Tuning the Oxygen Reduction Activity of Pd Shell Nanoparticles with Random Alloy Cores

Abstract

Pd-based nanoparticles are promising candidates for non-Pt catalysts of the oxygen reduction reaction (ORR). Trends in ORR activity of Pd/Cu-alloy-core@Pd-shell nanoparticles are studied by calculating the oxygen binding energy on the Pd surface with different Cu compositions in the alloy core. Density functional theory calculations show that several properties of the nanoparticle surface, including the average oxygen binding energy, d-band center, and the net charge of Pd, are linearly related to the ratio of Cu in the core, demonstrating the capacity to tune ORR activity. Trends in oxygen binding of other core alloys are also studied and show similar linear trends with core composition, providing a design strategy for new ORR catalysts.