Reactions of chloride ions on Au surface in electrolyte

抄録

The reaction of halogen atoms with metal surfaces is important in applications such as catalysis, dissolution, deposition, complex formation, and energy conversion [1-3]. Chloride ions on gold surfaces are a typical system for such applications, however, the elementary processes of the reaction are not fully understood. In this presentation, we report the results of our analysis of the reaction mechanism of chloride ions with gold surfaces in aqueous solution by scanning probe microscopy.

When the potential of the Au electrode is swept in the positive direction in an aqueous solution containing chloride ions, dissolution of Au is observed. This reaction is generally considered to proceed by the reaction of chloride ions with Au atoms on the surface. However, the atomic structure related to this reaction has not been clarified. In this study, we successfully observed atomic resolution image of the surface and found a structure different from that of chloride ions on the Au surface observed in ultrahigh vacuum. This structure is considered to be related to the progress of the dissolution reaction. In addition, a change in the mechanical properties of the surface at the dissolution zone was observed with the progress of the dissolution reaction. This change in physical properties is thought to trigger the dissolution reaction.

References

[1] Yuan Fang, Song-Yuan Ding, Meng Zhang, Stephan N. Steinmann, Ren Hu, Bing-Wei Mao, Juan M. Feliu, and Zhong-Qun Tian, J. Am. Chem. Soc. 142, 9439−9446 (2020).

[2] T. Tansel and O. M. Magnussen, Phys. Rev. Lett, 96, 026101 (2006).

[3] Hiroaki Konishi, Taketoshi Minato, Takeshi Abe, and Zempachi Ogumi, J. Phys. Chem. C 123, 10246−1025 (2019).