Degradation of Membrane Electrode assemblies utilizing PtRu catalysts under high potential conditions

We investigated the degradation of membrane electrode assemblies (MEAs) utilizing PtRu catalysts by way of an accelerated anode degradation test (anode potential cycling) that simulated localized fuel starvation. We predicted that anode potential would be high (approx. 1.4 V vs. RHE) when localized fuel starvation occurred during start-up of the stack. Although the dissolution of Ru in the anode increased with increasing upper potential limits in anode potential cycling that simulated localized fuel starvation, the Ru crossover from anode to cathode and Ru deposition in the cathode reached a maximum at an upper potential limit of 1.2 V. In addition, we investigated a method for restoring the performance of MEAs deteriorated by Ru deposition. With this method more than 90% of cathode performance (H₂-O₂ voltage) and 79% of H₂-Air voltage can be recovered.