Green-synthesized CeVO4-carbon hybrid supports for enhanced Pd utilization in PdRu cathode catalysts for PEM fuel cells

Abstract

In this study, PdRu-based cathode catalysts with different support structures were investigated for PEMFC applications, with emphasis on catalyst efficiency under low Pd loading conditions. PdRu nanoparticles were supported on Vulcan carbon (VC), CeVO4-modified carbon, and green-synthesized activated carbon-CeVO4 (AC-CeVO4) hybrids, and evaluated in MEAs at 40-70 degrees C. The results show that PEMFC performance is strongly influenced by the nature of the catalyst support and the integration of CeVO4 with carbon rather than by alloy composition alone. The PdRu/AC-CeVO4@VC catalyst exhibited the best performance, reaching 111.4 mWcm-2 at 70 degrees C. This improved PEMFC performance is associated with improved nanoparticle dispersion, a higher electrochemically active surface area, and more efficient Pd utilization. Although the absolute power density is lower than that of some previously reported systems, this is primarily attributable to the lower Pd loading and ambient-pressure operating conditions employed in this study. When normalized to Pd loading, the catalyst demonstrated improved Pd utilization, highlighting the potential of green-synthesized CeVO4-carbon hybrid supports for the development of efficient Pt-free PEMFC cathodes.