Catalytic activity study of NixSny intermetallics

Abstract

Cinnamyl alcohol (COL), versatile chemical in fragrance, flavoring, and pharmaceutical industries, can be found in only small amounts in nature. Generally, COL can be synthesized via selective hydrogenation of cinnamaldehyde (CALD), natural oil, at aldehyde functional group under high pressure of hydrogen gas. In this work, NixSny intermetallics were used as catalysts in selective hydrogenation to obtain COL. These catalysts were synthesized via mechanical alloying, economic and environmental method, and characterized by X-ray diffraction (XRD). By using 43, 58, and 75% tin contents with nickel, Ni3Sn, Ni3Sn2, and Ni3Sn4 intermetallics were prepared, respectively. In addition, formic acid was used as a proton-hydride source to convert CALD to COL. The optimal time, temperature, type and amount of NixSny catalyst, and also rate of formic acid adding were studied. The result showed that the optimal conditions were 300 mg Ni3Sn4, 5 mmol CALD and 25 µl per 5 min of FA in 10 ml THF at 60 ˚C for 3 h reaction time to the maximum yield of COL. Under these conditions, COL was obtained at 1.8% yield with 36.7% conversion. However, other products (hydrocinnamyl alcohol, hydrocinnamaldehyde, cinnamic acid, and benzaldehyde) were also detected by gas chromatography-flame ionization detector (GC-FID).