Impact of catalyst structure and synthesis route on the ORR performance of Pt–Co₃O₄/C catalysts for PEM fuel cells

The development of high-performance cathode catalysts remains a challenge for proton exchange membrane (PEM) fuel cells. In this study, the effect of catalyst configuration was investigated using Co₃O₄-based supports for Pt. Two catalyst structures were prepared: Pt nanoparticles directly deposited on Co₃O₄ (Pt@Co₃O₄/C) and Pt nanoparticles supported on carbon-coated Co₃O₄ (Pt/Co₃O₄@C).Structural characterization indicates that the Pt/Co₃O₄@C catalyst exhibits a more homogeneous Pt distribution and higher Pt loading, resulting in an increase in electrochemically active surface area (ECSA) from 74 to 137 m2g−1Pt compared to Pt@Co₃O₄/C. Durability evaluation based on ECSA retention after 1000 potential cycles shows improved stability for Pt/Co₃O₄@C (55%) compared to Pt@Co₃O₄/C (36%). In single-cell PEM fuel cell tests, the Pt/Co₃O₄@C catalyst achieves a higher maximum power density of 109 mWcm−2 at 80 °C, compared to 73.2 mWcm−2 for Pt@Co₃O₄/C. These results suggest that interfacial and structural features, together with Pt loading, contribute to improved fuel cell performance.