The structural, electronic and catalytic properties of Aun (n=1-4) nanoclusters on monolayer MoS2

The structural stability, electronic and catalytic properties of Aun (n = 1-4) nanoclusters supported on monolayer MoS2 have been investigated based on first principle DFT calculation with van der Waals (vdW) corrections. Our results show that all Aun (n = 1-4) nanoclusters prefer to bind vertically on the top S sites of the monolayer MoS2. And the relative stability of Au-n (n = 1-4) clusters in gas phase is not preserved after landing on monolayer MoS2. By including van der Waals (vdW) corrections with different approaches, we found that the van der Waals correction increased the adsorption energies for all supported Au-n (n = 1-4) clusters with the order of E-ads(PBE-D2) > E-ads(PBE-D3) > Eads(optB86b-vdW) > E-ads(PBE). And the van der Waals effects can also change the order of stability and the energy differences of various deposition configurations. In addition, the binding of O-2 is also modeled, showing significantly enhanced adsorption properties and catalytic activation toward O-2 adsorption, especially for that on supported Au-1 and Au-3 clusters with magnetic properties, with respect to that on supported Au-2 and Au-4 clusters with nonmagnetic properties. The current study provides further insight into the adsorption and catalytic properties of small gold clusters supported on monolayer MoS2, which play a crucial role in the activation of O-2.