Fe-N-C Catalysts for Proton Exchange Membrane Fuel Cells: Advances from Synthesis to Practical Applications
Mohamed Barakat
*
Department of Mechanical Engineering, Suez Canal University, Ismailia, Egypt.
Khaled Ramzy
Department of Mechanical Engineering, Suez Canal University, Ismailia, Egypt.
Tamer M. Mansour
Department of Mechanical Engineering, Suez Canal University, Ismailia, Egypt.
Tamer M. Ismail *
Department of Mechanical Engineering, Suez Canal University, Ismailia, Egypt.
*Author to whom correspondence should be addressed.
Abstract
Proton exchange membrane fuel cells (PEMFCs) represent a cornerstone technology for sustainable energy conversion, yet their widespread deployment remains constrained by reliance on platinum-group-metal (PGM) catalysts. This comprehensive review critically examines the development of iron-nitrogen-carbon (Fe–N–C) catalysts as a viable PGM-free alternative, addressing key challenges from atomic-scale active site engineering to full-cell integration. We present a systematic analysis of synthetic methodologies including pyrolysis, sacrificial templating, and MOF-derived approaches that enable precise control over Fe–N₄ moiety density and accessibility. Advanced characterization techniques, such as operando X-ray absorption spectroscopy and electron microscopy, reveal fundamental structure–activity–stability relationships governing oxygen reduction reaction (ORR) kinetics in acidic media. While the catalytic activity of the state-of-the-art Fe–N–C catalysts approaches promising half-wave potentials (E₁/₂ > 0.9 V vs. RHE) under specific conditions, these values can significantly vary with synthetic, testing procedures and electrode configuration. Their translation to practical membrane electrode assemblies (MEAs) necessitates innovative solutions to address durability limitations (<500 h operational stability) and mass transport constraints in thick catalyst layers (>50 μm). We further discuss emerging strategies in electrode architecture design, ionomer–catalyst interactions, and accelerated stress testing protocols. By bridging fundamental insights with engineering considerations, this review provides a roadmap for advancing Fe–N–C catalysts toward commercial viability in next-generation PEMFC systems.
Keywords: Proton exchange membrane fuel cells (PEMFCs), Fe-N-C catalysts, Oxygen reduction reaction (ORR), PGM-free electrocatalysts, Membrane electrode assembly (MEA), durability and degradation