Electrochemical Synthesis of Ammonium from Nitrates via Surface Engineering in Cu2O(100) Facets

• Published in: ACS applied energy materials Vol. 5; no. 1; pp. 71 - 76
• Main Authors: Qin, Jiangzhou, Chen, Liuzhou, Wu, Kun, Wang, Xintao, Zhao, Quanlin, Li, Lei, Liu, Baojun, Ye, Zhengfang
• Format: Journal Article
• Language: English
• Published: American Chemical Society 24.01.2022
• Subjects: surface engineering; nitrate reduction; ammonium synthesis; electrocatalysis
• ISSN: 2574-0962; 2574-0962
• DOI: 10.1021/acsaem.1c02319

Revealing the reactivity of different exposed facets is crucial for designing highly effective electrocatalysts to selectively reduce nitrate (NO3 –) to ammonia (NH4 +). Herein, two dominant exposures of Cu2O­(100) and Cu2O­(111) facets are designed to explore the effects of interfaces on properties. Cu2O­(100) achieved a relatively high NH4 + yield rate of 743 μg h–1 mgcat. –1 associated with a Faradic efficiency of 82.3% at −0.6 V vs the reversible hydrogen electrode (RHE), attributed to a relatively lower energy barrier (0.18 eV) for NH3 production than the Cu2O­(111) surface (1.43 eV). In addition, 15N isotope-labeling experiments were used to quantitatively analyze the yield rate of NH4 + and further confirmed the reliability of nitrogen sources. This work provides reliable evidence to improve the selectivity of NO3 – to NH4 + by crystal facet engineering.