The voltammetry of surfaces vicinal to Pt{110}: structural complexity simplified by CO cooling

Attard, Gary Anthony, Hunter, Katherine, Wright, Edward, Sharman, Jonathan, Martínez-Hincapié, Ricardo and Feliu, Juan M. 2017. The voltammetry of surfaces vicinal to Pt{110}: structural complexity simplified by CO cooling. Journal of Electroanalytical Chemistry 793 , pp. 137-146. 10.1016/j.jelechem.2016.10.005

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Abstract

By flame-annealing and cooling a series of Pt n{110} × {111} and Pt n{110} × {100} single crystal electrodes in a CO ambient, new insights into the nature of the electrosorption processes associated with Pt{110} voltammetry in aqueous acidic media are elucidated. For Pt n{110} × {111} electrodes, a systematic change in the intensities of so-called hydrogen underpotential (Hupd) and oxide adsorption voltammetric peaks (for two dimensionally ordered (1 × 1) terraces and linear {111} × {111}step sites) point to a lack of surface reconstruction with all surfaces adopting a (1 × 1) configuration. This is in contrast to hydrogen cooled analogues which give rise to significant residual surface disorder, probably associated with the excess 50% of atoms remaining atop of the surface upon deconstruction of the {110} − (1 × 2) terrace phase. In contrast, Pt n{110} × {100} stepped electrodes, when cooled in gaseous CO following flame-annealing, show a marked tendency towards surface reconstruction, even at low step densities. Variations in potential of the Pt{110}-(1 × 1) Hupd electrosorption peaks as a function of specific ion adsorption strength and pH point to weak specific adsorption for both anions (including perchlorate and fluoride) and cations (including Na+ and K+). CO charge-displacement measurements of the potential of zero total charge (PZTC) allow inferences to be made concerning the nature of the electrosorbed species in the hydrogen underpotential deposition (Hupd) region. Hence, a coherent interpretation of the complex voltammetric phenomena often displayed by platinum surfaces vicinal to the {110} plane is proposed.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Chemistry
Subjects:	Q Science > QD Chemistry
Uncontrolled Keywords:	Pt{110}; Cyclic voltammetry; Stepped surfaces; Electrosorption
Publisher:	Elsevier
ISSN:	1572-6657
Funders:	EPSRC
Date of First Compliant Deposit:	20 October 2016
Date of Acceptance:	3 October 2016
Last Modified:	12 Nov 2024 19:45
URI:	https://orca.cardiff.ac.uk/id/eprint/95486

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