Theoretical study of CO adsorption on FexCuy (x + y = 3) clusters and reactive activity of their carbonyl complexes

Abstract

In this paper, the adsorption of CO on Fe x Cu y (x + y = 3) clusters were studied by BPW91 method, all conceivable geometries and electronic states of carbonyl complexes were explored. The results show that bimetallic clusters tend to have higher stepwise CO adsorption energy than corresponding pure clusters, and the adsorption capacity of FeCu 2 (CO) 3 with CO is substantially larger than that of other carbonyl complexes. Moreover, the frontier molecular orbital theory was used to analyze the effect of the second element in the ligand reactions, which also con rmed that the reactions of CO with bimetallic clusters are easier than that of pure cluster systems. Finally, the energy gaps of HOMO and LUMO were use to explore the reactive activity of carbonyl complexes, it was found that the bimetallic clusters are lower than that of the Fe 3 or Cu 3 , and the Fe 2 Cu(CO) 1 has lower energy gap than that of other carbonyl complexes. This suggests that it may be possible to tune bimetallic cluster to get higher activity carbonyl complexes in the reactions.