Redox‐Mediated Ambient Electrolytic Nitrogen Reduction for Hydrazine and Ammonia Generation. (16th July 2021)

• Record Type: Journal Article
• Authors: Wang, Xun; Yang, Jing; Salla, Manohar; Xi, Shibo; Yang, Yi; Li, Mengsha; Zhang, Feifei; Zhu, Ming‐Ke; Huang, Songpeng; Huang, Shiqiang; Zhang, Yong‐Wei; Wang, Qing
• Is Part Of: Angewandte Chemie. Volume 133:Number 34(2021)
• Page Start: 18869
• Page End: 18875
• Publication Date: 2021-07-16
• Subjects: ammonium production -- decoupled catalyst and electrode -- flow battery based NRR -- hydrazine production -- redox-mediated N2 reduction; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202105536
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: This work presents a redox‐mediated electrolytic nitrogen reduction reaction (RM‐eNRR) using polyoxometalate (POM) as the electron and proton carrier which frees the TiO2 ‐based catalyst from the electrode and shifts the reduction of nitrogen to a reactor tank. The RM‐eNRR process has achieved an ammonium production yield of 25.1 μg h −1 or 5.0 μg h −1 cm −2 at an ammonium concentration of 6.7 ppm. With high catalyst loading, 61.0 ppm ammonium was accumulated in the electrolyte upon continuous operation, which is the highest concentration detected for ambient eNRR so far. The mechanism underlying the RM‐eNRR was scrutinized both experimentally and computationally to delineate the POM‐mediated charge transfer and hydrogenation process of nitrogen molecule on the catalyst. RM‐eNRR is expected to provide an implementable solution to overcome the limitations in the conventional eNRR process. Abstract : A redox‐mediated electrolytic nitrogen reduction reaction (RM‐eNRR) system is presented. This system decouples the catalyst from the electrode, which gives the system huge versatility in catalyst design, loading and gas flow. By modifying the catalyst, either hydrazine or ammonium can be obtained selectively. The process has achieved ammonium production yield of 25.1 μg h −1 and 61 ppm ammonium can be accumulated by continuous operation.