CO Adsorption on Au(332): Combined Infrared Spectroscopy and Density Functional Theory Study

The interaction of molecules with low coordinated sites and possible modification of surfaces caused by adsorbates are of crucial importance for an understanding of chemical processes on surfaces. Herein, CO adsorption on a stepped Au(332) surface is investigated by combining infrared spectroscopy and density functional theory calculations. It is shown that infrared spectroscopic characterization of isotopically diluted mixtures allows distinguishing different components. These components exhibit significantly different adsorption energies as well as vibrational characteristics which can be understood with the help of a theoretical analysis based on density functional theory (DFT). In addition, it is shown that CO induces a restructuring of the surface, leading to a significantly more heterogeneous ensemble of adsorption sites and a significant reduction of sites with the highest CO adsorption energy.