Boosting Electrocatalytic N₂ Reduction to NH₃ by Enhancing N₂ Activation via Interaction between Au Nanoparticles and MIL‐101(Fe) in Neutral Electrolytes

Abstract

Electrocatalytic nitrogen reduction reaction (NRR) has attracted much attention as a sustainable ammonia production technology, but it needs further exploration due to its slow kinetics and the existence of competitive side reactions. In this research, xAu/MIL‐101(Fe) catalysts were obtained by loading gold nanoparticles (Au NPs) onto MIL‐101(Fe) using a one‐step reduction strategy. Herein, MIL‐101(Fe), with high specific surface area and strong N2 adsorption capacity, is used as a support to disperse Au NPs to increase the electrochemical active surface area. Au NPs, with a high NRR activity, is introduced as the active site to promote charge transfer and intermediate formation rates. More importantly, the strong interaction between Au NPs and MIL‐101(Fe) enhances the electron transfer between Au NPs and MIL‐101(Fe), thereby enhancing the activation of N2 and achieving efficient NRR. Among the prepared catalysts, 15%Au/MIL‐101(Fe) has the highest NH3 yield of 46.37 μg h‐1mg‐1cat and a Faraday efficiency of 39.38 % at ‐0.4 V (vs. RHE). In‐situ FTIR reveals that the NRR mechanism of 15%Au/MIL‐101(Fe) follows the binding alternating pathway and also indicates that the interaction between Au NPs and MIL‐101(Fe) strengthens the activation of the N≡N bond in the rate‐limiting process, thereby accelerating the NRR process.