DENSITY-FUNCTIONAL STUDY OF ETHYLENE ADSORPTION ON PALLADIUM CLUSTERS

Fully optimized geometries and adsorption energies obtained from nonlo cal density functional calculations are presented for Pd-n(C2H4) (n = 1-6) clusters. The adsorption mode can be pi or di-a according to the cluster size. The di-sigma adsorption mode is characterized by a stron g distortion for both the ethylene and the metal cluster. The potentia l energy surfaces for the C-H activation show that the d(10) configura tion of palladium is suitable for the formation of the it molecular co mplexes, whereas the d(9)s(1) configuration is suitable for the format ion of the sigma bonds of the vinyl-hydride products.