Carbon Catalyst Supports for Pt-Based Polymer Electrolyte Membrane Fuel Cells: Porosity, Graphitization, and Chemical...

Understanding the properties of carbon supports is essential for optimizing the performance and durability of Pt-based catalysts in polymer electrolyte membrane fuel cells (PEMFCs). This review examines recent advances in the characterization and functional role of carbon supports, focusing on porosity, graphitization, and chemical modifications. Key methods used to assess the ordering of carbon phases and structural features are discussed, with attention to how these characteristics influence catalyst behavior. Particular emphasis is placed on the importance of fair comparison between Pt/C catalysts with different carbon supports, ensuring reliable performance assessments. The review then explores the interplay between graphitic and amorphous domains, highlighting how surface chemistry and chemical modifications can affect catalyst activity and stability. The impact of porosity and platinum nanoparticle locality is also examined, with special focus on how pore architecture can offer protection from ionomer-induced poisoning and inhibit nanoparticle coalescence during operation. Throughout, the review identifies challenges in current characterization techniques and underscores the need for a holistic understanding of support architecture. Finally, it outlines design principles for next-generation carbon supports that can better stabilize Pt nanoparticles and enhance the overall performance and durability of PEMFC cathodes.