Effect of metal oxide nanoparticles on PEM fuel cell performance

In this study, three different platinum (Pt)-supported cathode catalysts were synthesized for Proton Exchange Membrane (PEM) fuel cell applications, namely Pt-MnFe2O4/C, Pt-LaMnFe2O4/C ve Pt-MoMnFe2O4/C. These catalysts were employed as cathode catalysts in membrane electrode assemblies (MEAs) of PEM fuel cells, and their performances were comparatively investigated. Both the physical/structural properties and electrochemical behaviors of the synthesized catalysts were comprehensively evaluated. The physical and structural properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Electrochemical properties were analyzed by cyclic voltammetry (CV). PEM fuel cell performance tests were conducted at five different cell temperatures in the range of 40–80 °C under constant gas flow rates (H2: 40 ml/dk, O2: 80 ml/dk). The results revealed that the performance of the catalysts strongly depended on the operating temperature. The Pt-LaMnFe₂O₄/C catalyst exhibited the highest performance at 80 °C with a maximum current density of 401 mA/cm2 and a power density of 253 mW/cm2. Pt-MnFe2O4/C and Pt-MoMnFe2O4/C catalysts showed optimum performance at 60 °C and 70 °C, respectively. Furthermore, mass activity calculations based on the optimum temperature data showed that the highest value was achieved with the Pt-LaMnFe2O4/C catalyst at 4177 mA/mgPt. These findings demonstrate that Pt-based catalysts supported with rare-earth elements (La) or transition metals (Mn, Mo) and metal oxide additives provide not only higher performance but also greater Pt utilization efficiency compared to conventional Pt/C catalysts. This study contributes to the development of high-performance, durable, and cost-effective alternative catalysts for PEM fuel cell applications.