X-Ray Structural Characterization of Heterogeneous Catalysts
Current Topics in Catalysis
Moroz Ella Mikhailovna
Boreskov Institute of Catalysis SB RAS
X-ray diffraction structural characterization of heterogeneous catalysts, which are typical nanomaterials, requires development of special methods taking into account X-ray scattering from small objects. Data on the development of an X-ray diffraction method of radial electron density distribution (REDD) or pair distribution function method (PDF analysis) based on the integrated analysis of X-ray scattering are presented. The method gives information on interatomic distances and coordination numbers and is primarily used to detect and evaluate the size of nanoassociates (phases) < 3 nm, which are not detected by the conventional powder X-ray diffraction analysis of interplanar distances. Being sensitive to changes in the local structure in the length range of 1-3 unit cells, the method is successfully applied to detect defects in the local atomic structure of nanoobjects. Examples of the method application for structural studies of nanosized supports and supported catalysts are presented.