Evaluation of the catalytic potential of melt-spun and dealloyed aluminum-based intermetallic ribbons
Creators: name: Zięba, Amelia
name: Stan-Głowińska, Katarzyna
name: Rogal, Łukasz
name: Duraczyńska, Dorota
name: Lityńska-Dobrzyńska, Lidia
Publisher: name: Zenodo
Year: 2023
Subjects: microstructure
melt spinning
SEM
TEM
catalyst
dealloying

description: The development of effective, environmentally friendly, and readily available catalysts remains one of the most important goals in the chemical and energy industries. One area of research is the development of noble-metal-free heterogeneous catalysts that can facilitate efficient reactions under mild conditions, such as low temperatures and gas pressures. Intermetallic compounds with unique crystalline structures and long-range atomic order are particularly promising in this regard.

The present work concerns aluminium-based intermetallic catalysts for hydrogenation reactions. Two ternary alloys containing aluminium and transition metals that form catalytically active sites were manufactured using the melt-spinning method. The chemical compositions of the produced alloys are referred to Al-Ni-Co and Al-Ni-Fe decagonal quasicrystalline phases, revealing structural features favorable for catalytic performance. Melt-spun materials were cast in the form of brittle ribbons, easily applicable as catalysts for liquid environment reactions after milling. Some of the obtained ribbons were chemically leached with NaOH solution to improve the catalytic performance by providing a higher specific surface area. The microstructure and phase composition of the obtained materials were characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction techniques.

 Al-Ni-Co ribbons have a uniform microstructure and contain only a decagonal quasicrystalline phase. Al-Ni-Fe ribbons revealed diversified morphology and multiphase composition, including complex intermetallic phases and quasicrystal. The leaching process resulted in the formation of a hierarchical porous structure corresponding to the grain structure of the as-spun material. Simultaneously, aluminium was dissolved and rinsed out in the preserved material, and the transition metal oxides remained. The catalytic properties of all the materials were tested using pulverized ribbons in a phenylacetylene hydrogenation reaction, which is a polystyrene production stage. The catalytic properties were characterized by evaluating the composition of the reaction mixture by gas chromatography. All materials exhibited catalytic activity under the applied reaction conditions. The composition of catalysts was preserved after the experiments. However, further work will aim to increase the specific surface area of the examined materials without substantially changing the phase and chemical composition.

 

Casting of melt-spun ribbons: Łukasz Rogal

Microstructure and composition investigations: Amelia Zięba, Katarzyna Stan-Głowińska, Lidia Lityńska-Dobrzyńska

Catalytic tests: Dorota Duraczyńska

 

Acknowledgements: This work was financially supported by the National Science Centre (NCN) Poland within project No. 2021/41/N/ST8/02533