Facile Preparation of a Stable Fe3 O4 @LDH@NiB Magnetic Core-Shell Nanocomposite for Hydrogenation

A novel NiB deposited layered double hydroxide (LDH) coated ferroferric oxide (Fe3O4@LDH@NiB) magnetic core-shell nanocomposite was successfully fabricated by the combination of coprecipitation and impregnation-reduction. During the Fe3O4@LDH preparation, a facile template-free approach was employed to introduce the LDH shell, which was more efficient than the conventional method for the preparation of mesoporous materials that always needs to introduce and remove templates. The resulted Fe3O4@LDH has a relatively high surface area and abundant surface hydroxyl group, which can adsorb metal ions, making it favorable to disperse and stabilize the active Ni species, as demonstraed by TEM, XPS, FT-IR and BET characterizations. Therefore, it exhibited good activity in the selective hydrogenation of cinnamic acid to hydrocinnamic acid with the conversion and selectivity both approaching to 100%. Notably, the obtained Fe3O4@LDH@NiB can be easily separated by an external magnetic field and recycled eleven times without appreciable loss of its initial catalytic activity.