Catalysis Letters, Vol.149, No.9, 2500-2507, 2019
Zirconium Exchanged Phosphotungstic Acid Catalysts for Esterification of Levulinic Acid to Ethyl Levulinate
Zirconium exchanged phosphotungstic acid catalysts were prepared and studied for esterification of levulinic acid with ethanol. The catalysts were characterized by powder XRD, BET surface area, Raman spectroscopy, FT-infrared spectroscopy, Temperature programmed desorption of NH3 and Pyridine adsorbed FT-IR analysis. The presence of Zr resulted in the generation of strong Lewis acidic sites. Among all the catalysts the catalyst with partially exchanged Zr (Zr(0.75)TPA) showed higher activity due to the present of stronger BrOnsted and Lewis acidic sites. The Zr(0.75)TPA catalyst exhibits amazing reusability with constant activity.Graphic AbstractZr exchanged TPA is active in the esterification of levulinic acid into ethyl levulinate. [GRAPHICS] .
Keywords:Levulinic acid;Ethanol;TPA;Zirconium;Ethyl levulinate