Density Functional Theory Study of HCN Adsorption on Small Gold Clusters

摘要

A theoretical study was carried out on the adsorption of hydrocyanic acid on small Aun (n ≤ 7) clusters using density functional methods. For HCN adsorption on gold clusters, no dependence was found with respect to the even-odd alternation in relation to the number of gold atoms in the cluster. The HCN molecule is adsorbed at simple adsorption sites (1-fold coordination), perpendicular to the adsorption site. The largest adsorption energy is only about 74.61 kJ·mol-1, which indicates that the HCN molecule does not decompose and the C–N bond retains triple bond, and that the C–H and C–N stretching frequencies are only weakly perturbed. The adsorbed C–N and C–H stretching frequencies are blue- and red-shifted compared with the values of free HCN, respectively.