Direct Measurement of the Reaction H+CO₂ at Elevated Temperatures

Abstract

The reaction CO₂+H has been investigated at elevated temperatures in the postshock region behind reflected shocks. The thermal decomposition of very low concentrations (0.2–3 ppm) of C₂H₅I served as H-atom source. Atomic resonance absorption spectrometry (ARAS) was used to record simultaneously H-atom and I-atom profiles. The experiments cover the temperature range 1450 to 1820 K, at total pressures from 1.5 to 7.8 bar. The values of the deduced rate coefficient (k in cm³ mol^-1 sec^-1, uncertainties on one standard deviation level) is:

$${k_1} = (1.0 \pm 0.05) \times {10^{14}}\exp ( - (12000 \pm 50)/T)$$

((R1))