A novel method for the synthesis of CexZr1-xO2 solid solution with high purity of κappa phase and excellent reactive activity

Ceria-zirconia solid solution (Ce1-xZrxO2) had been widely used in environmental catalysis as catalyst and support due to its excellent oxygen storage/release capacity (OSC). Furthermore, the performance of Ce1-xZrxO2 was dependent on the phase. Notably, kappa appa-type CeZrO4 solid solution (kappa-Ce2Zr2O8) with the highly ordered arrangement of Ce and Zr cations possessed the highest OSC. However, the synthesis of CexZr1-xO2 with high special surface area and high purity of kappa-Ce2Zr2O8 was still a huge challenge by now. Herein, a new method for the synthesis of kappa-Ce2Zr2O8 solid solution was proposed, based on ceria-zirconia solid solution precursor prepared by an improved solvent-thermal method. The reduction time can be shortened to 4h at 1500 degrees C to produce the CeZrO4 solid solution with pure kappa-Ce2Zr2O8 and relative high special surface area. Consequently, this catalyst existed high ratio of Ce3+/Ce on the surface, a large amount of surface oxygen species and excellent OSC, leading to the high activities for CO oxidation and CH4 combustion.