Abstract The oxidation of di-n-butyl-ether (DBE) was performed in a jet-stirred reactor (JSR) at 1 atm, 520 and 530 K, and from 480 to 670 K at 10 atm, at a residence time of 1 s, an equivalence ratio of 0.5, and an initial fuel concentration of 5000 ppm. Ignition experiments on DBE/air mixtures were also performed in a rapid compression machine (RCM) under stoichiometric conditions, 5 bar, and from 550 to 630 K. Low-temperature products formed in JSR and RCM experiments were characterized. To this end, high-resolution mass spectrometry analyses (HRMS) with flow injection analyses or ultra-high pressure liquid chromatography coupling were used to characterize hydroperoxides and diols (C8H18O3), ketohydroperoxides (C8H16O4), carboxylic acids (C2H4O2, C3H6O2, C4H8O2), di-keto ethers (C8H14O3), and highly oxygenated molecules (C8H14O5, C8H16O6, C8H14O6, C8H14O7, C8H16O8, and C8H14O9) resulting from up to five O2 additions on fuel's radicals. Whereas HOMs are of minor importance in combustion, they are considered key species for the formation of secondary organic aerosols. In addition, cyclic ethers and esters (C8H16O2) were observed. Heated electrospray and atmospheric pressure chemical ionizations (HESI and APCI) were used in positive and negative modes for MS analyses. H/D exchange with D2O was used to confirm the presence of –OH or –OOH groups in the products. The present results show that DBE oxidation proceeds similarly under JSR and RCM conditions. Whereas the CH2 groups neighboring the ether group are the most favorable sites for H-atom abstraction reactions, speciation indicated that other sites can react by metathesis forming a large pool of intermediates and products. Our kinetic reaction mechanism needs to be extended for simulating the formation of newly detected species.

中文翻译：

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二正丁基醚的氧化：JSR 和 RCM 中低温产物的实验表征

摘要 二正丁基醚 (DBE) 在喷射搅拌反应器 (JSR) 中于 1 atm、520 和 530 K 以及 480 至 670 K、10 atm、停留时间为 1 s，当量比为 0.5，初始燃料浓度为 5000 ppm。DBE/空气混合物的点火实验也在快速压缩机 (RCM) 中在化学计量条件、5 bar 和 550 至 630 K 下进行。表征在 JSR 和 RCM 实验中形成的低温产物。为此，使用流动注射分析或超高压液相色谱耦合的高分辨率质谱分析 (HRMS) 来表征氢过氧化物和二醇 (C8H18O3)、酮氢过氧化物 (C8H16O4)、羧酸 (C2H4O2、C3H6O2、C4H8O2) 、二酮醚 (C8H14O3) 和高度氧化的分子 (C8H14O5、C8H16O6、C8H14O6、C8H14O7、C8H16O8 和 C8H14O9）是由燃料自由基上最多五个 O2 添加产生的。尽管 HOM 在燃烧中不太重要，但它们被认为是形成二次有机气溶胶的关键物质。此外，还观察到环醚和酯 (C8H16O2)。加热电喷雾和大气压化学电离（HESI 和 APCI）用于 MS 分析的正负模式。H/D 与 D2O 交换用于确认产品中是否存在 –OH 或 –OOH 基团。目前的结果表明，DBE 氧化在 JSR 和 RCM 条件下类似地进行。尽管与醚基相邻的 CH2 基团是最有利于 H 原子提取反应的位点，但物种形成表明其他位点可以通过复分解反应形成大量中间体和产物。