Reactivity of anionic gold oxide clusters towards CO:: experiment and theory

In this paper, we present results from our joint experimental and theoretical study of the reactivity of anionic gold oxide clusters Au2,3O1-4- towards CO. We provide clear evidence that, although O-O bond weakening/dissociation is important to enable CO oxidation, the presence of atomic oxygen can be favorable but is not always sufficient. Furthermore, we show that with the addition of a single gold atom the reactivity channels can be changed. As a consequence, in contrast to CO oxidation in the case of anionic gold dimer oxides, association of CO or replacement of O-2 by CO become the dominant reaction channels for Au3On-. This demonstrates the nonscalable properties of gold clusters in the size regime in which each atom counts.