Optical emission spectroscopy measurement of plasma parameters in a nanosecond pulsed spark discharge for CO2/CH4 dry reforming

In this paper, a nanosecond pulsed spark discharge in CO2/CH4 mixture gas at atmospheric pressure is studied with optical emission spectroscopy. A high-voltage pulse is applied across two plate-shaped electrodes at a repetition frequency of 1 kHz. Emphatically, plasma parameters of this discharge are estimated by spectroscopic methods for giving an insight into the underlying dry reforming reaction mechanism. The time-averaged optical emission is mainly caused by atomic spectral lines of excited O, H, and C., and C-2 swan bands. The vibrational temperature of 8500 +/- 50 K and rotational temperature of 3200 +/- 100 K are estimated by the excited C-2 molecules, respectively. The electron density is calculated by Stark broadening of O (844.6 nm), Ham, (656.3 nm), and Hb (486.1 nm) for 3.4 similar to 7.71 x 10(17) cm(-3) while C. (723.6 nm) for 4.37 x 10(18) cm(-3) with an electron excitation temperature of 0.58 eV that is estimated by the intensity ratio of Ham, and Hb. The determination of plasma parameters offers essential data for subsequent reaction kinetics research of the plasma-assisted dry reforming of CH4. (c) 2021 Elsevier B.V. All rights reserved.