An Experimental Setup for Measuring Mass Transport in Micro-Capillaries and Fuel Cell Electrodes

由于质量传输的限制，估计目前聚合物电解质燃料电池电极中只有10-20%的铂被利用。降低电极中铂的含量将大大降低燃料电池的成本，这是成功实现燃料电池商业化的最后障碍之一。然而，人们对燃料电池电极和多孔介质中的质量传递知之甚少。在过去的十年中，至少有三种新的数学模型被提出用于分析质量输运，如二元摩擦模型。此外，用于将燃料电池电极特性（例如孔隙率和孔径分布）与其有效扩散系数（即表征质量传递的常数）联系起来的方程，如Bruggeman方程，已被证明对有效扩散系数的预测超出了四倍以上。因此，为了准确地表征电极的传质特性，仍然需要进行实验测量。然而，阿尔伯塔大学目前还没有一个测量电极和多孔材料中质量传输的实验装置。

Due to mass transport limitations, it is estimated that only 10-20% of the platinum in polymer electrolyte fuel cell electrodes is currently utilized. Lowering the amount of platinum in the electrodes would substantially reduce the cost of fuel cells, one of the last remaining hurdles to successful fuel cell commercialization. Mass transport in fuel cell electrodes, and porous media, is however poorly understood. In the past decade, at least three novel mathematical models for analyzing mass transport have been proposed such as the binary friction model. Further, equations used to link fuel cell electrode properties (e.g., porosity and pore size distribution) to its effective diffusivity (i.e., a constant that characterizes mass transport), such as Bruggeman equation, have been shown to over predict effective diffusivity by more than a factor of four. Therefore, in order to accurately characterize the electrode's mass transport properties, experimental measurements are still required. However, an experimental setup to measure mass transport in electrodes and porous materials is not currently available at the University of Alberta.