Dispersion of Fe2O3 supported on metal oxides studied by Mössbauer spectroscopy and XRD
Abstract
The dispersion of Fe
2
O
3
on various metal oxide supports (SiO
2
, γ-Al
2
O
3
, CeO
2
, ZrO
2
and TiO
2
) has been studied by Mössbauer spectroscopy and XRD. The vacant sites on the surface of the support significantly influence the form of the iron oxide. For silica-supported iron oxide, Fe
3+
cations concentrate readily to form crystalline α-Fe
2
O
3
particles, owing to the lack of vacant surface sites on silica. However, for other metal oxide supports, such as γ-Al
2
O
3
, CeO
2
, ZrO
2
and TiO
2
, which have vacant surface sites, Fe
3+
cations are preferentially incorporated into the vacant surface sites and the chemical surroundings of these Fe
3+
cations, incorporated in different types of surface sites, are different. Crystalline α-Fe
2
O
3
particles appear after all usable vacant sites have been occupied by Fe
3+
cations.
Please wait while we load your content...
