Organic chemistry of NH₃ and HCN induced by an atmospheric abnormal glow discharge in N₂-CH₄ mixtures

The formation of the chemical products produced in an atmospheric glow discharge fed by a N2-CH4 gas mixture has been studied using Fourier Transform InfraRed (FTIR) and Optical Emission Spectrometry (OES). The measurements were carried out in a flowing regime at ambient temperature and pressure with CH4 concentrations ranging from 0.5% to 2%. In the recorded emission spectra the lines of the second positive system CN system and the first negative system of N2 were found to be the most intensive but atomic Hα, Hβ, and C (247 nm) lines were also observed. FTIR-measurements revealed HCN and NH3 to be the major products of the plasma with traces of C2H2. These same molecules have been detected in Titan's atmosphere and the present experiments may provide some novel insights into the chemical and physical mechanisms prevalent in Titan's atmosphere with these smaller species believed to be the precursors of heavier organic species in Titan's atmosphere and on its surface

Packed bed DBD discharge experiments in admixtures of N₂ and CH₄

The physical, chemical and electrical properties of a coaxial Dielectric Barrier Discharge (DBD) fed by various mixtures of N2 and CH4 at atmospheric pressure and ambient temperature has been studied. FTIR spectral measurements of the products formed in the discharge have shown that the main chemical products are C2H2, HCN and C2H6 produced by dissociation of CH4, with small but significant traces of NH3, such a chemical transformation may provide some insight into the chemical processes prevalent in the atmosphere of Titan. During operation of the discharge a solid brown-yellowish deposit was formed on the central rod electrode and the dielectric pellets. Such a deposit is similar to that observed in other N2:CH4 discharges and is believed to be an analogue of the aerosol and dust observed in Titan’s atmosphere being composed of chemical species commonly known as ‘tholins’

Study of nitrogen-methane post-discharge by NO titration coupled with optical emission spectroscopy

This study extends our experiments with nitrogen post-discharge and continues on chemical simulation of Titan's atmosphere. The Titan's atmosphere was simulated by nitrogen-methane DC post-discharge in flowing regime with methane concentrations under 1%. The titration by nitrogen oxide into the post-discharge allows measuring the atomic nitrogen concentration for different methane concentrations at the total gas pressure of 1000 Pa

Titan's atmosphere chemistry simulation in atmospheric glow discharge

The formation of products produced in an atmospheric glow discharge fed by a N2-CH4 gas mixture with CH4 contents in range from 0.5% to 2% CH4 has been studied using Fourier Transform Infrared (FTIR). The measurements were carried out in flowing regime at ambient temperature and pressure. Measurements revealed HCN and NH3 to be the major products of the plasma with traces of C2H2. These same molecules were observed by the Cassini-Huygens probe in Titan's atmosphere

An optical emission spectroscopy of atmospheric glow discharge between shaped electrodes in N2-CH4 gas mixture

An optical emission spectroscopy (OES) of an atmospheric glow discharge induced between shaped electrodes has been studied in N2-CH4 gas mixture with CH4 contents in range from 0.5% to 2%. The measurements were performed in flowing regime at ambient temperature and atmospheric pressure. In the emission spectra the lines of the second positive system of N2, the CN system and the first negative system of N2 were found to be the most intensive, the atomic Hα, Hβ, and C (247 nm) lines were also observed