Investigation by means of H2 adsorption, diffraction, and electron microscopy techniques of a cerium/terbium mixed oxide supported on a lanthana-modified alumina

N-2 adsorption at 77 K, temperature-programmed desorption (TPD), X-ray and neutron diffraction, and high-resolution electron microscopy (HREM) were used to characterize a Ce0.8Tb0.2O2-x/La2O3-Al2O3 oxide. This research shows that the supported cerium/terbium mixed oxide has good thermal stability up to 700 degreesC under H-2 (5%)/Ar and above this temperature in air or inert atmosphere. A combination of HREM and hydrogen chemisorption is shown to be a good method for estimating the dispersion of the supported cerium/terbium mixed oxide. The parallel study of its structural evolution also provides some interesting data on the deactivation of the supported Ce0.8Tb0.2O2-x by reaction with the supporting alumina at 900 degreesC under H-2 (5%)/Ar and the formation of a LnAlO(3) perovskite phase.