Hydrogenation of Nitroarenes by Onsite-Generated Surface Hydroxyl from Water

Abstract

Directly using water as a hydrogen source for hydrogenation of nitroarenes to anilines (HNA) without using H2 is an ideal reduction reaction route but is limited by unfavorable thermodynamics. Herein, we report a high-efficiency and durable H2O-based HNA process achieved by using in situ-generated hydroxyl species from water as a hydrogen donor and low-cost CO as an oxygen acceptor over a molybdenum carbide-supported gold catalyst (Au/α-MoC1–x). It affords nitroarene conversion of over 99% with aniline selectivity of over 99% and excellent functional group tolerance at 25 °C and remains stable after 10 cycles, outperforming the traditional H2-involved route. Spectroscopic and theoretical studies reveal the key role of Au/α-MoC1–x boundaries, at which not only hydroxyl species are generated as a soft reductant on α-MoC1–x but also the nitro group is selectively hydrogenated to anilines with other unsaturated groups intact, and residual O* is removed by adsorbed CO on the atomically thin Au layer. This process provides a durable H2O-based route for aniline production at room temperature.