1. Highly Crystalline Multimetallic Nanoframes with Three-Dimensional Electrocatalytic Surfaces
- Author
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Chen, Chen, Kang, Yijin, Huo, Ziyang, Zhu, Zhongwei, Huang, Wenyu, Xin, Huolin L, Snyder, Joshua D, Li, Dongguo, Herron, Jeffrey A, Mavrikakis, Manos, Chi, Miaofang, More, Karren L, Li, Yadong, Markovic, Nenad M, Somorjai, Gabor A, Yang, Peidong, and Stamenkovic, Vojislav R
- Subjects
Engineering ,Macromolecular and Materials Chemistry ,Materials Engineering ,Chemical Sciences ,General Science & Technology - Abstract
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 PtNi3 polyhedra, transforms in solution by interior erosion into Pt3Ni nanoframes with surfaces that offer three-dimensional molecular accessibility. The edges of the Pt-rich PtNi3 polyhedra are maintained in the final Pt3Ni 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 Pt3Ni 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.
- Published
- 2014