Fig. 2: Experimental and numerical research on the mechanism of the plasma-assisted nitrogen fixation.
From: Nitrogen fixation in a non-equilibrium spatially distributed electric field
a The NO, NO2, N2O, and O3 concentrations before absorption (Position I) in DBD and spark. b The NO3− and NO2− concentrations in the solution (Position II) in DBD and spark. c The NO, NO2, N2O, and O3 concentrations after absorption (Position III) in DBD and spark. d The absorption ratio of NO, NO2, and N2O using DBD and spark. e Energy loss fractions of electrons deposited into different molecular degrees of freedom for a 0.8 N2/0.2 O2 mixture as a function of E/N. The region in purple indicates the corresponding E/N values of the spark mode, and the region in red indicates the corresponding E/N values of the DBD mode (rot: rotational excitation, vib: vibrational excitation, ele: electronic excitation, dis: dissociation, and ion: ionization). f Schematic of the mechanism of the plasma-assisted nitrogen fixation in plasma and water. In plasma, the color of the reduced electric field intensity determines the strength of the reaction pathways. (Reaction condition in Fig. 2a–d: Total flow rate: 500 ml/min, N2/O2 = 2:8, Frequency: 10 kHz, Voltage of DBD: 15 kV, Voltage of spark: 5 kV, Volume of absorption solution: 200 ml).
