The fly ash loading SO42-/ZrO2solid superacid samples have been prepared by ageing at low temperature. The acidity of samples were determined with flowing indicator method, and the characterization of the samples were performed by IR and XPS. The samples were used in the esterification between lactic acid and n-butyl alcohol. The results show that the sample aged at low temperature have better performance comparing with others samples aged at room temperature, the absorption peak of S=O bond in IR spectra has been strengthened remarkably; The peak position of Zr3d in XPS speetra have a bigger chemical shift. The process of ageing at low temperature is responsible for the stronger acidity and higher activity of FZ samples.
