Extended X-ray absorption fine structure and X-ray diffraction studies on supported nickel catalysts

In the first part of paper we present extended X-ray absorption fine structure analysis on supported Ni catalysts. The present study is aimed toward the elucidation of the local structure of Ni atoms. The second part of the paper consists of X-ray diffraction measurements on the same samples. An X-ray diffraction method that is capable of determining average particle size, microstrains, probability of faults, as well as the particle size distribution of supported Ni catalysts is presented. The method is based on the Fourier analysis of a single X-ray diffraction profile. The global structure is obtained with a new fitting method based on the generalised Fermi function facilities for approximation and Fourier transform of the experimental X-ray line profiles. Both types of measurements were performed on Beijing Synchrotron Radiation Facilities. The results obtained on supported nickel catalysts which are used in H/D isotopic exchange reactions are reported. (C) 2000 Elsevier Science B.V. All rights reserved.