Non-destructively incorporating ceria in Nafion membrane as hydroxyl radical scavenging agent for long-term PEMFC application

Aiming at enhancing the long-term operation of proton exchange membrane fuel cell (PEMFC), Nafion as a typical example of perfluorosulfonic acid proton exchange membrane is non-destructively modified by sulfonated ceria (CeO2-DS) nanoparticles via a swelling-filling strategy. CeO2-DS nanoparticles in Nafion matrix can not only act as radical scavenging agent to improve the durability of Nafion, but also assist the re-construction of the efficient proton conduction channel in the composite Nafion membrane. Both oxidative stability and proton conductivity of the Nafion membrane are therefore remarkably improved with the great mechanical and thermal stability of Nafion maintained. PEMFC equipped with the modified Nafion membrane therefore outperforms that with the pristine Nafion membrane in terms of both power output and durability. Specifically, the maximum power density of the PEMFC equipped with modified Nafion after Fenton accelerated degradation test was significantly improved by ca. 25 % compared with that of the pristine Nafion membrane. This work hence provides a facile way to improve the durability of the PEMFC for practical applications.