Branched platinum-on-palladium bimetallic heteronanostructures supported on reduced graphene oxide for highly efficient oxygen reduction reaction

In this work, a facile one-pot wet-chemical approach is developed for synthesis of three-dimensional platinum-on-palladium (Pt-on-Pd) bimetallic nanodendrites supported on reduced graphene oxide (rGO), where octylphenoxypolye thoxyethanol (NP-40) acts as a growth-directing agent and formic acid serves as a reducing agent under mild conditions. The nanocomposites exhibit enhanced oxygen reduction reaction activity (onset potential of 0.05 V, half-wave potential of -0.15 V, electron transfer number >3.99) and better stability in alkaline media. The diffusion-limited current densities of Pt-on-Pd/rGO at -0.60 V (3.99 mA cm(-2) and 22.72 mA mg(-1)) are much higher than those of PtPd/rGO, Pt/rGO, Pd/rGO, PtPd nanoparticles/rGO, Pt black, Pd black, Pt/C, and Pd/C catalysts. This method is general, facile, and green for preparation of rGO-supporting bimetallic electrocatalysts. (C) 2014 Elsevier B.V. All rights reserved.