Degradation phenomena of fuel cells components can be classified in three

categories: mechanical, chemical or thermal degradation. Which of the following

describes the effects of chemical degradation? $($Select all correct answers$)(15$p$)$

a$.$ Formation of cracks, tears, punctures, pinholes, and delamination

b$.$ Catalyst activity losses and decrease in conductivity, which results in aging

c$.$ Severe dehydration of the membrane's polymer material, increasing the

ohmic losses and alter the mechanical strength of the membrane

d$.$ Polymer decomposition, catalyst poisoning, surface oxidation, and

corrosion