Electrochemically Selective Ammonia Extraction from Nitrate by Coupling Electron- And Phase-Transfer Reactions at a Three-Phase Interface
Document Type
Article
Publication Date
8-3-2021
Abstract
As an attractive alternative to the Haber-Bosch process, an electrochemical process for nitrate (NO3-) reduction to ammonia (NH3) has made great strides in the development of advanced electrocatalysts to suppress the unavoidable H2 evolution reaction (HER) and side production of N2. However, isochronous NH3 separation and recovery from the mother liquor, especially wastewaters, are awfully neglected in state-of-the-art electrochemical systems. Here, we designed electrochemical three-phase interfaces constructed by a CoP cathode and a flat-sheet gas membrane to achieve NO3- reduction to ammonia and simultaneous NH3 recovery in the form of (NH4)2SO4 from wastewaters. The partial current density for ammonia yield and its recovery rate were 37.3 mA cm-2 and 306 g »NH3-N m-2 day-1, respectively, accompanying 100% NO3- removal and 99.7% NH3 extraction. By favoring the originally unfavored side reaction HER, it served as the driving force for NH3 separation from the wastewater through gas stripping and membrane separation at the three-phase interfaces. Unexpectedly, the timely NH3 separation could also promote the reduction of NO3- to ammonia due to the release of much more active sites. From these, we envision that the present electrochemical process can be routinely employed as an effective strategy to address energy and environmental issues with NH3 recovery from NO3- wastewater.
Identifier
85110499157 (Scopus)
Publication Title
Environmental Science and Technology
External Full Text Location
https://doi.org/10.1021/acs.est.0c08552
e-ISSN
15205851
ISSN
0013936X
PubMed ID
34259503
First Page
10684
Last Page
10694
Issue
15
Volume
55
Grant
2017ZX07101-006
Fund Ref
Major Science and Technology Program for Water Pollution Control and Treatment
Recommended Citation
Gao, Jianan; Shi, Ning; Guo, Xiaobin; Li, Yifan; Bi, Xuejun; Qi, Yuanfeng; Guan, Jing; and Jiang, Bo, "Electrochemically Selective Ammonia Extraction from Nitrate by Coupling Electron- And Phase-Transfer Reactions at a Three-Phase Interface" (2021). Faculty Publications. 3890.
https://digitalcommons.njit.edu/fac_pubs/3890
