Atomically dispersed Co-N4 sites anchored on N-doped carbon for aqueous phase transfer hydrogenation between nitroarenes and saturated N-heterocycles

Transfer hydrogenation reactions using non-noble metal-based nanocatalysts are extensively attractive due to their low-cost and green reaction conditions. But construction of such catalysts with maximum metal atom efficiency and high catalytic activity is still a challenging research goal. Here, atomically dispersed Co catalysts with Co-N-4 active sites were fabricated, which builds a bridge for transfer hydrogenation between nitroarenes and saturated N-heterocycles in aqueous solution. The TOF value of the transfer hydrogenation reaction is much higher than nanoparticle catalyst for this reaction. Density functional theory (DFT) calculations and control experiments reveal that the excellent performance origins from the Co-N-4 sites, which combines the dehydrogenation of 1,2,3,4-tetrahydroquinoline with hydrogenation of nitrobenzene in one-pot. This work not only has an in-depth understanding of active sites but also shows a unique activity to the challenging, highly efficient, and green transfer hydrogenation reaction.