Corrosion behavior of two bipolar plate materials in simulated PEMFC environment by electrochemical noise technique

The corrosion behavior of 316L stainless steel (316L) and bulk amorphous Zr₇₅Ti₂₅ (AB) alloy was studied using electrochemical noise (EN) in simulated polymer electrolyte membrane fuel cell (PEMFC) conditions at 25 and 80 °C. At open circuit potential, under H₂ environment, AB exhibited a higher corrosion-resistance than 316L and the contrary was observed under O₂ environment. At imposed cathodic potential, under H₂ environment for PEMFC anodic simulation, the reduction mechanism of 316L at 80 °C gave the most important EN signals of all other conditions. At imposed anodic potential, under O₂ environment for cathodic simulation, the passive state was observed for 316L while severe localized corrosion for AB was obvious at 80 °C. It is concluded from the corrosion data of this work that in the anode environment of a PEMFC, the AB alloy could be a better candidate than 316L for bipolar plates. The contrary was observed in the simulated cathode environment.