Pt₃Re alloy nanoparticles as electrocatalysts for the oxygen reduction reaction

Development of renewable energy technologies requires advanced catalysts for efficient electrical-chemical energy conversion reactions. Here we report the study of Pt-Re alloy nanoparticles as an electrocatalyst for the oxygen reduction reaction (ORR). An organic solution approach is developed to synthesize monodisperse and homogeneous Pt₃Re alloy nanoparticles. Electrochemical studies show that these nanoparticles exhibit an improvement factor of 4 in catalytic activity for the ORR compared to commercial Pt catalysts of similar particle sizes. Fundamental understanding of the structure-property relationship is established by combining material characterization using X-ray spectroscopy and atomically resolved electron microscopy, as well as Density Functional Theory (DFT) calculations. Our work revealed that an electronic modification of the surface properties of Pt by subsurface Re (ligand effect) accounts for the catalytic enhancement.