Strong metal-support interactions(SMSI)play significant roles in a series of heterogeneous catalysis,especially when involving reducible support.To probe metal particle/reducible oxide interactions,ab initio molecular dynamics(AIMD)simulations based on density functional theory(DFT)were performed on a prototypical metal cluster(Au20)[1] supported on reducible oxides(rutile TiO2(110))to implicitly account for finite temperature effects and the role of excess surface charge in the metal oxide [2].We find that the charge state of the Au particle is negative in a reducing chemical environment whereas in the presence of oxidizing species co-adsorbed to the oxide surface the cluster obtained a net positive charge.In the context of the well-known CO oxidation reaction,charge transfer facilitates the plasticization of Au20,which allows for a strong adsorbate-induced surface reconstruction upon addition of CO,leading to the formation of mobile Au-CO species on the surface.The charging/discharging of the cluster during the catalytic cycle of CO oxidation enhances and controls the amount of O2 adsorbed at oxide/cluster interface and strongly influences the energetics of all redox steps in catalytic conversions.A detailed comparison of the current findings with previous studies is presented,and generalities about the role of surface-adsorbate charge transfer for metal cluster/reducible oxide interactions are discussed.