杨培栋新文：Highly Crystalline Multimetallic Nanoframes with Three-Dimensional Electrocatalytic Surfaces

Control of structure at the atomic level can precisely and effectively tune catalytic properties of materials, enabling enhancement in both activity and durability. We synthesized a highly active and durable class of electrocatalysts by exploiting the structural evolution of platinum-nickel (Pt-Ni) bimetallic nanocrystals. The starting material, crystalline PtNi 3 polyhedra, transforms in solution by interior erosion into Pt 3 Ni nanoframes with surfaces that offer three-dimensional molecular
accessibility. The edges of the Pt-rich PtNi 3 polyhedra are maintained in the final Pt 3 Ni nanoframes. Both the interior and exterior catalytic surfaces of this open-framework structure are composed of the nanosegregated Pt-skin structure, which exhibits enhanced oxygen reduction reaction (ORR) activity. The Pt 3 Ni nanoframe catalysts achieved a factor of 36 enhancement in mass activity and a factor of 22 enhancement in specific activity, respectively, for this reaction (relative to state-of-the-art platinum-carbon catalysts) during prolonged exposure to reaction conditions.
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