Yu Jidong, Gao Rui-Ting, Ren Shijie, Nguyen Nhat Truong, Wu Limin, Wang Lei
College of Chemistry and Chemical Engineering, College of Energy Material and Chemistry, Inner Mongolia Key Laboratory of Low Carbon Catalysis, Inner Mongolia University, Hohhot, 010021, China.
Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China.
Angew Chem Int Ed Engl. 2025 Jul 8:e202507696. doi: 10.1002/anie.202507696.
Ammonia from nitrate-containing wastewater demands the catalysts with high activity, stability, and selectivity toward acidic electrochemical nitrate reduction owing to the corrosion effect of the catalyst and the competitive hydrogen evolution reaction (HER). Herein, we synthesized single Ag atoms induced Ag-N/O bonds on one-dimensional WO nanowires for highly efficient and stable electrochemical nitrate reduction to ammonia under acidic conditions. The resultant catalyst achieved a Faradaic efficiency (FE) of ammonia exceeding ∼90% over a potential range of -0.6 to -0.2 V with a maximum FE approaching 100% at -0.4 V and a maximum NH yield at -0.55 V. Importantly, the catalyst maintained a current density at 480 mA cm over 1100 h with a stable FE of ∼94%. By integrating the catalyst into a membrane electrode assembly (MEA), we succeeded in obtaining an NH production rate of 12.75 mmol h at -4 V and maintained the stability for over 30 h with FE > 90%. Experimental and theoretical analysis have demonstrated that the formation of Ag-N/O bonds enhanced nitrate adsorption and lowered the energy barrier for the rate-determining step of *NO→*NHO, thereby considerably improving the efficiency of ammonia synthesis and inhibiting HER at amperometric current densities. This work provides insights into acidic nitrate reduction for ammonia electrosynthesis, which develops corrosion-resistant electrocatalysts for energy conversion.
由于催化剂的腐蚀作用和竞争性析氢反应（HER），含硝酸盐废水中的氨需要对酸性电化学硝酸盐还原具有高活性、稳定性和选择性的催化剂。在此，我们在一维WO纳米线上合成了单原子银诱导的Ag-N/O键，用于在酸性条件下高效稳定地将电化学硝酸盐还原为氨。所得催化剂在-0.6至-0.2 V的电位范围内实现了超过90%的氨法拉第效率（FE），在-0.4 V时最大FE接近100%，在-0.55 V时NH产量最高。重要的是，该催化剂在1100 h内保持480 mA cm的电流密度，稳定FE约为94%。通过将催化剂集成到膜电极组件（MEA）中，我们成功地在-4 V下获得了12.75 mmol h的NH生成速率，并在FE>90%的情况下保持了30 h以上的稳定性。实验和理论分析表明，Ag-N/O键的形成增强了硝酸盐吸附，降低了*NO→*NHO速率决定步骤的能垒，从而显著提高了氨合成效率，并在安培电流密度下抑制了HER。这项工作为氨电合成的酸性硝酸盐还原提供了见解，开发了用于能量转换的耐腐蚀电催化剂。
