Oxyfunctionalization of linear alkanes is important but challenging to achieve. Herein, we demonstrate a biphasic gas–liquid modular plasma microreactor utilizing Ar/O₂ gas to selectively oxidize liquid n-dodecane (C₁₂) in an electrified, catalyst-free fashion. C₁₂ secondary alcohols and ketones are the major products, with selectivities of 45–60% and a maximum yield of 23%. Fine-tuning gas and liquid flow rates enhance the plasma–liquid interfacial area, leading to a conversion of >50%. Difunctional and oligomerized oxygenates, alongside lighter hydrocarbons stemming from carbon–carbon cleavage, form at higher conversions. The energy efficiency (0.189 μmol/J) of the modular microreactor is the highest reported among plasma systems. Alkane conversion can be further improved by increasing the length of the plasma region while maintaining excellent energy efficiencies. Similarly, sequential processing/recirculation can enhance the extent of the reaction. This system is also amenable to treating mixtures of liquid n-alkanes, where smaller hydrocarbons are oxidized preferentially to a certain extent. The vapor pressure and liquid temperature are the key parameters. The chemistry occurs primarily in the gas phase for the lighter hydrocarbons and switches to interfacial reactions for the larger ones.

中文翻译：

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用于液态烃氧官能化的双相等离子体微反应器


直链烷烃的氧官能化很重要，但实现起来具有挑战性。在此，我们展示了一种双相气液模块化等离子体微反应器，利用 Ar/O ₂ 气体以带电、无催化剂的方式选择性氧化液体正十二烷 (C ₁₂ )。主要产品为C ₁₂ 仲醇和酮，选择性为45%~60%，最高产率为23%。微调气体和液体流速可增强等离子体-液体界面面积，从而实现 >50% 的转化率。双官能团和低聚含氧化合物以及源自碳-碳裂解的较轻烃在较高转化率下形成。模块化微反应器的能量效率（0.189 μmol/J）是等离子体系统中报道最高的。通过增加等离子体区域的长度可以进一步提高烷烃转化率，同时保持优异的能量效率。类似地，连续处理/再循环可以增强反应程度。该系统还适合处理液态正烷烃的混合物，其中较小的烃在一定程度上优先被氧化。蒸气压和液体温度是关键参数。对于较轻的碳氢化合物，化学反应主要发生在气相中，而对于较大的碳氢化合物，化学反应则转向界面反应。