Ferric oxide catalysts dispersed on silica and acidic silicas modified by the introduction of Al (SiO2-Al2O3), Nb (SiO2-Nb2O5) and Zr (SiO2-ZrO2) (ca. 30 mass%) were prepd. by wet impregnation from ferric acetylacetonate. The structural (by XRD studies), morphol. (by nitrogen adsorption/desorption studies) and electronic (by DRS/UV-vis) properties of both the fresh and used catalysts after their employment in the decompn. of N2O were studied. Ferric oxide species with different nuclearity, and in different relative proportions, were obsd. on the surface of each support, viz. isolated Fe(III) species, 2d FeOx dimer/oligomer aggregates and 3d Fe2O3 nanoparticles. Isolated Fe(III) species were most abundant on silica and silica-alumina, while 2d FeOx oligomers and 3d Fe2O3 predominated on silica-niobia and silica-zirconia. The nature of the support considerably influenced the speciation of iron, thereby affecting the activity of the catalyst and its stability in the N2O decompn. reaction. The introduction of Al2O3 into silica had a pos. effect on the course of the reaction but the catalytic activity was not maintained, while the presence of Nb2O5 substantially limited the course of the reaction.
|Titolo:||Study of the influence of the nature of the support on the properties of ferric oxide in relation to its activity in the decomposition of N2O|
GERVASINI, ANTONELLA (Primo)
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Data di pubblicazione:||2011|
|Digital Object Identifier (DOI):||10.1260/0263-618.104.22.1685|
|Appare nelle tipologie:||01 - Articolo su periodico|