Decalin is considered as an important compound of high-energy-density endothermic fuel, which is an ideal on-board coolant for thermal management of advanced aircraft. However, decalin contains two isomers with a tunable composition, and their effects on the pyrolysis performance, such as the heat sink and coking tendency have not been demonstrated. Herein, we investigated the pyrolysis of decalin isomers, i.e., cis-decalin, trans-decalin and their mixtures (denoted as mix-decalin), in order to clarify the effects of the cis-/trans-structures on the pyrolysis performance of decalin fuels. The pyrolysis results confirmed that conversion of the tested fuels (600–725 °C, 4 MPa) decreased in the order cis-decalin > mix-decalin > trans-decalin. Detailed analyses of the pyrolysis products were used to compare the product distributions from cis-decalin, mix-decalin and trans-decalin, and the yields of some typical components (such as cyclohexene, 1-methylcyclohexene, benzene and toluene) showed significant differences, which could be ascribed to deeper cracking of cis-decalin. Additionally, the heat sinks and coking tendencies of the decalins decreased in the order cis-decalin > mix-decalin > trans-decalin. This work demonstrates the relationship between the cis/trans structures and the pyrolysis performance of decalin, which provides a better understanding of the structure-activity relationships of endothermic hydrocarbon fuels.

十氢萘被认为是高能量密度吸热燃料的重要化合物，是先进飞机热管理的理想机载冷却剂。然而，十氢萘含有两种组成可调的异构体，它们对热解性能（例如散热和结焦倾向）的影响尚未得到证实。在此，我们研究了十氢萘异构体，即顺式十氢萘、反式十氢萘及其混合物（表示为混合十氢萘）的热解，以阐明顺式/反式结构对十氢萘热解性能的影响。燃料。热解结果证实，测试燃料的转化率（600–725 °C，4 MPa）按顺式十氢化萘 >混合十氢化萘 >反式十氢化萘的顺序降低。通过对热解产物的详细分析，比较了顺式十氢化萘、混合十氢化萘和反式十氢化萘的产物分布，一些典型组分（如环己烯、1-甲基环己烯、苯和甲苯）的产率表现出显着差异。这可能归因于顺式十氢化萘的更深裂解。此外，十氢化萘的散热和结焦倾向按顺式十氢化萘>混合十氢化萘>反式十氢化萘的顺序降低。这项工作证明了十氢萘的顺式/反式结构与热解性能之间的关系，这有助于更好地理解吸热烃燃料的结构-活性关系。