Contrast-matching small-angle neutron scattering (SANS) has been used
to independently characterize the structures of two-phase aerogels con
sisting of a metal oxide supported on silica aerogel. Ru oxide was for
med on silica aerogel by oxidation at 400 degrees C of ruthenocene, im
pregnated from the vapor phase, or Ru(III)acetylacetonate, impregnated
via an acetone solution. Fe oxide was formed by vapor-phase impregnat
ion of ferrocene, followed by reduction at 400 degrees C and exposure
to ambient air. The Ru oxide forms particles several tens of nanometer
s in diameter in the aerogel mesopores. The Fe oxide forms a coating w
hich mimics the structure of the support. The silica aerogel structure
is not affected by the deposition and heat treatment processes. (C) 1
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