The Reactivity of Pt<i>_n</i>⁺ Clusters With N₂O 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 ⁺ (n = 1-40) clusters with N₂O is studied and a significant dependence on the size of these clusters is noticed. Interestingly, the small Pt_n ⁺ clusters like Pt₃ ⁺ and Pt₄ ⁺ are inclined to form N₂O complexes; some larger clusters, such as Pt₁₉ ⁺, Pt₂₁ ⁺, and Pt₂₃ ⁺, appear to be unreactive; however, the others such as Pt₃ _, _9,15 ⁺ and Pt₁₈ ⁺ are capable of decomposing N₂O. While Pt₉ ⁺ rapidly reacts with N₂O to form a stable quasitetrahedron Pt₉O⁺ product, Pt₁₈ ⁺ experiences a series of N₂O decompositions to produce Pt₁₈O_1-7 ⁺. Utilizing high-precision theoretical calculations, it is shown how the atomic structures and active sites of Pt_n ⁺ clusters play a vital role in determining their reactivity. Cooperative dual Lewis-acid sites (CDLAS) can be achieved on specific metal clusters like Pt₁₈ ⁺, rendering accelerated N₂O 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 N₂O is illustrated, offering insights into cluster catalysis in reactions that include the donation of electron pairs.