High PEMFC performance at reduced platinum loadings using La₂O₃-supported catalysts synthesized via a green route from agricultural waste extracts

The development of proton exchange membrane fuel cells (PEMFCs) requires cost-effective, efficient, and durable electrocatalysts with reduced noble metal content. In this study, La₂O₃ nanoparticles were synthesized via a green route using bean shell extract and employed as oxide supports for Pt-based cathode catalysts. Two catalyst structures, denoted as Pt–La₂O₃/C and Pt/La₂O₃–C, were prepared through a chemical reduction method. The structural, morphological, and compositional properties of the catalysts were systematically characterized using XRD, XPS, TEM, SEM, and EDX. Electrochemical analyses revealed that the Pt–La₂O₃/C catalyst exhibited a higher electrochemically active surface area (137 m²gPt^{− 1}) and improved electrochemical performance compared to Pt/La₂O₃–C (118 m²gPt^{− 1}). PEMFC performance tests conducted at 70 °C demonstrated that Pt–La₂O₃/C achieved a maximum current density of 397 mAcm^{− 2}, outperforming Pt/La₂O₃–C (269 mAcm^{− 2}), despite employing a lower platinum loading. Furthermore, durability assessments showed that the Pt–La₂O₃/C catalyst retained approximately 78% of its initial activity after 1000 electrochemical cycles. These results demonstrate that La₂O₃-supported Pt catalysts can enhance PEMFC performance while reducing platinum usage, providing a promising strategy for the development of cost-effective fuel cell cathodes.