Synthesis and characterization of bimetallic Au-Pd nanoparticles for the electrocatalysis of the oxygen reduction reaction.

Abstract

In this project, we propose to prepare and characterize Au-Pd bimetallic nanoparticles and to study their behavior as active materials for the oxygen reduction reaction (ORR). We are seeking for Pt-free electrocatalysts stabilized against dissolution under potential cycling regimes, a continuing problem in the cathodes of low temperature fuel cells in vehicle applications. Both the formation of Au-Pd alloys and the underpotential deposition (UPD) of Pd on preformed Au nanoparticles would stabilize the more active metal to avoid its dissolution. The alloyed nanoparticles will be prepared by the co-reduction method; while Pd will be deposited by means of UPD on preformed Au nanoparticles to form Au@Pd particles. The comparison of different structures of similar composition would illuminate with regards to mechanistic aspects. The electrocatalytic properties of the supported nanoparticles toward the ORR will be studied and analyzed considering the composition, geometric and electronic structure of the systems. (AU)