Asymmetric design of a Pt/C catalyst layer for enhanced performance in proton exchange membrane fuel cells

The physicochemical properties of catalysts significantly influence the overall performance of proton exchange membrane fuel cells (PEMFCs). However, the complexity arising from numerous interrelated parameters presents significant challenges in establishing comprehensive structure-performance relationships for advanced PEMFC systems. This study systematically evaluates three commercial Pt/C catalysts with distinct morphology and structural characteristics to reveal their specific functional impacts on fuel cell performance. The results indicate the abundant micropores and small-sized Pt nanoparticles, embedded in micropores, can significantly enhance the catalytic performance at the cathode side. Conversely, hydrogen oxidation reaction (HOR), at the anode side, prefers to occur on the surface-active site of carbon support. Furthermore, an asymmetric membrane electrode assembly configuration incorporating optimized catalysts and gas diffusion layer achieves a maximum power density of 2.52 W cm^-2 (200 kPa absolute pressure with H₂ and O₂ supplying) with good stability, attributed to synergistic improvements in active site utilization and the mass transfer process. This work enhances the fundamental understanding of catalyst microstructure-performance correlations while offering practical insights for Pt/C catalyst selection and electrode architecture design in PEMFC applications.