Sulfur vacancy MoS2 for electrocatalytic reduction of nitrate to ammonia with enhanced selectivity

As an important raw material, ammonia consumes a significant amount of the world’s energy. The electrocatalytic reduction of nitrate to ammonia provides a new way to generate NH3 from waste water under benign conditions. However, NO3− conversion toward N2 and H2 evolution reaction (HER) competition...

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Bibliographic Details
Published in:Journal of alloys and compounds 2023-09, Vol.955, p.170199, Article 170199
Main Authors: Wang, Jiali, Sun, Zijun, Li, Yaru, Guo, Lijun, Wang, Yunfang, Fan, Caimei, Wang, Yawen, Li, Rui, Zhang, Xiaochao, Li, Feifei, Yu, Zhuobin, Liu, Jianxin
Format: Article
Language:English
Subjects:
Ammonia synthesis
MoS2
Nitrate reduction
Sulfur vacancies
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Summary:As an important raw material, ammonia consumes a significant amount of the world’s energy. The electrocatalytic reduction of nitrate to ammonia provides a new way to generate NH3 from waste water under benign conditions. However, NO3− conversion toward N2 and H2 evolution reaction (HER) competition limit the development of nitrate reduction to ammonia. In this study, we synthesized MoS2 with sulfur vacancies (SVs) using a one-step hydrothermal method, and we used the SVs to utilize the H* from the side reaction HER and accelerate the process of *N to NH3. MoS2 with SVs exhibits higher ammonia synthesis performance and faradaic efficiency (FE) than that of MoS2, with ammonia yield enhancing from 76.67 μg h−1 mgcat.−1 to 111.33 μg h−1 mgcat.−1 and FE expanding from 44.62 % to 78.04 % at − 0.6 V vs. RHE at ambient conditions. Calculations using density functional theory discovered that the presence of SVs effectively lowered the energy barrier in the potential-determining step for nitrate reduction, and H* couples with nearby *N at Mo sites promote activity. This research enhances our knowledge of how to handle the content of MoS2 with SVs when preparing monolayered MoS2 with special catalytic properties. [Display omitted] •MoS2 with sulfur vacancy was prepared by one-step hydrothermal method.•Sulfur vacancy is helpful for electrocatalytic reduction of nitrate to ammonia.•Utilize the H* from the side reaction hydrogen evolution reaction.•High ammonia yield and faradaic efficiency were achieved.
ISSN:0925-8388
1873-4669
DOI:10.1016/j.jallcom.2023.170199