Flow-induced viability for sintered titanium fiber felt as anodic porous transport layer in proton exchange membrane water electrolyzer

The performance and durability of proton exchange membrane water electrolysis (PEMWE) are influenced not only by the intrinsic properties of components but also by various operational conditions. The porous transport layer (PTL), a key component in water management, has received limited research attention regarding its flow-induced degradation, particularly from a corrosion perspective. Due to the inherent challenges of in situ characterization, this study systematically investigates the degradation of sintered titanium fiber felt under ex-situ conditions, replicating flowing PEMWE anodic environment as closely as possible. The results demonstrate that increasing stirring speeds significantly improves corrosion resistance, as evidenced by reduced irregular corrosion during potentiodynamic polarization. This improvement is primarily attributed to enhanced passivation — facilitated by accelerated point defects dynamics and incorporation of reactive species—which overweights the dissolution effect associated with increased F− concentration. During potentiostatic polarization, a higher current response and fewer current transients under increasing stirring speeds indicate a more intensified passivation process. Notably, the passive film formed under the static condition exhibits stronger F− adsorption, which is mitigated under stirring conditions.