LAUSR

A series of ordered mesoporous sulfated zirconia (OMSZ) with different calcination temperatures (400–650 °C) have been synthesized by a self-assembly method using zirconium n-propoxide as raw material, P123 (EO20PO70EO20) as structure-directing agent and ammonium sulfate as sulfonating agent. The transmission electron microscopy results indicated that the OMSZ had the ordered mesoporous structure and the X-ray diffraction analysis further revealed that the OMSZ had hexagonal ordering structure. The N2–BET results showed that the OMSZ were mesoporous materials and, when the calcination temperature was 500 °C, the BET surface area could reach 183 m2/g. Temperature-programed desorption of NH3 (NH3–TPD) analysis confirmed that the OMSZ possessed a superacid when the calcination temperature was higher than 450 °C. FTIR-pyridine adsorption results indicated that the OMSZ surfaces were mainly the Lewis acid sites. The catalytic activity of OMSZ was observed for transesterification of waste frying oil, and 92% of yield could be obtained after 6 h at 200 °C.