Study of cupric oxide nanopowders as efficient catalysts for low-temperature CO oxidation

摘要: Abstract CuO nanopowders were prepared by precipitation from alkaline solutions and studied TPR-CO + O 2 , XRD, TGA, TPD-He XPS. All of the precipitated samples characterized excellent catalytic properties toward low-temperature (LT) oxidation CO with similar T 50 values 110 °C. In contrast, bulk oxides sizes greater than 450 nm exhibited no activity at low temperatures. Several monolayers chemisorbed species, such as water/hydroxyls carbonate/hydrocarbonates, typically observed surface nanopowders. These species not critical for LT CO, their preliminary removal did substantially change XPS results indicated a high deficiency oxygen sublattice 1− x (  = 0.1–0.15) nanopowders, whereas, lattice CuO, Cu/O ratio was 1. The highly deficient resulted in disproportionation process, which, turn, two forms. An form E b (O1s) = 531.3 eV that is reactive proposed to be responsible Slight differences Cu2p shake-up satellite structures between nanosized samples, which electronic structure cationic had changed.