A molybdenum-promoted nickel-aluminum alloy catalyst for high-efficient hydrogenation reduction of nitrate to ammonia and nitrogen.

Nitrate pollution in water necessitates efficient catalytic solutions for its conversion into harmless or valuable products. In this work, a molybdenum-promoted nickel-aluminum alloy (NAMCat) catalyst via alkaline leaching for the hydrogenation reduction of nitrate to N2 and NH3 was developed. The catalyst achieves over 99% nitrate conversion with brilliant product selectivity of N2/NH3 under mild conditions. The characterization results revealed that Mo doping critically induces a sponge-like porous architecture and fosters synergistic Ni-Mo active sites, which collectively enhance mass transport, hydrogen activation and reaction kinetics. The catalyst also demonstrates remarkable stability, recyclability, and tolerance to common interfering ions. A reaction mechanism based on the porous and electronic structure of NAMCat was also proposed. This work provides a cost-effective, non-noble-metal catalyst strategy for simultaneous nitrate remediation and nitrogen resource recovery.