结构化气液接触器中界面稳定性的相场模拟：气体扩散电极的设计规则
Phase-field simulation of interfacial stability in structured gas-liquid contactors: design rules for gas diffusion electrodes
- Technische Universität Darmstadt（达姆施塔特工业大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过相场模拟量化结构化介质形状、润湿性和拓扑对气液界面稳定窗口的影响，发现拉长孔口可提升压力差和刚度，并据此提出气体扩散电极的设计规则。
AI中文摘要：
许多过程工程应用通过控制压力差将气液界面保持在结构化固体内部。气体扩散电极（GDEs）就是这样一个案例，其中界面将液体电解质与气态反应物分隔开。在有机电合成中维持这一界面尤其具有挑战性，因为低表面张力降低了整个过程中的允许压力，而小接触角使电极几乎没有防淹的余量。在此，我们利用Cahn-Hilliard-Navier-Stokes方程的相场模拟，量化了结构化介质的形状、润湿性和三维拓扑如何设定这一窗口。每个几何体都通过其Laplace压力曲线来表征，该曲线既给出了最大允许压力差，也给出了界面抵抗压力波动的刚度。对于恒定开口面积的单个平面孔口，将开口从纵横比1拉长到6，可使允许压力差提高40%，刚度提高3.3倍。与等宽狭缝的比较表明，这一增益完全源于开口宽度的减小。剪切变形、菱形开口的效果明显较差。在编织网中，润湿性使操作窗口的位移幅度是拉伸幅度的数倍。因此，较不润湿的表面在很大程度上以突破余量为代价换取了防淹余量，而几何路线（此处针对平面开口建立）则拓宽了窗口本身。根据这些结果，我们为结构化气液接触器和改进的有机电合成GDE架构推导出了设计规则。
英文摘要：
Many process engineering applications hold a gas-liquid interface stationary inside a structured solid by a controlled pressure difference. Gas diffusion electrodes (GDEs) are one such case, where the interface separates the liquid electrolyte from the gaseous reactant. Maintaining it is particularly challenging in organic electrosynthesis, where low surface tensions lower the admissible pressures throughout and small contact angles leave the electrode with little margin against flooding. Here, we quantify how the shape, wettability, and three-dimensional topology of a structured medium set this window, using phase-field simulations of the Cahn-Hilliard-Navier-Stokes equations. Each geometry is characterised by its Laplace pressure curve, which yields both the maximum admissible pressure difference and the stiffness of the interface against pressure fluctuations. For single flat orifices at constant open area, elongating the opening from an aspect ratio of one to six raises the admissible pressure difference by 40 % and the stiffness by a factor of 3.3. Comparison with slits of equal width shows that this gain originates entirely from the reduced opening width. Sheared, diamond shaped openings are markedly less effective. In woven meshes, the wettability displaces the operating window several times as far as it stretches it. A less wetting surface therefore buys flooding margin largely at the expense of breakthrough margin, whereas the geometric route, established here for flat openings, widens the window itself. From these results we derive design rules for structured gas-liquid contactors and improved GDE architectures for organic electrosynthesis.
