Synthesis and electrochemical decontamination of platinum-palladium nanoparticles prepared by water-in-oil microemulsion

The synthesis and electrochemical decontamination of platinum-palladium nanoparticles prepared by reduction with hydrazine of H2PtCl6 and K2PdCl4 in a water-in-oil microemulsion of water/poly(ethylene glycol)-dodecyl ether (BRIJ 30)/ n-heptane is reported. X-ray photoelectron spectroscopy experiments were carried out to determine the composition of the nanoparticles obtained. Due to the presence of surfactant molecules coating on the nanoparticles, a decontamination procedure was developed. The decontamination procedure applied allows a cleaning of the surface of the nanoparticles without modification or damage for the crystalline surface structure as a result of synthesis conditions. The influence of the classical electrochemical activation or cleaning of the surface on the electrochemical behavior of the nanoparticles is also compared. The results obtained show a deep modification of the electrocatalytic behavior of the nanoparticles after the electrochemical activation treatment. They demonstrate that this activation process should not be applied in studies where the influence of the size, surface structure, and surface composition of the nanoparticles on their electrocatalytic and catalytic properties are studied. (C) 2003 The Electrochemical Society.