The role of nitrogen sources and hydrogen adsorption on the dynamic stability of Fe-N-C catalysts in oxygen reduction reaction.

ABSTRACT: Fe-N-C catalysts are promising alternatives to Pt-based electrocatalysts for the oxygen reduction reaction (ORR) in various electrochemical applications. However, their practical implementation is impeded by their instability during prolonged operation. Various degradation mechanisms have been proposed, yet the real origin of the intrinsic instability of Fe-N-C structures under ORR operations is still disputed. Herein, we observed a new type of protonation mechanism based on advanced first-principles simulations and experimental characterizations. The results revealed strong evidence of pyrrolic-N protonation in pyrrolic-type FeN₄, which plays a vital role for the low kinetic barrier of Fe leaching. Conversely, the pyridinic-type FeN₄ prefers protonation at the Fe sit

SUBMITTER: Huang Z 

PROVIDER: S-EPMC10793592 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature