In the past decades, the proton exchange membrane fuel cell (PEMFC) components, cell/stack designs and system architecture have been significantly improved. However, despite great initial performance, PEMFC systems still suffer technological limitations, such as their initial cost, partly due to the use of expensive Pt-based electrocatalyst, which prevents widespread industrial deployment. Lowering the cathode catalyst loading while keeping high (and durable) catalytic activity has been intensively studied. In this work, low-loaded catalyst layers (20 and 100 µgPt cmgeo−2) are tested in PEMFC differential single-cell (DC) under high reactant stoichiometry to characterize their intrinsic electrochemical properties under various ideal and well-controlled operating conditions of cell temperature (T) and relative humidity (RH). Particularly, the change of the membrane hydration state, via the ohmic resistance measurement, and the Pt-oxides surface coverage are investigated to gather information on the physico-chemical and electrochemical mechanisms involved in the cathode active layer, and the typical performance hysteresis observed during dynamic operation such as polarization curves. These specific electrochemical measurements further enable to build a dataset, that can be used to improve PEMFC models taking into account the complex ORR mechanism, and the role of the Pt oxides in catalyst layer transient operation and degradation.

中文翻译：

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用于质子交换膜燃料电池动态运行的低负载催化剂层第 1 部分：实验研究


在过去的几十年里，质子交换膜燃料电池 （PEMFC） 组件、电池/电堆设计和系统架构得到了显著改进。然而，尽管初始性能出色，但 PEMFC 系统仍然存在技术限制，例如其初始成本，部分原因是使用了昂贵的铂基电催化剂，这阻碍了广泛的工业部署。在保持高（和持久）催化活性的同时降低阴极催化剂负载已经得到了深入的研究。在这项工作中，在高反应物化学计量法下，在 PEMFC 差分单电池 （DC） 中测试了低负载催化剂层 （20 和 100 μgPt cmgeo-2），以表征它们在电池温度 （T） 和相对湿度 （RH） 的各种理想和良好控制的操作条件下的内禀电化学性质。特别是，通过欧姆电阻测量研究膜水合态的变化和 Pt-氧化物表面覆盖率，以收集有关阴极活性层中涉及的物理化学和电化学机制的信息，以及在动态运行期间观察到的典型性能滞后，例如极化曲线。这些特定的电化学测量进一步有助于构建一个数据集，该数据集可用于改进 PEMFC 模型，同时考虑到复杂的 ORR 机制以及 Pt 氧化物在催化剂层瞬态操作和降解中的作用。