Highly stable and Active Cu1/CeO2 Single‐Atom Catalyst for CO Oxidation: A DFT Study

: We carried out density functional theory simulations to examine the stability and CO oxidation activity of single Cu atoms supported on CeO2 (111). Both the strong binding energy and high activation energy for Cu single atom diffusion indicate a high stability of the Cu1 /CeO2 single-atom catalyst. Electronic structure analysis verifies the formation of Cu+ cation due to electron transfer. The frequency analysis further corroborates that the experimentally observed IR bands around 2114-2130 cm-1 of CO adsorption at the boundary of Cu/CeO2 correspond to Cu+ -carbonyl species. Cu1 /CeO2 single-atom catalyst displays a promising catalytic activity for CO oxidation via Mars van Krevelen mechanism.