The Identification of Radial Structure Peaks of EXAFS Fourier Transform of NiO Dispersion Phase

Abstract
A comparison of backscattering amplitudes and APCFT of XAFS of dispersed and crystalline NiO were used to identify radial structural peaks. The results show that there are coordination peaks in the FT function of dispersed phase corresponding to the first, third and forth Ni-Ni coordination shells in the crystalline NiO, although their area may very different depending on the loadings of NiO. But there are no peak corresponding to the second Ni-Ni coordination shell of NiO. It is to say that the second Ni-Ni shell in crystalline NiO disappears as in spinel and the other Ni-Ni coordination shells may still exist when NiO disperses on the surface of support. It also implies that the structure of surface-dispersed NiO has both similarity and difference to NiAl₂O₄ or NiO.