Aluminum-doped ceria-zirconia solid solutions with enhanced thermal stability and high oxygen storage capacity

A facile solvothermal method to synthesize aluminum-doped ceria-zirconia (Ce(0.5)Zr(0.5-x)Al(x)O(2-x/2), x = 0.1 to 0.4) solid solutions was carried out using Ce(NH(4))(2)(NO(3))(6), Zr(NO(3))(3)·2H(2)O Al(NO(3))(3)·9H(2)O, and NH(4)OH as the starting materials at 200°C for 24 h. The obtained solid solutions from the solvothermal reaction were calcined at 1,000°C for 20 h in air atmosphere to evaluate the thermal stability. The synthesized Ce(0.5)Zr(0.3)Al(0.2)O(1.9) particle was characterized for the oxygen storage capacity (OSC) in automotive catalysis. For the characterization, X-ray diffraction, transmission electron microscopy, and the Brunauer-Emmet-Teller (BET) technique were employed. The OSC values of all samples were measured at 600°C using thermogravimetric-differential thermal analysis. Ce(0.5)Zr(0.3)Al(0.2)O(1.9) solid solutions calcined at 1,000°C for 20 h with a BET surface area of 18 m(2) g(−1) exhibited a considerably high OSC of 427 μmol-O g(−1) and good OSC performance stability. The same synthesis route was employed for the preparation of the CeO(2) and Ce(0.5)Zr(0.5)O(2). The incorporation of aluminum ion in the lattice of ceria-based catalyst greatly enhanced the thermal stability and OSC.