Article

Polymer electrolyte membrane fuel cells (PEMFCs) offer a clean and efficient energy solution, producing only water and heat as byproducts. However, their widespread use is limited by slow oxygen reduction reaction (ORR) kinetics and the high cost of platinum (Pt) catalysts. To overcome these challenges, researchers are developing bi- and tri-metallic catalysts with reduced Pt content and enhanced reactivity and durability. Techniques like atomic layer deposition (ALD) and post-synthesis modifications help tailor catalyst properties. A multi-technique surface analysis approach provides detailed insights into surface and subsurface composition, bonding, and contamination, which are critical for optimizing electrocatalytic performance. 

In this research, platinum nickel (PtNi) and platinum nickel cobalt (PtNiCo) nanowires were investigated with the complementary surface analysis techniques of AES, XPS, and TOF-SIMS. The ALD-synthesized nanowires were exposed to annealing and acid leaching processes to improve electrocatalytic properties of the Pt as well as create more durable catalysts that can withstand device conditions. Results highlight a tradeoff in properties between initial annealing and acid leaching with the final catalysts having a blend of beneficial properties for high activity and long-term stability with reduced platinum content.