Impact of Polymer Electrolyte Membrane Degradation Products on the Activity of the Oxygen Reduction Reaction for Platinum Catalysts

Cyclic voltammetry (CV) utilizing a rotating disk electrode was used in order to investigate the potential impact on electrochemical performance of platinum catalysts in the presence of perfluorinated model compounds representing polymer electrolyte membrane degradation products. Under the experimental conditions tested, it was found that the carboxylic acid functional group caused an impact on catalyst electrochemical surface area whereas the sulfonic acid functional group did not. However, neither produced a direct impact on the oxygen reduction reaction (ORR). Performance effects on the ORR were observed for two model compounds each containing both sulfonic and carboxylic acid functionalities indicating that processes other than direct adsorption due to either chemical functionality are occurring at the electrode/solution interface.