Modulating Hydrogen Species for Efficient and Sustainable Nitrate Electroreduction to Ammonia

ABSTRACT The electrochemical nitrate reduction reaction (NO 3 RR) represents a promising strategy for sustainable NH 3 synthesis and environmental remediation. However, developing an NH 3 production process that achieves both high current density and Faradaic efficiency (FE) is challenging owing to the strong electrostatic repulsion of NO 3 − from the electrode surface and the competing hydrogen evolution reaction at high current densities. Here, Cu/C electrode, modified using 1‐dodecanol (C 12 OH), achieves an exceptional NH 3 yield rate of 4.50 mmol cm −2 h −1 and FE NH3 of 98.9% at 1.0 A cm −2 . This performance significantly surpasses that of the pristine Cu/C catalyst and most reported state‐of‐the‐art catalysts. C 12 OH modification, which induces the reconstruction of the hydrogen‐bonded network on the electrode surface, not only enhances NO 3 − enrichment but also promotes H • radical generation. This new pathway, mediated by H • radicals, is both thermodynamically and kinetically favorable and underlies the promoted NH 3 production.