High-temperature synthesis of PtCo/C catalysts: The effect of Pt loading on their structure and activity

This study presents a high-performance PtCo/C catalyst synthesized from commercial Pt/C (10–40 wt% Pt) via high-temperature treatment (700 °C, H₂/inert atmosphere) of cobalt-deposited precursors. Increasing platinum content was found to promote nanoparticle coalescence, reducing the electrochemically active surface area (ECSA) and diminishing catalytic activity. Among the tested variants, the 20 wt% Pt-loaded PtCo/C catalyst demonstrated exceptional performance, achieving 4.7-fold higher activity than commercial Pt/C benchmarks. Accelerated stability tests (AST) revealed superior durability, with the PtCo/C-20 catalyst exhibiting higher post-AST activity, lower ECSA degradation, and minimal half-wave potential loss. When integrated into membrane electrode assemblies (MEAs), the catalyst showed enhanced functional performance, confirming its potential for low-temperature fuel cell applications.