Thin-film ionomers, pivotal in the function of fuel-cell catalyst layers (CLs), are undercharacterized compared to their bulk membrane counterparts, especially with respect to cation effects. Cerium cations, used as an additive in fuel-cell membranes, tend to migrate from the membrane into the CL ionomer during operation. This study investigates whether cerium doping of perfluorinated sulfonic acid ionomer changes under confinement (to a nanometer thin film) and affects the hydration behavior. Confinement has a negligible effect on the ionomer’s cerium partitioning, yet it reduces the ionomer water uptake. Thus, cerium replaces protons similarly in a membrane or CL ionomer; however, its presence affects the thermodynamics of hydration differently.
BT - ACS Applied Polymer Materials DO - 10.1021/acsapm.4c00827 IS - 11 LA - eng N2 -Thin-film ionomers, pivotal in the function of fuel-cell catalyst layers (CLs), are undercharacterized compared to their bulk membrane counterparts, especially with respect to cation effects. Cerium cations, used as an additive in fuel-cell membranes, tend to migrate from the membrane into the CL ionomer during operation. This study investigates whether cerium doping of perfluorinated sulfonic acid ionomer changes under confinement (to a nanometer thin film) and affects the hydration behavior. Confinement has a negligible effect on the ionomer’s cerium partitioning, yet it reduces the ionomer water uptake. Thus, cerium replaces protons similarly in a membrane or CL ionomer; however, its presence affects the thermodynamics of hydration differently.
PY - 2024 EP - 6192–6198 ST - ACS Appl. Polym. Mater. T2 - ACS Applied Polymer Materials TI - Does Confinement Mediate Cerium Exchange and Its Impact on Ionomer Properties? UR - https://pubs.acs.org/doi/10.1021/acsapm.4c00827 VL - 6 SN - 2637-6105 ER -