Platinum-based nanoalloys for the oxygen reduction reaction: exposing the true active phase via in situ/operando techniques

Platinum-based nanoalloys are efficient electrocatalysts for the oxygen reduction reaction (ORR). In situ/operando measurements have revealed that key properties including induced strain, chemical composition, coordination environment, evolve significantly during operation, which can hampertheir effective implementation in fuel cells. In fact, recent studies indicate that the impact of the early surface activation steps of Pt-based nanoalloys has been hitherto underestimated and is an important factor contributing to loss of their initial electroactivity. In this short perspective, we highlight the importance of in situ/operando characterization of Pt-based electrocatalysts during the initial operation steps in the ORR and discuss recent insights into their early degradation and evolution of their key properties during electrochemical characterization.