Raney-Nickel Catalysts Produced by Mechanical Alloying

摘要

Raney catalysts were prepared by a combination of mechanical alloying and leaching as an alternative in the synthesis of Raney-Nickel catalysts. Binary Al-Ni and ternary Al-Ni-Fe alloys with nominal compositions Al₆₅Ni₃₅, Al₇₅Ni₂₅, Al₆₅Ni₃₀Fe₅, Al₇₅Ni₂₀Fe₅ (in atomic percent), were processed from pure elemental powders; they consisted mainly of the intermetallic B2 AlNi phase. Aluminum was selectively removed from the alloys by means of a chemical treatment with hydroxide solutions, resulting in a highly porous solid. Higher Al contents in the alloys produced larger surface area values of the catalysts. Increasing Ni proportion in the final product resulted in higher catalytic activity, while the addition of Fe improved the stability of the catalysts. The Raney-Ni catalysts produced by mechanical alloying and leaching were highly active in the hydrogenation reaction of benzene.