Antimonio (V) disperso na superficie de silica gel : sintese, caracterização e propriedades

AUTOR(ES)
DATA DE PUBLICAÇÃO

1992

RESUMO

The antimony (V) oxide was obtained in highly dispersed form on a silica gel surface (Sb/SiO2), at a concentration of 0.65 atoms.nm, by grafting synthesis, and was reproducible for several preparations. After carrying out the XPS analysis, only Sb(V) ions in the Sb/SiO2 material were observed, which unlike the unsupported form, did not suffer any reduction by thermal treatment, but reticulate with the silica gel surface. Through the use of infrared spectroscopy, utilizing pyridine as a probe moIecule, it was determined that the acid property of Sb/SiO2 is different from bulk Sb2O5. Using the ion exchange process, Fe(III) ions were supported on the Sb/SiO2 surface. This material was characterized by Mössbauer and XPS analyses, where it was shown that Fe(III) ions reacted with the Sb(V) ions forming a new phase. This new phase was thermally more stable than iron (III) oxide supported through Fe(CO)5 deposition and much more dispersed than iron (III) oxide impregnated directly onto a siIica gel surface. In the oxidation of ethanol to acetaldheyde the catalytic activity of Fe(III) ions dispersed on the Sb/SiO2 surface by exchange synthesis was larger than those obtained by the Fe(CO)5 deposition and impregnation methods.

ASSUNTO(S)

oxidos metalicos quimica inorganica

ACESSO AO ARTIGO

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