Unprecedentedly high activity and selectivity for hydrogenation of nitroarenes with single atomic Co1-N3P1 sites

Modulating the atomic coordination structure has emerged as a promising strategy to further improve catalytic performance. Here, the authors report an atomic Co1/NPC catalyst with unsymmetrical single Co1N3P1 sites that displays high activity and chemoselectivity for hydrogenation of functionalized nitroarenes. Transition metal single atom catalysts (SACs) with M-1-N-x coordination configuration have shown outstanding activity and selectivity for hydrogenation of nitroarenes. Modulating the atomic coordination structure has emerged as a promising strategy to further improve the catalytic performance. Herein, we report an atomic Co-1/NPC catalyst with unsymmetrical single Co-1-N3P1 sites that displays unprecedentedly high activity and chemoselectivity for hydrogenation of functionalized nitroarenes. Compared to the most popular Co-1-N-4 coordination, the electron density of Co atom in Co-1-N3P1 is increased, which is more favorable for H-2 dissociation as verified by kinetic isotope effect and density functional theory calculation results. In nitrobenzene hydrogenation reaction, the as-synthesized Co-1-N3P1 SAC exhibits a turnover frequency of 6560 h(-1), which is 60-fold higher than that of Co-1-N-4 SAC and one order of magnitude higher than the state-of-the-art M-1-N-x-C SACs in literatures. Furthermore, Co-1-N3P1 SAC shows superior selectivity (>99%) toward many substituted nitroarenes with co-existence of other sensitive reducible groups. This work is an excellent example of relationship between catalytic performance and the coordination environment of SACs, and offers a potential practical catalyst for aromatic amine synthesis by hydrogenation of nitroarenes.

Automated summary

Modulating the atomic coordination structure has been proven to be a promising strategy for improving catalytic performance. In this study, the authors introduce an atomic Co1/NPC catalyst with unsymmetrical single Co1N3P1 sites, which exhibits high activity and chemoselectivity in the hydrogenation of functionalized nitroarenes.