Zhou Zi-Kai, Li Shu-Qi, Chen Chao-Jun, Li Yao, Wen Xiao-Qiong, Yang De-Zheng
Key Lab of Materials Modification by Laser, Ion, and Electron Beams Dalian University of Technology, Ministry of Education, Dalian 116024, People's Republic of China.
Phys Chem Chem Phys. 2025 Jul 2;27(26):14015-14028. doi: 10.1039/d5cp01500f.
The environmental and energy challenges associated with the Haber-Bosch nitrogen fixation process present significant ecological concerns. In contrast, low-temperature plasma technology has emerged as a highly promising alternative for nitrogen fixation, capable of converting air to NO and producing NO in the liquid phase using only electrical energy. In this study, nanosecond pulsed power is employed to drive an underwater microporous coaxial reactor, generating bubble spark discharges for the efficient synthesis of NO in water. The variation in the concentration of gas-liquid two-phase products is systematically investigated by adjusting key parameters, including pulse voltage, gas flow rate, and gas composition. Optimal nitrogen fixation is achieved at a rate of 153 μmol min, with energy consumption as low as 4.93 MJ mol for gas-liquid nitrogen fixation products. Results indicated that increasing the pulse voltage enhanced the NO yield, promoting the formation of HNO and NO. However, excessive air flow rates reduced nitrogen fixation efficiency due to inadequate activation and decreased mass transfer efficiency. The addition of an optimal O ratio significantly improved the NO yield. Plasma emission spectroscopy and energy loss pathway analysis are employed to investigate the formation mechanisms of gas-phase reactive species, and potential reactions in the liquid phase are explored through modifications in reactor design. This work provides valuable insights into the regulation of gas-liquid two-phase product formation, highlighting the impact of the controlled parameters on nitrogen fixation performance.
哈伯-博施法固氮过程所带来的环境和能源挑战引发了重大的生态问题。相比之下，低温等离子体技术已成为一种极具前景的固氮替代方法，它能够仅利用电能将空气转化为一氧化氮并在液相中生成一氧化氮。在本研究中，采用纳秒脉冲电源驱动水下微孔同轴反应器，产生气泡火花放电以在水中高效合成一氧化氮。通过调整包括脉冲电压、气体流速和气体组成等关键参数，系统地研究了气液两相产物浓度的变化。气液固氮产物的最佳固氮速率为153 μmol/min，能量消耗低至4.93 MJ/mol。结果表明，增加脉冲电压可提高一氧化氮产率，促进亚硝酸和一氧化氮的形成。然而，过高的空气流速会因活化不足和传质效率降低而降低固氮效率。添加最佳的氧比例可显著提高一氧化氮产率。利用等离子体发射光谱和能量损失途径分析来研究气相活性物种的形成机制，并通过改进反应器设计探索液相中的潜在反应。这项工作为气液两相产物形成的调控提供了有价值的见解，突出了控制参数对固氮性能的影响。
