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 CO 2 in prebiotic atmospheric chemistry. The gas mixture was composed of nitrogen with 2-4% methane and 1% CO 2 . 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 CO 2 admixture leads to the generation of CO and H 2 O, 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. KEYWORDSFTIR spectroscopy, negative corona discharge, prebiotic atmosphere 1

Antibacterial Thin Films Deposited from Propane–Butane Mixture in Atmospheric Pressure Discharge

“…The optical spectra were measured in the same experimental setup [ 20 ] and CN and O I spectra were observed. Moreover, the emission line of H and bands of NH and CH were observed in the optical spectra from the discharge in N /CH /CO mixture [ 21 ]. Observation of the CN, CH and NH bands demonstrated the rich chemistry occurring in the discharge.…”

“…FTIR and GC-MS analyses of gaseous products from the discharges in the nitrogen–methane mixture detected hydrogen cyanide, acetylene and acetonitrile as dominant products. Ethane, ethylene and other nitriles were observed [ 21 , 22 ]. Nitrile groups are common products of the reaction of hydrocarbons (e.g., propane and butane) with nitrogen in discharges, see e.g., [ 23 ].…”