Mixed-oxide formation during preparation of alumina-supported zirconia: an EXAFS and DFT study

• DOI: 10.1039/b304815b
• Publication Date: 2003-08-18T10:25:30Z
• Authors: A. C. Faro, Jr.; K. R. Souza; J. G. Eon; A. A. Leitão; A. B. Rocha; R. B. Capaz
• Keywords: 02 engineering and technology; 0210 nano-technology

Alumina-supported zirconia catalysts, containing from 2.1 to 20.1 wt% ZrO2 and prepared by multiple incipient wetness impregnation using benzene solutions of zirconium acetylacetonate, were characterised the EXAFS technique. The results indicated that supported phase consists Zr4+ species do not have Zr as second neighbours, hexacoordinated oxide anions, suggesting these ions occupy octahedral positions in defective spinel structure γ-alumina support. In order test this hypothesis, an idealised unit cell was constructed with formula ZrAl4O8, structure. Atomic optimised theoretical calculations based on DFT. smallest energies corresponded structures where sites Simulations spectra provided excellent agreement between experimental spectra.