Green-synthesized ZrFeO nanoparticles as efficient cathode materials in PEM fuel cells

This study explores the application of ZrFeO nanoparticles, synthesized from fig leaf extract through a green synthesis method, as cathode materials for PEM fuel cells. The nanoparticles, doped with FeO and varying Zr ratios, were combined with Pt metal and characterized using XRD, SEM, EDX, and TEM to analyze their structural and morphological properties. The particle sizes for FeO and Zr-doped FeO were determined to be 2 nm and 2.5 nm, respectively. The electrochemical active surface areas of the catalysts—Pt-FeO/C and Zr-doped variants (PtFeO/C-1 wt%Zr, PtFeO/C-5 wt%Zr, and PtFeO/C-10 wt%Zr)—were measured as 97, 154, 138, and 119 m²/gPt, respectively, demonstrating a significant enhancement in surface area with the incorporation of Zr at optimal doping levels. Catalyst retention after 250 cycles was 29% for Pt–FeO/C, 60% for 1 wt% Zr-doped Pt–ZrFeO/C, 93% for 5 wt% Zr-doped Pt–ZrFeO, and 71% for 10 wt% Zr-doped Pt–ZrFeO. Performance testing at 70 °C revealed a hierarchy of catalytic activity: Pt–ZrFeO/C > Pt–FeO/C > Pt/C. The findings highlight the potential of green-synthesized ZrFeO nanoparticles as effective support materials for cathode catalysts, offering improved performance in PEM fuel cells while markedly reducing platinum dependency. This innovative approach integrates environmental sustainability with technological progress in fuel cell applications.