Nature of Cu_xCe_1-xO₂ solid solution catalysts

Identifying the local environments of active sites of Cu_xCe_1-xO₂ solid solution for low-temperature CO oxidation remains significant challenges. In this study, we coupled density functional theory and microkinetic modeling to thoroughly investigate local structures of Cu_xCe_1-xO₂ solid solution catalysts, as well as its catalytic performance for low-temperature CO oxidation. Combined with the infrared spectra simulations, we propose that the substitution of Cu₃ or Cu₄ clusters for one Ce atom accounts for the experimentally observed vibrational peaks of the adsorbed CO, rather than the Cu single atom or dimer. Cu single-atom and Cu_n clusters (n = 2–4) doped into CeO₂ all exhibit an excellent stability against ripening and a promising catalytic activity for low-temperature CO oxidation. This research for the first time elucidates the nature of Cu_xCe_1-xO₂ solid solution catalysts and paves the way for the rational design of Cu/CeO₂ catalysts for CO oxidation.