2020 年 63 巻 12 号 p. 635-640
We investigated the rate coefficient of CO2 splitting via vibrational excited states using recombining H2 and He plasmas with ultralow electron temperatures between 0.1 and 0.3 eV. The ultralow-temperature plasmas were useful for investigating the CO2 splitting via vibrational excited states, since the rate coefficients of dissociation of CO2 via electronic excited states are negligible. The rate coefficient of the CO2 splitting decreased clearly with the electron temperature. In addition, the rate coefficient observed in the ionizing H2 plasma with an electron temperature of 4 eV was one order of magnitude smaller than that observed in the recombining plasmas. It has been shown that the CO2 splitting via vibrational excited states has a larger rate coefficient than that via electronic excited states.