Fe3C纳米晶体电催化一氧化氮还原合成氨
收稿日期: 2024-12-17
录用日期: 2025-02-08
网络出版日期: 2025-02-15
Electrocatalytic Nitric Oxide Reduction to Yield Ammonia over Fe3C Nanocrystals
Received date: 2024-12-17
Accepted date: 2025-02-08
Online published: 2025-02-15
一氧化氮(NO)通常来自汽车尾气和工业烟气,是最严重的空气污染物之一。为解决这一问题,电催化一氧化氮还原反应(NORR)被提出,其不仅能去除NO大气污染物,还能产生有价值的氨(NH3)。因此,通过对Fe3C纳米晶体进行改性,制备的Fe3C/C-900样品在常温常压条件下可作为高效NORR催化剂。电化学测试结果表明,Fe3C/C-900催化剂在-0.8 V(vs. RHE)时的合成NH3法拉第效率为76.5%,在-1.2 V(vs. RHE)时的NH3产率为177.5 μmol·h-1·cm-2。同时,其在长时间电解过程中,也能保持稳定的NORR活性。此外,我们将Fe3C/C-900的高NORR特性归因于两个方面:一方面,Fe3C纳米晶体的内在活性,包括降低决速步骤(*NOH→*N)能垒和抑制氢析出副反应;另一方面,多孔碳基底有利于活性成分的分散、气态NO反应物的有效吸附和液态NH3产物的释放。
林森 , 张浪 , 侯童 , 丁俊阳 , 彭紫默 , 刘亦帆 , 刘熙俊 . Fe3C纳米晶体电催化一氧化氮还原合成氨[J]. 电化学, 2025 , 31(4) : 2412171 . DOI: 10.61558/2993-074X.3525
Nitric oxide (NO), which generally originates from vehicle exhaust and industrial flue gases, is one of the most serious air pollutants. In this case, the electrochemical NO reduction reaction (NORR) not only removes the atmospheric pollutant NO but also produces valuable ammonia (NH3). Hence, through the synthesis and modification of Fe3C nanocrystal catalysts, the as-obtained optimal sample of Fe3C/C-900 was adopted as the NORR catalyst at ambient conditions. As a result, the Fe3C/C-900 catalyst showed an NH3 Faraday efficiency of 76.5% and an NH3 yield rate of 177.5 μmol·h-1·cm-2 at the working potentials of -0.8 and -1.2 V versus reversible hydrogen electrode (vs. RHE), respectively. And it delivered a stable NORR activity during the electrolysis. Moreover, we attribute the high NORR properties of Fe3C/C-900 to two aspects: one is the enhanced intrinsic activity of Fe3C nanocrystals, including the lowering of the energy barrier of rate-limiting step (*NOH→*N) and the inhibition of hydrogen evolution; on the other hand, the favorable dispersion of active components, the effective adsorption of gaseous NO, and the release of liquid NH3 products facilitated by the porous carbon substrate.
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