Photochemical Synthesis and Characterization of Pd@Pt Core-Shell Nanoparticles with Low Cost and High Activity for Methanol Electro-catalytic Oxidation

In the PEG-acetone solution system, the Pd@Pt core-shell nanoparticles were prepared by photochemical reduction of Pt(IV) on the surface of Pd nanoparticles which were firstly in-situ synthesized as the seed by a photochemical method. The thickness of Pt shell of the composite particles could be efficiently adjusted by changing the molar ratio of Pd seed to Pt(IV). Core-shell composite structure of the obtained nanoparticles with average diameter in the range of 5.3∼7.1 nm was confirmed by HR-TEM and XPS. The electrochemical tests indicate that Pd@Pt core-shell nanoparticles, in which Pd: Pt is 1:1 or 1:4, have the similar catalytic activity and the stability to those of Pt, while lower cost. Therefore, they can be used for anode catalyst materials of direct methanol fuel cell.