Highly efficient and anti-poisoning single-atom cobalt catalyst for selective hydrogenation of nitroarenes

Developing non-precious metal catalysts to selectively reduce functionalized nitroarenes with high efficiency is urgently desirable for the production of value-added amines. Herein, we report a novel, efficient, anti-poisoning single-atom cobalt catalyst (Co-NAC) for the highly selective hydrogenation of the nitro to amino group for nitroarenes baring various functional groups, including vinyl, cyano, and halogen. Using a combination of structure characterization techniques, we have confirmed that the cobalt species are predominantly present in the form of four-coordinated Co single sites anchored on nitrogen-assembly carbon (NAC) as the ordered mesoporous support. Co-NAC catalysts enable the full conversion and > 99% selectivity with molecular H-2 as a green reductant under mild conditions (80 degrees C, 2 MPa H-2). As for the selective hydrogenation of 3-nitrostyrene, Co-NAC catalyst affords high catalytic productivity (19.7 h(-1)), which is superior to the cobalt nanoparticles (NPs) catalysts and most of the recently reported Co-based catalysts. This is attributed to the highly accessible atomically-dispersed Co active sites, the high surface area with ordered-mesoporous morphology and the prominent high content of nitrogen dopants. Notably, Co-NAC catalyst displays resistance towards sulfur-containing poisons (20 equivalents) and strong non-oxidizing acid (8 M), showing great potential for continuous application in the chemical industry.