Regensburg 2022 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 49: Oxide Surfaces 1

O 49.9: Vortrag

Mittwoch, 7. September 2022, 17:00–17:15, S053

Synergistic Effects of Co and Fe on the Oxygen Evolution Reaction Activity of LaCo_xFe_1−xO₃ — •Achim Füngerlings and Rossitza Pentcheva — Universität Duisburg-Essen, Fakultät für Physik, Lotharstr. 1, 47057 Duisburg

The efficiency of the perovskite LaCo_xFe_1−xO₃ as a catalyst for the oxygen evolution reaction was investigated by DFT+U calculations. The overpotential required to drive the reaction is significantly reduced upon Co incorporation, with a subsequent nonmonotonic behaviour for larger amounts of Co. This is supported by electrocatalytic measurements of phase-pure LaCo_xFe_1−xO₃ samples [1]. With the deprotonation of adsorbed ^*OH being the potential determining step in all cases, the reason for the observed trend is twofold: Co turns out to be a more favorable reaction site than Fe, whereas the overpotential of the latter is decreased upon Co substitution. Variations of the magnetic moments of the Co and Fe cations during OER reveal the participation of several, particularly Co, cations up to several layers below the surface. This extends the concept of the active site.

[1] A. Füngerlings, A. Koul, M. Dreyer, A. Rabe, D. M. Morales, W. Schuhmann, M. Behrens, R. Pentcheva, Chem. Eur. J. 27, 17145-17158 (2021)