新型碳基固体酸催化剂在酯化反应中的催化性能研究

STUDY ON THE ESTERIFICATION OVER CARBON-BASED SOLID ACID CATALYST

通过膨化淀粉和对甲基苯磺酸混合物的部分炭化制备新型碳基固体酸催化剂,研究新型碳基固体酸催化剂在油酸与乙醇的酯化反应中的催化性能,考察乙醇与油酸比、催化剂用量和反应时间等因素的影响。XRD分析和酸碱电位滴定结果表明,膨化淀粉和对甲基苯磺酸混合物的部分炭化生成含高密度—SO3H基的芳香碳薄层组成的无定形炭。新型碳基固体酸在油酸与乙醇的酯化反应中具有较好的催化活性。在乙醇与油酸摩尔比为8、催化剂与油酸质量比为5.0%、回流反应时间为6h的条件下,油酸乙酯收率可达到83.78%。催化剂重复使用6次后,活性下降很小。

A carbon based solid acid catalyst was prepared from the partial carbonification of expanded starch and p-toluene sulfonic acid, and its catalytic performance during the esterification of oleic acid with ethanol was studied. The effects of the ratio of ethanol to oleic acid, catalyst dosage and reaction time on the ethyl oleate yield were discussed. The results of XRD and acid-base titration indicated that the partial carbonization of the mixture of expanded starch and p-toluene sulfonic acid resulted in forming amorphous coke consisting of polycyclic aromatic carbon sheets with high density of SOa H groups. Results also indicated that carbon-based solid acid catalyst was highly active during the esterification of oleie acid with ethanol,under the reaction conditions of a molar ratio of ethanol to oleic acid of 8,a reaction time of 6.0 h and the catalyst dosage of 5.0%（in oleie acid） ,the yield of ethyl oleate reached 83.78%. The catalyst was reusable,and the ethyl oleate yield was only slightly dropped after six cycles.