Highly active Ce1−xCuxO2 nanocomposite catalysts for the low temperature oxidation of CO

► The Ce1−xCuxO2 nanocomposite catalysts were synthesized by a simple hydrothermal method. ► The particle size of Ce0.80Cu0.20O2 nanocomposites is about 5.0 nm with a narrow distribution. ► The optimum catalytic activity and stability is achieved for the Ce0.80Cu0.20O2 nanocomposites.