Probing the Halide鈥揗etal Interaction by Monolayer Metal Deposition at the Electrochemical Interface

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• 作者：Yvonne Gr眉nder ; Paul Thompson ; Alex Brownrigg ; Michael Darlington ; Christopher A. Lucas
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：March 15, 2012
• 年：2012
• 卷：116
• 期：10
• 页码：6283-6288
• 全文大小：328K
• 年卷期：v.116,no.10(March 15, 2012)
• ISSN：1932-7455

文摘

The atomic structure at the Au(001) electrode surface has been studied by in situ surface X-ray diffraction in 0.1 M HClO₄ + 10^鈥? M KBr and 0.1 M HClO₄ + 10^鈥? M KBr + 10^鈥? M Cu(ClO₄)₂ electrolytes. Potential-dependent X-ray diffraction measurements indicate that the commensurate c(鈭?脳2鈭?)R45掳-Br_ad structure, formed on the Au(001) surface in the potential range of 0.0鈥?.4 V (versus Ag/AgCl) in the absence of Cu cations, re-forms during the underpotential deposition (UPD) of Cu and then transforms into a c(2脳2)-Br adlayer at E = 鈭?.4 V when the Cu UPD monolayer is complete. Detailed analysis of the surface X-ray diffraction data shows subsurface relaxation induced by Br_ad structure formation and shows that the bonding of Br_ad on the UPD Cu monolayer is identical to that observed on a bulk Cu(001) electrode. The results indicate that bonding of the halide adlayer is determined by the chemical properties of the first atomic layer of the metal substrate and demonstrates how halide adsorption can stabilize the UPD monolayer.