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Abstract Recently, lithium‐mediated nitrogen reduction reaction (Li‐NRR) in nonaqueous electrolytes has proven to be an environmentally friendly and feasible route for ammonia electrosynthesis, revealing tremendous economic and social advantages over the industrial Haber‐Bosch process which consumes enormous fossil fuels and generates massive carbon dioxide emissions, and direct electrocatalytic nitrogen reduction reaction (NRR) which suffers from sluggish kinetics and poor faradaic efficiencies. However, reaction mechanisms of Li‐NRR and the role of solid electrolyte interface (SEI) layer in activating N2remain unclear, impeding its further development. Here, using electronic structure theory, we discover a nitridation‐coupled reduction mechanism and a nitrogen cycling reduction mechanism on lithium and lithium nitride surfaces, respectively, which are major components of SEI in experimental characterization. Our work reveals divergent pathways in Li‐NRR from conventional direct electrocatalytic NRR, highlights the role of surface reconstruction in improving reactivity, and sheds light on further enhancing efficiency of ammonia electrosynthesis.
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Alternative ammonia production processes and the use of renewables
The Haber–Bosch synthesis of ammonia is an energy-intensive process that uses coal or natural gas as a fuel and feed. Direct electrochemical nitrogen reduction represents a potential alternative to the Haber–Bosch process that can be less polluting. This alternative route to ammonia from dinitrogen is not likely to require the same large capital investments as does the Haber–Bosch process, thus suggesting a distributive production structure of ammonia relative to the existing ammonia industry. In addition, the flexibility borne from the use of electrochemistry yields technologies that are better fit for the use of renewable energy sources that supply intermittent electricity. We show that under certain scenarios, at levels of efficiency (as determined by the required overpotential and the Faradaic efficiency) that might reasonably be achieved, direct electrochemical nitrogen reduction would be a sustainable and economically viable alternative to the Haber–Bosch process.
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- Award ID(s):
- 1955014
- PAR ID:
- 10347839
- Editor(s):
- Murthy, G. S.; Gnansounou, E.; Khanal, S. K.; Pandey, A.
- Date Published:
- Journal Name:
- Biomass, Biofuels, Biochemicals
- Page Range / eLocation ID:
- 243-258
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1016/B978-0-12-819242-9.00007-5
