SBA-15固载离子液体功能化脯氨酸的制备及其催化Knoevenagel缩合反应

Knoevenagel Condensation Catalyzed by Immobilized Ionic Liquids-Proline on SBA-15

以L-脯氨酸为原料合成了离子液体功能化脯氨酸前驱体（IL-Pro）,并将其固载到SBA-15介孔分子筛上,制得IL-Pro/SBA-15催化剂.用红外光谱、热重、N2吸附-脱附、X射线衍射和透射电镜等手段表征了IL-Pro/SBA-15催化剂,并考察了该催化剂在Knoevenagel缩合反应中的催化性能.结果表明,固载离子液体功能化脯氨酸没有破坏SBA-15的有序介孔结构,但孔体积、孔径和比面表积有所下降;IL-Pro/SBA-15的失重峰在250-360℃（峰值为310℃）.在以苯甲醛和丙二腈为底物的Knoevenagel反应中,IL-Pro/SBA-15催化剂表现出较高的活性,缩合产物收率高达94%;经简单分离后催化剂可重复使用7次以上而活性基本保持不变.

The IL-Pro/SBA-15 catalyst was prepared using SBA-15 as the support to immobilize ionic liquid proline,which was synthesized from L-proline.The IL-Pro/SBA-15 catalyst was characterized by FT-IR spectroscopy,thermal gravity analysis-derivative thermogravimetry,N2 adsorption-desorption,X-ray diffraction,and transmission electron microscopy,and the catalytic performance of the catalyst was measured for Knoevenagel reaction.The results showed that the mesoporous structure of SBA-15 was not affected by immobilization;however,the pore diameter,pore volume,and surface area were decreased.Mass loss of the supported ionic liquid occurred at 250-360 oC,and reached the maximum at 310 oC.The Pro-IL/SBA-15 catalyst had higher activity in Knoevenagel reaction of benzaldehyde with malononitrile and gave the corresponding product yield of 94%.The supported catalyst could be easily separated from the reaction system and reused at least seven times without loss of catalytic activity.