Generation of dielectric barrier discharge in high-pressure N2 and CO2 environments up to supercritical conditions

The generations of dielectric barrier discharge (DBD) in high-pressure nitrogen and carbon dioxide environments up to supercritical conditions with or without flow fields were performed. From the second positive system of nitrogen, the rotational temperature of N2 was estimated to be approximately 400 K under a supercritical N2 condition (4 MPa and 313 K). On the other hand, from emission spectra of DBD in a high-pressure CO2 environment (1–8 MPa), C2 and O spectra were remarkable in intensity instead of CO, CO+, CO2 and CO2+ spectra that were remarkable at atmospheric pressure. Furthermore, porous carbon film synthesis by DBD under a supercritical CO2 condition (7.5 MPa and 305 K) was also identified by scanning electron microscopy observation.