PNNL

Abstract

Contrast-matching small-angle neutron scattering (SANS) has been used to independently characterize the structures of two-phase aerogels consisting of a metal oxide supported on silica aerogel. Ru oxide was formed on silica aerogel by oxidation at 4008C of ruthenocene, impregnated from the vapor phase, or Ru(III) cetylacetonate, impregnated via an acetone solution. Fe oxide was formed by vapor-phase impregnation of ferrocene, followed by reduction at 4008C and exposure to ambient air. The Ru oxide forms particles several tens of nanometers in diameter in the aerogel mesopores. The Fe oxide forms a coating which mimics the structure of the support. The silica aerogel structure is not affected by the deposition and heat treatment processes.