Rate Coefficient of CO₂ Splitting via Vibrational Excited States in Recombining Plasmas with Ultralow Electron Temperatures

Abstract

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.