Thermal Stabilization of CexZr1-xO2 oxygen storage promoters by addition of Al2O3: Effect of thermal ageing on textural, structural and morphological properties

Thermal stability and dispersion of CeO2 supported on Al2O3 is greatly improved by insertion of ZrO2 into the CeO2 lattice. It is shown that homogeneous nano-sized CexZr1xO2 solid solutions can be prepared on the Al2O3 surface by using a citrate complexation synthesis method. Investigation of effects of CexZr1xO2 composition and loading of the Ce0.2Zr0.8O2 phase on thermal stability and nanostructure of the prepared materials revealed that strong interactions between supported phase and Al2O3 are induced by the high temperature treatment. High contents of ZrO2, choice of the CexZr1xO2 precursors and loading of the mixed oxide are critical factors leading to nanocomposite systems with high thermal and structural stability, consisting of particles of Ce0.2Zr0.8O2 as small as 9-20 nm in close contact with a q-Al2O3 matrix even after calcination at 1373 K. The enhanced stability of the present materials was confirmed also under hydrothermal conditions.