Metal-Tuned W₁₈O₄₉ for Efficient Electrocatalytic N₂ Reduction

Electrochemical N₂ reduction (ENR) offers a promising route for NH₃ production. To promote this kinetically sluggish process, the design and development of electrocatalysts with high performance, good durability, low cost, and earth abundance are highly demanded. Here, we report a facile approach for the synthesis of metal-doped ultrafine W₁₈O₄₉ nanowires with significantly enhanced capability for electrocatalytic N₂ reduction to produce NH₃ within a wide pH range. In particular, the Mo-doped W₁₈O₄₉ catalyst can reduce N₂ to NH₃ with a faradaic efficiency approaching 12.1% at −0.2 V (versus the reversible hydrogen electrode, vs. RHE) and an NH₃ yield rate of 5.3 μgNH₃ h–¹ mgcₐₜ.–¹ at −0.5 V (vs. RHE) in 0.1 M Na₂SO₄, which is about two times higher than that of pristine W₁₈O₄₉. We find occurrence of strong electron transfer from Mo to W, which facilitates N₂ adsorption and activation, thus accelerating the ENR to generate NH₃. This work provides a simple and effective method to modify metal oxides for efficient electrochemical N₂ fixation.