生物质碳基固体酸催化剂的制备及其对酯化反应的催化性能

为了寻找一种以生物质为原料，能够温和地合成磁性碳基固体酸催化剂的路径，以生物质柚子果皮为原料合成磁性固体酸催化剂，并将其用于催化油酸和乙醇的酯化反应中。结果表明：MPC-0.4-SO₃H和MPC-0.8-SO₃H在反应温度为80 ℃、催化剂用量为油酸质量的7%、油醇比为1∶20、反应时间为8 h时，酯化率可达到68.0%和68.8%，高于商用催化剂Amberlyst-15的酯化率；2种催化剂耐水性好，稳定性高，重复使用3次和4次时，酯化率仍高于或接近Amberlyst-15。通过分析可知，2种固体酸活化能较低，与Amberlyst-15相比，其催化反应的速率常数更大，在生物柴油的合成中具有较好的应用前景。

Preparation of magnetic carbonaceous solid acid catalyst from biomass and its catalytic activity in esterification

In order to find a way for mildly synthesizing magnetic carbonaceous solid acid catalyst from biomass, pomelo peel was used to prepare a new magnetic carbonaceous solid acid catalyst for catalytic esterification reaction of oleic acid and ethanol, which was selected as model for producing biodiesel. The structure characteristics for the prepared catalysts were identified by FT-IR, XRD and TGA. The results showed that when the reaction temperature was 80 ℃, the catalyst mass was 7% of oleic acid, the ratio of oil to alcohol was 1∶20 and reaction duration was 8 h, the esterification rates of MPC-0.4-SO3H and MPC-0.8-SO3H reached 68.0% and 68.8%, respectively, which was significantly higher than that of the commercial amberlyst-15. Both catalysts had good water resistance and high stability, the esterification rates of three or four times-reused catalysts were still higher than or close to the value of amberlyst-15. The activation energies of both solid acids were low. From the analysis, it is known that the two catalysts have good water resistance and high stability, compared with amberlyst-15, the rate constants of MPC-0.4-SO3H and MPC-0.8-SO3H were higher in catalytic reactions, and which presents good application prospects in biodiesel synthesis.