Structural characterization of a novel catalyst obtained from nanoscopic NiAl by X-ray absorption spectroscopy

Information on geometric and electronic structure of a promising novel NiAl catalyst is presented. It is based on the analysis of both X-ray absorption near edge (XANES) and extended X-ray absorption fine structure (EXAFS) data measured at the Ni K-edge of the catalyst, its precursor materials, and conventional Raney Nickel samples. The interpretation of these results is supported by real space full multiple scattering calculations using the "FEFF-8" code. In contrast to standard Raney Nickel, the new material cannot be described assuming a pure Ni-based sponge structure. Instead, although direct Ni-Ni bonds are observed, there is also a considerable amount of Ni-Al bonds remaining in the sample even after the leaching process is completed. This finding can tentatively be related to the nanoscopic nature of the catalyst.