Cerium Migration through Hydrogen Fuel Cells during Accelerated Stress Testing

Component durability of polymer-electrolyte membrane (PEM) fuel cells can be improved by adding cerium cations, which serve to scavenge harmful free radicals and selectively decompose hydrogen peroxide, which are formed during the oxidation reduction reaction (ORR). We have investigated the change in distribution of cerium cations in a hydrogen fuel cell as a function of operating time, considering both cerium containing membranes (commercial XL by DuPont) as well as fuel cells with CeO2 in the cathode catalyst layer. Our results show cerium cations are very mobile in Nafion, and migrate into both the anode and cathode catalyst layers.