Hydrogenation Reactions with Synergistic Catalysis of Pd single atoms and nanoparticles under Near-Ambient Conditions.

Due to the limited resources and high cost of noble metals, boosting their catalytic activities is highly desired in the current catalysis industry. Here, we report a synergetic catalyst, combining Pd and Pd species in a nitrogen-doped porous carbons (NPC), which shows boosted catalytic activities in hydrogenation reactions of organic nitro compounds (nitrobenzene, 4-nitrophenol, 1-nitronaphthalene and 1-nitropropane) under near ambient conditions. This synergetic catalyst NPC-[Pd] was synthesized by partial reduction of a palladium-loaded NPC. The catalytic activities and selectivity of NPC-[Pd] for hydrogenation were enhanced significantly compared with those of NPC-Pd or NPC-Pd nanoparticles. Theoretical calculations show that H preferentially dissociates on Pd nanoparticles, and then organic molecules (nitrobenzene) can be captured and react with the dissociated H atom on Pd sites. Similar reaction procedure also occur on Pt or Rh. Hydrogenation of different aromatic compounds with different functional groups (naphthalene, 4-nitrochlorobenzene, benzaldehyde and acetophenone) confirmed the broad excellent catalytic activity of this synergistic catalyst.