The Haber-Bosch process converts nitrogen (N₂) and hydrogen (H₂) into ammonia (NH₃) over iron-based catalysts. Today, 50% of global agriculture uses Haber-Bosch NH₃ in fertilizer. Efficient synthesis requires enormous energy to achieve extreme temperatures and pressures, and the H₂ is primarily derived from methane steam reforming. Hence, the Haber-Bosch process accounts for at least 1% of global greenhouse gas emissions (1). Electrochemical N₂ reduction to make NH₃, powered by renewable electricity under ambient conditions, could provide a localized and greener alternative. On page 1187 of this issue, Suryanto et al. (2) report highly efficient and stable electrochemical N₂ reduction based on a recyclable proton donor. This study builds on earlier work showing that an electrolyte containing a lithium salt in an organic solvent with a sacrificial proton donor was unmatched in its ability to unequivocally reduce N₂ (3, 4). In both studies, it is still unclear why lithium is so critical.

Haber-Bosch 工艺通过铁基催化剂将氮 (N ₂ ) 和氢 (H ₂ ) 转化为氨 (NH ₃ )。今天，全球 50% 的农业在肥料中使用 Haber-Bosch NH ₃。有效的合成需要巨大的能量来实现极端的温度和压力，而 H ₂主要来自甲烷蒸汽重整。因此，Haber-Bosch 过程至少占全球温室气体排放量的 1% ( 1 )。在环境条件下由可再生电力提供动力的电化学 N ₂还原生成 NH ₃可以提供局部和更环保的替代方案。在本期第 1187 页，Suryanto等人。( 2 ) 报道了基于可回收质子供体的高效且稳定的电化学 N ₂还原。这项研究建立在早期工作的基础上，该研究表明，在具有牺牲质子供体的有机溶剂中含有锂盐的电解质在明确还原 N _{2 的}能力方面是无与伦比的( 3 , 4 )。在这两项研究中，目前还不清楚为什么锂如此重要。