeneous discharge. NO density measurements are compared with predictions of a 0D model on a large range of parameter values, such as the specific deposited energy and the ethene initial concentration. It is shown that dissociation of NO through collision with the N2(a′1Σu−) state play the main part in the NO removal kinetic. Moreover, quenching of N2(a′1 Σu−) by C2H4 leads to a drastic decrease of the NO removal efficiency when ethene is added to N2/NO. The determined rate coefficient value for the quenching mechanism is (4±2)×10−10 cm3 s−1.

Kinetic mechanisms of NO removal are studied in N 2 /NO and N 2 /H 2 O/NO gas mixtures. A very short duration (60 ns) photo-triggered discharge is used to create a homogeneous plasma at a total pressure between 230 and 460 mbar. Measurements of the NO density are performed in the afterglow by time-resolved laser-induced fluorescence, for a time scale between 2 and 200 µs after the current pulse excitation. Plasma homogeneity allows effective comparison between experimental results and predictions of a fully self-consistent discharge and kinetic modelling. It is shown that the NO removal efficiency is mainly determined through loss mechanisms balance for nitrogen metastable singlet states. In the absence of H 2 O, NO is in great part dissociated owing to collisions with singlet states. When water vapour is added, these states are destroyed through collisions with H 2 O with a rate constant k = (3.0 ± 1.5) × 10 −10 cm 3 s −1 , and it leads to the decrease of the NO removal efficiency. This reaction is invoked for the first time.