Version 1
: Received: 2 December 2023 / Approved: 4 December 2023 / Online: 5 December 2023 (04:30:54 CET)
Version 2
: Received: 26 December 2023 / Approved: 27 December 2023 / Online: 27 December 2023 (09:10:18 CET)
Avcı, Ö.N.; Sementa, L.; Fortunelli, A. Atomistic Modeling of Spinel Oxide Particle Shapes and Reshaping under OER Conditions. Physchem2024, 4, 43-60.
Avcı, Ö.N.; Sementa, L.; Fortunelli, A. Atomistic Modeling of Spinel Oxide Particle Shapes and Reshaping under OER Conditions. Physchem 2024, 4, 43-60.
Avcı, Ö.N.; Sementa, L.; Fortunelli, A. Atomistic Modeling of Spinel Oxide Particle Shapes and Reshaping under OER Conditions. Physchem2024, 4, 43-60.
Avcı, Ö.N.; Sementa, L.; Fortunelli, A. Atomistic Modeling of Spinel Oxide Particle Shapes and Reshaping under OER Conditions. Physchem 2024, 4, 43-60.
Abstract
The surface configurations of the low-index facets of a set of spinel oxides are investigated using DFT+U calculations to derive surface energies and predict equilibrium nanoparticle shapes via the Wulff construction. Two very different conditions are investigated, corresponding to appli-cation either in heterogeneous catalysis or in electrocatalysis. First, the bare stoichiometric sur-faces of NiFe2O4, CoFe2O4, NiCo2O4, ZnCo2O4 spinels are studied to model their use as high-temperature oxidation catalysts. Second, focusing attention on the electrochemical oxygen evolution reaction (OER), and on the CoFe2O4 inverse spinel as the most promising OER catalyst, we generate systematically surface configurations by adsorbing OER intermediates, and recal-culate surface energies taking into account adsorption and environmental conditions, i.e., ap-plied electrode potential and O2 pressure. We predict that, under OER operating conditions, (111) facets are dominant in CoFe2O4 nanoparticle shapes, in fair agreement with microscopy meas-urements. Importantly, in the OER case we predict a strong dependence of nanoparticle shape upon O2 pressure. Increasing O2 pressure increases the size of the higher-index (111) and (110) facets at the expense of the (001) catalytically active facet, whereas the opposite occurs at low O2 pressure. These predictions should be experimentally verifiable and help define the optimal OER operative conditions.
Keywords
oxygen evolution reaction; Density Functional Theory; reaction mechanisms; spinel oxides
Subject
Chemistry and Materials Science, Theoretical Chemistry
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
