Short Current Cycle Li-Mediated Nitrogen Reduction

July 19, 2022
Molybdenum thin films in N2 saturated, per-deuterated tetrahydrofuran (d8-THF) based electrolyte were studied with time-resolved neutron reflectometry (schematic in upper left). The graph shows the thickness of the plated layer at constant current during the first 6 minutes of processing.

Scientific Achievement

Real-time in-situ measurements of lithium mediated electrochemical nitrogen reduction reaction (NRR) showed the early formation of a lithium-rich layer at the electrode-electrolyte interface with no evidence of an undesirable thick solid-electrolyte interphase (SEI).

Significance and Impact

NRR could be an alternative to the energy intensive Haber-Bosch process for ammonia production and this work demonstrates that short current cycles may be able to mitigate the efficiency-limiting effect of SEI formation.

Research Details

  • In situ neutron reflectometry was performed on Mo thin film electrodes in contact with tetrahydrofuran/LiClO4 electrolyte at constant current (-0.1 mA/cm2) to follow the formation of the electrode-electrolyte layer.
  • Measurements with and without ethanol (EtOH) proton source in the electrolyte were compared.

“Lithium-Mediated Electrochemical Nitrogen Reduction: Tracking Electrode−Electrolyte Interfaces via Time-Resolved Neutron Reflectometry”
Sarah J. Blair, Mathieu Doucet, James F. Browning, Kevin Stone, Hanyu Wang, Candice Halbert, Jaime Aviles Acosta, José A. Zamora Zeledón, Adam C. Nielander, Alessandro Gallo, Thomas F. Jaramillo
ACS Energy Letters 7, 1939 (2022). DOI: https://doi.org/10.1021/acsenergylett.1c02833