EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

One of the intensively developed research areas on intermetallic phases is the use of these chemical compounds as catalyst materials. Promising results of the research conducted so far indicate the applicability of these compounds as a replacement for catalysts based on noble metals. An area of interest is aluminum-based intermetallic compounds, which exhibit high catalytic properties in partial hydrogenation of unsaturated hydrocarbons.
In the presented research, the alloy corresponding to the Al5Co2 intermetallic phase has been investigated. The alloy was manufactured by the melt spinning method, which allows quick and easy production of rapidly solidified materials in the form of thin (60-80 µm) and brittle ribbons. The microstructure of the as-spun and annealed ribbons were examined using X-ray diffraction, scanning and transmission electron microscopy. In the as-spun state, the material exhibits a single-phase structure of a decagonal quasicrystalline D-phase. The SEM observation of the ribbon cross-section revealed columnar grains with an average diameter of 8 µm. It was found that after annealing at 900°C by 48 hours, the D-phase partially transformed to the orthorhombic Al5Co2 phase.
The investigations of catalytic properties were performed for the phenylacetylene hydrogenation reaction using pulverized ribbons in the initial state and after annealing. The catalytic tests exhibited a high conversion of about 80% and selectivity to styrene of 60% for examined materials in both (as spun and heat-treated) stages, after the reaction time of 2 hours at 60 °C. The performed investigations indicate that the melt spinning process is a promising technique that can be applied to obtain intermetallic compounds for catalytic applications.

Acknowledgments: This work was financially supported by the National Science Centre (NCN) Poland within project No. 2017/25/B/ST8/02804.