Low‐Temperature Synthesis of Ni ₂ Mo ₃ N Catalysts From NiMoO ₄ and N ₂ Molecules for Hydrogenation of 4‐Nitrophenol and Methyl Orange

Ni 2 Mo 3 N catalysts were synthesized from NiMoO 4 and N 2 molecules using CaH 2 as a reducing agent in molten LiCl at 600° C. This low‐temperature synthesis was enabled by the strong reducing capacity of the reaction atmosphere composing of hydride ions (H − ) in the diffusion media of molten salt, which facilitated activation of N 2 molecules. X‐ray diffraction confirmed the formation of a well‐crystallized Ni 2 Mo 3 N phase. Transmission electron microscopy coupled with energy‐dispersive X‐ray spectrometry revealed nanoscale morphologies with uniform distributions of Ni, Mo, and N. These results demonstrate that N 2 molecules can serve as an effective nitrogen source for producing metal nitride catalysts at 600° C. In NaBH 4 ‐assisted hydrogenation of 4‐nitrophenol (1.6 mM) and methyl orange (3.1 mM) at 25° C, the synthesized Ni 2 Mo 3 N catalysts achieved complete conversion within 5 and 60 min, respectively. These findings indicate that Ni 2 Mo 3 N is a promising catalyst for water remediation applications.