Precise synthetic control of exclusive ligand effect boosts oxygen reduction catalysis.

Ligand effect, induced by charge transfer between catalytic surface and substrate in core/shell structure, was widely proved to benefit Pt-catalyzed oxygen reduction reaction by tuning the position of d-band center of Pt theoretically. However, ligand effect is always convoluted by strain effect in real core/shell nanostructure; therefore, it remains experimentally unknown whether and how much the ligand effect solely contributes electrocatalytic activity improvements. Herein, we report precise synthesis of a kind of Pd 3 Ru 1 /Pt core/shell nanoplates with exclusive ligand effect for oxygen reduction reaction. Layer-by-layer growth of Pt overlayers onto Pd 3 Ru 1 nanoplates can guarantee no lattice mismatch between core and shell because the well-designed Pd 3 Ru 1 has the same lattice parameters as Pt. Electron transfer, due to the exclusive ligand effect, from Pd 3 Ru 1 to Pt leads to a downshift of d-band center of Pt. The optimal Pd 3 Ru 1 /Pt 1-2L nanoplates achieve excellent activity and stability for oxygen reduction reaction in alkaline/acid electrolyte.