Regulating Local Electron Distribution of Cu Electrocatalyst via Boron Doping for Boosting Rapid Absorption and Conversion of Nitrate to Ammonia

Abstract

AbstractThe electrochemical reduction of nitrate to ammonia (NO3RR) is an effective route to ammonia synthesis with the characteristics of low energy input. However, the complex multi‐electron/proton transfer pathways associated with this reaction may trigger the accumulation of competitive by‐products. Herein, boron (B)‐doped Cu electrode (denoted as B–Cu2O/Cu/CP) as “all‐in‐one” catalyst is prepared by one‐step electrodeposition strategy. Caused by the B doping, the charge redistribution and local coordination environment of Cu2O/Cu species are modulated, resulting in the exposure of active sites on the Cu2O/Cu/CP catalyst. In‐situ Fourier transform infrared spectroscopy and theoretical investigations demonstrate that both Cu2O and Cu sites modulated by B can effectively enhance the adsorption of NO3− and facilitate the conversion of intermediate by‐products, thus promoting the direct reduction of NO3− to NH3. Consequently, a remarkable Faradaic efficiency of 92.74% can be obtained on B–Cu2O/Cu/CP catalyst with minimal accumulation of by‐products. It is expected that this work, based on the heterogeneous B doping, will open a maneuverable and versatile way for the design of effective catalysts.