Enhanced Performance of Proton Exchange Membrane Fuel Cells Using Platinum–Iron Oxide Catalysts Supported on Activated Carbon Spheres

In this study, the electrochemical performance of Fe₃O₄-supported Pt/C catalysts was evaluated in a Proton exchange membrane fuel cell (PEMFC), with a focus on enhancing oxygen reduction reaction (ORR) kinetics. Fe₃O₄ nanoparticles reduced catalyst particle sizes and improved structural stability. Among the catalysts tested—Pt-Fe₃O₄ magnetic nanoparticle (MNP)/C, Pt/ Fe₃O₄ MNP-C, and Pt/ Fe₃O₄ activated carbon sphere (ACS)-C—the Pt/ Fe₃O₄ MNP-C variant achieved the highest power density (215 mW/cm² at 346 mA/cm²) and displayed superior activity. Analytical techniques such as XRD, SEM–EDX, and TEM confirmed the superior crystallinity and phase purity of the Pt/ Fe₃O₄-based catalysts. Particle sizes were found to be 3.16 nm, 2.71 nm, and 4.70 nm, respectively, for Pt-Fe₃O₄ MNP/C, Pt/ Fe₃O₄ MNP-C, and Pt/Fe₃O₄ ACS-C. The high ORR activity of Pt/Fe₃O₄ MNP-C is attributed to the high surface area and conductivity provided by activated carbon spheres, alongside enhanced Pt-Fe₃O₄ interactions. Mass activities were recorded at 2829, 2307, and 1893 mA/mg_Pt, with Pt-Fe₃O₄ MNP/C showing the fastest kinetics and highest efficiency. Pt/ Fe₃O₄ MNP-C emerges as a promising low-platinum, high-efficiency electrocatalyst for PEMFCs, marking a significant step toward sustainable fuel cell technologies.