Implications of the fractional charge of hydroxide at the electrochemical interface
Abstract
Rational design of materials that efficiently convert electrical energy into chemical bonds will ultimately depend on a thorough understanding of the electrochemical interface at the atomic level. Towards this goal, the use of density functional theory (DFT) at the generalized gradient approximation (GGA) level has been applied widely in the past 15 years. In the calculation of electrochemical reaction energetics using GGA-DFT, it is frequently implicitly assumed that ions in the Helmholtz plane have unit charge. However, the ion charge is observed to be fractional near the interface through both a capacitor model and through Bader charge partitioning. In this work, we show that this spurious charge transfer can be effectively mitigated by continuum charging of the electrolyte. We then show that, similar to hydronium, the observed fractional charge of hydroxide is not due to a GGA level self-interaction error, as the partial charge is observed even when using hybrid level exchange–correlation functionals.
Additional Information
© 2020 the Owner Societies. Submitted 01 Nov 2019; Accepted 14 Feb 2020; First published 03 Mar 2020. This work was performed under the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993. This work uses computational resources at the Stanford Research Computing Center and also of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility, supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Some of the computing for this project was performed on the Sherlock cluster. KC acknowledges support by a research grant (9455) from VILLUM FONDEN. There are no conflicts to declare.Attached Files
Submitted - implications-of-the-fractional-charge-of-hydroxide-at-the-electrochemical-interface.pdf
Supplemental Material - c9cp05952k1.pdf
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Additional details
- Eprint ID
- 109780
- Resolver ID
- CaltechAUTHORS:20210712-221642048
- Department of Energy (DOE)
- DE-SC0004993
- Department of Energy (DOE)
- DE-AC02-05CH11231
- Villum Foundation
- 9455
- Created
-
2021-07-12Created from EPrint's datestamp field
- Updated
-
2021-07-12Created from EPrint's last_modified field
- Caltech groups
- JCAP