Journal article
Enhancement of lithium-mediated ammonia synthesis by addition of oxygen
Department of Physics, Technical University of Denmark1
Surface Physics and Catalysis, Department of Physics, Technical University of Denmark2
Stanford University3
Catalysis Theory Center, Department of Physics, Technical University of Denmark4
VISION – Center for Visualizing Catalytic Processes, Centers, Technical University of Denmark5
Owing to the worrying increase in carbon dioxide concentrations in the atmosphere, there is a need to electrify fossil-fuel–powered chemical processes such as the Haber-Bosch ammonia synthesis. Lithium-mediated electrochemical nitrogen reduction has shown preliminary promise but still lacks sufficient faradaic efficiency and ammonia formation rate to be industrially relevant.
Here, we show that oxygen, previously believed to hinder the reaction, actually greatly improves the faradaic efficiency and stability of the lithium-mediated nitrogen reduction when added to the reaction atmosphere in small amounts. With this counterintuitive discovery, we reach record high faradaic efficiencies of up to 78.0 ± 1.3% at 0.6 to 0.8 mole % oxygen in 20 bar of nitrogen.
Experimental x-ray analysis and theoretical microkinetic modeling shed light on the underlying mechanism.
Language: | English |
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Publisher: | American Association for the Advancement of Science |
Year: | 2021 |
Pages: | 1593-1597 |
ISBN: | 0080879934 , 0444818472 , 1281716480 , 9780080879932 , 9780444818478 and 9781281716484 |
ISSN: | 10959203 and 00368075 |
Types: | Journal article |
DOI: | 10.1126/science.abl4300 |
ORCIDs: | Li, Katja , Andersen, Suzanne Z. , 0000-0002-7923-6029 , Saccoccio, Mattia , 0000-0002-0105-863X , Krempl, Kevin , Sažinas, Rokas , Pedersen, Jakob B. , Shadravan, Vahid , 0000-0001-5268-5644 , Chakraborty, Debasish , Kibsgaard, Jakob , Vesborg, Peter C.K. , Nørskov, Jens K. and Chorkendorff, Ib |