Nienow Amanda M, Roberts Jeffrey T, Zachariah Michael R
Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA.
J Phys Chem B. 2005 Mar 31;109(12):5561-8. doi: 10.1021/jp045418o.
The kinetics of the reaction between soot nanoparticles and molecular oxygen were studied by tandem differential mobility analysis (TDMA). The particles were extracted from the tip of an ethene diffusion flame. Reactions were studied at atmospheric pressure in mixtures of nitrogen and oxygen. The studies involved particles of an initial mobility diameter of 30 nm over broad ranges of temperature (500-1100 degrees C) and oxygen volume fraction (0-1). Measurements as a function of oxygen partial pressure establish that the oxidation kinetics are not first-order in oxygen volume fraction (F(O2)). Rather, the oxidation rate increases rapidly and linearly with F(O2) between 0 and 0.05 and then more slowly but still linearly between 0.05 and 1. Temperature dependent measurements are consistent with a reaction pathway involving two kinetically distinguishable oxidation sites which interconvert thermally and through oxidation. Results and conclusions are compared to those of earlier studies on the oxidation of soot.
通过串联差分迁移率分析（TDMA）研究了烟灰纳米颗粒与分子氧之间反应的动力学。颗粒是从乙烯扩散火焰的尖端提取的。在氮气和氧气的混合物中于大气压下研究反应。研究涉及初始迁移直径为30 nm的颗粒，温度范围为500 - 1100摄氏度，氧气体积分数范围为0 - 1。作为氧分压函数的测量结果表明，氧化动力学在氧气体积分数（F(O2)）方面不是一级反应。相反，氧化速率在0至0.05之间随F(O2)迅速线性增加，然后在0.05至1之间增加得较慢但仍呈线性。与温度相关的测量结果与涉及两个动力学上可区分的氧化位点的反应途径一致，这两个位点通过热和氧化相互转化。将结果和结论与早期关于烟灰氧化的研究结果进行了比较。
