Facile synthesis and electrocatalytic properties of dendritic palladium nanostructures

Abstract

In this work, palladium dendritic nanocrystals (DNs) have been synthesized by simply mixing an aqueous solution containing the cationic surfactant cetyltrimethylammonium bromide (CTAB) with the metal precursor Na₂PdCl₄, a little nickel acetate, and the reductant ascorbic acid under mild experimental conditions. The presence of a small amount of nickel ions was proved to be critical for the formation of the dendritic nanocrystals. The morphology, nanostructure, size and composition of the as-prepared Pd DNs are characterized by transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry, chronoamperometry and CO-stripping voltammetry tests demonstrate that the Pd DNs have higher electrocatalytic activity, better electrochemical stability, and higher resistance to CO poisoning than commercial Pd nanoparticles for formic acid oxidation (FAO) owing to their unique dendritic structure.