Facile synthesis of 3D flowerlike CeO2 microspheres under mild condition with high catalytic performance for CO oxidation

►Three-dimensional flowerlike CeO2 microspheres were firstly synthesized under very mild conditions (100 °C). ► An interesting mechanism for the formation of CeO2 microspheres was discussed. ► The synthesized CeO2 shows excellent catalytic performance for CO oxidation.