CeO2 nanorod decorated NrGO additives for boosting PEMFC performance

This study presents a novel and highly efficient CeO2-based type of additives to improve the performance of PEM fuel cells. Cerium(IV) oxide (CeO2) nanorods and CeO2 nanorod decorated nitrogen-doped reduced graphene oxide (NrGO) (CeO2/NrGO) were synthesized and utilized to enhance the ORR performance of PEMFCs. With a low energy transition between Ce+3 to Ce+4 and its high catalytic activity, CeO2 could promote O2 reduction. The structural properties of CeO2 nanorods and the CeO2/NrGO composite were investigated using XRD, RAMAN, SEM, TEM, TGA, BET, and XPS. The synthesized CeO2 nanorods and CeO2/NrGO composite were mixed with a low platinum loading (0.09 mgPt.cm−1), and ex-situ electrochemical characterizations were performed (CV and LSV) to evaluate their catalytic activities. Fuel cell performance tests and in-situ impedance analyses were also conducted to confirm the electrochemical results. Compared to commercial Pt/C-based MEA (269 mW.cm−2), the addition of both CeO2 nanorods (382 mW.cm−2) and CeO2/NrGO (389 mW.cm−2) to the catalyst layer showed a significant enhancement in fuel cell performance, due to the unique oxygen buffer ability of the synthesized additives.