Ambient electrochemical N₂ reduction to NH₃ under alkaline conditions enabled by a layered K₂Ti₄O₉ nanobelt

Using electrocatalytic N₂ reduction to make NH₃ is considered to be an attractive environmentally-friendly alternative to the Haber-Bosch process, which is rather energy-intensive and has heavy CO₂ emissions. However, only limited success has been achieved in identifying metal oxides as effective electrocatalysts for the N₂ reduction reaction (NRR) under alkaline conditions. In this communication, we report that a K₂Ti₄O₉ nanobelt is able to effectively electrocatalyze the ambient NRR for N₂-to-NH₃ fixation at alkaline pH. When tested in 0.1 M KOH, a high NH₃ yield of 22.88 μg h^-1 mg^-1_cat. and a faradaic efficiency of 5.87% were attained. Moreover, K₂Ti₄O₉ also demonstrates good selectivity and high electrochemical stability for NH₃ formation.