Raney-nickel-iron catalysts obtained by mechanical alloying: Characterization and hydrogenation activity

Raney type catalysts were prepared by means of two steps procedure: i) Mechanical alloying of the metals and, ii) Alkaline aluminum leaching. Mechanical alloying (MA) is a novel alternative related to the synthesis of skeletal Ni catalysts. Catalysts characterisation was performed by atomic absorption (AA), x-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersion (EDS), and Mössbauer spectroscopies (MS). Textural studies were also carried out. Binary Al-Ni and ternary Al-Ni-Fe alloys were produced by mechanical alloying from pure metallic powders; in particular, the intermetallic β-(AlNi) phase was formed with a fine microstructure as a non-equilibrium phase; then, aluminum was selectively removed. After aluminum leaching the β-(AlNi) phase was transformed into the more stable nickel fee structure. The effect of iron addition to the Ni-Al catalysts, depends on iron concentration and reduction temperature, both parameters determine catalysts composition and activity. In this work physicochemical properties and benzene hydrogénation activity of these materials, are discussed.