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

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.
 [1] ;  [2] ;  [3] ;  [1]
  1. Inst. of High Performance Computing (Singapore)
  2. Ames Lab., Ames, IA (United States)
  3. Ames Lab., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
IS-J 8202
Journal ID: ISSN 1932-7447
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry. C; Journal Volume: 117; Journal Issue: 44
American Chemical Society
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
36 MATERIALS SCIENCE; Electrochemistry