Stabilizing Pd on the surface of hollow magnetic mesoporous spheres: a highly active and recyclable catalyst for hydrogenation and Suzuki coupling reactions

We describe here a method to stabilize Pd(0) on the surface of hollow magnetic mesoporous spheres (HMMS), with Fe3O4 nanoparticles embedded in the mesoporous shell. The catalyst was characterized using TEM, XRD, VSM, BET and XPS. The catalyst afforded fast conversion for various aromatic nitro and unsaturated compounds in ethanol under an H-2 atmosphere even at room temperature. The catalyst showed an efficient hydrogenation of unsaturated compounds rather than nitro compounds. Furthermore it was found that the catalyst also exhibited a high activity in the Suzuki coupling reaction. The catalyst could be recovered in a facile manner from the reaction mixture and recycled six times without any loss in activity.