采用共沉淀法制备了不同锂-铝比[n(Li)(Al)]的Li-Al类水滑石,经不同温度下焙烧得到复合氧化物；将复合氧化物作为大豆油与甲醇反应制备生物柴油的催化剂,考察了其对大豆油酯交换反应的催化性能.结果表明,n(Li)(Al)=13的类水滑石在400℃下焙烧得到的复合氧化物对大豆油酯交换反应具有极高的催化活性.在反应温度65℃、醇/油物质的量之比为15、催化剂用量为大豆油质量的0.5％条件下反应2h,生物柴油产率可达96.5％.与此同时,所制备的催化剂的回收再生性能良好,重复使用3次时生物柴油收率仍高达约90％.%A series of Li-Al hydrotalcite compounds with different n(Li)n(Al) ratio was prepared via co-precipitation process. Resultant Li-Al hydrotalcite compounds were calcined at different temperatures to give their derivatives, Li-Al composite oxides. As-synthesized Li-Al composite oxides were used as solid alkali catalysts to prepare biodiesel via the transesterifica-tion of soybean oil and methanol, and the catalytic performance of the catalysts for the transes-terification of soybean oil was investigated. It was found that the catalyst obtained by calcining Li-Al hydrotalcite sample with n(Li)(Al) = 13 at 400 °C had the best catalytic performance for the transesterification reaction of soybean oil. Biodiesel was harvested in a yield of 96.5% after the reactant system containing 0.5% catalyst and 15 : 1 methanol plus soybean (molar ratio) was allowed to take part in transesterification reaction at 65 °C for 2 h. Moreover, the catalyst could be well recovered and reused, with the yield of biodiesel being as much as about 90% after three cycle of reuse.
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