Effects of Electronic Structure Modifications on the Adsorption of Oxygen Reduction Reaction Intermediates on Model Pt(111)-Alloy Surfaces

In this work, the relationship between electronic structure and adsorption energies of oxygen reduction reaction (ORR) intermediates (O, OH, OOH, O 2, and H 2 O) is investigated for modified Pt surfaces. Model surfaces were constructed to examine lattice strain and electronic ligand effects. Compressive strain, which broadens the metal d band, was found to destabilize adsorption of all of the intermediates. Whereas binding energy shifts due to strain correlate well for all of the intermediates examined, shifts in O adsorption energy resulting from ligand contributions were found not to correlate with the other intermediates. Additionally, the adsorption energy of oxygenate intermediates was found not to depend solely on the d-band center of the surface. Although the d-band center is important, adsorption is also dependent on the electron density near the Fermi level.