Iizuka Kazuki, Kumeda Tomoaki, Suzuki Kota, Tajiri Hiroo, Sakata Osami, Hoshi Nagahiro, Nakamura Masashi
Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba, 263-8522, Japan.
Research and Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8, Kouto 1-1-1, Sayo-gun, Hyogo, 679-5198, Japan.
Commun Chem. 2022 Oct 13;5(1):126. doi: 10.1038/s42004-022-00748-7.
Highly active electrocatalysts for the oxygen evolution reaction (OER) are essential to improve the efficiency of water electrolysis. The properties of OER active sites on single-crystal Pt electrodes were examined herein. The OER is markedly enhanced by repeated oxidative and reductive potential cycles on the Pt(111) surface. The OER activity on Pt(111) is nine times higher in the third cycle than that before the potential cycles. OER activation by potential cycling depends on the (111) terrace width, with wider (111) terraces significantly enhancing the OER. The oxidation/reduction of the Pt(111) surface produces atomic-sized vacancies on the terraces that activate the OER. Structural analysis using X-ray diffraction reveals that the active sites formed by potential cycling are defects in the second subsurface Pt layer. Potential cycling induces the bowl-shaped roughening of the electrode surface, wherein high-coordination number Pt atoms at the bottom of the cavities activate the OER.
用于析氧反应（OER）的高活性电催化剂对于提高水电解效率至关重要。本文研究了单晶铂电极上OER活性位点的性质。在Pt(111)表面上，通过重复的氧化和还原电位循环可显著增强OER。在第三个循环中，Pt(111)上的OER活性比电位循环前高九倍。通过电位循环实现的OER活化取决于(111)台阶宽度，较宽的(111)台阶能显著增强OER。Pt(111)表面的氧化/还原在台阶上产生原子尺寸的空位，从而激活OER。使用X射线衍射进行的结构分析表明，通过电位循环形成的活性位点是第二亚表面铂层中的缺陷。电位循环会导致电极表面呈碗状粗糙化，其中空穴底部高配位数的铂原子会激活OER。
