Application of SiO2-La2O3 amorphous mesoporous nanocomposites obtained by modified sol–gel method in high temperature catalytic reactions

Authors:

• Zbigniew Stefan Piskuła,
• Mikołaj Stodolny,
• Elżbieta Gabała,
• Piotr Kirszensztejn,
• Waldemar Nowicki

Abstract

Silica composite materials doped with lanthanum oxide were studied as supports for catalysts to be used at elevated temperatures. A series of SiO2-La2O3 composites with Si to La molars ratio of 1:0, 1:0.05, 1:0.1, 1:0.25, 1:0.5, 1:1 and 0:1 were synthesized by a modified sol–gel technique using citric acid and glycerine. The samples were characterized by TGA, XRD, BET, TEM-EDS, XPS and acetic acid TPD methods. The catalytic properties of the systems studied were tested in N2O decomposition. The catalytic activity of the samples was found to increase with increasing lanthanum content. The conversion of nitrous oxide over the composite material SiO2-La2O3 (Si:La = 1:0.5) was 64% at 973 K (WHSV = 30000 ml g−1 · h−1). The nanocomposites obtained were characterized by well-developed specific surface and high stability, besides they were easy to prepare and relatively inexpensive. Thanks to these properties they are expected to be attractive materials for a wide range of applications, e.g. as adsorbents, catalysts or metallic phase catalyst supports