Hematite nanoparticle-templated hollow carbon nanonets supported palladium nanoparticles: preparation and application as efficient recyclable catalysts

Hollow carbon nanonets (HCN), which are attractive materials for catalyst support, were fabricated using the pre-synthesized hematite nanoparticles as the hard template. And then the HCN supported Pd nanoparticles (Pd/HCN) were prepared by precipitation-reduction method. The catalytic performance of Pd/HCN was investigated using Suzuki and Heck coupling reactions as model reactions. The results demonstrated that the as-prepared Pd/HCN nanocomposites exhibit high catalytic activity for the two types of coupling reactions under ligand free conditions. Especially, the Suzuki reactions between various aryl halides and phenylboronic acid gave excellent yields in water. Moreover, the as-prepared Pd/HCN catalysts can be easily recovered from the reaction medium by centrifugation for recycling, and the catalytic efficiency shows no obvious loss even after 6 repeated cycles.