Morphological and Interfacial Control of Platinum Nanostructures for Electrocatalytic Oxygen Reduction

Abstract

The catalytic performance of noble metal nanocrystals highly depends on their surface structure and interface structure. Effective surface/interface control over noble metal nanocrystals can significantly improve their electrocatalytic activity, durability, and selectivity for the various important electrochemical reactions in low-temperature polymer electrolyte fuel cells. In this work, the polyallylamine (PAA)-functionalized Pt nanostructures with long-spined sea-urchin-like morphology (Pt-LSSUs@PAA) have been synthesized successfully through a simple chemical reduction route. The high branching degree of Pt-LSSUs@PAA nanostructures and the sheet morphology of the branches effectively improve the utilization of the Pt metal. The particular 3D interconnected architecture of Pt-LSSUs@PAA nanostructures significantly enhances the electrochemical stability. Loose-packed PAA layers on the surface of Pt-LSSUs@PAA nanostructures efficiently modify the electronic property of Pt atoms and serve as barrier networks to restrain the accessibility of alcohol molecules. As a result, the as-prepared Pt-LSSUs@PAA nanostructures show high activity, excellent durability, and particular alcohol tolerance for the oxygen reduction reaction in acidic media.