Abstract Thermal oxidation stability is a key issue for jet fuel when serving as a coolant in aircraft. However, the deposition propensity and mechanism of hydrocarbons with different molecule structures remain ambiguous. In this study, the oxidation stability and deposition propensity of C10 hydrocarbon fuels, i.e., tetralin, cis-/trans-decalin, exo-tetrahydrodicyclopentadiene (exo-THDCPD), and n-decane, were determined. The oxidation stability of hydrocarbons follows the order of n-decane > exo-THDCPD > trans-decalin > cis-decalin > tetralin, which is highly associated with the molecular-structure-dependent C–H bond dissociation enthalpy. Differently, the deposition propensity follows the order of trans-decalin > exo-THDCPD > n-decane > cis-decalin > tetralin, which can be associated with the stability of oxidation intermediates, especially the hydroperoxides. The more stable the intermediates are, the fewer deposits will be produced. These results demonstrate the relationship between thermal oxidation stability and hydrocarbon molecular structure, which is helpful for a better understanding of jet fuel deposition mechanism.

中文翻译：

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C10 碳氢燃料热氧化沉积的机理研究

摘要 热氧化稳定性是喷气燃料作为飞机冷却剂的关键问题。然而，具有不同分子结构的碳氢化合物的沉积倾向和机理仍然不明确。在这项研究中，测定了 C10 烃燃料的氧化稳定性和沉积倾向，即四氢萘、顺式/反式萘烷、外型四氢二环戊二烯 (exo-THDCPD) 和正癸烷。碳氢化合物的氧化稳定性遵循正癸烷> exo-THDCPD > 反式十氢化萘> 顺式十氢化萘> 萘满的顺序，这与依赖于分子结构的C-H 键解离焓高度相关。不同的是，沉积倾向遵循反式十氢化萘> exo-THDCPD > 正癸烷> 顺式十氢化萘> 萘满，这可能与氧化中间体的稳定性有关，尤其是氢过氧化物。中间体越稳定，产生的沉积物就越少。这些结果证明了热氧化稳定性与烃分子结构之间的关系，有助于更好地理解喷气燃料沉积机理。