Water-dispersable hybrid Au–Pd nanoparticles as catalysts in ethanol oxidation, aqueous phase Suzuki–Miyaura and Heck reactions

The catalytic activities of water-dispersable Au@Pd core–shell nanoparticles (NPs) and Au–Pd alloy NPs were examined. There is growing interest in Au–Pd hybridized NPs in a supported matrix or non-supported forms as catalysts in various reactions that are not limited to conventional Pd-related reactions. Four different Au@Pd core–shell NPs in this study were prepared at room temperature with help from the emulsion phase surrounding the Au core NPs. Au–Pd alloy NPs were prepared over 90 °C, and underwent phase transfer to aqueous medium for their catalytic use. Au@Pd core–shell NPs show catalytic activity in ethanol oxidation reactions as electrocatalysts, and both core–shell and alloy NPs are good to excellent catalysts in various Suzuki–Miyaura and Heck reactions as heterogeneous catalysts. Specifically, Au@Pd core–shell NPs with sharp branched arms show the highest yield in the reactions tested in this study. A relatively small amount (0.25 mol%) was used throughout the catalytic reactions.