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SYEM: Symposium Emerging Materials for Renewable Energy Conversion

SYEM 1: Emerging Materials for Renewable Energy Conversion

SYEM 1.5: Invited Talk

Wednesday, March 20, 2024, 12:00–12:30, H 0105

Understanding and tailoring the catalytic activity of spinel and perovskite surfaces from first principles calculations — •Rossitza Pentcheva — University of Duisburg-Essen, Department of Physics, Germany

The optimization of catalysts for chemical energy conversion such as the (photo-) electrocatalytic water splitting requires mechanistic understanding at the atomic level. Based on density functional theory (DFT) calculations with a Hubbard U term, we focus on the oxygen evolution reaction (OER) at iron, cobalt and nickel containing spinels [1-3] vs. perovskites [4-5]. This allows us to disentangle the role of structural motifs, crystallographic orientation, termination and dopants. Analysis of the underlying electronic and magnetic properties reveals dynamic variation of oxidation state of surface cations during OER with marked differences in the degree of localization in spinels and perovskites. Octahedral Co at the (001) surface emerges as a potential active site with the lowest overpotentials. Finally, we assess the effect surface transformation into an oxyhydroxide layer at LaNiO₃ and identify important distinctions for different surface facets that eventually control the OER activity [5]. Funding by the German Research Foundation within CRC TRR247 and computational time at the Leibniz Rechenzentrum and the supercomputer MagnitUDE at UDE are gratefully acknowledged. [1] ACS Catal. 8, 11773 (2018); [2] ACS Catal. 11, 5601, (2021); [3] Adv. Funct. Mater. 33, 2210945 (2023); [4] Chem. Eur. J. 27, 17145 (2021); [5] A. Füngerlings et al, Nat. Commun, in press.

Keywords: Transition Metal Oxides; Density Functional Theory; water splitting; oxygen evolution reaction