School of Chemistry, Monash University, Clayton, VIC 3800, Australia.
ARC Centre of Excellence for Electromaterials Science, Monash University, Clayton, VIC 3800, Australia.
Science. 2021 Jun 11;372(6547):1187-1191. doi: 10.1126/science.abg2371.
Ammonia (NH) is a globally important commodity for fertilizer production, but its synthesis by the Haber-Bosch process causes substantial emissions of carbon dioxide. Alternative, zero-carbon emission NH synthesis methods being explored include the promising electrochemical lithium-mediated nitrogen reduction reaction, which has nonetheless required sacrificial sources of protons. In this study, a phosphonium salt is introduced as a proton shuttle to help resolve this limitation. The salt also provides additional ionic conductivity, enabling high NH production rates of 53 ± 1 nanomoles per second per square centimeter at 69 ± 1% faradaic efficiency in 20-hour experiments under 0.5-bar hydrogen and 19.5-bar nitrogen. Continuous operation for more than 3 days is demonstrated.
氨（NH）是全球重要的肥料生产原料，但通过哈伯-博世工艺合成氨会导致大量二氧化碳排放。目前正在探索电化学锂介导的氮还原反应等零碳排放的氨合成方法，但这些方法需要牺牲质子来源。在这项研究中，一种鏻盐被引入作为质子穿梭体，以帮助解决这一限制。该盐还提供了额外的离子导电性，使得在 0.5 巴氢气和 19.5 巴氮气下，20 小时的实验中每平方厘米每秒可产生 53±1 纳摩尔的氨，法拉第效率为 69±1%。实验还证明了该方法可以连续运行超过 3 天。
