Ionic liquid on the acidic organic-inorganic hybrid mesoporous material with good acid-water resistance for biodiesel production

Different amounts of acidic ionic liquid sulfonic acid functionalized imidazolium hydrogen sulfate ([Ps-im] HSO4) were immobilized on the acidic organic-inorganic hybrid mesoporous material SO42-/ZrO2-SiO2(Et) by the chemical grafting. The structure of the catalyst was characterized by FT-IR, XRD, N2 absorption-desorption measurement, XPS and TG. The results showed that the ethane-bridge organosilica moieties were incorporated into the framework of SO42-/ZrO2, enhancing the acidity of SO42-/ZrO2-SiO2(Et) with respect to SO4 (2-)/ZrO2. Meanwhile, the ionic liquid was successfully immobilized onto the acidic mesoporous materials SO42-/ZrO2--SiO2(Et) and with the increase of ionic liquid loading, the BET surface areas and the pore volumes decreased and the average pore diameters increased. SO42-/ZrO2-SiO2(Et)-IL-i were very efficient in the transesterification of soybean oil with methanol and gave an approximate 99% biodiesel yield when the reaction was carried out at 150 degrees C with a 5 wt% catalyst amount at 18: 1 methanol/oil molar ratio for 3.0 h. And they not only own the abilities of water and acid resistance, but also maintain satisfactory catalytic activity after five runs.