Pyrolytic coking of endothermic hydrocarbon fuel (EHFs) is a critical issue for the regenerative cooling channels of advanced engines. This work focuses on the development and evaluation of bifunctional CeO₂/Al₂O₃ coatings for coke inhibition and catalytic removal from the inner surfaces of GH3128 alloy tubes. The CeO₂/Al₂O₃ coating prepared by in-situ grown strategy presents superior bonding strength and thermal stability due to its unique bilayer structure, in which pyramidal Al₂O₃ nanocones densely cover substrate surface as an intermediate layer and utilize their gaps to immobilize the CeO₂ to decrease decoking temperature. The performance of coating was evaluated by supercritical pyrolysis and decoking cycles using EHFs. Compared to bare tubes whose cokes amount increased by 40.5% throughout three cycles, the bifunctional coatings suppress deteriorating coking behavior by inhibiting the migration of Ni-species to the interface, improving the inhibition rate from 37.2% to 53.9%.

中文翻译：

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双官能 CeO2/Al2O3 涂层，用于抑制和催化去除航空燃料的热解焦炭


吸热烃燃料 （EHF） 的热解焦化是先进发动机蓄热式冷却通道的一个关键问题。这项工作的重点是开发和评价双功能 CeO ₂ /Al ₂ O ₃ 涂层对 GH3128 合金管内表面的焦炭抑制和催化去除作用。采用原位生长策略制备的 CeO ₂ /Al ₂ O ₃ 涂层由于其独特的双层结构而具有优异的粘合强度和热稳定性，其中金字塔形 Al ₂ O ₃ 纳米锥作为中间层密集地覆盖衬底表面，并利用其间隙固定 CeO ₂ 以降低除焦温度。通过使用 EHF 的超临界热解和除焦循环来评估涂层的性能。与裸管的焦炭量在 3 个循环中增加了 40.5% 相比，双功能涂层通过抑制 Ni 物种向界面的迁移来抑制恶化的焦化行为，将抑制率从 37.2% 提高到 53.9%。