Catalytic Potential of Supported Superatoms.

ABSTRACT

The importance of catalysts in industrial products is a driving factor in the search of efficient and cost-effective catalysts, creating considerable interest in the past decade in single-atom catalysis. One of the first requirements of a good catalyst is that it should bind to the molecules with energies intermediate between physisorption and chemisorption while simultaneously activating them. Herein, it is shown that superatoms, which are atomic clusters with fixed size and composition, can meet this challenge even better than the atoms whose chemistry they mimic. The reactions of molecules such as H2, O2, N2, CO, NO, and CO2 with an atom (Li) and its corresponding superatom (Li3O) are confirmed through study. As these clusters need to be supported on a substrate for practical applications, the study focuses on the reaction of CO2 with Li and Li3O supported on graphene, Au(111), and Cu(111) substrates. Using density functional theory, it is shown that the Li3O superatom can activate CO2 far greater than the Li atom - stretching the CO bond from 1.16 Å to as large as 1.30 Å and bending the O─C─O bond angle from 180° to as low as 120°. Equally interesting, the results are not very sensitive to the substrate.