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@PHDTHESIS{Tesch:981735,
author = {Tesch, Rebekka},
othercontributors = {Eikerling, Michael and Groß, Axel},
title = {{S}tructure and properties of electrochemical interfaces
from first principles simulations},
volume = {629},
school = {RWTH Aachen University},
type = {Dissertation},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH, Zentralbibliothek, Verlag},
reportid = {RWTH-2024-03189},
isbn = {978-3-95806-753-0},
series = {Schriften des Forschungszentrums Jülich. Reihe Energie
$\&$ Umwelt/ Energy $\&$ environment},
pages = {xvi, 161 Seiten : Illustrationen},
year = {2024},
note = {Dissertation, RWTH Aachen University, 2024},
abstract = {The transition to a sustainable energy system relies on the
availability of high-performing and cost-effective energy
storage and conversion devices, such as batteries, fuel
cells and electrolysers. The performance of these devices is
directly related to the properties of the employed
electrocatalyst materials. In order to develop
electrochemical devices that can respond to societal,
economical and environmental needs, catalyst materials must
be improved in terms of activity, long-term stability and
production cost. This requires significant progress in the
fundamental understanding of relevant electrochemical
processes. The majority of electrochemical processes take
place at the interface between a solid electrode and a
liquid electrolyte. Atomic-scale modeling is a powerful tool
that can yield important information on structural,
electronic and electrostatic properties of the interface.
However, self-consistently modeling the two parts of the
interface as well as their non-linear coupling is very
challenging. Existing computational methods are limited in
terms of accuracy and/or efficiency. The aim of this thesis
is to address some of the limitations of existing methods
and provide accurate computational methodologies for a
realistic description of the local reaction conditions at
the electrochemical interface and of the electrocatalytic
processes. We focus on two aspects: (1) the efficient and
accurate computation of the electronic structure of
materials with strongly correlated electrons, such as d- or
f-electrons, and (2) the self-consistent description of
phenomena at electrochemical interfaces, including the
effects of electrolyte species and electrode potential. For
these purposes, two methods have been studied in detail in
this thesis: (1) the DFT+U approach for the description of
strongly correlated electrons and (2) the recently developed
effective screening medium reference interaction site method
(ESM-RISM) for the description of electrochemical
interfaces. The conducted research enabled us to establish
an improved DFT+U approach for the computation of the
electronic structure of electrode materials. In this
methodology, we derive the Hubbard U parameter from an
existing first principles-based linear response method.
Additionally, we use Wannier projectors instead of standard
atomic orbitals projectors for more accurate counting of
orbital occupations. The resulting scheme provides an
improved electronic structure description of various d- and
f-materials and allows, for example, for enhanced studies of
catalytically active sites in oxide electrocatalysts. These
results indicate that a correct electronic structure
description is an important precondition for an accurate
computational modeling of electrochemical interfaces.
Regarding the electrochemical interface, we extensively
tested, validated and applied the ESM-RISM for
metal/electrolyte interfaces. Our research showed that the
ESM-RISM is a powerful method for the computation of
electrochemical interfaces, when applied with care regarding
the parameterization of interactions and the description of
the near-surface electrolyte structure. It is capable of
delivering accurate information on various interface
properties like the double layer structure, electrostatic
interfacial potentials and surface charging relations. In
particular, we were able to reproduce the measured
non-monotonic charging relation of the partially oxidized
Pt(111)/electrolyte interface. Finally, we combined both
computational approaches to study NiOOH materials as
catalysts for the electrochemical oxygen evolution reaction
(OER). This investigation was possible only with the
non-standard DFT+U scheme, since the standard DFT+U approach
incorrectly predicts a metallic state for this
semiconducting material. In this respect, we discuss
problems of grand canonical approaches for simulating
electrified semiconductor/electrolyte interfaces. Accounting
for the local reaction environment, we computed
thermodynamic overpotentials for the OER, surface charging
relations and properties of active sites depending on the
potential-dependent degree of surface deprotonation. These
results pave the way for more realistic simulations of
electrochemical systems. The outcome of this thesis enables
improved and more accurate treatments of atomic-scale
processes at electrochemical interfaces at reasonable
computational cost. Providing a sound methodological basis,
the investigated methods allow going beyond previous
computational studies in terms of the description of
electrochemical conditions. These methodologies, although
still far from being able to self-consistently account for
all relevant electrochemical phenomena, should lead to
improved understanding of electrochemical materials. In this
way, they help develop improved catalyst materials for
energy devices that are required for implementing the energy
transition.},
cin = {526810 / 520000},
ddc = {620},
cid = {$I:(DE-82)526810_20191118$ / $I:(DE-82)520000_20140620$},
typ = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
url = {https://publications.rwth-aachen.de/record/981735},
}
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