Atomically Dispersed Cu Catalyst for Efficient Chemoselective Hydrogenation Reaction.

The Cu-based nanocatalysts have shown a high selectivity toward selective hydrogenation reaction, but the underlying catalytic mechanism is still murky. Herein, we report a new gram-scale strategy for realizing the single atom Cu site incorporated into the melem ring of graphitic carbon nitride (Cu/CN) for understanding the catalytic mechanism of a hydrogenation reaction. The as-synthesized Cu/CN exhibits unprecedented selectivity (100%), high activity (TOF = 2.9 × 10 h), and outstanding stability for selective hydrogenation of 4-nitrostyrene. We reveal that the presence of hydroxymethyl from trimethylolmelamine is beneficial to atomically disperse Cu atoms in the CN. X-ray absorption fine structure tests reveal that the Cu atom of Cu/CN is dominated by the quaternary coordination way (Cu-N) in the melem ring of CN. Density functional theory calculations confirm that the high reactivity and selectivity originate from the anchored Cu sites creating the optimal chemical environment for the highly efficient hydrogenation reaction.