Sulfated iron oxide catalysts, prepared
by a simple and solvent
free method, were studied in the esterification of butanoic acid with
glycerol. The effect of the series of preparation parameters such
as mixing time, sulfate loading, and calcination conditions, i.e.,
temperature and its duration, were explored. The catalyst containing
6 wt % sulfate loading with 40 min of mixing time, calcined at 500
°C for 7 h, performed optimally for the conversion of butanoic
acid. The characterization of catalysts was carried out by using X-ray
powder diffraction (XRD), scanning electron microscopy (SEM)-energy
dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy
(FT-IR), differential scanning calorimetry (DSC)-thermogravimetric
analysis (TGA), zeta potential, acidity measurements, and leaching
tests. The performance of the catalyst has revealed that it is a low
cost, stable, efficient heterogeneous catalyst for this reaction when
compared with ion exchange resins and other heterogeneous catalysts.
Furthermore, the catalyst can be easily separated by filtration and
found to be reusable and active.