Preparation of a novel Fe_3O_4@SiO_2@Ni-La-B magnetic core-shell nanocomposite for catalytic hydrogenation

摘要

A novel Fe_3O_4@SiO_2@Ni-La-B magnetic core-shell nanocomposite was prepared by a combination of the Stober method and self-assembly. In this process, Fe_3O_4 nanoparticles were first coated with amorphous silica, forming Fe_3O_4@SiO_2 core-shell structural nanocomposites. Ni~(2+) and La~(3+) were then loaded onto the surface of Fe_3O_4@SiO_2, followed by reduction with KBH_4 to assemble a layer of Ni-La-B onto the surface of Fe_3O_4@SiO_2. The obtained Fe_3O_4@SiO_2@Ni-La-B core-shell nanocomposite has high saturation magnetization (20.6 emu/g), compared to that of Ni-La-B (only 0.4 emu/g). This magnetic core-shell nanocomposite showed high activity and good selectivity in the catalytic hydrogenation of benzophenone to benzhydrol, and can be easily separated and recycled after reaction.