Effective utilization of glycerol for the synthesis of 2-methylpyrazine over ZnO-ZnCr2O4 catalyst

• Published in: Journal of chemical sciences (Bangalore, India) India), 2014-03, Vol.126 (2), p.387-393
• Main Authors: VENUGOPAL, A, SARKARI, R, NAVEEN KUMAR, S, KOTESH KUMAR, M, SYED JOHN, S, KRISHNA REDDY, J, HARI PADMASRI, A
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science
• ISSN: 0974-3626; 0973-7103
• DOI: 10.1007/s12039-014-0585-0

Bioglycerol an inevitable by-product in the production of biodiesel was effectively utilized for the synthesis of 2-methylpyrazine (2-MP) by vapour phase dehydrocyclization with ethylenediamine over ZnO-ZnCr 2 O 4 (Zn-Cr-O) mixed oxides. These Zn-Cr-O samples were obtained from hydrotalcite precursors synthesized by precipitation method at different pH (∼7 and 9) and calcination in air at 450°C. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) analysis confirmed the presence of ZnCr 2 O 4 species. Transmission electron microscopy (TEM) images indicated spherical particles with mean diameter of 35.8 and 24 nm for the Zn-Cr-O prepared at pH ∼ 7 and ∼9, respectively. Surface Zn enrichment was observed in the near-surface region of Zn-Cr-O prepared at pH ∼9. Differences in dehydrocyclization activity of Zn-Cr-O mixed oxides were established based on spectroscopic data that emphasized changes in structural properties of Zn-Cr-O obtained at different pH. ᅟ Dehydrocyclization of glycerol and ethylenediamine proceeded through a cyclic transition of 2-pyrazinylmethanol to produce 2-methylpyrazine.