Electrochemically active surface area (ECSA) loss is the main cause of proton exchange membrane fuel cell performance degradation. It involves interactions between kinetics of Pt particle size distribution (PSD) and several degradation mechanisms, including particle dissolution, redeposition, coagulation and detachment from carbon support. A population balance equation was established to relate the PSD evolutions with the loss of ECSA. Dimensionless Damköhler numbers (, , ) were defined to characterize the relative magnitudes between different degradation rates. Systematic studies revealed the dimensionless transition criterions form dissolution limit to other degradation modes. Sensitivity analysis indicated the redisposition rate and dissolution rate were the two most influential parameters. The initial parameters, rather than the initial function type of the unimodal distribution, is the dominating factors for PSD degradation process. This study provides theoretical foundation for optimization of catalyst layer design and durability.

中文翻译：

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基于群体平衡方程的质子交换膜燃料电池Pt/C催化剂粒径分布退化模型


电化学活性表面积（ECSA）损失是质子交换膜燃料电池性能下降的主要原因。它涉及 Pt 粒径分布 (PSD) 动力学与多种降解机制之间的相互作用，包括颗粒溶解、再沉积、凝结和与碳载体的分离。建立了种群平衡方程，将 PSD 演变与 ECSA 损失联系起来。定义无量纲 Damköhler 数 (, , ) 来表征不同降解率之间的相对大小。系统研究揭示了对其他降解模式形成溶解极限的无量纲转变标准。敏感性分析表明再处置率和溶解率是两个最有影响的参数。初始参数，而不是单峰分布的初始函数类型，是 PSD 退化过程的主导因素。该研究为催化剂层设计和耐久性的优化提供理论基础。