O₂(b¹Σ_g⁺) Removal by H₂, CO, N₂O, CH₄, and C₂H₄ in the 300–800 K Temperature Range

Abstract

Rate constants for the removal of O bΣ by collisions with species relevant to combustion, H, CO, NO, CH and CH have been measured in the temperature range 297-800 K. O(bΣ) was produced from ground-state molecular oxygen by photoexcitation pulses from a tunable dye laser, and the deactivation kinetics were followed by observing the temporal behavior of the bΣ-XΣ fluorescence. The removal rate constants for H, CO, NO, CH, and CH could be represented by the modified Arrhenius expressions k = (1.44 ± 0.02) × 10 T exp[(0 ± 10)/ T], k = (6.9 ± 0.4) × 10 T exp[(939 ± 33)/ T], k = (2.63 ± 0.14) × 10 T exp[(590 ± 26)/ T], k = (3.5 ± 0.2) × 10 T exp[(-220 ± 24)/ T], and k = (2.34 ± 0.10) × 10 T exp[(680 ± 16)/ T] cm molecule s, respectively. All of the rate constants measured at room temperature were found to be in good agreement with previously reported values, whereas the values at elevated temperatures up to 800 K were systematically measured for the first time.

Virtual Issue on Combustion Chemistry

“…The work of Johansson et al particularly highlights the critical need for foundational data used to quantify soot precursors in flames. Several studies flesh out new combustion chemistry, whether involving hydrocarbon oxidation, O 2 ( 1 Σ g + ) chemistry, or the more exotic chemistry involved in silane oxidation …”