Dissolution Trends of Platinum-Based Intermetallic Nanocatalysts toward the Acidic Oxygen Reduction Reaction

Platinum-based intermetallic nanostructures hold great potential as proton-exchange membrane fuel cell catalysts for the sluggish cathodic oxygen reduction reaction (ORR). Notwithstanding, metal dissolution during operation is still a critical issue to be overcome, and fundamental insights are needed. Herein, we have produced a systematic series of L12-Pt3M (M = V, Mn, Co, or Zn) intermetallics the structure, chemical composition, and morphology of which are similar and directly rationalize their electrochemical activity-stability trends with the nature of the alloying metal. The time- and potential-resolved metal dissolution was tracked in real time, from the first catalyst/electrolyte contact until the end of potential cycling accelerated stress tests. Our results indicate that the dissolution event triggered by the first catalyst/electrolyte contact should not be overlooked. The observed electrochemical dissolution trends are correlated to the activity losses, providing insightful guidelines for the rational design of robust ORR catalysts.