Re-evaluation of the adsorption mode of ethene on the {111} surface of palladium using density functional theory

Density functional theory calculations have been performed on ethene adsorption on the Pd{111} surface. The results indicate that adsorption in the di-sigma mode (to two metal atoms) is more stable than pi adsorption (to one metal atom) by 17 kJ mol(-1). This result is in variance to the interpretation of most of the experimental data for this system but the calculations gives rise to structure, electronic structure and vibrational frequencies that are consistent with this experiment data. The study concludes that the experimental data is more consistent with a di-sigma adsorption mode indicating that a re-evaluation of the adsorption mode is required. (C) 2003 Elsevier B.V. All rights reserved.