Effect of a step defect on the adsorption of benzene on the (221) surface of nickel: Anab initiostudy

By employing an ab initio DFT approach we study the adsorption of benzene on a (221) step surface of nickel. We find an enhancement of about 0.30.3em0exeV for the maximum adsorption energy compared to that of the flat (111) surface. We perform an electron density analysis to characterize the nature of the molecule--surface bonds and compare it to the case of a flat (111) surface. We also find that the range of attraction in z direction is more extended than in the flat case; this result has important consequences in predicting adhesion properties of larger molecules, such as polymers at metal surfaces.