Jacobse Leon, Huang Yi-Fan, Koper Marc T M, Rost Marcel J
Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands.
Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, the Netherlands.
Nat Mater. 2018 Mar;17(3):277-282. doi: 10.1038/s41563-017-0015-z. Epub 2018 Feb 12.
Platinum plays a central role in a variety of electrochemical devices and its practical use depends on the prevention of electrode degradation. However, understanding the underlying atomic processes under conditions of repeated oxidation and reduction inducing irreversible surface structure changes has proved challenging. Here, we examine the correlation between the evolution of the electrochemical signal of Pt(111) and its surface roughening by simultaneously performing cyclic voltammetry and in situ electrochemical scanning tunnelling microscopy (EC-STM). We identify a 'nucleation and early growth' regime of nanoisland formation, and a 'late growth' regime after island coalescence, which continues up to at least 170 cycles. The correlation analysis shows that each step site that is created in the 'late growth' regime contributes equally strongly to both the electrochemical and the roughness evolution. In contrast, in the 'nucleation and early growth' regime, created step sites contribute to the roughness, but not to the electrochemical signal.
铂在各种电化学装置中起着核心作用，其实际应用取决于防止电极退化。然而，要理解在反复氧化和还原条件下导致不可逆表面结构变化的潜在原子过程颇具挑战性。在此，我们通过同时进行循环伏安法和原位电化学扫描隧道显微镜（EC-STM），研究了Pt(111)电化学信号的演变与其表面粗糙度之间的相关性。我们确定了纳米岛形成的“成核与早期生长”阶段，以及岛合并后的“后期生长”阶段，该阶段至少持续170个循环。相关性分析表明，在“后期生长”阶段产生的每个台阶位点对电化学和粗糙度演变的贡献同样显著。相比之下，在“成核与早期生长”阶段，产生的台阶位点对粗糙度有贡献，但对电化学信号没有贡献。
