Yu Li, Li Yuchan, Ruan Yuefei
Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay, Guangzhou University, Guangzhou, 510006, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Angew Chem Int Ed Engl. 2021 Nov 22;60(48):25296-25301. doi: 10.1002/anie.202111761. Epub 2021 Oct 21.
Atomically dispersed metal-nitrogen sites show great prospect for the oxygen reduction reaction (ORR), whereas the unsatisfactory adsorption-desorption behaviors of oxygenated intermediates on the metal centers impede improvement of the ORR performance. We propose a new conceptual strategy of introducing sacrificial bonds to remold the local coordination of Fe-N sites, via controlling the dynamic transformation of the Fe-S bonds in the Fe-N-C single-atom catalyst. Spectroscopic and theoretical results reveal that the selective cleavage of the sacrificial Fe-S bonds induces the incorporation of the electron-withdrawing oxidized sulfur on the Fe centers. The newly functionalized moieties endow the catalyst with superior ORR activity and remarkable stability, owing to the reduced electron localization around the Fe centers facilitating the desorption of ORR intermediates. These findings provide a unique perspective for precisely controlling the coordination structure of single-atom materials to optimize their activity.
原子分散的金属-氮位点在氧还原反应（ORR）中显示出巨大的前景，然而，含氧中间体在金属中心上不尽人意的吸附-解吸行为阻碍了ORR性能的提高。我们提出了一种新的概念策略，即通过控制Fe-N-C单原子催化剂中Fe-S键的动态转变，引入牺牲键来重塑Fe-N位点的局部配位。光谱和理论结果表明，牺牲性Fe-S键的选择性断裂诱导了吸电子氧化硫在Fe中心上的掺入。由于Fe中心周围电子定域性的降低促进了ORR中间体的解吸，新功能化的部分赋予了催化剂优异的ORR活性和显著的稳定性。这些发现为精确控制单原子材料的配位结构以优化其活性提供了独特的视角。
