Porous Iron-Nitrogen-Carbon Electrocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC)

High-performance platinum group metal-free (PGM-free) electrocatalysts were prepared from porous organic polymers (POPs) precursors with highly-porous structures and adjustable surface area. A resin phenol-melamine-based POP and an iron salt were used to synthesize Fe-N-C catalysts with different iron contents (0.2-1.3 wt.%). Electrochemical and spectroscopical characterization allowed us to elucidate the effect of Fe content on the material's structure, surface chemistry, and electrocatalytic activity toward the oxygen reduction reaction (ORR). The increase of iron content led to a specific surface area decrease, preserving the morphological structure, with the formation of highly-active catalytic sites, as indicated by X-ray photoelectron spectroscopy (XPS) analysis. The rotating ring disk electrode experiments, performed at pH=13, confirmed the high ORR activity of both 0.5 Fe (E-1/2=0.84 V) and 1.3 Fe (E-1/2=0.83 V) catalysts, which were assembled at the cathode of a H-2-fed anion exchange membrane fuel cells (AEMFC) equipped with a FAA-3-50 membrane, evidencing promising performance (0.5 Fe, maximum power density, Max PD=69 mA cm(-2) and 1.3 Fe, Max PD=87 mA cm(-2)) with further advancement prospects.

Automated summary

High-performance platinum group metal-free (PGM-free) electrocatalysts were prepared from porous organic polymers (POPs) precursors with highly-porous structures and adjustable surface area. The effect of Fe content on the material's structure, surface chemistry, and electrocatalytic activity toward the oxygen reduction reaction (ORR) was elucidated through electrochemical and spectroscopical characterization. The Fe-N-C catalysts with different iron contents showed promising ORR activity, with further advancement prospects for fuel cell applications.