While it is well documented iron oxide can reduce soot through burnout in the oxidative regions of flames, it may also impact molecular growth and particle inception. The role of Fe2O3 nanoparticles in mass growth of soot from 1-methylnapthalene (1-MN) was studied in a dual-zone, high-temperature flow reactor. An iron substituted, dendrimer template was oxidized in the first zone to generate ~5 nm Fe2O3 nanoparticles, which were seeded into the second zone of the flow reactor containing 1-MN at 1100°C and ϕ = 1.4-5.0. Enhanced molecular growth in the presence of Fe2O3 nanoparticles resulted in increased yields of polycyclic aromatic hydrocarbons (PAH) and soot compared to purely gas-phase reactions of 1-MN at identical fuel-air equivalence ratios. This also resulted in an increase in soot-number concentration and a slight shift to smaller particles with increasing addition (from no addition to 3 mM) of Fe2O3. Introduction of Fe2O3 nanoparticles resulted in the formation of stabilization of environmentally persistent free radicals (EPFRs), including benzyl, phenoxyl, or semiquinone-type radicals as well as carbon-centered radicals, such as cyclopentadienyl or a delocalized electron in a carbon matrix. At the high concentrations in the flow reactor, these resonance-stabilized free radicals can undergo surface-mediated, radical-radical, molecular growth reactions which may contribute to molecular growth and soot particle inception.

中文翻译：

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Fe2O3 纳米颗粒介导 1-甲基萘氧化热解的分子生长和烟灰产生。


虽然有充分证据表明，氧化铁可以通过火焰氧化区域的燃尽来减少烟灰，但它也可能影响分子生长和颗粒形成。在双区高温流动反应器中研究了 Fe2O3 纳米颗粒在 1-甲基萘 (1-MN) 烟灰质量生长中的作用。铁取代的树枝状聚合物模板在第一个区域中被氧化，生成约 5 nm Fe2O3 纳米颗粒，将其接种到含有 1-MN 的流动反应器的第二个区域中，温度为 1100°C，φ = 1.4-5.0。与相同燃料-空气当量比下 1-MN 的纯气相反应相比，Fe2O3 纳米颗粒存在下分子生长的增强导致多环芳烃 (PAH) 和烟灰的产量增加。随着 Fe2O3 添加量的增加（从不添加到 3 mM），这也导致烟灰数浓度增加并轻微转向较小的颗粒。 Fe2O3 纳米粒子的引入导致环境持久性自由基 (EPFR) 的稳定形成，包括苄基、苯氧基或半醌型自由基以及碳中心自由基，例如环戊二烯基或碳基质中的离域电子。在流动反应器中的高浓度下，这些共振稳定的自由基可以经历表面介导的自由基-自由基分子生长反应，这可能有助于分子生长和烟灰颗粒的形成。