Effects of anions on the underpotential deposition behavior of Cu on polycrystalline Pt. Issue 34 (23rd May 2018)

• Record Type: Journal Article
• Authors: Liu, Jiao; Xu, Zhen; Zhu, Benfeng; Du, Xiaoqing; Yang, Yumeng; Yi, Chenxi; Zhang, Zhao; Cai, Chao; Li, Jianmei
• Is Part Of: RSC advances. Volume 8:Issue 34(2018)
• Page Start: 19103
• Page End: 19115
• Publication Date: 2018-05-23
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra00921j
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Effects of anions on underpotential deposition behavior of Cu at polycrystalline Pt has been investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy techniques. Abstract : The process of Cu underpotential deposition (UPD) on polycrystalline Pt (pc Pt) has been investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy techniques using (bi)sulfate and perchlorate (with/without the addition of a small amount of NaCl) as supporting electrolytes, respectively. The results showed that the adsorption capacity of the anions influences both the reversibility and charge transfer resistance ( R ct ) of Cu UPD reactions on pc Pt. With a negative shift of the applied potential, R ct of the (bi)sulfate system decreases monotonously, whereas R ct of the perchlorate system (with/without Cl − ions) decreases at first and then increases. Cu UPD on pc Pt follows Langmuir-type adsorption and two-dimensional nucleation/growth mechanisms. The specific adsorption anions ((bi)sulfate and chloride ions) can not only enhance the Cu UPD process by decreasing R ct, but also favor instantaneous 2D nucleation and subsequent grain growth. Finally, the possible deposition mechanisms of the Cu UPD process in the presence of specific adsorption anions were proposed.