Pd@Pt Core–Shell Nanodots Arrays for Efficient Electrocatalytic Oxygen Reduction

Conformal deposition of Pt-dots arrays on polyhedral Pd nanocrystals can enhance Pt catalytic properties and reduce its loading. Herein, a simple method for the fabrication of Pd@Pt core–shell nanodot arrays (Pd@PtNAs) heterostructures via reducing H2PtCl6 and Na2PdCl4 by l-ascorbic acid in an aqueous solution with cetylpyridinium chloride and KBr is reported. The Pt nanodots arrays with a small size (about 3 nm in diameter) were dispersed on the surface of Pd decahedra. Such ultrasmall size Pt dots arrays can effectively increase the proportion of low-coordination Pt atoms. Compared with commercially available Pt/C catalysts, the Pd@PtNAs show obvious improvement in catalytic performance applied to oxygen reduction reaction. The mass activity (0.20 A/mgPt) of the obtained Pd@PtNAs with 36.9 wt % Pt shows 2.2 times relative to Pt/C catalyst (0.09 A/mgPt) for ORR. What’s more, the Pd@PtNAs with 36.9 wt % Pt exhibited highly stable property and mass activity with only 11% loss after 10 000 testing cycle.