Unraveling the Potential-Dependent Degradation Mechanism of Fe-N-C Catalysts for the Oxygen Reduction Reaction

With the rapid advancement of hydrogen energy development in China, developing novel catalytic materials to address the high cost and resource scarcity of platinum-based catalysts is of great strategic significance for the industrialization of proton exchange membrane fuel cells (PEMFCs).

Recently, the research group led by Professor Wei Xing at the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, had a paper accepted by SCIENCE CHINA Chemistry (JCR Q1), titled Unraveling the Potential-dependent Degradation Mechanism in Fe-N-C Catalysts for Oxygen Reduction Reaction. The study monitored real-time electrode evolution during the oxygen reduction reaction (ORR) and revealed the intrinsic potential-dependent degradation mechanism of Fe-N-C catalysts.

By utilizing in-situ differential electrochemical mass spectrometry, three distinct potential regions with varying degrees of performance attenuation were identified. Notably, carbon corrosion signals were observed at low potentials. Combined with theoretical calculations and fluorescence probe experiments, the research confirms that catalyst degradation at high potentials is driven by strong oxidative potentials that overcome the energy barrier for carbon oxidation. In contrast, performance decay at low potentials is primarily induced by high-concentration reactive oxygen species (ROS) generated during the ORR process.

This work clarifies the internal correlations among multiple degradation pathways and provides new insights into improving the long-term durability of Fe-N-C catalysts for practical PEMFC applications.