Study of the Durability of Faceted Pt 3 Ni Oxygen–Reduction Electrocatalysts

The durability of truncated octahedral Pt 3 Ni ( t , o ‐Pt 3 Ni) electrocatalysts in the oxygen–reduction reaction (ORR) was investigated by using an accelerated‐durability‐testing procedure. The Pt 3 Ni/C catalyst lost 21 % of its initial electrochemical surface area (ECSA) and 40 % of the mass‐current density (0.55 to 0.33 A mg Pt −1 ) after 30 000 potential cycles under acidic conditions. In comparison, the reference commercial Pt/C catalyst lost 44 % of its initial ECSA and had a final mass‐specific activity of only 0.09 A mg Pt −1 under identical testing conditions. This study shows the potentials of this class of Pt 3 Ni/C nanostructures as highly active and durable ORR catalysts.