Catalitic Activity of Gold Clusters

摘要

The adsorption of O_2 and C_2H_4 molecules on neutral gold clusters consisting of up to 10 atoms has been investigated using density-functional theory. It is shown that in addition to a conventional mechanism of the catalytic activation of O_2 adsorbed on a gold cluster, the interaction of C_2H_4 with gold clusters results in considerable weakening of the carbon-carbon double bond. It is demonstrated that C_2H_4 can be adsorbed on small gold clusters in two different configurations, corresponding to the p- and di-s-bonded species. Adsorption in the p-bonded mode dominates over the di-s mode for all considered cluster sizes n, with the exception of the neutral C_2H_4-Au_5 system. A striking difference is found in the size-dependence of the adsorption energy of C_2H_4 bonded to the neutral gold clusters in the p and di-cr configurations. The important role of the electronic shell effects in the di-s mode of ethylene adsorption on neutral gold clusters is demonstrated.