Icosahedral Pt-Ni Nanocrystalline Electrocatalyst: Growth Mechanism and Oxygen Reduction Activity.

Engineering the structure of Pt alloy offers an effective way to the design of high performance electrocatalysts. Herein, we synthesize a sandwich-structured, icosahedral Pt Ni catalyst through a hot injection method. Its growth involves three steps: 1) burst nucleation of Pt atoms to form a Pt-enriched core, 2) heterogeneous nucleation of Ni atoms onto the Pt core to form a Ni-enriched interlayer, and 3) kinetic controlled growth of a Pt-enriched shell.