Superacid Catalyst SO42-/ZrO2-La2O3 Prepared by Ultrasonic Co-precipitation and Low Temperature Aging

Sulfated zirconia-lanthana (SO₄^2-/ZrO^2-La₂O₃) precursors were prepared by ultrasonic co- precipitation method and followed by aging at different temperature. The precursors were treated by 0.5 mol/L H₂SO₄. Samples of SO₄^2-/ZrO^2-La₂O₃nano-crystalline catalysts were obtained by baking the treated precursors at different temperatures. The acidic properties of SO₄^2-/ZrO^2-La₂O₃ were tested by the Hammett indicator method. The phase composition, specific area, particle structure, and surface state were characterized by X-ray diffraction, BET, transmission electron microscopy, infrared spectrum, and X-ray photoelectron spec- troscopy. The catalytic activities were estimated by esterification of acetic acid with glycerin. It was shown that the catalyst prepared by ultrasonic stirring and low temperature (-15 ºC) exhibited highly active sites and high catalytic property.