Tuning selectivity in Ni-Catalyzed hydrogenation of functional nitroarenes: Unveiling the surprising role of defective vanadium oxide

Great efforts have been devoted to designing novel catalysts for the chemo-selective hydrogenation of nitroarenes into amines. Herein, we reported that the interfacial structure between defective V 2 O 3 and metallic Ni nanoparticles was crucial in the chemo-selective hydrogenation of 4-nitrostyrene and other functional nitroarenes under mild conditions (80 °C, 1.5 MPa H 2 ), affording the corresponding amines with excellent yields. Generally, the defective sites in metal oxides of metal oxide/metal nanoparticle interface were responsible for the chemo-selective hydrogenation of nitroarenes via the selective adsorption of the nitro group. However, our mechanistic study revealed that the oxygen-defective Ni-V 2 O 3 interface was the active site, and nitroarenes preferred to adsorb on Ni. Theoretical calculation results revealed that defective sites in V 2 O 3 effectively turned the electron density of metallic Ni to chemo-selective adsorption of the nitro group by reducing electron transfer from metallic Ni to defective V 2 O 3 . In this case, defective sites in V 2 O 3 also boost the electron transfer from metallic Ni to nitro group, significantly lowering the energy barrier for the hydrogenation of nitro group. This work provides a novel method for the non-noble metal catalyzed chemo-selective hydrogenation of nitroarenes by finely tuning the electron effects of metallic sites the interfacial defective metal oxides sites.