Electronic structures of CO adsorbed Pt-skin surface on Pt-Co and Pt-Ni alloys

Abstract Using angle resolved photoemission spectroscopy, the electronic structures of Pt-skin layer of Pt-Co and Pt-Ni alloys are investigated as CO molecules are adsorbed on the surface. Measured Fermi surface maps and band dispersions reflect the signatures of chemical bonding between Pt-skin layer with CO molecules. Furthermore, the degree of chemical bonding strength is estimated from the shift of the participating band structure, exhibiting the reduced chemical bonding strength of CO molecules on both Pt bimetallic alloys. Our results reveal how the surface band structure of Pt bimetallic alloys is modified with molecular orbitals of CO molecules at the surface, revealing the important role of the electronic structure in the determination of chemical properties of bimetallic alloys.