固体超强酸S2O2-8/Fe2O3-ZrO2-La2O3催化制备生物柴油

用沉淀—浸渍法制备固体超强酸S₂O^2-₈/Fe₂O₃-ZrO₂-La₂O₃催化剂，通过XRD和FTIR对其结构进行表征。将该催化剂用于催化制备生物柴油并考察了反应条件对生物柴油产率的影响。结果表明，当Fe、Zr和La的摩尔比为1∶0.42∶0.075时，催化剂活性最高。其催化制备生物柴油的最佳工艺条件为，催化剂用量为菜籽油质量的2%，醇和油的摩尔比为12∶1，反应温度为220℃，反应时间为10h，产率可达90.3%。催化剂重复使用5次反应时间达50h，产率仍达83%。GC-MS表征表明制得的生物柴油的纯度较高。

Synthesis of biodiesel catalyzed by an S2O8^2-/Fe2O3-ZrO2-La2O3 solid superacid

Biodiesel has been synthesized from vegetable seed oil and methanol using an S₂O^2-₈/Fe₂O₃-ZrO₂-La₂O₃ solid superacid catalyst in a pressure kettle. The S₂O^2-₈/Fe₂O₃-ZrO₂-La₂O₃ solid superacid was prepared by a precipitation-impregnation method and was characterized by XRD and FTIR. The effects of catalyst synthesis and transesterification conditions on the yield of biodiesel were investigated. The results showed that the maximum biodiesel yield of 90.3% was obtained when the Fe/Zr/La atom molar ratio in the catalyst was 1∶0.42∶0.075. The optimum transesterification reaction conditions were as follows: reaction temperature 220℃, molar ratio of methanol to oil 12∶1, reaction time 10h and a catalyst quantity of 2.0% relative to the vegetable seed oil. The biodiesel yield decreased from 90.3% to 83.0% after the catalysts were reused for five successive 10h periods. GC-MS characterization of the biodiesel indicated that its purity was relatively high.