J. Phys. IV France 7 (1997) C2-273-C2-274
XAS-Investigation of Local Disorder in Metallic Nickel and Raney-Nickel CatalystB. Frenzel1, J. Rothe1, J. Hormes1 and P. Fomasini2
1 Physikalisches Institut der Universität Bonn, Nussallee 12, 53115 Bonn, Germany
2 Dipartimento di Fisica dell'Université di Trento, 38050 Povo, Trento, Italy
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.
© EDP Sciences 1997