煤基固体酸催化合成席夫碱反应

以煤基活性炭(AC)和苯胺(ANI)为原料,通过原位-溶液聚合法制备了煤基固体酸催化剂AC@PANI-SO_3H(APS),利用扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)和热重分析(TG)等技术手段对催化剂进行了结构和性能的表征。研究了该催化剂在微波辐射下催化合成Schiff碱化合物的活性,并对其催化工艺条件进行了优化考察。结果表明,催化剂用量5%(以每摩尔邻苯二胺用量为基准),反应时间3~20 min,溶剂选用乙醇(Et OH),Schiff碱化合物产率可达80%~93%,说明该催化剂在微波催化合成席夫碱反应中变现出良好的催化活性,反应时间短,工艺简单操作,且催化剂能重复使用5次。通过红外发现,催化剂重复5次后活性下降的主要原因是固体酸表面键合的磺酸基官能团消失,从而导致活性降低。

Synthesis of Schiff Base Catalyzed by Coal-based Solid Acid Catalyst

A coal-based solid acid catalyst AC@PANI-SO₃H(APS) was prepared in situ by solution polymerization using coal-based activated carbon(AC) and aniline(ANI) as raw materials. The catalyst was characterized by scanning elecrton microscopy(SEM), Fourier transform infrared spectrometer(FTIR), X-ray photoelectron spectroscopy(XPS), and thermal gravimetric analyzer(TGA). Its catalytic activity on yield of Schiff bases was studied under microwave irradiation. The results show that with 5 %(based on the amount of o-phenylenediamine per mole) catalyst, the reaction in ethanol is performed for 3 to 20 min, the yield of Schiff-bases is 80% to 93%. It is proved that the catalyst exhibits good catalytic activity in the microwave-catalyzed synthesis of Schiff base. The reaction time is short, the process is simple to operate, and the catalyst can be reused 5 times. The main reason for the decrease of the activity of the catalyst after repeated 5 times is that the sulfonic acid functional groups bonded to the solid acid surface is disappeared and the activity is decreased.