The infrared (IR) spectroscopy by the Attenuated total
reflectance (ATR) was used to characterize surface functional
groups on the ZrO2 catalyst before and after the xylose conversion
reactions. The ATR-FTIR spectroscopy was recorded on the ThermoScientific Nicolet 6700 FT-IR equipment with the 16 scanr. The background spectrum was recorded first to remove the air effect before the sample test.