O2(b 1σ(g)+)与几种大气分子反应的动力学研究。

Kinetic studies of the reactions of O2(b 1sigma(g)+) with several atmospheric molecules.

作者信息

Dunlea Edward J, Talukdar Ranajit K, Ravishankara A R

机构信息

Aeronomy Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305, USA.

出版信息

J Phys Chem A. 2005 May 5;109(17):3912-20. doi: 10.1021/jp044129x.

DOI:10.1021/jp044129x

PMID:16833709

Abstract

Thermal rate coefficients for the removal (reaction + quenching) of O2(1sigma(g)+) by collision with several atmospheric molecules were determined to be as follows: O3, k3(210-370 K) = (3.63 +/- 0.86) x 10(-11) exp((-115 +/- 66)/T); H2O, k4(250-370 K) = (4.52 +/- 2.14) x 10(-12) exp((89 +/- 210)/T); N2, k5(210-370 K) = (2.03 +/- 0.30) x 10(-15) exp((37 +/- 40)/T); CO2, k6(298 K) = (3.39 +/- 0.36) x 10(-13); CH4, k7(298 K) = (1.08 +/- 0.11) x 10(-13); CO, k8(298 K) = (3.74 +/- 0.87) x 10(-15); all units in cm3 molecule(-1) s(-1). O2(1sigma(g)+) was produced by directly exciting ground-state O2(3sigma(g)-) with a 762 nm pulsed dye laser. The reaction of O2(1sigma(g)+) with O3 was used to produce O(3P), and temporal profiles of O(3P) were measured using VUV atomic resonance fluorescence in the presence of the reactant to determine the rate coefficients for removal of O2(1sigma(g)+). Our results are compared with previous values, where available, and the overall trend in the O2(1sigma(g)+) removal rate coefficients and the atmospheric implications of these rate coefficients are discussed. Additionally, an upper limit for the branching ratio of O2(1sigma(g)+) + CO to give O(3P) + CO2 was determined to be < or = 0.2% and this reaction channel is shown to be of negligible importance in the atmosphere.

摘要

通过与几种大气分子碰撞来去除（反应 + 猝灭）O₂(¹σg⁺) 的热速率系数测定如下：对于 O₃，k₃(210 - 370 K) = (3.63 ± 0.86) × 10⁻¹¹ exp((-115 ± 66)/T)；对于 H₂O，k₄(250 - 370 K) = (4.52 ± 2.14) × 10⁻¹² exp((89 ± 210)/T)；对于 N₂，k₅(210 - 370 K) = (2.03 ± 0.30) × 10⁻¹⁵ exp((37 ± 40)/T)；对于 CO₂，k₆(298 K) = (3.39 ± 0.36) × 10⁻¹³；对于 CH₄，k₇(298 K) = (1.08 ± 0.11) × 10⁻¹³；对于 CO，k₈(298 K) = (3.74 ± 0.87) × 10⁻¹⁵；所有单位均为 cm³ 分子⁻¹ s⁻¹。O₂(¹σg⁺) 通过用 762 nm 脉冲染料激光直接激发基态 O₂(³σg⁻) 产生。O₂(¹σg⁺) 与 O₃ 的反应用于产生 O(³P)，并在反应物存在的情况下使用真空紫外原子共振荧光测量 O(³P) 的时间分布，以确定去除 O₂(¹σg⁺) 的速率系数。我们的结果与之前可用的值进行了比较，并讨论了 O₂(¹σg⁺) 去除速率系数的总体趋势以及这些速率系数对大气的影响。此外，O₂(¹σg⁺) + CO 生成 O(³P) + CO₂ 的分支比的上限被确定为 ≤ 0.2%，并且该反应通道在大气中的重要性可忽略不计。