In Situ Synthesis of CuxO/N Doped Graphdiyne with Pyridine N Configuration for Ammonia Production via Nitrate Reduction

CuxO/N-doped graphdiyne with pyridine N configuration are in situ prepared in one pot. Pyridinic N in GDY and CuxO synergistically allowed to achieve NH3 faradaic efficiencies greater than 85% both in a commercial H-cell and an anion exchange membrane (AEM) flow electrolyzer. The high selectivity and production rate in this device configuration demonstrate its potential for industrial application. AbstractElectroreduction of nitrate to ammonia provides an interesting pathway for wastewater treatment and valorization. Cu-based catalysts are active for the conversion of NO3− to NO2− but suffer from an inefficient hydrogenation process of NO2−. Herein, CuxO/N-doped graphdiyne (CuxO/N-GDY) with pyridine N configuration are in situ prepared in one pot. Benefiting from the synergistic effect of pyridinic N in GDY and CuxO, the prepared CuxO/N-GDY tested in a commercial H-cell achieved a faradaic efficiency of 85% toward NH3 at -0.5  V versus RHE with a production rate of 340 µmol h−1 mgcat−1 in 0.1  M KNO3. When integrating the CuxO/N-GDY in an anion exchange membrane flow electrolyzer, a maximum Faradaic efficiency of 89% is achieved at a voltage of 2.3  V and the production rate is 1680 µmol h−1 mgcat−1 at 3.3  V in 0.1 M KNO3 at room temperature. Operation at 40  °C further promoted the overall reaction kinetics of NO3− to NH3, but penalized its selectivity with respect to hydrogen evolution reaction. The high selectivity and production rate in this...

Source: Small - March 29, 2024 Category: Nanotechnology Authors: Jian Li, Roberto Valenza, Sophia Haussener Tags: Research Article Source Type: research