| Autor: |
Westhead O; Department of Materials, Imperial College London, UK. i.stephens@imperial.ac.uk., Tort R; Department of Chemical Engineering, Imperial College London, UK. a.bagger@imperial.ac.uk., Spry M; Department of Materials, Imperial College London, UK. i.stephens@imperial.ac.uk., Rietbrock J; Department of Materials, Imperial College London, UK. i.stephens@imperial.ac.uk., Jervis R; Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, UK., Grimaud A; Solid-State Chemistry and Energy Laboratory, UMR8260, CNRS, Collège de France, France.; Réseau sur le Stockage Electrochimique de l'Energie (RS2E), CNRS FR 3459, 80039 Amiens Cedex 1, France.; Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA., Bagger A; Department of Chemical Engineering, Imperial College London, UK. a.bagger@imperial.ac.uk., Stephens IEL; Department of Materials, Imperial College London, UK. i.stephens@imperial.ac.uk. |
| Abstrakt: |
The verification of the lithium-mediated nitrogen reduction system in 2019 has led to an explosion in the literature focussing on improving the metrics of faradaic efficiency, stability, and activity. However, while the literature acknowledges the vast intrinsic overpotential for nitrogen reduction due to the reliance on in situ lithium plating, it has thus far been difficult to accurately quantify this overpotential and effectively analyse further voltage losses. In this work, we present a simple method for determining the Reversible Hydrogen Electrode (RHE) potential in the lithium-mediated nitrogen reduction system. This method allows for an investigation of the Nernst equation and reveals sources of potential losses. These are namely the solvation of the lithium ion in the electrolyte and resistive losses due to the formation of the solid electrolyte interphase. The minimum observed overpotential was achieved in a 0.6 M LiClO 4 , 0.5 vol% ethanol in tetrahydrofuran electrolyte. This was -3.59 ± 0.07 V vs. RHE, with a measured faradaic efficiency of 6.5 ± 0.2%. Our method allows for easy comparison between the lithium-mediated system and other nitrogen reduction paradigms, including biological and homogeneous mechanisms. |
