Microstructure and catalytic properties of rapidly solidified Al-28.5 at% Fe and Al-28.5 at% Co alloys applied for selective hydrogenation of phenylacetylene
Abstrakt
The Al71.5Fe28.5 and Al71.5Co28.5 (at%) melt-spun alloys were examined in terms of microstructure evolution and catalytic response in the semihydrogenation reaction of phenylacetylene to styrene. In the as-spun state ribbons showed a single-phase composition. The Al71.5Co28.5 alloy contained columnar grains of a metastable decagonal quasicrystal, which transformed into hexagonal Al5Co2 and monoclinic Al3Co phases after heat treatment at 900 ◦C. The Al71.5Fe28.5 ribbon had an ordered orthorhombic Al5Fe2 phase structure in both the as-spun and annealed states. The pulverized ribbons revealed considerable catalytic activity for selective hydrogenation of phenylacetylene to styrene. The best results were achieved for the as-spun quasicrystalline Al71.5Co28.5 alloy, showing a conversion rate of above 80% after 2 h reaction time. The selectivity to styrene was 60% for all catalysts. The tested powders retained their phase composition following liquid reaction therefore the proposed materials can be considered for catalytic use.
