磷对TiO_(2)/MCM-41催化环己胺无溶剂氧化制备环己酮肟的调变作用

Phosphorus Modulation Effect on the Solvent-free Oxidation of Cyclohexylamine to Cyclohexanone Oxime Catalyzed by TiO_(2)/MCM-41

采用液相水解法制备了TiPO/MCM-41系列催化剂,通过BET、FT-IR、XRD、XPS、SEM和TEM技术对催化剂的结构和组成进行了表征,进一步研究了其在环己胺无溶剂氧化制备环己酮肟中的催化性能,并探讨了环己胺液相氧化的催化机理.结果表明,TiPO/MCM-41表面的钛羟基是催化氧化环己胺的活性中心,当反应温度为90℃、压力为1.0 MPa、时间为5 h和催化剂用量为0.3 g时,胺转化率为59.0%,肟选择性为87.9%,显示出不错的催化活性和重复使用性,为环己酮肟的高效制备提供了一种绿色路线,有一定的工业应用潜力.

TiPO/MCM-41 was synthesized by liquid phase hydrolysis method.The structure and properties of these catalysts were characterized by BET,FT-IR,XPS,XRD,SEM and TEM characterization techniques.The catalytic performance of TiPO/MCM-41 in the solvent-free oxidation of cyclohexylamine to cyclohexanone oxime was further studied.The probable liquid phase oxidation pathway of cyclohexylamine was also suggested.The results indicated that the titanium hydroxyl groups on the surface of TiPO/MCM-41 were the active centers for catalytic oxidation of cyclohexylamine.It was verified that TiPO/MCM-41 demonstrated goodish catalytic activity and repeatability.The optimal reaction conditions were obtained that temperature was 90℃,pressure was 1.0 MPa,time was 5 h and catalyst amount was 0.3 g,and 59.0%of cyclohexylamine conversion with 87.9%of selectivity to cyclohexanone oxime was achieved.The method developed in this study provides a green route for the highly efficient synthesis of cyclohexanone oxime,and has certain industrial application potential.