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Position of Cu Atoms at the Pt(111) Electrode Surfaces Controls Electrosorption of (H)SO 4 (2)− from H 2 SO 4 Electrolytes
Author(s) -
Tymoczko Jakub,
Schuhmann Wolfgang,
Bandarenka Aliaksandr S.
Publication year - 2014
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201300107
Subject(s) - overlayer , electrolyte , adsorption , electrode , metal , chemistry , monolayer , copper , inorganic chemistry , electrode potential , half cell , crystallography , materials science , chemical physics , working electrode , organic chemistry , biochemistry
Selective positioning of monolayer amounts of foreign atoms at the surface and subsurface regions of metal electrodes is a promising way to fine‐tune the properties of the electrode/electrolyte interface. The latter is critical as it largely governs the adsorption of electrolyte components and reaction intermediates and, therefore, controls many key electrocatalytic processes. Using model Pt(111) single‐crystal electrodes, we demonstrate how the relative position of Cu atoms at the surface drastically changes the adsorption energies for (bi)sulfate anions. Our measurements involve pseudomorphic overlayers of Cu on Pt(111) as well as Cu–Pt(111) surface and sub‐surface alloys, where Cu atoms were located either in the first or in the second atomic layers of Pt, respectively. In the case of Cu–Pt(111) surface alloys, specific adsorption of the anions starts earlier compared to the unmodified Pt(111) surface. In contrast, placing Cu atoms into the second atomic layer weakens the binding between the surface and the anions. Surprisingly, Cu pseudomorphic overlayers do not reveal any specific adsorption of (bi)sulfates (within the region of the overlayer stability). Taking into account that electrified interfaces between Pt(111) electrodes and sulfate‐containing electrolytes often play the role of benchmark systems in fundamental physico‐chemical and, particularly, electrocatalytic studies, our findings demonstrate a promising and relatively easy route of tuning the properties of these interfaces.