丹麦技术大学Chorkendorff, Ib团队报道了长期连续氨电合成。相关研究成果于2024年3月19日发表在《自然》。

氨在化肥和化学工业中至关重要，被视为无碳燃料。在环境条件下由氮进行的氨电合成为Haber Bosch工艺提供了一种有吸引力的替代方案。锂介导的氮还原（Li-NRR）代表了一种很有前途的连续流氨电合成方法，将氮还原与氢氧化相结合。然而，通常用作溶剂的四氢呋喃（THF）由于聚合和挥发性问题而阻碍了氨的长期生产。

该文中，研究人员展示了基于链醚的电解质能够实现长期连续的氨合成。研究发现，链醚基溶剂表现出非聚合性质，具有高沸点（162°C），并在气体扩散电极（GDE）上形成致密的固体电解质界面（SEI）层，促进氨在气相中的释放，确保电解质的稳定性。研究人员展示了在具有25 cm²电极的流动电解槽中在1bar和室温下连续运行300小时，并实现了64±1%的电流-氨效率，气相氨含量达到了前所未有的~98%。

研究工作强调了溶剂在长期连续氨合成中的关键作用。

附：英文原文

Title: Long-term continuous ammonia electrosynthesis

Author: Li, Shaofeng, Zhou, Yuanyuan, Fu, Xianbiao, Pedersen, Jakob B., Saccoccio, Mattia, Andersen, Suzanne Z., Enemark-Rasmussen, Kasper, Kempen, Paul J., Damsgaard, Christian Danvad, Xu, Aoni, Sainas, Rokas, Mygind, Jon Bjarke Valbk, Deissler, Niklas H., Kibsgaard, Jakob, Vesborg, Peter C. K., Nrskov, Jens K., Chorkendorff, Ib

Issue&Volume: 2024-03-19

Abstract: Ammonia is crucial in fertilizer and chemical industries and is seen as a carbon-free fuel1. The ammonia electrosynthesis from nitrogen at ambient conditions offers an attractive alternative to the Haber-Bosch process2,3. The lithium-mediated nitrogen reduction (Li-NRR) represents a promising approach for continuous-flow ammonia electrosynthesis, coupling nitrogen reduction with hydrogen oxidation4. However, tetrahydrofuran (THF), commonly used as a solvent, impedes long-term ammonia production due to polymerization and volatility issues. Here we show that a chain ether-based electrolyte enables long-term continuous ammonia synthesis. We find that a chain ether-based solvent exhibits non-polymerization properties, a high boiling point (162°C), and forms a compact solid-electrolyte interphase (SEI) layer on the gas diffusion electrode (GDE), facilitating ammonia release in the gas phase and ensuring electrolyte stability. We demonstrate 300h continuous operation in a flow electrolyzer with 25 cm2 electrode at 1bar and room temperature, and achieve a current-to-ammonia efficiency of 64±1% with unprecedented gas phase ammonia content of~98%. Our work highlights the crucial role of the solvent in long-term continuous ammonia synthesis.

DOI: 10.1038/s41586-024-07276-5

Source: https://www.nature.com/articles/s41586-024-07276-5