Mo-Catalyzed Direct Nitrogen-to-Amine Conversion in Flow via Active N-H Species

Direct conversion of N₂ into valuable nitrogen-containing chemicals (NCCs), such as amines, without involving NH₃, is highly attractive but challenging, as forming C-N bonds from N₂ is thermodynamically unfavorable. Here, we demonstrate that N-H species on Mo-based catalysts enable this transformation efficiently. Unlike conventional batch processes by homogeneous catalysts that rely on ammonia or strong reductants, our scalable flow system achieves direct N₂-to-amine conversion using commercial Mo, MoO₂, and MoO₃ with various alcohols (MeOH, EtOH, and n-PrOH), demonstrating broad applicability. Remarkably, the Mo catalysts exhibit exceptional low-temperature activity (>95% conversion at 225 °C), reducing the operating temperature by ∼100 °C compared to industrial mordenite (MOR) catalysts. Mechanistic studies reveal NH_x species as key intermediates, with the reaction proceeding via sequential nitrogen hydrogenation and alkylation. This strategy, combining efficient N₂ utilization with a continuous flow design, meets industrial practicality and offers a promising scalable route to amine synthesis.