First-Principles Study on the Mechanism of Nitrobenzene Reduction to Aniline Catalyzed by a N-Doped Carbon-Supported Cobalt Single-Atom Catalyst

A density functional theory study was performed to investigate the nature of the reduction of nitrobenzene to aniline catalyzed by a N-doped carbon-supported cobalt single-atom catalyst (Co-N-4/C). The calculated results indicate that the presence of water molecules plays an important role in the reduction of nitrobenzene to aniline and that the single H-induced dissociation mechanism of N-O bonds (PhNO2* -> PhNOOH* -> PhNO* -> PhNOH* -> PhN* -> PhNH* -> PhNH2*) is more favorable than the double H-induced dissociation mechanism (PhNO2* -> PhNOOH* -> PhN(OH)(2)* -> PhNOH* -> PhNHOH* -> PhNH* -> PhNH2*) for the reduction of nitrobenzene to aniline. The rate-determining step of the overall reaction using H-2 as the hydrogen source is the dissociation of hydrogen in the presence of nitrobenzene, having an energy barrier of 1.10 eV. This implies that Co-N-4/C could be an efficient and cheap metal single-atom catalyst for the reduction of nitrobenzene to aniline.

Automated summary

The study indicates that the N-doped carbon-supported cobalt single-atom catalyst plays an important role in the reduction of nitrobenzene to aniline, with the single H-induced dissociation mechanism favoring the reaction. When using H2 as the hydrogen source, the rate-determining step of the overall reaction is the dissociation of hydrogen in the presence of nitrobenzene.