In situ-formed cobalt embedded into N-doped carbon as highly efficient and selective catalysts for the hydrogenation of halogenated nitrobenzenes under mild conditions

Inhibiting the dehalogenation is the main challenge when halogenated nitrobenzenes are hydrogenated using H₂ as hydrogen source by heterogeneous catalysis. Herein, the earth-abundant cobalt embedded into N-doped carbon (Co@CN) catalysts were fabricated via one-pot pyrolysis of tannic acid, Co(NO₃)₂·6H₂O and melamine, which can function as a highly efficient non-noble-metal-based heterogeneous catalyst for selective hydrogenation of halogenated nitrobenzenes. Chloroanilines, bromoanilines, and iodoanilines, including all regioisomers, could be obtained with excellent selectivity (typically >99 %) at 60 °C under 1 MPa H₂, at almost complete conversion of the substrates. Additionally, Co@CN demonstrated excellent catalytic stability and could be reused at least five times without obvious loss of catalytic activity and selectivity. Therefore, the Co@CN catalyst exhibits vast potential for future industrial application in the selective hydrogenation of halogenated nitrobenzenes.