Synthesis and Characterization of Pt-Ag Icosahedral Nanocages with Enhanced Catalytic Activity toward Oxygen Reduction

There is an urgent need to develop cost-effective electrocatalysts based on Pt for a broad spectrum of applications, including those vital to the operation of fuel cells. Hollowing out the interior of Pt nanocrystals offers a simple and viable strategy for maximizing the utilization efficiency of this precious metal while enhancing the electrocatalytic performance. Herein, we report the synthesis and electrocatalytic evaluation of Pt−Ag icosahedral nanocages with an average wall thickness of 1.6 nm. The Pt atoms are coated on the surface of Ag icosahedral seeds, leading to the formation of Ag@PtnL core-shell icosahedral nanocrystals with tunable shell thicknesses. The core-shell nanocrystals are then converted to icosahedral nanocages by selectively etching away the Ag in the core. The as-obtained nanocages with a composition of Pt4.5Ag exhibit an almost 3-fold enhancement in specific activity toward oxygen reduction relative to the commercial Pt/C in acid media.

Duke Scholars

Author Miaofang Chi Thomas Lord Department of Mechanical Engineering and Materia ...