Investigation of the performance of metal oxide based catalysts obtained by green synthesis method in pem fuel cell applications

Fuel cells are among the environmentally friendly and highly efficient technologies for clean energy production and are gaining increasing importance, particularly in portable and stationary power systems. Proton exchange membrane fuel cells (PEMFCs) stand out due to their low operating temperatures, high power densities, and fast response times. The electrocatalysts used in these systems directly influence the overall performance of the fuel cell. Therefore, the development of alternative catalysts with high electrochemical activity and thermal stability is of critical importance for the widespread adoption of PEMFC technology. In this thesis, the electrochemical performances of four different platinum-based nanoparticle catalysts (Pt@ZrMnO/C, Pt@ZrWO/C, Pt@NiMnO/C, and Pt@NiWO/C) were comparatively investigated under varying cell temperatures in a PEMFC system. Performance evaluations were conducted based on key parameters such as polarization curves, current density, and power density. While Pt@ZrMnO/C and Pt@ZrWO/C nanoparticles exhibited high cell potentials at lower temperatures (40–50 °C), Pt@NiMnO/C and Pt@NiWO/C nanoparticles demonstrated stable and high performance across a wider temperature range. The highest power densities for all catalysts were achieved at 60 °C, whereas a decrease in performance was observed at 70 °C, likely due to the deterioration of membrane hydration and reduced proton conductivity at higher temperatures. These findings highlight that the selection of suitable catalysts for PEMFC systems should be optimized not only based on material composition but also in relation to operating temperature conditions.