磁性负载钌催化剂的制备及其在吗啉存在下的稳定性研究

Preparation of magnetically loaded ruthenium catalyst and its stability in presence of morpholine

通过碱性条件下二氯化铁和三氯化铁的共沉淀法制备Fe3O4,表面SiO2包覆后得到磁性纳米粒子Fe3O4-SiO2,经过硅烷偶联剂上的Si—OMe与磁性载体上的Si—OH的异相缩合,将不同结构的硅烷偶联剂接到载体上,实现了磁性载体的表面功能化。利用载体上的官能团与钌的络合,成功地制备出磁性负载钌催化剂。应用UV-Vis分析技术考察了磁性载体与三氯化钌的络合性能及其与吗啉的络合平衡,分析了载体上的配体结构与负载催化剂上钌流失程度的关系,载体羧基及有机膦配体的引入,提高了载体对钌离子的络合能力,从而减少钌的流失程度。

Magnetic nanoparticles Fe3O4-SiO2 were prepared by co-precipitation of FeCl2 and FeCl3 with the surface modified by SiO2.The surface functionalized magnetic carriers were deposited by condensation of Si—OMe of different silane coupling agents with Si—OH groups of magnetic support.Functional groups on the carrier can coordinate with ruthenium to form magnetically loaded ruthenium catalyst.The complex process of ruthenium trichloride with magnetic carrier and its coordination equilibrium with morpholine were investigated by means of the UV-Vis spectroscopy.The relationship between the structure of ligand on the surface of magnetic carrier and the loss of ruthenium catalyst was elucidated.The introduction of carboxyl and organic phosphine ligands can enhance the complex ability to carry ruthenium ions,thereby reducing the extent of ruthenium loss.