Composition-tuned porous Pd-Ag bimetallic dendrites for the enhancement of ethanol oxidation reactions

Porous Pd-Ag bimetallic dendrites of various compositions were prepared using a galvanic replacement reaction between Ag dendrites and Pd(NO3)(2), in which the compositional variation could be effectively controlled by adjusting the concentration of Pd(NO3)(2). The structural and morphological results revealed that the Ag-rich bimetallic dendrites had hollow structures with porous surface layers, whereas the Pd-rich bimetallic dendrite structures collapsed into large aggregates composed of Pd fragments. The electrochemical measurements for the ethanol oxidation revealed that in terms of electrocatalytic activity, the Pd40Ag60 bimetallic dendrites were superior to the other Pd-Ag catalysts. This could be attributed to the geometric and electronic effects of the porous Pd-Ag bimetal dendritic structure. (C) 2016 Elsevier B.V. All rights reserved.