This paper describes new methods to characterize the hydraulic behavior of porous transport layers (PTL) by using capillary flow porometry (CFP). We present the standard procedure of CFP to gain access to the biggest pore, the mean flow pore and the smallest pore size as well as the absolute through-plane gas permeability of PTLs. An extended method is introduced to measure the relation of capillary pressure versus liquid saturation. It is shown that capillary pressure has a significant influence on mass transport limitation (MTL) in PEM electrolysis cells using a flow field. Furthermore, a new method is proposed to measure the intrinsic contact angle of PTLs by using water and a reference liquid with a contact angle of zero. It is shown that knowing the pore size distribution and the contact angle is essential for studying the influence on capillary pressure. In the course of this study results of CFP are compared to results from mercury porosimetry. We prove that the contact angle is strongly influenced by the titanium oxide layer which forms during electrolysis operation due to electrochemical oxidation of titanium. In summary, we propose a simple key parameter that describes the ability of partially saturated PTLs to transport gas in through-plane direction, termed gas transportability. The latter is introduced and employed to analyze polarization curves of different PTLs.

本文介绍了使用毛细管流孔法（CFP）表征多孔传输层（PTL）的水力行为的新方法。我们提出了CFP的标准程序，以获取PTL的最大孔，平均流量孔和最小孔径以及绝对平面通气率。引入了扩展方法来测量毛细管压力与液体饱和度之间的关系。结果表明，毛细管压力对使用流场的PEM电解池中的质量迁移限制（MTL）具有重大影响。此外，提出了一种新方法，该方法通过使用水和接触角为零的参考液体来测量PTL的固有接触角。结果表明，了解孔径分布和接触角对于研究对毛细管压力的影响至关重要。在本研究过程中，将CFP的结果与汞孔隙率法的结果进行了比较。我们证明，接触角受钛电解氧化过程中形成的氧化钛层的强烈影响。总之，我们提出了一个简单的关键参数，该参数描述了部分饱和的PTL在整个平面方向上传输气体的能力，称为气体传输能力。引入后者，并用于分析不同PTL的极化曲线。我们证明，接触角受钛电解氧化过程中形成的氧化钛层的强烈影响。总之，我们提出了一个简单的关键参数，该参数描述了部分饱和的PTL在整个平面方向上传输气体的能力，称为气体传输能力。引入后者，并用于分析不同PTL的极化曲线。我们证明，接触角受钛电解氧化过程中形成的氧化钛层的强烈影响。总之，我们提出了一个简单的关键参数，该参数描述了部分饱和的PTL在整个平面方向上传输气体的能力，称为气体传输能力。引入后者，并用于分析不同PTL的极化曲线。