First-Principles Study on the Mechanism of Nitrobenzene Reduction to Aniline Catalyzed by a N-Doped Carbon-Supported Cobalt Single-Atom Catalyst
Haohao Wang, Wei Zhang, Yangqiu Liu, Min Pu, Ming Lei
Abstract
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–N4/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 H2 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–N4/C could be an efficient and cheap metal single-atom catalyst for the reduction of nitrobenzene to aniline.