Shape-dependent electrocatalytic activity of monodispersed palladium nanocrystals toward formic acid oxidation

Abstract

The catalytic activity of different-shaped and monodispersed palladium nanocrystals, including cubes, octahedra and rhombic dodecahedra, toward the electrochemical oxidation of formic acid has been systematically evaluated in both HClO₄ and H₂SO₄ solutions. Notably, the cubic palladium nanocrystals wholly exposed with {100} facets exhibit the highest activity, while the rhombic dodecahedra with {110} facets show the lowest electrocatalytic performance. Furthermore, compared with HClO₄ electrolyte, the catalytic activity is found to be obviously lower in H₂SO₄ solution likely due to the competitive adsorption of SO₄²⁻ ions and formic acid on the surface of Pd nanocrystals.