J. Phys. IV France 7 (1997) C2-909-C2-910
Structural Investigation of Amorphous Ni2B by EXAFS and XRDL. Ma1, W. Huang1, J. Yang2 and J. Deng2
1 Research Center for Analysis and Measurement, Fudan University, 220 Handan Road, Shanghai 200433, China
2 Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433, China
The structure and thermostability of hyperfine amorphous Ni2B catalysts (HA-Ni2B) have been studied by EXAFS, XPD and DSC. The samples prepared by chemical reduction have been proved to be amorphous. The grain size is between 5 nm and 20 nm. A short-range order cluster is formed. The distances of Ni-B or Ni-Ni did not alter due to the change of the conditions but the coordination number of Ni is changed. The HA-Ni2B is only stable up to 140°C. Over 140°C, the crystal Ni and an intermediate formed. Finally the intermediate disappears but some B2O3 can be detected.
© EDP Sciences 1997