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

Abstract

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 m(2)gPt(- 1)) and improved electrochemical performance compared to Pt/La2O3-C (118 m(2)gPt(- 1)). PEMFC performance tests conducted at 70 degrees 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.