活性炭负载壳聚糖催化室温无溶剂Knoevenagel缩合反应

Knoevenagel Condensation Reaction at Room Temperature under Solvent-Free Conditions Catalyzed by Activated Carbon-Supported Chitosan

通过活性炭(AC)负载壳聚糖(CS)的方法,制备了负载型的"壳聚糖/活性炭"催化剂(CS/AC)。利用FT-IR、XRD、TG-DTG、SEM、BET、元素分析等方法对催化剂进行表征,并系统研究了该催化剂在Knoevenagel缩合反应中的催化性能。结果表明,催化剂具有较好的活性,在室温无溶剂条件下,可以催化一系列芳香醛化合物与活泼亚甲基化合物进行缩合反应,产率均在80%以上;且反应体系放大100倍时,仍然保持较高的催化效率;此外,该催化剂具有较好稳定性,重复使用8次后,仍然保持较高的催化活性。

The activated carbon（ AC） supported chitosan（ CS） catalyst, denoted as CS/AC, was prepared by a simple method. The physicochemical properties of the as-prepared catalyst were characterized by FT-IR,XRD,TG-DTG,SEM,BET,and elemental analysis. The catalytic performance was tested by the Knoevenagel condensation reaction, and the results showed that the catalyst can efficiently catalyze the Knoevenagel condensation reaction of a series of aromatic aldehydes with active methylene compounds at solventfree and room temperature conditions,affording more than 80 % products yield. Furthermore,when the reaction system is scaled up by 100 times,the catalyst still maintains high catalytic efficiency. Moreover,the catalyst can be recovered by simple filtration and reused at least 8 times without significant loss of activity,indicating that the catalyst is very stable.