1. Introduction / Haijiang Wang, Hui Li, and Xiao-Zi Yuan -- 2. Catalyst degradation / Shengsheng Zhang, Xiao-Zi Yuan, and Haijiang Wang -- 3. Catalyst support degradation / Zhongwei Chen and Ryan Hsu -- 4. Membrane degradation / Yinghao Luan and Yongming Zhang -- 5. Porous transport layer degradation / Walter Merida -- 6. Degradation of bipolar plates and its effect on PEM fuel cells / Lars Kuhnemann. [et al.] -- 7. Degradation of other components / Daijun Yang. [et al.] -- 8. Contaminant-induced degradation / Olga A. Baturina. [et al.] -- 9. Environment-induced degradation / Eric Pinton, Sebastien Rosini, and Laurent Antoni -- 10. Operation-induced degradation / Pucheng Pei -- 11. Design-related durability issues / Kui Jiao and Xianguo Li.