Factors controlling surface oxygen exchange in oxides.
Reads0
Chats0
TLDR
Ab initio methods are used to model oxygen exchange in a representative cathode material to better understand the active molecular mechanism toward optimized design and predict that dramatically enhanced oxygen exchange performance could potentially be obtained by suppressing the (La,Sr)O termination and stabilizing highly active CoO2 termination.Abstract:
Reducing the working temperature of solid oxide fuel cells is critical to their increased commercialization but is inhibited by the slow oxygen exchange kinetics at the cathode, which limits the overall rate of the oxygen reduction reaction. We use ab initio methods to develop a quantitative elementary reaction model of oxygen exchange in a representative cathode material, La0.5Sr0.5CoO3−δ, and predict that under operating conditions the rate-limiting step for oxygen incorporation from O2 gas on the stable, (001)-SrO surface is lateral (surface) diffusion of O-adatoms and oxygen surface vacancies. We predict that a high vacancy concentration on the metastable CoO2 termination enables a vacancy-assisted O2 dissociation that is 102–103 times faster than the rate limiting step on the Sr-rich (La,Sr)O termination. This result implies that dramatically enhanced oxygen exchange performance could potentially be obtained by suppressing the (La,Sr)O termination and stabilizing highly active CoO2 termination. The performance of solid oxide fuel cells relies on oxygen exchange kinetics, which can limit oxygen reduction at the cathode. Here the authors use ab initio methods to model oxygen exchange in a representative cathode material to better understand the active molecular mechanism toward optimized design.read more
Citations
More filters
Journal Article
First-principles calculations of electronic structure and spectra of strongly correlated systems: the LDA+U method
TL;DR: In this paper, a generalization of the Local Density Approximation (LDA) method for the systems with strong Coulomb correlations is presented which gives a correct description of the Mott insulators.
Journal ArticleDOI
Perovskite Oxide Based Electrodes for the Oxygen Reduction and Evolution Reactions: The Underlying Mechanism
TL;DR: One hindrance to the development of fuel cells and electrolyzers is the oxygen electrodes, which suffer from high overpotentials and slow kinetics as discussed by the authors. But this hindrance can be overcome by using perovskite oxides.
Journal ArticleDOI
Acidity of surface-infiltrated binary oxides as a sensitive descriptor of oxygen exchange kinetics in mixed conducting oxides
Clément Nicollet,Clément Nicollet,Cigdem Toparli,George F. Harrington,George F. Harrington,George F. Harrington,Thomas Defferriere,Bilge Yildiz,Harry L. Tuller,Harry L. Tuller +9 more
TL;DR: In this paper, the acidity scale for binary oxides is used as a descriptor for tuning and predicting oxygen surface exchange kinetics on mixed conducting oxides, and it is shown that the acidscale of infiltrated surface oxides can serve as a descriptors of the oxygen surface ratio on mixed-conducting oxides.
Journal ArticleDOI
Constructing a pathway for mixed ion and electron transfer reactions for O2 incorporation in Pr0.1Ce0.9O2−x
Di Chen,Di Chen,Zixuan Guan,Dawei Zhang,Lena Trotochaud,Lena Trotochaud,Ethan J. Crumlin,Slavomír Nemšák,Hendrik Bluhm,Hendrik Bluhm,Harry L. Tuller,William C. Chueh +11 more
TL;DR: In this paper, the authors developed a generalizable experimental and analysis framework for constructing the reaction pathway for the incorporation of O2(g) in Pr0.1Ce0.9O2−x.
Journal ArticleDOI
A high-entropy manganite in an ordered nanocomposite for long-term application in solid oxide cells.
Federico Baiutti,Francesco Chiabrera,Matias Acosta,David R. Diercks,David Parfitt,José Santiso,Xiaodong Wang,Andrea Cavallaro,Alex Morata,Haiyan Wang,Alexander Chroneos,Judith L. MacManus-Driscoll,Albert Tarancón +12 more
TL;DR: In this article, a self-assembled vertically aligned nanocomposites of lanthanum strontium manganite and doped ceria with straight applicability as functional layers in high-temperature energy conversion devices is presented.
References
More filters
Journal ArticleDOI
Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set.
Georg Kresse,Jürgen Furthmüller +1 more
TL;DR: An efficient scheme for calculating the Kohn-Sham ground state of metallic systems using pseudopotentials and a plane-wave basis set is presented and the application of Pulay's DIIS method to the iterative diagonalization of large matrices will be discussed.
Journal ArticleDOI
Projector augmented-wave method
TL;DR: An approach for electronic structure calculations is described that generalizes both the pseudopotential method and the linear augmented-plane-wave (LAPW) method in a natural way and can be used to treat first-row and transition-metal elements with affordable effort and provides access to the full wave function.
Journal ArticleDOI
Ab initio molecular dynamics for liquid metals.
Georg Kresse,Jürgen Hafner +1 more
TL;DR: In this paper, the authors present an ab initio quantum-mechanical molecular-dynamics calculations based on the calculation of the electronic ground state and of the Hellmann-Feynman forces in the local density approximation.
Journal ArticleDOI
Accurate and simple analytic representation of the electron-gas correlation energy
John P. Perdew,Yue Wang +1 more
TL;DR: A simple analytic representation of the correlation energy for a uniform electron gas, as a function of density parameter and relative spin polarization \ensuremath{\zeta}, which confirms the practical accuracy of the VWN and PZ representations and eliminates some minor problems.
Journal ArticleDOI
First-principles calculations of the electronic structure and spectra of strongly correlated systems: the LDA+ U method
TL;DR: In this paper, a generalization of the Local Density Approximation (LDA) method for the systems with strong Coulomb correlations is presented which gives a correct description of the Mott insulators.