Electronic structure of leached Al–Cu–Fe quasicrystals used as catalysts

Abstract

We used X-ray emission spectroscopy to investigate the electronic structure of various catalysts obtained by leaching a quasicrystalline Al–Cu–Fe compound in 5% Na₂CO₃ aqueous solution. The study of Al states confirmed that Al is almost totally oxidized in the catalysts. Fe is not as much oxidized probably because it is embedded in Cu–Al₂O₃ grains. Cu is only partly oxidized. However, it is not excluded that the catalytic activity could be due to a size effect that prevents the formation of a band as in metallic Cu, and gives to the electronic structure an atomic-like character. New measurements should be done from fresh specimens in order avoid further oxidation interference with the Cu spectral distributions.