Dissolution-Resistant Core-Shell Materials for Acid Medium Oxygen Reduction Electrocatalysts

One of the most important hindrances for the use of platinum alloyed with other transition metals as oxygen reduction electrocatalysts. in polymer exchange membrane fuel cells is the rapid dissolution of the transition metals in an acid Medium. We introduce a core shell material that based on density functional theory calculations, is predicted to have improved durability and better activity than pure platinum and platinum alloys. The improvement is based on the addition of a small-radius species that locates in the interstitial sites of the top subsurface layers locking the core transition-metal atoms in their positions, thus avoiding their segregation to the surface and posterior dissolution, which is driven by the oxidative acid environment. Here, we demonstrate the durability and activity enhancement for the platinum/iron-carbon/iridium system.