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

First-principles calculations are performed to study the interaction of cluster Au₃₂ with small molecules, such as CO, H₂, and O₂. The cagelike Au₃₂(I_h) shows a higher chemical inertness than the amorphous Au₃₂(C₁) with respect to the interaction with small molecules CO, H₂, and O₂. H₂ can only be physically adsorbed on Au₃₂(I_h), while it can be dissociatively chemisorbed on Au₃₂(C₁). Although CO can be chemically adsorbed on Au₃₂(I_h) and Au₃₂(C₁) with one electron transferred from Au₃₂ to the antibonding π^* orbit of CO, it is bound more strongly on Au₃₂(C₁) than on Au₃₂(I_h). Spin polarized and spin nonpolarized calculations result almost identical ground state structures of Au₃₂(I_h)–O₂ and Au₃₂(C₁)–O₂, in which O₂ is dissociatively chemisorbed. [ABSTRACT FROM AUTHOR]