The Reactivity of Pt Clusters With NO Facilitated by Dual Lewis-Acid Sites.

The size dependence of metal cluster reactions frequently reveals valuable information on the mechanism of nanometal catalysis. Here, the reactivity of the Pt (n = 1-40) clusters with NO is studied and a significant dependence on the size of these clusters is noticed. Interestingly, the small Pt clusters like Pt and Pt are inclined to form NO complexes; some larger clusters, such as Pt , Pt , and Pt , appear to be unreactive; however, the others such as Pt and Pt are capable of decomposing NO. While Pt rapidly reacts with NO to form a stable quasitetrahedron PtO product, Pt experiences a series of NO decompositions to produce PtO . Utilizing high-precision theoretical calculations, it is shown how the atomic structures and active sites of Pt clusters play a vital role in determining their reactivity. Cooperative dual Lewis-acid sites (CDLAS) can be achieved on specific metal clusters like Pt , rendering accelerated NO decomposition via both N- and O-bonding on the neighboring Pt atoms. The influence of CDLAS on the size-dependent reaction of Pt clusters with NO is illustrated, offering insights into cluster catalysis in reactions that include the donation of electron pairs.