Effect of Aging Temperature and Fe/Zr on the Structure and Performance of the Solid Superacid Catalyst SO42- /Fe2O3-ZrO2

The solid superacid SO42-/Fe2O3-ZrO2 as a catalyst was prepared by aging at a low temperature. The samples were characterized by IR and XRD, and used in catalytic esterification of n-butyl alcohol and sebacic acid. IR spectra show that the intensity of the peak at 1070 cm-1 for the samples aged at a low temperature is much stronger than that aged at a normal temperature. XRD demonstrates a metastable tetragonal phase of ZrO2 for the samples aged at a low temperature. The activity of the catalytic esterification for the samples aged at low temperatures is higher than that of other samples by about 30%. It is suggested that the metastable tetragonal phase of ZrO2 is responsible for the stranger acidity and higher activity of the catalytic esterification of SO42-/Fe2O3-ZrO2.