Polymer-Supported Pd\nNanoparticles for Solvent-Free\nHydrogenation

Breaking the trade-off between activity\nand stability\nof supported\nmetal catalysts has been a long-standing challenge in catalysis, especially\nfor metal nanoparticles (NPs) with high hydrogenation activity but\npoor stability. Herein, we report a porous poly(divinylbenzene) polymer-supported\nPd NP catalyst (Pd/PDVB) with both high activity and excellent stability\nfor the solvent-free hydrogenation of nitrobenzene, even at ambient\ntemperature (25 °C) and H<sub>2</sub> pressure (0.1 MPa). Pd/PDVB\ngave a turnover frequency as high as 22,632 h<sup>–1</sup> at\n70 °C and 0.4 MPa, exceeding 5556 h<sup>–1</sup> of the\nclassical Pd/C catalyst under equivalent conditions. Mechanistic studies\nreveal that the polymer support benefits the desorption of the aniline\nproduct from the Pd surface, which is crucial for rapid hydrogenation\nunder solvent-free conditions. In addition, the polymer support in\nPd/PDVB efficiently hindered Pd leaching, resulting in good stability.