A CeO2 Modified Phenylenediamine-Based Fe/N/C with Enhanced Durability/stability As Non-Precious Metal Catalyst for Oxygen Reduction Reaction

The poor durability/stability of non-precious metal catalysts (NPMCs) hampers their substitution for Pt-based catalysts. Here, phenylenediamine-based Fe/N/C catalysts modified with CeO2 were synthesized by a hydrothermal method to eliminate hydrogen peroxide (H2O2), thereby improving the durability/stability of the catalyst. Oxygen reduction reaction (ORR) and catalytic durability/stability were evaluated by linear sweep voltammetry and accelerated durability tests (ADTs). The results show that the yield of H2O2 evaluated by rotating ring disk electrode (RRDE) measurement decreased obviously when the CeO2 mass ratio in catalyst is optimal. The loss of current density at 0.8 V of catalyst with 6 wt% CeO2 and catalyst without CeO2 were 51.1% and 91.5%, respectively. The addition of CeO2 can improve the durability/stability of Fe/N/C catalysts obviously due to the elimination of H2O2 during ORR.