Catalysis by amorphous metal alloys. Part 6.—Factors controlling the activity of skeletal nickel catalysts prepared from amorphous and crystalline Ni–Zr powder alloys

Abstract

New skeletal nickel catalysts have been prepared by treating pulverised amorphous and crystalline Ni–Zr alloys with an HF solution, and the surface states have been determined by using electron spectroscopy, X-ray diffraction and carbon monoxide chemisorption techniques. The activity of the catalyst for the hydrogenation of ethene is dependent on (1) the number of surface nickel atoms present on porous nickel species, (2) the electron deficiency of the surface nickel species and (3) the size of nickel particles formed by the segregation of nickel atoms. A catalyst prepared from an amorphous Ni–Zr alloy exhibits a much higher catalytic activity than those of crystalline Ni–Zr alloys and Raney nickel. The high activity of the catalyst prepared from the amorphous alloy is ascribed to the small size of the nickel particles, which is brought about by the highly homogeneous structure of the amorphous alloy.