过电位
法拉第效率
可逆氢电极
催化作用
氨生产
化学
无机化学
电化学
氨
氧化还原
氮气
电极
物理化学
工作电极
有机化学
作者
Li Ji,Yuan Zhang,Chao Liu,Lirong Zheng,Eddy Petit,Kun Qi,Yang Zhang,Hao Wu,Wensen Wang,Antoine Tiberj,Xuechuan Wang,Manish Chhowalla,Luc Lajaunie,Ruohan Yu,Damien Voiry
出处
期刊:Research Square - Research Square
日期:2021-07-16
标识
DOI:10.21203/rs.3.rs-687134/v1
摘要
Abstract Electrochemical synthesis of NH 3 is a carbon-free alternative to the traditional Haber-Bosch process. The challenge with nitrogen reduction reaction (NRR) to NH 3 is cleavage of the inert N≡N triple bond of nitrogen gas. Obtaining NH 3 from environmental pollutants, such as nitrates or nitrites, is a more practical route than NRR. However, reduction of nitrates or nitrites to ammonia is currently hampered by modest Faradaic efficiencies, typically below 10 %. Here, we report a novel heterogeneous catalyst based on iron (Fe) single-atoms supported on two-dimensional MoS 2 (Fe-MoS 2 ) for the nitrate reduction reaction (NO 3 RR). We have found that Fe-MoS 2 exhibits remarkable performance with a maximum Faradaic efficiency of 98 % for NO 3 RR to NH 3 at an overpotential of -0.48 V vs. the reversible hydrogen electrode (RHE) as confirmed by our isotopic nuclear magnetic resonance (NMR) analyses. Density function theory (DFT) calculations reveal that the enhanced selectivity for the production of NH 3 from single Fe atoms supported on MoS 2 is attributed to a reduced energy barrier of 0.38 eV associated with de-oxidation of *NO to *N – the usual potential limiting step in NO 3 RR. We assembled our catalyst in a two-electrode electrolyzer coupled to an InGaP/GaAs/Ge triple-junction solar cell to demonstrate a solar-to-ammonia (STA) conversion efficiency of 3.4 % and a yield rate of 0.03 mmol h -1 cm -2 equivalent to 510 µg h -1 cm -2 . Our results open new avenues for design of single-atom catalysts (SAC) for the realization of solar-driven ammonia production.
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