CeO2–La2O3 catalytic system Part I. Preparation and characterisation of catalysts

Abstract

The CeO₂–La₂O₃ catalytic system was prepared by a sol–gel technique from inorganic precursors in the presence or absence of H₂O₂ . Samples were characterised by means of nitrogen physisorption, TG-DTA, XRD, IR, XPS and TEM. Preparation ia sol–gel in the presence of H₂O₂ produces certain interesting modifications in CeO₂–La₂O₃, both structurally and morphologically. Higher surface areas have been found for the CeO₂–La₂O₃ system prepared in the presence of H₂O₂. On the other hand, for La₂O₃ the structure obtained upon calcination at 873 K corresponds to La(OH)₃, and for the system prepared with hydrogen peroxide, to a mixture of La(OH)₃, and La₂O₃ which was detected by XRD. Interesting morphological differences were observed for both systems.