Cheng Dongfang, Wei Ziyang, Zhang Zisheng, Broekmann Peter, Alexandrova Anastassia N, Sautet Philippe
Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095, USA.
Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.
Angew Chem Int Ed Engl. 2023 May 8;62(20):e202218575. doi: 10.1002/anie.202218575. Epub 2023 Apr 5.
The dynamic restructuring of Cu surfaces in electroreduction conditions is of fundamental interest in electrocatalysis. We decode the structural dynamics of a Cu(111) electrode under reduction conditions by joint first-principles calculations and operando electrochemical scanning tunneling microscopy (ECSTM) experiments. Combining global optimization and grand canonical density functional theory, we unravel the potential- and pH-dependent restructuring of Cu(111) in acidic electrolyte. At reductive potential, Cu(111) is covered by a high density of H atoms and, below a threshold potential, Cu adatoms are formed on the surface in a (4×4) superstructure, a restructuring unfavorable in vacuum. The strong H adsorption is the driving force for the restructuring, itself induced by the electrode potential. On the restructured surface, barriers for hydrogen evolution reaction steps are low. Restructuring in electroreduction conditions creates highly active Cu adatom sites not present on Cu(111).
在电还原条件下铜表面的动态重构是电催化领域的一个基本研究兴趣点。我们通过第一性原理计算和原位电化学扫描隧道显微镜（ECSTM）实验相结合的方式，解析了还原条件下Cu(111)电极的结构动力学。结合全局优化和巨正则密度泛函理论，我们揭示了酸性电解质中Cu(111)的电位和pH依赖的重构。在还原电位下，Cu(111)表面覆盖着高密度的H原子，并且在低于阈值电位时，Cu吸附原子以(4×4)超结构的形式在表面形成，这种重构在真空中是不利的。强烈的H吸附是重构的驱动力，而重构本身是由电极电位诱导的。在重构后的表面上，析氢反应步骤的能垒较低。电还原条件下的重构产生了Cu(111)表面不存在的高活性Cu吸附原子位点。
