Catalysis by amorphous metal alloys. Part 7.—Formation of fine Fe particles on the surface of an alloy in the precrystallisation state prepared from an amorphous Fe90Zr10 powder alloy

Abstract

Alloys in metastable states have been prepared by the structural modification of an amorphous Fe₉₀Zr₁₀ powder alloy by heating, and the relationship between the surface state and the catalytic ability has been studied. The alloy in the precrystallisation state exhibited a higher catlytic activity for the hydrogenation of buta-1,3-diene than those of alloys in the amorphous and stable crystallised states. Conversion electron Mössbauer spectra indicate that on the surface of the alloy in the precrystallisation state, fine Fe particles having a b.c.c.-like crystal structure and comprised of Zr atoms grow in the amorphous Fe–Zr matrix. The high catalytic activity is ascribed to this type of Fe particle formed in the amorphous matrix.