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O: Fachverband Oberflächenphysik
O 65: Solid-Liquid Interfaces: Reactions and Electrochemistry III
O 65.8: Vortrag
Mittwoch, 19. März 2025, 16:45–17:00, H6
DFT Study of Aldehyde Oxidation and Hydrogen Evolution on Flat and Stepped Gold Surfaces — •Samuel Mattoso1, Stefan Wipperman1,2, Mira Todorova1, and Jörg Neugebauer1 — 1Max-Planck-Institut für Nachhaltige Materialien, Max-Planck-Straße 1, 40237 Düsseldorf — 2Philipps-Universität Marburg, Renthof 5, Marburg, 35032, Germany
Significant investments are being made in the development of greener industrial processes, with heterogeneous electrocatalysis playing a major role. Gold is known as a catalyst, which selectively oxidizes aldehydes to carboxylic acid. It may also catalyze the hydrogen evolution reaction (HER). These chemical reactions take place at the solid-liquid interface, where the role of step sites, pH, adsorption of intermediates, solvation and applied bias are largely unknown but may be relevant to understand in order to improve performance. We employ DFT simulations to provide mechanistic insights into this system, by probing the interaction of Au(111) and Au(331) surfaces with H, OH and acetaldehyde. The adsorption energies and work function changes as a function of H and OH coverage for different observed patterns will be reported for the two surfaces. In addition, we find that surface imperfections such as step edges are essential for the HER and aldehyde oxidation to proceed, as they dissociatively bind the aldehyde, leading to adsorbed H.
Keywords: Density Functional Theory (DFT); Hydrogen Evolution Reaction (HER); Stepped Surfaces; Ab Initio Molecular Dynamics; Electrocatalysis