First-principles DFT study of ethylene adsorption on Pd(110)

The structure and energetics of the ethylene-palladium adsorption system were investigated by means of first-principles DFT calculations. The calculations revealed that there exist two minimum energy configurations for the ethylene molecule -bonded on Pd(110), one with the C = C axis aligned parallely to the metal surface and the other, at very close energy, with the molecular axis tilted by about 6.5 deg. along the [1, 1, 0] direction. Hence, below 280 K, ethylene is likely to flip between two symmetrical tilted states therby lowering the local adsorption site symmetry to C1, as suggested by experimental observations. The calculated binding energy of the -bonded ethylene on Pd(110) is about 0.9 eV.