Density functional theory calculations for the hydrogen evolution reaction in an electrochemical double layer on the Pt(111) electrode.
We present results of density functional theory calculations on a Pt(111) slab with a bilayer of water, solvated protons in the water layer, and excess electrons in the metal surface. In this way we model the electrochemical double layer at a platinum electrode. By varying the number of protons/electrons in the double layer we investigate the system as a function of the electrode potential. We study the elementary processes involved in the hydrogen evolution reaction, 2(H(+) + e(-)) --> H(2), and determine the activation energy and predominant reaction mechanism as a function of electrode potential. We confirm by explicit calculations the notion that the variation of the activation barrier with potential can be viewed as a manifestation of the Brønsted-Evans-Polanyi-type relationship between activation energy and reaction energy found throughout surface chemistry.
Skúlason
Egill
E
Center for Atomic-scale Materials Design, Department of Physics, Building 307, NanoDTU, Technical University of Denmark, DK-2800, Lyngby, Denmark.
Karlberg
Gustav S
GS
Rossmeisl
Jan
J
Bligaard
Thomas
T
Greeley
Jeff
J
Jónsson
Hannes
H
Nørskov
Jens K
JK
D000465:Algorithms; D002412:Cations; D004563:Electrochemistry; D004566:Electrodes; D006859:Hydrogen / Q000737:chemistry*; D008962:Models, Theoretical; D010984:Platinum / Q000737:chemistry*; D011522:Protons; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
D002412:Cations; D011522:Protons; D012997:Solvents; D014867:Water; D010984:Platinum; D006859:Hydrogen