Numerical investigation on the discharge formation in micrometer pores in structured catalyst irradiated by a helium atmospheric pressure plasma jet
Numerical investigation on the discharge formation in micrometer pores in structured catalyst irradiated by a helium atmospheric pressure plasma jet
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DOI：
10.1088/1361-6595/ad208f
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发表时间：
2024-01
影响因子：
3.8
通讯作者：
Wenjun Ning;Shang Hao;Xueming Shen;Saikang Shen;Xiaolong Huang;Zhao Lihua;Shenli Jia
中科院分区：
文献类型：
--
作者：
Wenjun Ning;Shang Hao;Xueming Shen;Saikang Shen;Xiaolong Huang;Zhao Lihua;Shenli Jia
非热等离子体催化在能量转换和化学工程等领域具有很高的应用前景。虽然等离子体和催化剂之间的协同作用已被初步认为是这类催化的潜在机制，但在小尺寸催化剂孔中形成放电，这可能是等离子体活化催化的关键因素，但尚未得到很好的理解。本文采用二维流体模型研究了氦大气压等离子体射流（APPJ）与不同形状和大小微米孔径催化剂之间的相互作用。模拟结果表明，孔隙的存在通过改变等效电容对APPJ产生微妙的影响，表明APPJ-催化剂之间有实现适度稳定相互作用的潜力。氦气中微量的空气杂质可以促进催化剂孔隙中的放电，从而允许在较小的孔隙中形成放电。在催化剂通道太小而无法直接穿透APPJ的情况下，我们提出了一种方法，即在相对较大的腔内产生先验放电，以提供种子电子点燃通道内的放电。从放电行为和等离子体表面相互作用的角度讨论了通道和腔体尺寸的影响。这项工作将有助于制备结构催化剂，以潜在地实现更高效率的等离子体催化，并更好地理解微米孔内等离子体表面相互作用的物理过程。
Non-thermal plasma catalysis is a promising way to achieve high efficiency in applications such as energy conversion and chemical engineering. Although synergistic effects between plasmas and catalysts have been preliminarily considered as an underlying mechanism of this type of catalysis, the formation of discharges in small-size catalyst pores, which is possibly a crucial factor in plasma-activated catalysis, is still not well understood. In this paper, investigations on the interactions between a helium atmospheric pressure plasma jet (APPJ) and catalysts with micrometer-sized pores of different shapes and sizes are conducted with a 2D fluid model. Simulation results show that the existence of pores makes a subtle difference to the APPJ by changing the equivalent capacitance, indicating the potential to achieve moderate and stable APPJ-catalyst interactions. Traces of air impurities in helium can promote discharges in catalyst pores, and thus allow discharges to form in smaller pores. In the case when the catalyst channel is too small for direct APPJ penetration, we propose a method by producing a prior discharge in a relatively large cavity to supply seed electrons to ignite discharges inside the channel. The effects of channel and cavity sizes are discussed from the perspectives of discharge behavior and plasma-surface interactions. This work will contribute to the preparation of structured catalysts to potentially achieve higher efficient plasma catalysis, and better understanding of the physical processes in plasma-surface interactions inside micrometer pores.