Rapid Fabrication of N-, Cu-, and Co-Doped Electrodes with Strong Electronic Coupling by Cold Plasma for Electrocatalytic Reduction of Nitrate to Ammonia.

Electrochemical NO reduction (NORR) is a sustainable technology for ammonia synthesis. The development of a simple, fast, and economical catalytic electrode preparation technique is crucial for large-scale ammonia synthesis. Herein, we propose a plate-to-plate DBD plasma strategy to synthesize the catalytic electrodes M-N/CP (M = Cu, Co, Ni, CuCo, and CuNi), achieving in suit codoping of N and bimetals on carbon paper (CP) at room temperature within 3 h. N-doping improves the metal loading and the NORR performance by forming N-M bonds. The electronic coupling and synergistic effect of Cu and Co sites facilitate the relay conversion of NO to NO to NH. Notably, the NO removal efficiency of CuCo-N/CP reaches 82%, with NH yield rate of 346 μg h cm, and the faradaic efficiency is as high as 86% at -0.58 V vs RHE, which remains competitive in terms of NORR performance. Importantly, wet flue gas denitrification and desulfurization coupled with electrocatalytic reduction can convert NO and SO to (NH)SO, Additionally, the maneuverability of plasma technology offers the potential for batch preparation of CuCo-N/CP electrodes for electrochemically driven wet denitrification wastewater valorization.