Synthesis and Characterization of Core-Shell Cu-Ru, Cu-Rh, and Cu-Ir Nanoparticles

Optimizing the use of expensive precious metals iscritical to developing sustainable and low-cost processes forheterogeneous catalysis or electrochemistry. Here, we report asynthesis method that yields core-shell Cu-Ru, Cu-Rh, and Cu-Irnanoparticles with the platinum-group metals segregated on thesurface. The synthesis of Cu-Ru, Cu-Rh, and Cu-Ir particles allowsmaximization of the surface area of these metals and improvescatalytic performance. Furthermore, the Cu core can be selectivelyetched to obtain nanoshells of the platinum-group metalcomponents, leading to a further increase in the active surfacearea. Characterization of the samples was performed with X-rayabsorption spectroscopy, X-ray powder diffraction, and ex situ andin situ transmission electron microscopy. CO oxidation was usedas a reference reaction: the three core-shell particles and derivatives exhibited promising catalyst performance and stability afterredox cycling. These results suggest that this synthesis approach may optimize the use of platinum-group metals in catalyticapplications.