Hydrogen Deposition on Pt(111) during Electrochemical Hydrogen Evolution from a First-Principles Multiadsorption-Site Study

TitleHydrogen Deposition on Pt(111) during Electrochemical Hydrogen Evolution from a First-Principles Multiadsorption-Site Study
Publication TypeJournal Article
Year of Publication2013
AuthorsTan TL, Wang LL, Johnson DD, Bai KW
Journal TitleJournal of Physical Chemistry C
Volume117
Pages22696-22704
Date Published11
Type of ArticleArticle
ISBN Number1932-7447
Accession NumberWOS:000326845400028
Keywordsadsorption, alloys, basis-set, functional theory calculations, oxidation, phase-diagrams, platinum, SINGLE-CRYSTAL, surface, total-energy calculations, wave
Abstract

We study the simultaneous adsorption of H* on Pt(111) for multiple, interacting adsorption sites (i.e., fcc, atop, and hcp) and, over a wide range of electrode potential, examine the equilibrium site coverage during the hydrogen evolution reaction (HER) and oxidation reaction (HOR). We use a first-principles-based cluster expansion (CE) and Monte Carlo simulations. We predict the adsorption isotherm and cyclic voltammogram for -0.9 V < U < 0.5 V versus the standard hydrogen potential. Although strongly adsorbed H-fcc* are the majority species for U > 0, we show that traces of weakly adsorbed H*(atop) and H-hcp* are present, and they are expected to be active in the HER. For U < 0, we predict that H-atop* takes over as the majority species ca. U = -0.4 V, where a simultaneous decrease in H-fcc* occurs-contradicting the general assumption that H-fcc*, remains the majority species, even at very negative potential. We identify the favorable HER operating potentials by mapping out the coverage of the kinetically active species H-atop*.

URL<Go to ISI>://WOS:000326845400028
DOI10.1021/jp405760z