Oxygen reduction activity of Pt and Pt–Mn–Co electrocatalysts sputtered on nano-structured thin film support

We report on extensive measurements of oxygen reduction activity of Pt and Pt–Co–Mn electrocatalysts using the rotating ring-disk electrode (RRDE) method. The electrocatalysts were prepared by sputtering from Pt or Pt, Co and Mn targets onto 3M's nano-structured thin film support (NSTF) structures. The area specific activity of Pt/NSTF, measured in 0.1 M HClO4 and at room temperature, is similar to that of bulk Pt. The area specific measurements show a 20 mV reduction in the Pt–Co–Mn/NSTF overpotential compared to Pt/NSTF. The corresponding kinetic gain in the area specific activity of the ternary alloy is about a factor of two. This ORR enhancement factor observed in the ternary Pt–Co–Mn/NSTF by RRDE measurements is similar to the results obtained in 50 cm2 H2/air fuel cells.