Nonequilibrium plasma has a great potential in the lean combustion of gasoline engines. However, fundamental studies on plasma‐assisted combustion on gasoline components are limited. In the present study, Low‐temperature oxidation behaviors for n‐heptane and iso‐octane in a plasma flow reactor were investigated. Species measurements were performed at room temperature and low pressure of 40 mbar using the electron ionization molecular‐beam mass spectrometry (EI‐MBMS). A total of 72 and 57 species were quantified in n‐heptane and iso‐octane oxidation, respectively. Based on measured species data, reaction networks of n‐heptane and iso‐octane in the plasma system were discussed. Particularly, some typical low‐temperature intermediates, such as cyclic ethers, diones, and ketohydroperoxides, were observed, suggesting the applicability of the classical low‐temperature reaction scheme in the plasma system of large hydrocarbons. The results indicate that the major role of plasma discharge on the low‐temperature oxidation of large hydrocarbons is either to breakdown large fuel molecules or to accelerate the chain initiation reactions. We also investigated the parametric effects of voltage, frequency, and residence time on the species pools, and found that the increase of these parameters leads to higher production of intermediates. The whole system reactivity was most sensitive to the plasma voltage. The difference between plasma frequency and residence time on the species formation was found. Moreover, some highly temperature‐sensitive reactions, such as the RO₂ → QOOH, proceed at very low temperatures (around 340 K) in the plasma system, which was potentially attributed to the additional energy from plasma‐generated species.

中文翻译：

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MBMS研究流动反应器中正庚烷和异辛烷的等离子体辅助低温氧化

非平衡等离子体在汽油发动机的稀薄燃烧中具有巨大的潜力。但是，有关等离子辅助燃烧汽油成分的基础研究有限。在本研究中，对于低温氧化行为Ñ庚烷和异辛烷在等离子体流反应器进行了研究。使用电子电离分子束质谱（EI-MBMS）在室温和40 mbar的低压下进行物种测量。正庚烷和异辛烷氧化分别量化了72种和57种。根据测得的物种数据，n的反应网络讨论了等离子体系统中的庚烷和异辛烷。特别是，观察到一些典型的低温中间体，例如环醚，二酮和酮基氢过氧化物，这表明经典的低温反应方案在大烃的等离子体系统中的适用性。结果表明，等离子放电对大型烃的低温氧化的主要作用是破坏大型燃料分子或促进链引发反应。我们还研究了电压，频率和停留时间对物种库的参数影响，并发现这些参数的增加导致中间体产量更高。整个系统的反应性对等离子体电压最敏感。发现等离子体频率和停留时间对物种形成的差异。此外，一些对温度敏感的反应，例如反渗透₂ →QOOH，在极低的温度（约340 K）下在等离子体系统中进行，这可能归因于等离子体产生的物种产生的额外能量。