Foreword

XAS-Investigation of Local Disorder in Metallic Nickel and Raney-Nickel Catalyst

EXAFS measurements have been carried out at the Ni-K-edge both on a Raney-nickel sample and on a metallic nickel foil in the temperature range from 20 to 320 Kelvin using synchrotron radiation from the storage ring ELSA in Bonn. A cumulant data analysis shows that the first-shell distance distribution in nickel foil can be considered as nearly gaussian within the considered temperature range. In Raney-nickel catalyst, the non-negligible value of the third cumulant suggests an asymmetric distribution instead. The first-shell coordination number is much lower (N ≈ 6) than for metallic nickel. The MSRD is similar to that of metallic nickel, suggesting a low degree of static disorder.