Sustainable conversion of alkaline nitrate to ammonia at activities greater than 2 A cm-2.
Nat Commun
; 15(1): 1264, 2024 Feb 10.
Article
em En
| MEDLINE
| ID: mdl-38341446
ABSTRACT
Nitrate (NO3â) pollution poses significant threats to water quality and global nitrogen cycles. Alkaline electrocatalytic NO3â reduction reaction (NO3RR) emerges as an attractive route for enabling NO3â removal and sustainable ammonia (NH3) synthesis. However, it suffers from insufficient proton (H+) supply in high pH conditions, restricting NO3â-to-NH3 activity. Herein, we propose a halogen-mediated H+ feeding strategy to enhance the alkaline NO3RR 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 NO3â to high-purity NH4Cl 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 NO3â-to-NH3 conversion.
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MEDLINE
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En
Ano de publicação:
2024
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Article