Selective hydrogenation of nitroarenes over MOF-derived Co@CN catalysts at mild conditions

Abstract

N-doped porous carbons incorporating highly-dispersed non-noble metallic cobalt (Co) nanoparticle materials were synthesized by rapid pyrolysis of a zeolitic-type metal-organic framework (ZIF-9) and their structures, morphologies, topologies and relevant physical and chemical properties were fully measured by different characterization technologies. The resulting derived Co/CN materials were further evaluated as catalysts in nitrobenzene hydrogenation. It was found that Co/CN materials showed remarkbly catalytic activity and chemoselectivity for mild hydrogenation of nitrobenzene. Amongst the studied a series of Co/CN-x (pyrolyzed at x °C) materials, sample Co@CN-800 shows the most superior catalytic activity for hydrogenation of nitrobenzene. In particular, the catalytic conversion activity of Co@CN-800 is 100% with aniline being the sole product at 70 °C for 2 h, 27.5 times higher than that of cobalt powder (Co). It is believed that the large pore size, adsorption of nitroarenes substrate with high selectivity and strong interaction of Co nanoparticles with the doped N species can result in the high activity of Co@CN-800. This work therefore offers a cost-effective approach in developing highly efficient catalytic materials towards mild hydrogenation of nitrobenzene.