Li Pengxiang, Fu Wenzhi, Zhuang Peiyuan, Cao Yudong, Tang Can, Watson Angelica Blake, Dong Pei, Shen Jianfeng, Ye Mingxin
Institute of Special Materials and Technology, Fudan University, Shanghai, 200433, P. R. China.
Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, P. R. China.
Small. 2019 Oct;15(40):e1902535. doi: 10.1002/smll.201902535. Epub 2019 Aug 16.
Electrochemical nitrogen reduction reaction (NRR) as a new strategy for synthesizing ammonia has attracted ever-growing attention, due to its renewability, flexibility, and sustainability. However, the lack of efficient electrocatalysts has hampered the development of such reactions. Herein, a series of amorphous Sn/crystalline SnS (Sn/SnS ) nanosheets by an L-cysteine-based hydrothermal process, followed by in situ electrochemical reduction, are synthesized. The amount of reduced amorphous Sn can be adjusted by selecting electrolytes with different pH values. The optimized Sn/SnS catalyst can achieve a high ammonia yield of 23.8 µg h mg , outperforming most reported noble-metal NRR electrocatalysts. According to the electrochemical tests, the conversion of SnS to an amorphous Sn phase leads to the substantial increase of its catalytic activity, while the amorphous Sn is identified as the active phase. These results provide a guideline for a rational design of low-cost and highly active Sn-based catalysts thus paving a wider path for NRR.
电化学氮还原反应（NRR）作为一种合成氨的新策略，因其可再生性、灵活性和可持续性而受到越来越多的关注。然而，缺乏高效的电催化剂阻碍了此类反应的发展。在此，通过基于L-半胱氨酸的水热法合成了一系列非晶态Sn/晶态SnS（Sn/SnS）纳米片，随后进行原位电化学还原。通过选择不同pH值的电解质可以调节还原的非晶态Sn的量。优化后的Sn/SnS催化剂可实现23.8 µg h mg的高氨产率，优于大多数已报道的贵金属NRR电催化剂。根据电化学测试，SnS向非晶态Sn相的转变导致其催化活性大幅提高，而非晶态Sn被确定为活性相。这些结果为低成本、高活性Sn基催化剂的合理设计提供了指导，从而为NRR开辟了更广阔的道路。
