Two-dimensional Fe-TPPHZ nanosheets for electrohydrogenation of N2 to NH3 under ambient conditions

• Published in: Journal of applied electrochemistry 2022-09, Vol.52 (9), p.1295-1304
• Main Authors: Wang, Ying, Luo, Hui, Ye, Chaoxu, Shi, Yanjun, Chen, Zhidong, Wang, Wenchang, Cao, Jianyu, Xu, Juan
• Format: Article
• Language: English
• Subjects: Ammonia; Catalysts; Chemical reduction; Chemistry; Chemistry and Materials Science; Design; Electrocatalysts; Electrochemical Processes; Electrochemistry; Hydrogen evolution reactions; Industrial Chemistry/Chemical Engineering; Nanosheets; Physical Chemistry; Research Article
• ISSN: 0021-891X; 1572-8838
• DOI: 10.1007/s10800-022-01712-y

The design of high-performance and low-cost catalysts for mild electrocatalytic nitrogen reduction reaction (NRR) is particularly desirable and remains greatly challenging due to the unfavorably low ammonia yield rate and Faradaic efficiency (FE), which comes from the difficulty in making nitrogen activation superior to competitive hydrogen evolution reaction (HER). Herein, we report a well-designed two-dimensional nanosheet-like Fe-tetrapyridophenazine (Fe-TPPHZ) catalyst for ambient NRR process, which was facially prepared by coordinating Fe ions with TPPHZ ligand. The Fe-TPPHZ catalyst shows a remarkable NRR activity at ambient conditions with a high NH 3 yield rate of 29.07 µg h −1  mg −1 and an outstanding FE of 11.5% at − 0.3 V vs. RHE. An ammonia yield rate of 21.86 µg h −1  mg −1 is observed after 100 consecutive cycles, with a retention rate of 75.2%. This work will provide a rational design idea to use non-precious metal-based complex as highly effective electrocatalysts for NRR test. Graphical Abstract A two-dimensional nanosheet-like Fe-tetrapyridophenazine (Fe-TPPHZ) catalyst was successfully designed and utilized for ambient NRR process, showing a remarkable NRR activity with a high NH 3 yield rate of 29.07 μg h −1  mg −1 , outstanding FE of 11.5% at − 0.3 V vs. RHE and good retention rate of 75.2% after 100 cycles.