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Updated: Oct 27, 2025
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Electrochemically and Bioelectrochemically Induced Ammonium Recovery
Published on: January 22, 2015
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Unveiling Potential Dependence in NO Electroreduction to Ammonia.
Jun Long1,2,3, Chenxi Guo2, Xiaoyan Fu1,2,3
1School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, People's Republic of China.
The Journal of Physical Chemistry Letters
|July 20, 2021
Summary
Electrochemical reduction of nitric oxide (NO) to ammonia (NH3) selectivity is controlled by electrode potential. A new microkinetic model explains selectivity shifts from N2O to NH3 and then to H2 as potential becomes more negative.
Area of Science:
- Electrochemistry
- Catalysis
- Chemical kinetics
Background:
- Electrochemical NO reduction to ammonia (eNORR) offers dual benefits for ammonia synthesis and denitrification.
- Experimental observations show varying selectivity trends in eNORR with electrode potential, but mechanistic understanding is lacking.
Purpose of the Study:
- To develop a microkinetic model for electrochemical NO reduction (eNORR) using silver (Ag) as a model catalyst.
- To rationalize the selectivity trends of eNORR with varying electrode potential.
Main Methods:
- Development of a microkinetic model for eNORR.
- Simulation of eNORR selectivity at different potentials.
- Analysis of reaction pathways and rate-limiting steps.
Main Results:
- The model accurately reproduces experimental selectivity trends, including turnover from N2O to NH3 and NH3 to H2 with increasing negative potential.
- Selectivity turnover from N2O to NH3 is limited by the thermochemical coupling of NO* intermediates.
- Selectivity turnover from NH3 to H2 is attributed to the higher transfer coefficient of hydrogen evolution reaction (HER) compared to NH3 production.
Conclusions:
- Electrode potential is a critical factor in regulating eNORR selectivity.
- The model provides mechanistic insights into selectivity control, applicable to other electroreduction reactions like CO2 reduction.
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