Journal Article

Highly Crystalline Multimetallic Nanoframes with Three-Dimensional Electrocatalytic Surfaces

Li, Yadong, Kang, Yijin, Mavrikakis, Manos, Somorjai, Gabor A., Huang, Wenyu, Xin, Huolin L., Li, Dongguo, Chen, Chen, Snyder, Joshua D., Zhu, Zhongwei, Markovic, Nenad M., Huo, Ziyang, Yang, Peidong, Herron, Jeffrey A., Chi, Miaofang, More, Karren L., Stamenkovic, Vojislav R.

2014

Overview

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.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science,AAAS
• Subject: Age / carbon electrodes / Catalysts / Crystallization / Durability / Electrocatalysis / Electrocatalysts / fuel cells / Materials / MATERIALS SCIENCE / Molecular evolution / nanocrystals / nanoparticles / Nanostructures / Nickel / Platinum / Polyhedrons / Shergottites / Surface chemistry / Three dimensional imaging