Journal
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Volume 11, Issue 43, Pages 10108-10117Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/b909233a
Keywords
-
Funding
- National Science Foundation [CBET-0730502]
- National Science Council, Taiwan [NSC-095-SAF-I-564-022-TMS]
Ask authors/readers for more resources
The adsorption of molecular oxygen is the first step in the oxygen reduction reaction. Influences of interfacial water structure and electrode potential on oxygen adsorption to the Pt(111) surface were evaluated using density functional theory. Two approaches were used to model the electrification of the interface, an applied homogeneous electric field and the double-reference method of Filhol, Taylor, and Neurock. The free energy change for molecular oxygen replacement of water at the surface shows qualitatively different trends between the two models. The inclusion of solvation effects and direct control of the electrode potential offered by the double-reference method lead to the conclusion that O-2 replacement of water is favorable at all potentials studied, and O-2 binding becomes more favorable with increasing potential. This trend is contrary to that observed using an external electric field model to represent the electrochemical double layer, and arises due to the compounded effect of potential on water-surface, oxygen-surface, and water-molecular oxygen interactions. These results indicate that oxygen replacement of adsorbed water does not limit the overall oxygen reduction reaction rate at a proton-exchange membrane fuel cell cathode. The impacts of aspects of model construction ( number of water layers, water density) and variation of electrode potential on the O-2-Pt(111) interaction are described.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available