CeO2 precursors were prepared by the homogeneous precipitation method

hydrothermal synthesis method and hydrothermal precipitation coupling method using urea as a precipitator.The results indicated that urea was a reserve resource of CO2-3.CeO2 precursors were orthorhombic Ce2O(CO3)2·H2O

hexagonal Ce(OH)(CO3)

orthorhombic CeO(CO3)2·H2O respectively when the homogeneous precipitation method

hydrothermal synthesis method and hydrothermal precipitation coupling method were used.The synthesis technology had a great effect on the precursors.Different precursors were synthesized through various processes and mechanisms.When heated up to the temperature of 500℃

the precursors were all finally changed into face centred cubic CeO2 powders.