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O: Fachverband Oberflächenphysik

O 59: Oxide and Insulator Interfaces II

O 59.2: Vortrag

Mittwoch, 20. März 2024, 15:15–15:30, MA 144

Crystal-facet-dependent surface transformation dictates the oxygen evolution reaction activity in lanthanum nickelate — •Achim Füngerlings¹, Marcus Wohlgemuth², Denis Antipin³, Emma van der Minne⁴, Ellen Marijn Kiens⁴, Javier Villalobos³, Marcel Risch³, Felix Gunkel², Christoph Bäumer⁴, and Rossitza Pentcheva¹ — ¹Department of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Duisburg, Germany — ²Peter Gruenberg Institute and JARA-FIT, Forschungszentrum JuelichGmbH, Juelich, Germany — ³Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin, Germany — ⁴MESA+ Institute for Nanotechnology, Faculty of Science and Technology,University of Twente, Enschede, Netherlands

We present a combined experimental and theoretical study of the (001), (110) and (111) facets of LaNiO_3−δ electrocatalyst for water oxidation using electrochemical measurements, X-ray spectroscopy, and density functional theory calculations with a Hubbard U-term. We reveal that the (111) overpotential is ≈30−60 mV lower than for the other facets. While a surface transformation into oxyhydroxide-like NiOO(H) may occur for all three orientations, it is more pronounced for (111). A structural mismatch of the transformed layer with the underlying perovskite for (001) and (110) influences the ratio of Ni²⁺ and Ni³⁺ to Ni⁴⁺ sites during the reaction and thereby the binding energy of reaction intermediates, resulting in the distinct catalytic activities of the transformed facets.

Keywords: Electrocatalysis; Perovskite; Surface Reconstruction; Oxygen Evolution Reaction