Wang Shengkai, Davidson David F, Hanson Ronald K
High Temperature Gasdynamics Laboratory, Stanford University , Stanford, California-94305, United States.
J Phys Chem A. 2017 Nov 16;121(45):8561-8568. doi: 10.1021/acs.jpca.7b09362. Epub 2017 Nov 7.
The oxidation of Ar-diluted stoichiometric CHO-O mixtures was studied behind reflected shock waves over temperatures of 1332-1685 K, at pressures of about 1.5 atm and initial CHO mole fractions of 500, 1500, and 5000 ppm. Quantitative and time-resolved concentration histories of OH and CO (at both v″ = 0 and v″ = 1) were measured by narrow-linewidth laser absorption at 306.7 and 4854 nm, respectively. A time delay was observed between the formation of v″ = 0 and v″ = 1 states of CO, suggesting that CO was kinetically generated primarily in the ground state and then collisionally relaxed toward vibrational equilibrium. The measured CO and OH time-histories were used to evaluate the performance of four detailed reaction mechanisms regarding the oxidation chemistry of CHO. Further analyses of these time-history data have also led to improved determination for the rate constants of two key reactions, namely H + O = O + OH (R1) and OH + CO = CO + H (R2), as follows: k = 8.04 × 10 exp(-7370 K/T) cm mol s, k = 1.90 × 10 exp(-2760 K/T) cm mol s; both expressions are valid over 1428-1685 K and have 1σ uncertainties of approximately ±10%.
在反射激波后，研究了氩气稀释的化学计量比CHO - O混合物在1332 - 1685 K温度、约1.5 atm压力以及初始CHO摩尔分数为500 ppm、1500 ppm和5000 ppm条件下的氧化反应。分别通过306.7 nm和4854 nm处的窄线宽激光吸收测量了OH和CO（v″ = 0和v″ = 1）的定量及时间分辨浓度历程。观察到CO的v″ = 0和v″ = 1态形成之间存在时间延迟，这表明CO主要在基态通过动力学方式生成，然后通过碰撞弛豫至振动平衡。所测量的CO和OH的时间历程用于评估四种关于CHO氧化化学的详细反应机理的性能。对这些时间历程数据的进一步分析还改进了两个关键反应，即H + O = O + OH（R1）和OH + CO = CO + H（R2）的速率常数的确定，结果如下：k = 8.04×10 exp(-7370 K/T) cm³mol⁻¹s⁻¹，k = 1.90×10 exp(-2760 K/T) cm³mol⁻¹s⁻¹；这两个表达式在1428 - 1685 K范围内有效，1σ不确定度约为±10%。
