1. Sustainable conversion of alkaline nitrate to ammonia at activities greater than 2 A cm−2.
- Author
-
Liao, Wanru, Wang, Jun, Ni, Ganghai, Liu, Kang, Liu, Changxu, Chen, Shanyong, Wang, Qiyou, Chen, Yingkang, Luo, Tao, Wang, Xiqing, Wang, Yanqiu, Li, Wenzhang, Chan, Ting-Shan, Ma, Chao, Li, Hongmei, Liang, Ying, Liu, Weizhen, Fu, Junwei, Xi, Beidou, and Liu, Min
- Subjects
NITROGEN cycle ,NITRATES ,WATER quality ,POLLUTANTS ,SUPPLY & demand - Abstract
Nitrate (NO
3 ‒ ) pollution poses significant threats to water quality and global nitrogen cycles. Alkaline electrocatalytic NO3 ‒ reduction reaction (NO3 RR) emerges as an attractive route for enabling NO3 ‒ removal and sustainable ammonia (NH3 ) synthesis. However, it suffers from insufficient proton (H+ ) supply in high pH conditions, restricting NO3 ‒ -to-NH3 activity. Herein, we propose a halogen-mediated H+ feeding strategy to enhance the alkaline NO3 RR performance. Our platform achieves near-100% NH3 Faradaic efficiency (pH = 14) with a current density of 2 A cm–2 and enables an over 99% NO3 – -to-NH3 conversion efficiency. We also convert NO3 ‒ to high-purity NH4 Cl with near-unity efficiency, suggesting a practical approach to valorizing pollutants into valuable ammonia products. Theoretical simulations and in situ experiments reveal that Cl-coordination endows a shifted d-band center of Pd atoms to construct local H+ -abundant environments, through arousing dangling O-H water dissociation and fast *H desorption, for *NO intermediate hydrogenation and finally effective NO3 ‒ -to-NH3 conversion. Alkaline nitrate electroreduction to ammonia is restricted by insufficient H+ supply. Here, the authors propose a halogen-mediated H+ feeding strategy, by triggering dangling O-H water dissociation and fast *H desorption for *NO intermediate hydrogenation, to enhance the formation of ammonia. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF