Iridium Nanoparticles Confined within Partially Carbonized Hyperbranched Polymers for Selective Hydrogenation of Nitroarenes at Room Temperature

The high-efficiency catalyst for the reduction of nitroarenes with hydrogen under room temperature has always been paid much attention to. Herein, using a kind of hydroxyl-terminated hyperbranched polymer (H102) as both a template and a support, highly stable ultrafine Ir nanoparticles (Ir@H102-350) confined within the three-dimensional network cavities of the hyperbranched carbon skeletons, which were obtained from the partially carbonized self-assemblies of H102, were successfully prepared. At room temperature (25 degrees C), full conversion of nitrobenzene and >99.9% aniline selectivity were achieved over the Ir@H102-350 catalyst in 30 min under a H2 pressure of 1.5 MPa. A 100% conversion of various substituted nitroarenes and >99% selectivities of the corresponding aromatic amines were also obtained under the same conditions. The as-prepared Ir@H102-350 catalyst exhibited extremely high catalytic activity as well as high stability and excellent reusability toward the fast selective hydrogenation of various nitroarenes with H-2 at room temperature.