Probing the Size and Shape Effects of Cubic‐ and Spherical‐Shaped Palladium Nanoparticles in the Electrooxidation of Formic Acid

A systematic study of size and shape effects in the electrooxidation of formic acid over our controlled synthesized Pd nanospheres and nanocubes as material models by using infrared spectroscopy and density functional calculations was undertaken. The bridge formate intermediate on the metal terrace was identified as the main contributor to the electrooxidation activity of formic acid, whereas linear formate with much weaker adsorption energy was unstable and could not proceed to the product. It was also demonstrated that Pd(1 0 0) cubes could stabilize two bridge formate species, and thus, they show higher electrooxidation activity than Pd spheres at comparable sizes.