Hydrocarbon Proton Exchange Membranes for Fuel Cells: An Antioxidant Study

High Resolution Image Download MS PowerPoint Slide In fuel cells, hydrocarbon proton exchange membranes (HC PEMs) suffer from insufficient chemical stability caused by oxidative aging, hampering their commercial viability. Using sulfonated poly(ether ether ketone) as a model HC PEM, we conduct a first-of-its-kind systematic screening of relevant antioxidants, combining ex situ Fenton tests and in situ fuel cell tests. Ionic additives based on cerium, as well as phosphonic-acid-derived (12-phosphonododecyl)phosphonic acid (PDPA), are found to significantly increase membrane lifetime. While ionic additives impart a performance penalty, PDPA proves to be not only an effective antioxidant but also benign regarding cell performance, revealing its potential for use in HC PEMs.