ASAXS study of Au, Pd and Pd-Au catalysts supported on active carbon

Among the techniques commonly used, small angle X-ray scattering (SAXS) is, in principle, particularly suited for the analysis of nanostructured syste ms. However, catalysts supported on porous materials are three phase system s (support, voids and metal), so that the resulting spectrum contains more information than a single conventional SAXS measurement allows to extract. The use of synchrotron radiation source allows to circumvent this difficult y and to separate the scattering of the support from the one of metal by ta king advantage of the so-called anomalous or resonant behavior of the atomi c scattering amplitude of an element near its absorption edge. The results so far obtained on some Au, Pd and Pd-Au samples supported on active carbon are reported here. (C) 1999 Elsevier Science B.V. All rights reserved.