Fourteen-Membered Macrocyclic Copper Complex for Highly Selective Electrochemical Nitrate Reduction to Ammonia
Year: 2026
Type: preprint
Abstract: The selective electrochemical reduction of nitrate (NO3−) to ammonia (NH3) represents a promising route for sustainable NH3 production. However, achieving high NH3 selectivity remains challenging due to competing reactions. Additionally, many reported catalysts rely on noble metals and often require relatively elevated catalyst loadings to achieve high apparent activity, while most systems operate only at relatively low current densities. Herein, a fourteen-membered macrocyclic copper complex supported on Ketjenblack (Cu-14MR/KB) is reported as a cathode catalyst for the highly selective electrochemical reduction of NO3− to NH3. With a low Cu loading of 1.34 μmol cm−2, Cu-14MR/KB delivered a high Faraday efficiency for NH3 synthesis of up to 94.8% at a current density of −26.3 mA cm−2 and maintained high NH3 selectivity over a wide current density range from −26.3 to −150 mA cm−2. Notably, at −150 mA cm−2, Cu-14MR/KB achieved an NH3 yield rate of 604 μmol cm−2 h−1 with an NH3 Faraday efficiency of 86.4%. Furthermore, a more contracted Cu–N4 coordination environment was revealed in Cu-14MR than in CuPc, with a shorter Cu–N bond distance, suggesting relatively stronger Cu–N interactions. This work provides an efficient strategy for high-performance NO3− electroreduction using a low-loading and non-noblemetal catalyst.
Source: ChemRxiv
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7220468427