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

Rate constants for the removal of O₂ b¹Σ_g⁺ by collisions with species relevant to combustion, H₂, CO, N₂O, CH₄ and C₂H₄ have been measured in the temperature range 297-800 K. O₂(b¹Σ_g⁺) 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 b¹Σ_g⁺-X³Σ_g^- fluorescence. The removal rate constants for H₂, CO, N₂O, CH₄, and C₂H₄ could be represented by the modified Arrhenius expressions k_H = (1.44 ± 0.02) × 10^-16 T^1.5 exp[(0 ± 10)/ T], k_CO = (6.9 ± 0.4) × 10^-24 T³ exp[(939 ± 33)/ T], k_N = (2.63 ± 0.14) × 10^-18 T^1.5 exp[(590 ± 26)/ T], k_CH = (3.5 ± 0.2) × 10^-17 T^1.5 exp[(-220 ± 24)/ T], and k_C = (2.34 ± 0.10) × 10^-20 T^2.5 exp[(680 ± 16)/ T] cm³ molecule^-1 s^-1, 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.