Ambient ammonia synthesis from air via tandem water microdroplets-driven oxidation and pulsed photoelectrochemical reduction

• 成果类型: Article
• 署名作者: Li, Kejian; Dong, Wan Jae; Shen, Rui; Ye, Zhengwei; Zhang, Bingxing; Pan, Yuyang; Xia, Deming; Wang, Chunhua; Francisco, Joseph S.; Mi, Zetian
• 署名单位: University of Michigan System; University of Michigan; Korea University; Korea Institute of Science & Technology (KIST); University of Pennsylvania
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2529364123
• 发表日期: 2026-03-17
• 页码: e2529364123
• 关键词: ammonia synthesis; microdroplet; pulsed photoelectrocatalysis; air conversion; tandem scheme; carbon-dioxide; urea

摘要

Artificial N2 reduction offers a sustainable approach to green NH3 synthesis, but the practical implementation is challenged by N2 activation and competing hydrogen evolution. Photoelectrochemical nitrate and nitrite (NOx-, x = 2 and 3) reduction with favorable thermodynamics represents a promising alternative for NH3 production, provided that NOx-can be supplied from the atmosphere. Here, through leveraging water microdroplet chemistry and dynamic photoelectrode-electrolyte interface engineering, we report a tandem air-NOx--NH3 conversion system that integrates catalyst-free N2 oxidation with pulsed photoelectrochemical NOx-reduction (mNOR-pPNOxR). The system achieves efficient and selective NH3 production with a yield rate of 24.5 mu mol cm-2 h-1 at-0.2 VRHE, which are two to three orders of magnitude higher than conventional photo/electrocatalytic N2 fixation. This study introduces insights for decentralized, on-demand ammonia production from air and water and broadens horizons of microdroplet chemistry and pulse strategy for sustainable chemical manufacturing.