Regensburg 2022 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 62: Surface Reactions and Heterogeneous Catalysis 1
O 62.1: Vortrag
Donnerstag, 8. September 2022, 10:30–10:45, H4
Gaussian Approximation Potentials for Surface Catalysis — •Sina Stocker1, 2, Gábor Csányi3, Karsten Reuter1, and Johannes T. Margraf1 — 1Fritz Haber Institut der Max Planck Gesellschaft, Berlin, Germany — 2Technische Universität München, Germany — 3University of Cambridge, United Kingdom
Predictive-quality first-principles based microkinetic models are increasingly used to analyze (and subsequently optimize) reaction mechanisms in heterogeneous catalysis. In full rigor, such models require the knowledge of all possible elementary reaction steps and their corresponding reaction barriers. Unfortunately, for complex catalytic processes (such as the generation of ethanol from syngas) the number of possible steps is so large that an exhaustive first-principles calculation of all barriers becomes prohibitively expensive.
To overcome this limitation, we develop machine learned (ML) interatomic potentials to model syngas conversion on Rhodium. These ML potentials can be used to determine free energy reaction barriers for a large number of adsorbates at various CO coverages and at a fraction of the computational cost of the underlying first-principles method. Specifically, we use here the Gaussian Approximation Potential (GAP) framework and explore iterative training in combination with umbrella sampling.