Synergy of Pyridinic Nitrogen and Fe–Co Bimetallic Species on N-Doped Carbon for Highly Selective Ammoxidation of Aromatic Alcohols to Nitriles

Catalytic ammoxidation of alcohols to nitriles under cyanide-free conditions has attracted considerable attention. Conventional approaches often rely on toxic cyanide sources, which create environmental and safety concerns that conflict with the core principles of green chemistry. Herein, we report the synthesis of an efficient Fe–Co bimetallic catalyst supported on N-doped carbon, denoted as FexCoyN–C (where x and y represent the nominal Fe/Co molar ratios of the metal precursors used during catalyst preparation), for the selective ammoxidation of aromatic alcohols to nitriles using ammonia as the nitrogen source. In the ammoxidation of 1-naphthalenemethanol, the Fe3Co7N–C catalyst delivers outstanding performance, affording a remarkable 99.9% yield of 1-naphthonitrile. Across the catalyst series, the catalytic activity shows positive correlations with the relative proportions of pyridinic N and Fe2+ species. Together with the mechanistic experiments and literature precedents, these observations suggest that pyridinic N may facilitate interfacial electron transfer, while Fe2+/Fe3+ redox chemistry may contribute to alcohol dehydrogenation. Time-dependent product distribution experiments and stepwise catalytic tests confirm that 1-naphthalenemethanol is first oxidized to 1-naphthaldehyde, which then undergoes ammoxidation to yield 1-naphthonitrile. This work offers new mechanistic insights and practical catalytic strategies for the green synthesis of nitriles, with the potential to guide the development of sustainable processes in related industrial applications.