In-situ electrochemical degradation of anion exchange membranes

The degradation mechanisms of anion exchange membranes (AEMs) used in fuel cells, are of growing interest. To develop new, higher-performance AEMs, understanding of the molecular changes that occur during electrochemical aging must be studied. Spectroelectrochemical studies are useful because they combine insights from traditional electrochemical techniques with molecular information from spectroscopy. Additionally, spectroelectrochemical measurements facilitate comparison of these experiments with what might be happening to the polymer at the electrochemical interface during fuel cell operation. A double electrode channel flow cell was developed and outfitted with an optical window to allow the collection of Raman spectra while the potential, temperature, and flow conditions in the cell are varied. In initial experiments on AEMs, degradation was detected after 20 h at 80 °C as evidenced by the formation of carbonyl groups. Results will be reported for experiments at different temperatures and potentials and detailed degradation sites for AEMs will be reported.