X-Ray Technique Reveals How Pt-Ni Nanoparticles Change Under Operational Conditions

Platinum (Pt) can act as a catalyst to make reactive oxygen ions for many applications. In this research, scientists used a method called electrochemical cycling to modify the surface of Nickel (Ni)/Pt nanoparticles. The scientists then examined the particles using a specialized X-ray scattering imaging technique that is uniquely suited to probe three-dimensional particles in liquids. This revealed that the modified alloy had a Pt rich layer. This layer's structure left Pt at the surface of the nanoparticles, more concentrated than would be normal in a bulk Ni-Pt alloy. The technique reveals the composition, shape, and strain of nanometer scale particles that are used in electrodes and membranes.