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 NHx 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.