Analysis of the products of a negative corona discharge in a N2–CH4 mixture with added CO2 used as a laboratory mimic of a prebiotic atmosphere

Abstract

A negative corona discharge operating at atmospheric pressure has been used to initiate chemical reactions in a gaseous mixture of nitrogen, methane, and carbon dioxide. Such a mixture simulates the composition of the early Earth's atmosphere. This work extends our previous experimental studies of the chemistry of prebiotic atmospheres generated in an atmospheric‐pressure glow discharge. The present work is devoted to the study of the role of CO2 in prebiotic atmospheric chemistry. The gas mixture was composed of nitrogen with 2–4% methane and 1% CO2. The corona discharge was characterized by electrical measurements and optical emission spectroscopy. The reaction products from the discharge were further analysed by Fourier transform infrared (FTIR) spectroscopy. The composition of solid products deposited on the electrode tip was obtained by energy dispersive X‐ray (EDX) analysis. The specific input energy was altered during the experiments, and the concentration of all products was found to increase with its increase. It is further shown that while the addition of the CO2 admixture leads to the generation of CO and H2O, no other compounds containing oxygen were detected. The energy yields of products were calculated, and good agreement was found with the values obtained in previous experiments.