First-principles study of interaction of cluster Au32 with CO, H2, and O2

First-principles calculations are performed to study the interaction of cluster Au-32 with small molecules, such as CO, H-2, and O-2. The cagelike Au-32(I-h) shows a higher chemical inertness than the amorphous Au-32(C-1) with respect to the interaction with small molecules CO, H-2, and O-2. H-2 can only be physically adsorbed on Au-32(I-h), while it can be dissociatively chemisorbed on Au-32(C-1). Although CO can be chemically adsorbed on Au-32(I-h) and Au-32(C-1) with one electron transferred from Au-32 to the antibonding pi(*) orbit of CO, it is bound more strongly on Au-32(C-1) than on Au-32(I-h). Spin polarized and spin nonpolarized calculations result almost identical ground state structures of Au-32(I-h)-O-2 and Au-32(C-1)-O-2, in which O-2 is dissociatively chemisorbed. (c) 2006 American Institute of Physics.