Wang Lingxiao, Wang Jing, Gao Xiaoping, Chen Cai, Da Yunli, Wang Sicong, Yang Jia, Wang Zhiyuan, Song Jia, Yao Tao, Zhou Wu, Zhou Huang, Wu Yuen
School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China.
Linkway Technology Co., Ltd., Research Institute of Single-Atom Catalysts Industry Technology, Nanning 530000, China.
J Am Chem Soc. 2022 Sep 7;144(35):15999-16005. doi: 10.1021/jacs.2c05572. Epub 2022 Aug 23.
The orderly assembly of single atoms into highly periodic aggregates at the nanoscale is an intriguing but challenging process of high-precision atomic manufacturing. Here, we discover that an in-plane film surface shrinkage can induce molecular self-assembly to arrange single atoms with unconventional distribution, contributing them to periodic one-dimensional segregation on carbon stripes (one-dimensional single-atom arrays (SAA)). This originates from the fact that metal phthalocyanine (MPc) molecules gradually aggregate and melt to form a film under a thermal drive and the help of sodium chloride templates, accompanied by surface shrinkage, self-assembly, and deep carbonization. At the nanoscale, these periodic parallel arrays are formed due to MPc molecular interactions by π-π stacking. At the atomic scale, the single atoms are stabilized by the vertical phthalocyanine-derived multilayer graphene. This can significantly modify the electronic structure of the single-atom sites on the outermost graphene (e.g., Fe-based SAA), thus optimizing the adsorption energy of oxygen intermediates and resulting in a superior oxygen reduction reaction (ORR) performance concerning disordered single atoms. Our findings provide a general route for orderly single-atom manufacturing (e.g., Fe, Co, and Cu) and an understanding of the relationship between orderly allocation and catalytic performance.
在纳米尺度上，将单个原子有序组装成高度周期性的聚集体是一个引人入胜但具有挑战性的高精度原子制造过程。在此，我们发现平面内薄膜表面收缩可诱导分子自组装，从而使单个原子以非常规分布排列，促使它们在碳条纹上形成周期性的一维分离（一维单原子阵列（SAA））。这源于金属酞菁（MPc）分子在热驱动和氯化钠模板的帮助下逐渐聚集并熔化形成薄膜，同时伴随着表面收缩、自组装和深度碳化。在纳米尺度上，这些周期性平行阵列是由于MPc分子通过π-π堆积相互作用而形成的。在原子尺度上，单个原子由垂直的酞菁衍生多层石墨烯稳定。这可以显著改变最外层石墨烯上单个原子位点的电子结构（例如，铁基SAA），从而优化氧中间体的吸附能，并导致相对于无序单原子而言具有优异的氧还原反应（ORR）性能。我们的发现为有序单原子制造（例如铁、钴和铜）提供了一条通用途径，并有助于理解有序排列与催化性能之间的关系。
