Low-temperature plasma-assisted oxidation of C₂H₄ by CuO

In this work, the low-temperature plasma-assisted oxidation of C₂H₄ by CuO in a heated fixed bed, coaxial, double dielectric barrier discharge (DBD) reactor was studied through time-dependent species measurements by an electron-ionization molecular beam mass spectrometer (EI-MBMS). In the experiments, 10% ethylene mixed with noble gasses was flown at 50 sccm STP through 1g of CuO particles dispersed in quartz wool under plasma and non-plasma conditions. Time-dependent gas-phase species profiles were accumulated through the EI-MBMS approximately every 13s of the complete mass spectra up to a molecular weight of 220u. Plasma conditions were probed from 300 to 500 °C, while the non-plasma conditions were fixed from 300 to 600 °C. Insights into the oxidation of C₂H₄ by CuO at lower temperatures were obtained by quantifying the intermediate species, fuel oxidation, and CO/CO₂ production compared to the non-plasma conditions. We observed considerable enhancement of ethylene oxidation from the plasma discharge at lower temperatures. At more elevated temperatures, the differences between plasma and non-plasma conditions became limited. At lower temperatures, significantly more plasma reforming was measured. The resultant reduced Cu-based particles were free from carbon deposits under all plasma and non-plasma conditions.