Continuous-flow electrosynthesis of ammonia by nitrogen reduction and hydrogen oxidation

• 成果类型: Article
• 署名作者: Fu, Xianbiao; Pedersen, Jakob B.; Zhou, Yuanyuan; Saccoccio, Mattia; Li, Shaofeng; Salinas, Rokas; Li, Katja; Andersen, Suzanne Z.; Xu, Aoni; Deissler, Niklas H.; Mygind, Jon Bjarke Valbaek; Wei, Chao; Kibsgaard, Jakob; Vesborg, Peter C. K.; Norskov, Jens K.; Chorkendorff, Ib
• 署名单位: Technical University of Denmark
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12551
• DOI: 10.1126/science.adf4403
• 发表日期: 2023-02-17
• 页码: 707-712
• 关键词: finding saddle-points; oxygen-reduction; platinum-electrodes; current-density; EFFICIENCY; water

摘要

Ammonia is a critical component in fertilizers, pharmaceuticals, and fine chemicals and is an ideal, carbon-free fuel. Recently, lithium-mediated nitrogen reduction has proven to be a promising route for electrochemical ammonia synthesis at ambient conditions. In this work, we report a continuous-flow electrolyzer equipped with 25-square centimeter-effective area gas diffusion electrodes wherein nitrogen reduction is coupled with hydrogen oxidation. We show that the classical catalyst platinum is not stable for hydrogen oxidation in the organic electrolyte, but a platinum-gold alloy lowers the anode potential and avoids the decremental decomposition of the organic electrolyte. At optimal operating conditions, we achieve, at 1 bar, a faradaic efficiency for ammonia production of up to 61 +/- 1% and an energy efficiency of 13 +/- 1% at a current density of -6 milliamperes per square centimeter.