Microstructure and catalytic activity for selective hydrogenation of phenylacetylene of intermetallic Ni70Ga30, Ni70In30, and Ni70Sn30 melt-spun alloys

Abstract

The Ni70Ga30, Ni70In30, Ni70Sn30 alloys were manufactured by melt spinning technique. The as melt-spun ribbons showed a multiphase microstructure prone to alteration by heat treatment at 800 °C. The average grain size in the as melt-spun ribbons was circa 3–4 μm and it increased after heat treatment; the increase is tenfold in the case of the Ni70In30 ribbon due to its low homologues temperature. The ribbons show strongly developed <100> fiber texture with high concentration of high angle grain boundaries. Martensite microstructure was found in the Ni70Ga30 ribbon. At room temperature all the studied ribbons were found active for selective hydrogenation of phenylacetylene with conversion rates after 4 h reaction time of around 20%. Further improvement of catalytic activity is expected with surface pretreatment, pulverization and increasing of the reaction temperature. Altogether the as melt spun ribbons present an attractive alternative to cold rolled and annealed ribbons and to nanocrystalline intermetallics for application in a range of chemical reactions.