Elucidating the influence of ZrO2 crystal structures on reduction of nitrobenzene to aniline by H2S over MoS2/ZrO2 catalysts

The reduction of nitrobenzene (Ph-NO 2 ) to aniline (Ph-NH 2 ) utilizes H 2 S as a hydrogen donor. This approach alleviates environmental pollution while enabling resource utilization. However, it remains a challenge to develop sulfur-resistant catalysts. Herein, we fabricated a series of MoS 2 /ZrO 2 catalysts via crystalline phase modulation engineering for the reduction of Ph-NO 2 by H 2 S to Ph-NH 2 . Systematic experiments demonstrate that amorphous ZrO 2 has the highest concentration of oxygen vacancies (O v ), which exhibits the highest activity and stability. As a result, the MoS 2 /a-ZrO 2 achieves a Ph-NO 2 conversion of 92 % and a Ph-NH 2 selectivity of 85.7 % at 1.5 MPa and 90 °C, which is superior to MoS 2 /m-ZrO 2 , MoS 2 /t-ZrO 2 , MoS 2 and ZrO 2 . In situ FT-IR measurements combined with full two-dimensional time of flight chromatography suggest a double H-induced dissociation pathway for the reduction of Ph-NO 2 to Ph-NH 2 by H 2 S. This study offers a viable strategy for the valorization of H 2 S into valuable resources.