Water Increases the Faradaic Selectivity of Li-Mediated Nitrogen Reduction
Matthew Spry, Olivia Westhead, Romain Tort, Benjamin Moss, Yu Katayama, Maria‐Magdalena Titirici, Ifan E. L. Stephens, Alexander Bagger
Abstract
High Resolution Image Download MS PowerPoint Slide The lithium-mediated system catalyzes nitrogen to ammonia under ambient conditions. Herein we discover that trace amount of water as an electrolyte additive─in contrast to prior reports from the literature–can effect a dramatic improvement in the Faradaic selectivity of N 2 reduction to NH 3 . We report that an optimal water concentration of 35.9 mM and LiClO 4 salt concentration of 0.8 M allows a Faradaic efficiency up to 27.9 ± 2.5% at ambient pressure. We attribute the increase in Faradaic efficiency to the incorporation of Li 2 O in the solid electrolyte interphase, as suggested by our X-ray photoelectron spectroscopy measurements. Our results highlight the extreme sensitivity of lithium-mediated N 2 reduction to small changes in the experimental conditions.